United States
Environmental Protection
Agency
Office of Water
WH-552
Washington, DC 20460
April 1986
EPA 440/1-86/093
Water
Multimedia Technical
Support Document for the
Ethanol - for - Fuel Industry
-------
-* . r'» "- : i-i "-V ' * :• £ =••« = •-•--- t_* ^Wty^&jfX-r'^fft^™^"^''^??!^^^^ T'*"' JK*'''""i*''"'- ''"' "• •^•'1^.^ l^ji - A/'^3*-"".
-------
MULTIMEDIA TECHNICAL SUPPORT DOCUMENT
for the
ETHANOL-FOR-FUEL INDUSTRY
Lee M. Thomas
Administrator
Lawrence J. Jensen
Assistant Administrator
for the Office of Water
James M. Conlon
Acting Director for the
Office of Water Regulations and Standards
Devereaux Barnes
Acting Director, Industrial Technology Division
William Telliard
Energy and Mining Branch Chief
March 1986
Industrial Technology Division
Office of Water Regulations and Standards
U.S. Environmental Protection Agency
Washington, D.C. 20460
-------
-------
DISCLAIMER
This Multimedia Technical Support Document was primarily based
on the EPA/EGD Multimedia sampling and analysis program. Data
were also obtained from NPDES permits, an EPA Region IV
Surveillence and Analysis Division Program, the IBRL-Ci Source
Test Evaluation, published literature and EPA supported
•engineering calculations. No proprietary or confidential data
appear or have been used in the preparation of this document.
Although this document addresses various wastewater treatment
technologies, no process developer or process licensee was
involved in the development of this manual. Mention of trade
names or commercial products does not constitute endorsement or
recommendation for use.
ii
-------
-------
FOREWORD
This Multimedia Technical Support Document (MTSD) provides
process, discharge and pollution control data in summarized form
for the use of permit writers, developers, and. other interested
parties." This document presents examples of control technologies
both as individual process units and as integrated control
train's. These examples may be taken in part from applicable
NPDES or other permit applications and, therefore, reflect
specific plants. None of the examples are intended to convey an
Agency endorsement or recommendation but rather are presented
for illustrative purposes. The selection of control tech-
nologies for application to specific plants is the exclusive
function of the designers and permitters who have the flexi-
bility to utilize the lowest cost and/or most effective ap-
proaches. It is hoped that the readers will be able to relate
their waste streams and controls to those presented in this
document to enable them to better understand the extent to which
various technologies may control specific waste streams and
utilize the information in making control technology selections
for their specific needs.
The reader should be aware that this document contains no
legally binding requirements or guidance, and that nothing
contained in this document relieves a facility from compliance
with existing or future environmental regulations, or permit
requirements.
111
-------
-------
ABSTRACT
This Multimedia Technical Support Document presents the
technical data base developed by the Effluent Guidelines
Division of EPA for the ethanol-for-fuel point source category.
Data were originally collected between 1979 and 1981 with the
intent of using them as the basis for proposing effluent
limitations guidelines. However, in early 1982, an EPA policy
decision was made to develop guidance for the Ethanol-for-Fuel
industry instead of effluent limits. This decision was made
because of the decline in the growth of this industry when
foreign crude oil became more available and the fuel shortage
was somewhat abated.
The ethanol-for-fuel industry is defined as those commercial-
size (greater than one million gallons of ethanol per year)
facilities that convert biomass (via fermentation) to ethanol
for use as a fuel. On September 1, 1981 the ethanol-for-fuel
industry consisted of 15 such facilities with a total annual
capacity of 164 million gallons. Thirty-five plants with a
total capacity of 705 million gallons per year were under con-
struction, and 42 plants with a total capacity of 980 million
gallons per year were proposed. Approximately one-fourth of the
existing plants (in operation and under construction) were
direct dischargers (or discharging directly into a surface water
body).
In September 1985, there were 102 plants in 31 states, each with
a capacity of 1 million gallons per year or more. Out of these
102, there were 57 plants in operation and producing, with
capacity of approximately 764 million gallons per year. In 1985
there were 15 plants under construction in 12 states, with a
capacity of 220 million gallons per year.
This document discusses various sources of pollution generated
from the ethanol-for-fuel facilities on a multimedia basis: for
air, water, and solid waste. Also, various pollutants of con-
cern associated with each media waste stream are listed. These
lists come from an extensive data gathering program also dis-
cussed in this document. A presentation of pollution control
alternatives for each media waste stream is also included
followed by a discussion of costs for some of these control
systems.
v
-------
In regard to biomass sources, the pollution control strategies
discussed in this document for the ethanol-for-fuel industry
pertain to facilities that use grain, wood sugar, cane and cit-
rus molasses, and cheese whey as feedstocks. Biomass sources
such as cellulose, sugar crops (i.e., sweet sorghum, sugar
beets, and sugar cane), and potatoes could not be addressed with
the information available at the time this document was
completed.
VI
-------
TABLE OF CONTENTS
Page
Disclaimer »... ii
Foreword \ \ m
Abstract . v
Tables ix
Figures I xiii
Section 1 Introduction 1
1.1 Technology Overview 2
1.2 Regulatory Background 3
1.3' Industry Overview 8
1.4 Data Collection Methodology 9
1.5 Document Organization 10
Section 2 Industry Profile 12
2.1 Historical Development 12
2.2 Ethanol-For-Fuel Industry Status ... 15
2.3 Ethanol-For-Fuel Process Description . 33
Section 3 Waste Stream Characterization 52
3.1 Data Collection 52
3.2 Statistical Data" Evaluation 70
3.3 Water Use and Effluent Source 80
3.4 Wastewater Characterization ....... 88
3.5 Wastewater Pollutants of Concern . . . 108
3.6 Air Emissions 130
3.7 Solid Wastes 146
Section 4 Wastewater Treatment and Control Technology . 157
4.1 Background 157
4.2 In-Plant Source Control for
Wastewater Reduction 158
4.3 Preliminary Treatment Technologies . . 166
4.4 Primary Treatment Technologies .... 171
4.5 Secondary Treatment Technologies . . . 173
4.6 Tertiary Treatment 182
4.7 Disinfection 186
4.8 Sludge Handling . 187
Section 5 Solid Waste Treatment and Disposal
Technologies 192
5.1 Recycle/Reuse 192
5.2 Treatment Technologies ... 194
5.3 Disposal and Management Practices . . . 196
vii
-------
TABLE OF CONTENTS (Continued)
Page
Section 6 Cost, Energy, and Nonwater Quality Aspects
of Wastewater Treatment 198
6.1 Model Plant Costing 198
6.2 Treatment Options for Cost
Evaluation 206
6.3 Capital and Operation and
Maintenance Costs 208
6.4 Non-water Quality Aspects 214
Glossary 222
References 237
Bibliography 240
Appendix A Sampling Procedures . A~l
Appendix B Analytical Methods B~l
Appendix C Quality Assurance/Quality -Control Procedures. C-l
Appendix D Solid Waste and Air Sampling Results .... D-l
Appendix E Wastewater Sampling Results E-l
Appendix F Statistical Support Calculations F-l
Appendix G Ethanol-for-Fuel Effluent Guidelines
Cost Manual G~l
viii
-------
LIST OF TABLES
Table
1-1
2-1
2-2
2-3
2-4
2-5
2-6
2-7
2-8
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
No.
THE CLEAN WATER ACT AMENDMENTS OF 1977
ETHANOL-FOR-FUEL FACILITIES (1981) .
ETHANOL-FOR-FUEL OPERATING PLANTS (1985) ...
PLANTS UNDER CONSTRUCTION (1981)
ETHANOL-FOR-FUEL PLANTS UNDER CONSTRUCTION
(SEPTEMBER 1985) ...
PROPOSED PLANTS (1981) . „ .
ENTANOL-FOR-FUEL PLANTS PROPOSED (SEPTEMBER
1985)
PROJECTED MAXIMUM ETHANOL PRODUCTION FROM
U.S. BIOMASS RESOURCES
ETHANOL-FOR-FUEL PLANTS BY STATE (SEPTEMBER
1985)
ETHANOL-FOR-FUEL DATA BASE SUMMARY
LIST OF 129 PRIORITY POLLUTANTS .
CONVENTIONAL POLLUTANTS
NONCONVENTIONAL POLLUTANTS ANALYZED
EGD/EPA SAMPLING PROGRAM
DATA AVAILABLE FOR STATISTICAL ANALYSES ....
GROUPING OF FACILITIES BASED ON UNTREATED
EFFLUENT QUALITY ...
RELATIONSHIP BETWEEN ETHANOL FACILITIES AND
EVALUATION FACTORS FOR TSS
RELATIONSHIP BETWEEN ETHANOL FACILITIES AND
EVALUATION FACTORS FOR BOD5
RELATIONSHIP BETWEEN ETHANOL FACILITIES AND
EVALUATION FACTORS FOR FLOW RATIO
PERCENT VOLUME OF TOTAL UNTREATED EFFLUENT FOR
GRAIN DISTILLERS WITH BY-PRODUCT RECOVERY . . .
Page
6
16
17
20
23
24
27
29
32
53
56
61
62
64
72
74.
76
77
78
83
-------
LIST OF TABLES (Continued)
Table No.
3-12
3-13
3-14
3-15
3-16
3-17
3-18
3-19
3-20
3-21
3-22
3-23
3-24
3-25
3-26
3-27
SOLVENT STRIPPING COLUMN BOTTOMS FROM
DEHYDRATION SYSTEM/DISCHARGE VALUES
EVAPORATOR CONDENSATE CHARACTERIZATION:
PRIORITY POLLUTANTS
UNTREATED EFFLUENT ANALYSES SUMMARY — PRIORITY
POLLUTANT ORGANICS
UNTREATED EFFLUENT ANALYSES SUMMARY — PRIORITY
POLLUTANT METALS, . CYANIDE, AND ASBESTOS ....
UNTREATED EFFLUENT ANALYSES SUMMARY — CONVEN-
TIONAL POLLUTANTS
UNTREATED EFFLUENT ANALYSES SUMMARY — NONCONVEN-
TIONAL PARAMETERS
UNTREATED EFFLUENT ANALYSES SUMMARY — NONCONVEN-
TIONAL PARAMETERS .'
UNTREATED EFFLUENT ANALYSES SUMMARY — NONCONVEN-
TIONAL PARAMETERS
TREATED EFFLUENT ANALYSES SUMMARY — PRIORITY
POLLUTANT ORGANICS
TREATED EFFLUENT ANALYSES SUMMARY — PRIORITY
POLLUTANT METALS, AND CYANIDE
TREATED EFFLUENT ANALYSES SUMMARY — CONVEN-
TIONAL POLLUTANTS .
TREATED EFFLUENT ANALYSES SUMMARY — NONCONVEN-
TIONAL PARAMETERS ...
TREATED EFFLUENT ANALYSES SUMMARY — NONCONVEN-
TIONAL PARAMETERS
TREATED EFFLUENT ANALYSES SUMMARY — NONCONVEN-
TIONAL PARAMETERS
SETTLEMENT AGREEMENT EXCLUSION CRITERIA ....
TOXIC ORGANIC POLLUTANTS FOUND IN UNTREATED
EFFLUENT FROM ETHANOL PLANTS
X
Page
85
87
90
95
96
97
98
99
101
106
107
109
110
111
114
115
^^m
-------
LIST OF TABLES (Continued)
Table No. Page
3-44 RCRA RELATED SOLID WASTE ANALYSIS SUMMARY . . . 155
3-45 ANALYTICAL PARAMETERS ANALYZED FOR SOLID WASTE
TESTING 156
4-1 BOD5 AND TSS REDUCTION ACHIEVED BY ETHANOL
PLANT WASTEWATER TREATMENT SYSTEMS.' 159
4-2 TYPICAL INFLUENT WASTEWATER CHARACTERISTICS AT
GRAIN DISTILLERIES 175
5-1 TREATMENT AND DISPOSAL TECHNIQUES FOR ETHANOL
PLANT SOLID WASTES 193
6-1 ETHANOL-FOR-FUEL PLANT SIZE DISTRIBUTION . . . 200
6-2 UNTREATED EFFLUENT CHARACTERISTICS USED IN THE
DESIGN AND COSTING OF WASTEWATER TREATMENT
SYSTEMS FOR ETHANOL-FOR-FUEL PLANTS 201
6-3 PRODUCTION AND WASTEWATER GENERATION DATA FOR
BEVERAGE AND ETHANOL-FOR-FUEL PLANTS ..... 203
6-4 SUMMARY OF MODEL PLANT CHARACTERISTICS .... 205
6-5 BIOSLUDGE PRODUCED DURING WASTEWATER TREATMENT
FOR ETHANOL FACILITIES 207
6-6 ASSUMPTIONS USED IN THE DESIGN OF THE SOLID
WASTE HANDLING SYSTEM ............. 209
6-7 SUMMARY OF WASTEWATER TREATMENT CAPITAL COSTS
FOR NEW ETHANOL-FOR-FUEL FACILITIES 210
6-8 SUMMARY OF WASTEWATER TREATMENT CAPITAL COSTS
FOR EXISTING ETHANOL-FOR-FUEL FACILITIES ... 211
6-9 SUMMARY OF WASTEWATER TREATMENT O&M COSTS FOR
NEW AND EXISTING ETHANOL-FOR-FUEL FACILITIES. . 212
6-10 ASSUMPTIONS USED IN SYSTEM DESIGN ....... 216
6-11 ASSUMPTIONS USED IN COST ESTIMATION 218
6-12 COST OF SOLID WASTE HANDLING 219
6-13 SUMMARY OF WASTEWATER TREATMENT ENERGY
REQUIREMENTS FOR NEW AND EXISTING ETHANOL-
FOR-FUEL PLANTS ..... 221
-------
LIST OF TABLES (Continued)
Table No.
3-28
3-29
3-30
3-31
3-32
3-33
3-34
3-35
3-36
3-37
3-38
3-39
3-40
3-41
3-42
3-43
CONTROL AND METHOD BLANKS ANALYSES/PRIORITY
CONCENTRATIONS OF TOXIC ORGANIC POLLUTANTS
FOUND IN TREATED EFFLUENT FROM ETHANOL PLANTS .
BIOLOGICAL TREATABILITY OF CHLOROFORM AND
PHENOL PRESENT IN ETHANOL PLANT WASTEWATERS . .
PRIORITY METALS PRESENT' IN UNTREATED ETHANOL
PRIORITY POLLUTANT METALS PRESENT IN UNTREATED
MAJOR SOURCES OF AIR EMISSIONS FROM AN
TOTAL HYDROCARBON (THC) AND BENZENE ANALYSES
PARTICULATE MATTER ANALYSIS AND SAMPLING DATA
FOR PLANT A03/CYCLONE ON DIRECT-CONTACT
SULFUR DIOXIDE AND NITROGEN OXIDE ANALYSIS
FOR PLANT A03/CYCLONE ON DIRECT-CONTACT
1980 EPA SAMPLING PROGRAM/AIR EMISSIONS
FUGITIVE VOC EMISSION RESULTS FOR PLANT A06 . .
FUGITIVE VOC EMISSION RESULTS FOR PLANT EOS . .
ESTIMATED PARTICULATE AND VOC EMISSIONS FROM
THE CURRENT AND PROJECTED ETHANOL-FOR-FUEL
FACILITIES AND SOLID WASTE STREAMS TESTED . . .
POLLUTANT PARAMETERS ANALYZED TO DETERMINE
RCRA EP-TOXICITY
117
118
123
124
125
126
133
135
136
137
139
141
143
144
152
154
xii
-------
LIST OF FIGURES
Figure
No. Page
2-1 PROJECTED .GEOGRAPHIC DISTRIBUTION OF ETHANOL-
FOR-FUEL PLANTS IN 1990 BY U.S. EPA REGIONS . . 30
2-2 PROJECTED GEOGRAPHIC DISTRIBUTION OF ETHANOL-
FOR-FUEL PLANTS BY STATE. . 31
2-3 PROCESS DIAGRAM FOR CHEESE.WHEY PREPARATION . . 37
2-4 CONVENTIONAL DISTILLATION 41
2-5 CONVERTED BEVERAGE PLANT 43
2-6 CURRENT DISTILLATION DESIGNS 45
2-7 DEHYDRATION WITH SOLVENT RECOVERY 47
2-8 DEHYDRATION WITHOUT SOLVENT RECOVERY 48
2-9 PROCESS FLOW DIAGRAM: BY-PRODUCT RECOVERY . . 50
3-1 MAJOR SOURCES OF WASTEWATER FOR ETHANOL
FACILITIES 81
3-2 MAJOR SOURCES OF AIR EMISSION FOR ETHANOL
FACILITIES. ........ 132
3-3 SOLID WASTE STREAMS FROM ETHANOL PRODUCTION . . 149
3-4 SOLID WASTE STREAMS FROM PROCESS WASTEWATER
TREATMENT 150
4-1 SCHEMATIC FLOW DIAGRAMS OF EQUALIZATION
FACILITIES. 169
4-2 PLANT El3 AERATED LAGOON WASTEWATER TREATMENT
SYSTEM 177
4-3 PLANT A03 ACTIVATED SLUDGE WASTEWATER TREATMENT
SYSTEM 179
4-4 PLANT E17 TRICKLING FILTER WASTEWATER
TREATMENT SYSTEM 181
4-5 PLANT EOS ROTATING BIOLOGICAL CONTACTOR
WASTEWATER TREATMENT SYSTEM ..... 183
XI11
-------
LIST OF FIGURES
Figure
No.
4-6
6-1
6-2
6-3
A TYPICAL SLUDGE HANDLING AND DISPOSAL SYSTEM
RATIO OF WASTEWATER GENERATED TO ETHANOL
PRODUCED VERSUS ETHANOL PRODUCTION
SCHEMATIC DIAGRAM OF TREATMENT OPTIONS
1 AND 3 . . . ,
SCHEMATIC DIAGRAM OF TREATMENT OPTIONS
2 AND 4
Page
189
204
213
215
XXV
-------
SECTION 1
INTRODUCTION
The purpose of this document is to provide, guidance to permit
writers, industry, and the general public on multimedia
pollution control systems for the ethanol-for-fuel industry.
Information is provided on ethanol-for-fuel waste stream
characterization, process descriptions, and pollution control
options and costs on a variety of ethanol-for-fuel facilities.
The term "Ethanol-for-Fuel" in this document concerns only the
ethanol derived from biomass through fermentation. Ethanol can
also be derived from ethylene and ethanol derived in this
fashion is called synthetic ethanol. However, synthetic ethanol
is not considered as a source of ethanol for the Ethanol-for-
Fuel industry evaluations. Fermentation ethanol was first used
as a fuel in the United States, in the late 1800's; in the early
1900's ethanol was used both in stationary and mobile combustion
applications. By the end of World War II, ethanol production in
the United States totaled 600 million gallons per year. Using
ethanol as a fuel decreased after the war and nearly disappeared
until the late 1970's when interest was renewed because of
concern over dependence on insecure foreign oil supplies.
In light of this potential new industry, in 1979 the Agency
initiated the gathering of data with the intent of proposing
multimedia environmental regulations on the ethanol-for-fuel
industry. In January 1981, the Federal government cut back on
financial assistance for ethanol production. This action, along
with high corn prices and a more stable supply of petroleum
resources, resulted in a steep cutback of ethanol-for-fuel
production. In early 1982, the Agency reached the decision to
utilize the data gathered to provide guidance rather than issue
formal regulations on pollutant discharges in the ethanol-for-
fuel industry.
The Multimedia Technical Support Document (MTSD) contains no
legally binding requirements, no regulatory standards and
includes no preference for process technologies or controls.
Nothing within this document binds a facility to accepting the
example control technology(ies) nor relieves a facility from
compliance with existing or future environmental regulations or
permits.
-------
1.1 TECHNOLOGY OVERVIEW
All fermentation alcohol plants employ four basic processes:
feedstock preparation, fermentation, distillation and de-
hydration. A fifth process, byproduct recovery, is also
possible, but not necessarily included in all ethanol-for-fuel
plants. Variations within the fermentation, distillation and
dehydration processes do not result in significant changes in
the quality or amount of emissions or effluents from a facility.
Both feedstock preparation and byproduct recovery process
variations have greater impact on the characteristics of the
generated wastes.
Feedstock Preparation
Feedstock preparation includes all steps in converting the raw
material to a saccharified mash. Depending on the feedstock,
different methods of preparing the saccharified mash and for
removing valuable byproducts, such as germ or lignin, are
available. The feedstock preparation techniques in use in the
existing ethanol-for-fuel industry include: dry milling, wet
milling, wood sugar preparation, and cheese whey preparation.
Fermentation
The biological conversion of the saccharified mash by.yeast for
the production of ethanol can be rendered in continuous or batch
fermentation processes. The grain and wood sugars are converted
into ethanol and carbon dioxide. Other reactions also occur
producing small quantities of acetic acid, aldehydes and longer
chain alcohols.
Continuous and batch fermentation processes require temperature
control, agitation and pH control. Fermentation is an exo-
thermic process and cooling is usually employed for temperature
control. Depending on the choice of fermentation process, the
fermented mash will vary with respect to yeast reclamation,
vessel residence time, live yeast concentration and ethanol
concentration. These four parameters are closely interrelated
and require special attention for the maintenance of steady
state operation.
Distillation
In the distillation process the ethanol is removed from the
solids and most of the water. The process variations in the
distillation chain are a function of desired product quality.
Those plants which produce potable as well as fuel-grade ethanol
include additional stills to remove nearly all organic con-
taminants (e.g., fusel oils and aldehydes) whereas new grass
roots ethanol-for-fuel plants are designed to minimize energy
requirements and wastewater generation.
-------
Dehydration
When a mixture of ethanol and water is distilled, a minimum
boiling point azeotrope is found. At this point ( 96 percent
ethanol) further separation of ethanol and water is impossible
using simple distillation. To produce anhydrous ethanol, a
third compound, the dehydration agent, can be added to the
mixture to alter the azeotrope and subsequently permit the
removal of all water from the ethanol. This is the most common
technique used in the dehydration of ethanol to be used as fuel.
Byproduct Processing
The method of byproduct recovery is dependent upon the feedstock
and the feedstock preparation technique employed. The stillage
from the bottom of the beer still is often recovered as a
marketable, high-protein byproduct but may be discharged as
wastewater. In some cases, the quantity and/or quality of
stillage does not warrant the capital expenditure required for
byproduct recovery, particularly if feedstocks other than grain
are used. Those plants which do recover the stillage utilize
dewatering and drying processes such as cyclones, evaporators
and dryers for complete recovery of a dry solid. Those plants
that do not recover stillage have a substantially higher
wasteload since the byproduct recovery system is the major
contributor to total distillary wastes.
1.2 REGULATORY BACKGROUND
Wastewater Regulations
The Federal Water Pollution Control Act of 1972 established a
comprehensive program to "restore and maintain the chemical,
physical, and biological integrity of the Nation's waters"
[Section 101(a)]. By 1 July 1977, existing point source
industrial dischargers were required to achieve "effluent
limitations requiring the application of the best practicable
control technology currently available" (BPT) [Section
301(b)(A)]. Further, by 1 July 1983, these dischargers were
required to achieve "effluent limitations requiring the
application of the best available technology economically
achievable (BAT) which will result in reasonable further
progress toward the national goal of eliminating the discharge
of all pollutants" [Section 301(b)(2) (A)]. New industrial
direct dischargers were required to comply with Section 306 new
source performance standards (NSPS), based on best available
demonstrated technology (BAD), and new and existing dischargers
to publicly owned treatment works (POTWs) were subject to pre-
treatment standards under Sections 307(b) and (c) of the Act.
While the requirements for direct dischargers were to be
incorporated into National Pollution Discharge Elimination
System (NPDES) permits issued under Section 402 of the Act,
-------
pretreatment standards were made enforceable directly against
dischargers to POTWs (indirect dischargers).
Although Section 402(a)(l) of the 1972 Act authorized the set-
ting of requirements on a case-by-case basis, Congress intended
that, for the most part, control re- quirements would be based
on regulations promulgated by the Administrator of the EPA.
Section 304(b) of the Act required the Administrator to prom-
ulgate regulations providing guidelines for effluent limitations
setting forth the degree of effluent reduction attainable
through the application of BPT and BAT. Moreover, Sections
304(c) and 306 of the Act required promul- gation of regulations
for NSPS, and Sections 304(f), 307(b), and 307(c) required
promulgation of regulations for pretreatment standards. In
addition to these regulations for designated industry cate-
gories, Section 307(a) of the Act required the Administrator to
promulgate effluent standards applicable to all dischargers of
toxic pollutants. Finally, Section 501(a) of the Act authorized
the Administrator to prescribe any additional regulations
"necessary to carry out his functions" under the Act.
On 27 December 1977, the President signed into law the Clean
Water Act of 1977 (P.L. 95-217). Although•this law makes
several important changes in the federal water pollution control
program, its most significant feature is its incorporation into
the Act of several of the basic elements of the Settlement .
Agreement program for toxic pollution control. Sections 301(b)
(2)(A) and 301(b)(2)(C) of the Act now require the achievement,
by 1 July 1984, of effluent limitations requiring application of
BAT for toxic pollutants, including the 65 toxic pollutants and
classes of pollutants which Congress declared toxic under Sec-
tion 307(a) of the Act. Likewise, the EPA's programs for new
source performance standards and pretreatment standards are now
aimed principally at toxic pollutant controls. Section 306(b)
includes a list of industrial categories for which these per-
formance standards should be developed. Moreover, to strengthen
the toxics control program, Congress added Section 304(e) to the
Act, authorizing the Administrator to prescribe "best management
practices" (BMPs) to prevent the release of toxic and hazardous
pollutants from plant site runoff, spillage or leaks, sludge or
waste disposal, and drainage from raw material storage associ-
ated with, or ancillary to, the manufacturing or. treatment
process.
In keeping with its emphasis on toxic pollutants, the Clean
Water Act of 1977 also revised the control program for nontoxic
pollutants. Instead of BAT for "conventional" pollutants iden-
tified under Section 304(a)(4) (including biochemical oxygen
demand, total suspended solids, fecal coliform, pH, and oil and
grease), the new Section 301(b)(2)(3) requires achievement, by 1
July 1984, of "effluent limitations requiring the application of
the best conventional pollutant control technology" (BCT). The
-------
factors considered in assessing BCT for an industry include the
costs of attaining a reduction in effluents and the effluent
reduction benefits derived compared to the costs and effluent
reduction benefits from the discharge of publicly owned treat-
ment works [Section 304(b)(4)(B)]. For nontoxic, nonconven-
tional pollutants, Sections 301(b)(2)(A) and (b)(2)(F) require
achievement of BAT effluent limitations within three years after
their establishment or 1 July 1984, whichever is later, but not
later than 1 July 1987. Table 1-1 summarizes these levels of
technologies, sources affected, and deadlines for promulgation
and compliance.
BPT, BCT, BAT, and NSPS have not been developed for the ethanol-
for-fuel industry. This industrial category was not listed
among those in Section 306(b) of the Clean Water Agt. Yet in
1979, when it appeared that the industry was growing at a rate
requiring regulatory control, the Agency initiated a regulation
development program. However, by 1981 when projected growth of
the industry substantially declined, the Agency made the deci-
sion to develop guidance rather than regulations. The dif-
ference between the two is that regulations are legally binding
standards that require compliance. "Guidance" on the other hand
simply provides information which permit writers and industrial
developers can use (among other sources) in their determination
of appropriate pollution control measures.
Air Regulations
The Clean Air Act and its amendments created a comprehensive
program to protect and enhance the Nation's air quality and a
regulatory scheme for the control of air pollution. The
cornerstone of the Act is the development of uniform national
ambient air quality standards (NAAQS). The responsibility for
limiting emissions to meet the ambient standards lies with the
states. The Act required each State to develop state imple-
mentation plans (SIPs) which provide for implementing, main-
taining, and enforcing the ambient standards.
The Act also requires the United States Environmental Protection
Agency to establish three sets of nationally uniform emission
limitations: new source performance standards (NSPS), hazardous
pollution emission standards, and motor vehicle emission stand-
ards. The NSPS requires the application of "best demonstrated
technology" to new and modified stationary sources. However,
the Act allows the States to require more stringent emission
limitations than those developed for NSPS.
Part C of the Act, prevention of significant deterioration of
air quality, provides EPA a means to regulate any pollutant from
any major emitting facility which may adversely affect the pub-
lic health and welfare. A major emitting facility for the
ethanol-for-fuel industry would be any source which emits or has
-------
u
o
JJ
CO
J-l
r-l
3
"-3
CO
cn
t-i
a>
01
60
Cfl
< C
CU O
Ez2 *H
JJ
O 60
U-l i— 1
3
cu e
B 0
1-1 u
•o
to h
0) O
CU-I
CO
CO
CO
o.
Jj
cu
JJ
UH
to
(-1
^•l
•-4
0)
60
CO
CO
CO
co
o.
u
cu
JJ
U-l
to
p
^^
i-H
cu
o^
(0
(fl
(0
id
0<
J.J
0)
4-1
M-l
id
£
K^
H
t)
CU
JJ
u
co
O)
o
3
o
CO
co
01
ej
S
O
CO
60
co
0)
U
3
O
co
60
JJ
CO
§
CO
S1
•r)
to
•H
o
Vi
Q.
e
a
3
0)
>
JJ C
O O
0) -H
U-l JJ
U-l Cfl
W 60
0)
JJ
tu
CO
.
CO
JJ
>> 0)
60
co co
--. CO
t-H CO
1 S
•—4 O.
co
0)
o
tu
3
O
CO
cu
z
to
j-i
CO
O)
CO
e
^j
^j
CU
JJ
CO
iH
O
Z
JJ
CU
JJ
ll 1
*w
CO
CO
^
CO
'O
o
r*.
CN
co
0)
u
VJ
3
O
CO
60
e
•H
JJ
CO
i-l
^
U
O
1-1
JJ
CO
60
3
O
Q,
fci
(U
JJ
U-l
CO
0)
60
Cfl
co
co
S.
o
JJ
60
•H
60
CO
"S s
co H
•H 0
•O Du
iH
e
0
CL,
O
a
, 3
O>
>
i-l
jj g
CJ O
0) i-l
U-l JJ
UJ (0
W W)
01
JJ
U-4
Cfl
.
CO
l^
>s CU
60
CO CO
^- co
-H CO
JL a
log
i-l o
•O Pu
CO O
0) JJ
u
IJ 60
3 C
0 i-l
CO 60
l-i
S CO
01 J=
Z CJ
UH
o
o
•H
JJ
U
0)
CO
•3-
O
O
CO
o
co
o
CO
o
n
o
co
o
CO
o
CO
r-
O
co
oc
o
1
01
H
H
Oi
03
1
en
co
0-
to
CO
CU
-------
the potential to emit 227 metric tons/year (250 tons/year) or
more of any pollutant.
Solid Waste Regulations
The issue of federal legislative control for the safe disposal
of solid waste has been a primary environmental concern in the
1970's. Initially, regulation of solid waste was solely the
responsibility of the states. Later, federal solid waste pro-
grams were promulgated such as the Solid Waste Disposal Act of
1965 and the Resource Recovery Act of 1970. However, neither of
these acts gave any enforcement authority for solid waste con-
trol to the federal government. In order to obtain more uniform
solid waste control the Resource Conservation and Recovery Act
(RCRA) was passed in 1976.
RCRA was designed with the following principal features:
regulation of certain wastes, defined or characterized as
hazardous, are to be the responsibility of the federal
government; and regulation of nonhazardous wastes is to be a
state responsibility, in conformance with federal guidelines.
However, under RCRA Section 3006, states are authorized and
encouraged by EPA to develop and carry out their own hazardous
waste programs in lieu of a federally administered program.
Authorization for state run programs must be granted by EPA and
is being initially administered through an "interim status"
program. "Final authorization" will be possible after Section
3004, Part 264 requirements are promulgated.
For solid wastes, the prevailing factor is whether the waste is
considered hazardous or nonhazardous under the Resource Con-
servation and Recovery Act. If one or more of the solid waste
streams generated by ethanol-for-fuel facilities are considered
hazardous, the Administrator has the authority to "list" such
streams. When this occurs the generators, transporters, and
disposers of these wastes must comply with all appropriate
Subtitle C regulations of the Resource Conservation and Recovery
Act (RCRA 3000 Series). Wastes which are not hazardous are
subject to Subtitle D regulations (RCRA 4000 Series).
Additionally, there are regulations which deal with the reuse of
hazardous wastes. Under Section 3001, part 261.6, a hazardous
waste which meets specific criteria is excluded at this time
from some of the waste management requirements if it is always
used, reused, recycled, or reclaimed.
Prior EPA Regulations
The ethanol-for-fuel industry consists of facilities that con-
vert biomass to ethanol for use as a fuel. It is a new industry
which, for the most part, consists of converted beverage alcohol
plants. A review of environmental regulations reveals that
-------
there are no federal regulations which apply specifically to the
effluents, emissions, or solid wastes generated by either
ethanol-for-fuel facilities or beverage alcohol facilities. In
the absence of effluent guidelines, National Pollutant Discharge
Elimination System (NPDES) permits have been issued to dis-
tillers based on a permit authority's "best professional
judgment" under authority of Section 402(a)(l) of the Federal
Water Pollution Control Act. Also, state pollution control
boards have been responsible for monitoring and regulating air
emissions and solid wastes for existing ethanol facilities based
on "best professional judgment."
1.3 INDUSTRY OVERVIEW
As of September 1981, there were 15 plants which comprised the
ethanol-for-fuel industry. The combined capacity of these
plants was 600 million liters (163.5 million gallons) of ethanol
per year. At that time there were six beverage alcohol plants
being converted to produce ethanol-for-fuel and 29 new facili-
ties under construction. The plants under construction were
estimated to have a capacity of about 2.5 billion liters per
year (705 million gallons per year); most of these plants were
scheduled to be on-line by 1985. In addition, there were 42
plants under study or planned. The combined capacity of these
proposed plants was approximately 4.3 billion liters per year (1
billion gallons.per year).
In January 1984, a total of 70 ethanol-for-fuel plants were in
existence. Of these 70, however, only 43 were operational. The
capacity of these 70 plants was approximately 2.6 billion liters
per year (683 million gallons per year). (1) An industry
profile later performed in September 1985 showed a total of 102
ethanol-for-fuel plants in existence.* Of these, 57 were in
operation and producing. The total capacity of the 102 plants
was 3.6 billion liters per year (941 million gallons per year).
The 57 operating plants had a capacity of 2.9 billion liters per
year (764 million gallons per year). At this time, there were
also 15 plants under construction in 12 states with a capacity
of approximately 220 million gallons per year. .There were 38
proposed plants (capacity of 593 million gallons per year) with
another 36 projects "on hold."
*Note: All the data collection, literature searches, analyses,
statistics, and costing for this document were completed in
1981. Prior to publication in 1986, however, an updated
industry profile (September 1985) was included in this document
for informational purposes. EPA believes, however, that the
industry has not changed significantly enough in the past four
years to warrant an entire reanalysis of the 1981 data.
8
-------
Grain is the major feedstock for these facilities. Approximate-
ly 94 percent of the alcohol from the plants under construction
will be derived from grain. The remaining ethanol will be pro-
duced from wood sugars, corn syftip, and other biomass sources.
In the late 1800s, fermentation ethanol was used for cooking,
heating, and lighting. During World War II, ethanol was used
for fuel in submarines, aircraft, and land vehicles, as well as
in the production of synthetic rubber. However, after the war,
gasoline became plentiful and inexpensive, and industrial
ethanol was produced by a more economical method using ethylene.
The interest in fermentation ethanol was renewed by the Nebraska
legislature in 1971 when the state tax on gasoline was reduced
for fuels containing grain-derived ethanol. Public interest
continued, and the Department of Energy, United States Depart--
ment of Agriculture, White House, and Congress were-encouraging
research and development of ethanol for fuels.
1.4 DATA COLLECTION METHODOLOGY
To compile a data base for the evaluation of pollution control
in the ethanol-for-fuel industry, information was gathered from
the literature; beverage and ethanol-for-fuel facilities; trade
organizations such as the Distilled Spirits Council of the
United States (DISCUS), the National Gasohol Commission, the
National Alcohol Fuels Commission, and the National Alcohol
Fuels Producers Association; and government agencies such as the
DOE, EPA, and Bureau of Alcohol, Tobacco, and Firearms (ATF).
Data obtained from these sources included information on ethanol
production; location and distribution of ethanol-producing
facilities; process descriptions; water use; sources of waste-
water, air emissions, and solid wastes; pollutant concentra-
tions; and cost and treatability of control and treatment
technologies.
f
The data base collection efforts included contacts with govern-
ment and industry personnel, a program for sampling eight
ethanol distilleries, and preparation and submittal of two
industry questionnaires to 15 distilleries under authority of
Section 308 of the Clean Water Act, Sections 111 and 114 of the
Clean Air Act, and Section 3007 of RCRA. Also conducted as part
of the data gathering effort was a review of the NPDES moni-
toring data on file with regional EPA offices., and a review of
the information contained in the 1974 draft development docu-
ment for the Beverages Segment of the Miscellaneous Food and
Beverage Industry concerning the beverage alcohol industry.
After the data base was analyzed, the major sources of waste-
water, air emissions, and solid wastes were identified and their
contribution to total plant waste load quantified. The total
plant wastewater characteristics were summarized in terms of
pollutant concentration for the toxic (129 priority pollutants),
-------
conventional, and nonconventional pollutants. Also, point
source and fugitive air emissions were estimated for criteria
pollutants (NOx, SOX' an<* particulates) and volatile organic
compounds on a plant-by-plant and industry-wide base. Finally,
all solid wastes, plant feedstocks, and by-products were evalu-
ated for the characteristics of ignitability, corrosivity,
reactivity, and EP-toxicity.
The determination of wastewater pollutants of concern was based
on toxicity of pollutants, wastewater characteristics and the
treatability of these species by control and treatment
technologies.
The control and treatment technologies applicable to the indus-
try were assessed. Included were in-plant and end-of-pipe tech-
nologies which are used in the industry or can be adapted to it.
The identified technologies were evaluated for their ability to
treat the pollutants of concern. The problems, limitations, and
reliability of each control and treatment technology were also
identified.
In addition to treatability, the cost of treatment has been con-
sidered in developing pollution control systems. Thus, this
document includes an evaluation of the cost associated with
purchase,' installation, and operation of wastewater treatment
equipment. Capital costs, annual costs, energy requirements,
and land requirements were developed for new plants and for
retrofitting existing plants. Cost information was obtained
from the industry during plant visits, from engineering firms,
from equipment suppliers, and from the literature. Where data
were lacking, costs were developed from knowledge of necessary
equipment, processes employed, and construction and maintenance
requirements.
1.5 DOCUMENT ORGANIZATION
This Multimedia Technical Support Document is presented in seven
sections and seven appendices. Following this introductory
section are:
Section 2 - Industry Profile - The industry profile con-
tains information on the history of ethanol production,
process descriptions, total plant capacities, and other
important statistics, as well as water use and management
practices within the ethanol-for-fuel industry. This
profile provides a foundation for analysis of water use
and wastewater generation and treatment.
Section 3 - Waste Stream Characterization - The data col-
lected on the levels of pollutants in air emissions, waste-
waters and solid wastes from ethanol facilities is sum-
marized and evaluated in Section 3. Included are the test
10
-------
results from two EPA sampling programs and monitoring data
obtained from several distilleries. Also included is a
discussion of the major sources of emissions and effluents
and their composition and treatability.
Section 4 - Wastewater Treatment and Control Technology -
This section discusses applicable in-plant and end-of-pipe
technologies which can be used to reduce or eliminate the
pollutants of concern. The achievable effluent pollutant
reductions are discussed using treatability information
from the beverage alcohol and ethanol-for-fuel industries.
The applicable technologies are further analyzed according
to their cost effectiveness, energy requirements and
secondary pollutant potential.
Section 5 - Solid Waste Treatment and Disposal Technologies
- This section discusses applicable solid waste treatment
and disposal techniques including dewatering, drying, di-
gestion, land application and recycle/reuse. These tech-
niques are analyzed based on effectiveness, availability,
current use and cost.
Section 6 - Cost, Energy and Nonwater Quality Issues -
Cost, energy and nonwater quality issues are discussed for
each .treatment technology. Cost and energy information
contained in this manual was obtained from industry during
plant visits, from engineering firms, from equipment
vendors, and from the literature.
References.
Appendix A - Sampling procedures used to collect field
wastewater, solid waste and gaseous emissions.
Appendix B - Analytical methods and preliminary sample
treatment on preparations used to analyze the collected
samples.
Appendix C - Quality assurance/quality control procedures
to assure, assess and document the precision, accuracy, and
adequacy of the data.
Appendix D - Solid waste and air sampling results -
compilation of analytical data.
Appendix E - Wastewater sampling results - raw and treated
effluent analytical data.
Appendix F - Statistical support calculations.
Appendix G - Appendix G is the Ethanol-for-Fuel Effluent
Guidelines Cost Manual which presents a detailed evaluation
of the costs and energy requirements associated with treat-
ment and control alternatives discussed in this manual.
11
-------
SECTION 2
INDUSTRY PROFILE
This profile of the ethanol-for-fuel industry consists of a
short historical background on the ethanol industry; status of
the industry, including information on production capacity,
location/ number of plants, feedstocks, by-products, and plant
age or on-line dates for proposed plants; and a discussion of
ethanol-for-fuel processes.
2.1 HISTORICAL DEVELOPMENT
The production of ethanol originated with the discovery that
alcoholic beverages could easily be obtained by fermenting sub-
stances with naturally occurring sugars such as fruit. The pro-
duction of ethanol from grain is a more complex process because
the starch must be converted to sugar before fermentation; how-
ever, even this technique was known in ancient times. The
Egyptians and Mesopotamians brewed beer as early as 2500 B.C.,
and these processes were used until the middle 1800's when
modern fermentation techniques were developed by Kutzing and
Pasteur.
In the late 1800's, fermentation ethanol was used in the United
States for cooking, heating, and lighting because it provided
clean and odorless fuel. Henry Ford built a Model A car in the
early 1900's with an adjustable carburetor enabling the car to
be powered by pure ethanol, gasoline, or any mixture of the two.
By the 1930's, ethanol fuels were widely used in the United
States and 40 other nations, and an estimated four million cars
were powered by ethanol fuels in Europe (2).
With the advent of World War II and the subsequent scarcity of
oil, there was even more reliance on ethanol fuels. The Germans
powered their war machinery with ethanol derived mostly from
potatoes when their oil supply was severed. Also, in the United
States, whiskey distilleries and newly built ethanol facilities
supplied ethanol for use in submarines, aircraft, and land
vehicles. In addition, ethanol was used as a feedstock in the
developing synthetic rubber industry. In 1944, U.S. ethanol
production totaled 600 million gallons, half of which went for
synthetic rubber (3).
After the war, many distilleries were dismantled or converted to
beverage plants. Gasoline became plentiful and inexpensive, and
12
-------
-------
industrial ethanol needs could easily be met by the new, more
economically produced synthetic ethanol that was .derived from
ethylene. By 1949, only 10 percent of industrial ethanol was
produced from grain (3). In 1979, industrial ethanol con-
stituted over 60 percent (more than 300 million gallons per
year) of the ethanol produced in the United States.
In the 1970's, there was a renewed interest in ethanol from
biomass, sparked by concern about increased U.S. dependence on
insecure foreign oil supplies and an interest in finding
alternative uses for agriculture products. It was not until
1979, however, that this renewed interest resulted in any
significant use of ethanol for motor fuel.
The Nebraska state legislature acted in 1971 to reduce the
state's gasoline tax by 3 cents per gallon for fuels containing
at least 10 percent agriculturally derived ethanol, but this had
little impact on ethanol consumption. The Arab oil embargo in
1973-74 stimulated additional interest in ethanol as world crude
oil prices suddenly increased by nearly 400 percent. In spite
of this large increase in oil prices, economic studies showed
that ethanol from biomass would not be economically viable
without a large subsidy. However, support for using ethanol as
a motor fuel continued to grow among agriculture states. Iowa
provided an excise tax exemption for ethanol/gasoline blends and
developed a marketing program. Illinois joined in support and
conducted tests of these fuel blends in state vehicles. Fleet
tests were performed in Nebraska and Iowa. Sales of ethanol on
the market began in Illinois in January 1978, at three retail
stations. By mid-1978 market sales began in Iowa, and in
November 1978, 60,850 gallons of ethanol were sold as motor fuel
in that state (3).
By late 1978 the grassroots support for ethanol resulted in con-
gressional action. The Energy Tax Act of November 1978 provided
that ethanol/gasoline blends were exempt from the 4-cents-per-
gallon federal excise tax on motor fuel from 1 January 1979
through 1 October 1984. The exemption applied to blends con-
taining at least 10 percent ethanol produced from other than
petroleum, natural gas, or coal; the exemption had the effect of
providing a subsidy for ethanol of 40 cents per gallon (4 cents
for each one-tenth of a gallon of ethanol included in an
ethanol/gasoline blend).
The interruption of crude oil exports by Iran in early 1979 led
to serious gasoline shortages in the U.S. and an increase of
over 100 percent in world crude oil prices. The gasoline
shortages and rapid oil price increases created a sense of
urgency for U.S. efforts to reduce dependence on foreign oil,
and it was concluded that ethanol from biomass was the only
13
-------
alternative fuel that could provide a substitute for OPEC oil in
the short-term. By mid-1979, ethanol/gasoline blends were sold
in over 800 retail outlets in 28 states, and a large demand for
ethanol developed.
The crisis atmosphere of 1979 resulted in a host of government
actions (both federal and state) to encourage production of
ethanol-for-fuel from biomass as rapidly as possible. These
initiatives included exempting ethanol/gasoline blends from
gasoline taxes by many states, extension of the federal excise
tax exemption, and initiation of a variety of federal grant and
loan guarantee programs.
The rapidly increasing gasoline prices and the tax exemptions
for ethanol/gasoline blends induced additional firms to produce
ethanol for fuel. The initial production came entirely from
plants which had been producing ethanol for beverage or indus-
trial uses. A wave of announcements of plans for new or
expanded ethanol-for-fuel plants occurred after enactment of the
Crude Oil Windfall Profits Tax in April 1980, which extended the
4-cents-per-gallon federal excise tax exemption for ethanol/
gasoline blends from 1984 through 1992. Many other organiza-
tions indicated that they were studying plant feasibility or
applying for government loans or loan guarantees for their
plants. Hundreds of potential ethanol-for-fuel plants were in
various stages of study or planning by mid-1980.
In January 1981, the Reagan Administration announced that it was
proposing to cut back on financial assistance for ethanol
production, as part of its efforts to curtail federal spending.
Tne Administration proposed to rely primarily on the federal
excise tax exemption to support ethanol-for-fuel production.
This action, along with unusually high corn prices and a weak
gasoline market, resulted in reconsideration of decisions to
proceed with many projects. Construction was halted on some
projects, some existing plants reduced ethanol production or
decided not to start production, and many plans for new plants
were put on hold pending further analysis or resolution of
financing issues.
In addition to federal excise tax exemption, many states
exempted ethanol-for-fuel from state taxes. in thirty-four
states, ethanol-for-fuel was exempted from all or part of state
fuel taxes. With lower grain prices in 1984, and state tax
exemptions and federal tax exemptions, the ethanol-for-fuel
industry has continued to grow.
14
-------
2.2 ETHANOL-FOR-FUEL-INDUSTRY STATUS
2.2.1 1981 PRODUCTION LEVELS
The ethanol-for-fuel industry is defined as commercial-size
facilities (capacity greater than one million gallons of anhy-
drous ethanol per year) which convert biomass (via fermentation)
to ethanol for use as fuel. By September 1981, the ethanol-for-
fuel industry was composed of 15 plants with a combined produc-
tion capacity of about 164 million gallons of ethanol per year.
These plants are presented in Table 2-1.
Eight of these plants are grassroots facilities, six were con-
verted from beverage alcohol facilities, and the remaining plant
is an industrial grade ethanol facility. A variety of feed-
stocks are used which include grain, grain-derived high fructose
corn syrup (HFCS) from corn sweeteners, wood sugars from wood
pulping operations, and cheese whey. All the facilities, with
the exception of the plant which processes wood sugars, sell
their by-products, either wet or dry, as livestock feed. The
plant which processes wood sugars concentrates its by-product
lignin stream and then sends it to a lignin processing facility.
Approximately 60 percent of .the 1981 ethanol-for-fuel capac-
ity is from former beverage distilleries or from expansion of
facilities previously used for industrial, medical, or beverage
alcohol production. Grains such as corn, wheat, and milo are
the major feedstock and account for over 96 percent of the
ethanol produced. Natural gas or oil is used as the heat source
for most of the current ethanol-for-fuel plants, although there
are plans to convert some plants to coal. The plants are dis-
persed around the country, but over two thirds of the capacity
is located in the central region of the country.
2.2.2 1985 PRODUCTION LEVELS
By September 1985, 102 ethanol-for-fuel plants, each with a
capacity of 1 million gallons per year or greater, were located
in 31 states. Of these, 57 were operating and 45 non-operating.
Total production capacity was approximately 3.6 billion liters
per year (941 million gallons per year). Capacity of the 57
operating plants was 2.9 billion liters per year (764 million
gallons per year) as shown in Table 2-2.
Production of ethanol for fuel had expanded rapidly as shown by
the following yearly production figures. (37)
15
-------
Table 2-1
ETHANOL-FOR-FtJEL' FACILITIES
(1981)
Plant
Code
A01
A02
A03
A04
A05
A06 .
A07
A08
A09
A10
All
A12
A13
A14
A15
Capacity
(MM qal/yr)
60
20
3
.
10
3
3
2
1.2
1.2
2
1
1
2.5
8.6
45
Location
IL
PA
KS
IL
IA
AR
WA
AL
NC
WI
WA
SD
IA
GA
IA
Feedstock
HFCS*
Corn
Corn, Milo,
Wheat
Corn
Milo
Corn
Wood Sugars
Corn
Corn, Milo
Cheese Whey
Corn,
Potatoes
Corn
Corn
Corn
Corn
*High fructose corn syrup.
16
-------
Table 2-2
ETHANOL-FOR-FUEL OPERATING PLANTS
(1985)
State
Arkansas
California
Colorado
Idaho
Illinois
Indiana
Iowa
(476)
Kansas
Kentucky
Louisiana
Minnesota
Montana
Nebraska
New Jersey
New Mexico
(594.8)
North Dakota
Location
Van Buren
Selma
Winters
Cueamonga
Corona
Golden
Monte Vista
Heyburn
Rockford
Decatur
Peoria
Pekin
Batavia
Pekin
South Bend
Cedar Rapids
Muscatine
Bonaparte
Clinton
Hamburg
Elgin
Atchison
Garden City
Franklin
Jennings
Port Allen
Belle Chasse
Shrevport
Melrose
Mankato
Ringling
Amsterdam
Roc a
Hastings
Windsor
Clovis
Clovis
Tucumcari
Walahalla
(Thous. gal/yr)
3,000
10,000
1,000
5,000
2,000
2,400
4,000
3,000
3,000
150,000
90,000
70,000
2,000
11,000
50,000
60,000
10,000
4,000
20,000
5,000
1,500
6,000
1,750
20,000
25,000
4,000
7,000
2,000
1,000
2,000
1,500
1,850
1,500
11,000
1,000
1,200
1,500
4,500
11,200
Feedstock
Corn
Molasses
Industrial
Wastes
»
Cheese Whey
Brewery
Condensate
Potato
Potato Waste
& Hulls
Corn
Cornstarch
Corn
Corn
Sugary Wastes
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Molasses
Molasses
Blackstrap
Molasses
Milo
Cheese Whey
Hydrous Ethanol
Barley
Barley
Milo
Corn
Waste Sugar
Milo
Milo
Milo .
Barley
17
-------
Table 2-2 (Continued)
ETHANOL-FOR-FUEL OPERATING PLANTS
(1985)
Oklahoma
Pennsylvania
Tennessee
Texas
Utah
Virginia
Washington
Wisconsin
Location
South Point
Navarre
Hydro
Wadsfordsburg
Loudon
Euless
Tremonton
Reston
Charles City
Floyd
Nelson
New Church
Chesapeake
Wilsons
Charles City
Bellingham
Jim Falls
Juneau
(Thous. gal/yr)
60,000
1,000
5,000
1,650
40,000
5,000
2,500
5,000
6,000
7,000
2,600
1,600
6,600
1,000
1,650
2,500
1,500
2,000
Feedstock
Corn
Agricultural
Wastes
Milo
Corn
Corn
Milo
Barley
Hydrous Ethanol
Hydrous Ethanol
Hydrous Ethanol
Hydrous Ethanol
Corn
Hydrous Ethanol
Corn
Corn
Sulfite Waste
Liquor
Corn
Cheese Whey
18
-------
Actual Production
Year (In millions of gallons)
1979 20
1980 40
1981 75
1982 210
1983 375
1984 430
1985 625 (est. from 3 quarters)
2.2.3. PLANTS UNDER CONSTRUCTION (1981)
In 1981 35 ethanol-for-fuel plants were under construction; six
of these plants were beverage plants undergoing conversion and
the remaining 29 were grassroots facilities. Seventeen of the
plants under construction were scheduled to be on-line by 1980,
the rest were scheduled to be operational by 1982. These plants
are summarized in Table 2-3.
The total capacity for these 35 plants was about 705 million
gallons per year, over one-third (259 million gallons) will be
produced by converted beverage alcohol facilities. Approxi-
mately 81 percent of the ethanol will come from facilities which
produce 20 million gallons per year or more. The size distri-
bution for plants under construction is presented below.
Range (million gallons/year) Number of Plants
1-5 , 16
6-15 10
16-35 4
36-75 3
>75 2
Grains such as corn, wheat, milo, and barley are the predominant
feedstock and accounting for almost 94 percent of the designed
ethanol production. Sugar feedstocks such as sugarcane, sugar
beets, and molasses were projected to provide about seven
percent of the ethanol. Potatoes were projected to provide less
than 1 percent of the ethanol from plants under construction.
The plants were to be located in 20 states and dispersed in
almost all regions of the country. Almost half of the capacity
for plants under construction in 1981 were located in the
midwest.
2.2.4 PLANTS UNDER CONSTRUCTION (1985)
In September 1985, 15 ethanol-for-fuel plants were under
construction. These facilities have a combined capacity of 833
million liters per year (220 million gallons per year). All
19
-------
Code No.
Table 2-3
PLANTS UNDER CONSTRUCTION
(1981)
Location
Ethanol
Production
Feedstock
On-Line Date
C01*
C02
COS
C04
COS
C06
C07
COS
C09**
CIO
Cll
C12
CIS
C14
CIS
C16**
C17**
CIS
IL
LA
OH
IL
GA
IA
TN
LA
IL
KY
CO
NC
OK
• sc
ID
IN
KY
IN
(MM gal/yr)
190
120
60
60
10.5
10
40
34.6
21.5
21
8.5
25
12
11
4
8
8
6
HFCS
Corn
Corn
Corn
Corn
Corn
HFCS
Sugarcane,
Molasses
Corn
Corn
Grain,
Sugar Beets
Corn
Milo
Corn
Corn
Corn
Corn
Corn
Late 1981
Mid 1982
Mid 1982
1982
1982
Mid 1981
Jan. 1982
June 1981
Late 1982
1981
Spring 1982
*Expansion of plant A01.
**Converted beverage alcohol facilities.
20
-------
Code No.
Location
Table 2-3 (Continued)
PLANTS UNDER CONSTRUCTION
(1981)
Ethanol
Production Feedstock
On-Line Date
C19**
C20**
C21
C22
C23
C24
C25
C26
C27
C28
C29
C30
C31
C32
C33
C34
C35
KY
KY
ND
KS
MN
KY
CO
IA
MD
IA
CO
IN
OR
WI
OH
WI
WA
(MM gal/yr)
. 6
5.5
3.5
6
4
3.5
3
5.4
2.5
2.5
2.5
2
1.8
1.5
1.2
1
1
Grain
Corn
Potatoes
Milo
Wheat,
Barley
Corn
Milo
Corn
Corn, Barley
Corn
Barley,
Potatoes
Corn
Grain
Corn, Pota-
toes
Corn
Corn
Corn
1981
1981
Early 1982
1981
1981
Nov. 1981
. —
Jan. 1982
1981
1981
1981
1981
1981
—
**Converted beverage alcohol facility,
21
-------
of these new plants are grass roots facilities. Plants are
located in 12 states as shown in Table 2-4. Corn and other
grains will be the predominant feedstock of these new facilities
with 96 percent of production coming from grains. The other 4
percent will be produced from other feedstocks, including cheese
whey. One plant will be operating to dehydrate hydrous ethanol.
2.2.5 PROPOSED PLANTS (1981)
In 1981 there were 42 proposed ethanol-for-fuel plants. These
are presented in Table 2-5. Two to three years are needed for
the construction of a facility. Site location, funding, and
economic incentives determine how many of these plants will
actually be built. With the interest in ethanol fuels and
availability of various feedstocks, in 1981 it was expected that
many of these plants would be on,-line by December 1985. The
combined production capacity of the proposed plants is about 980
million gallons per year, with the plants falling into the
following ranges:
Range (million gallons/year) Number of Plants
1-5 7
6-15 11
16-39 17
40-75 6
>75 1
The feedstocks for these proposed plants are summarized below:
Feedstock No. of Plants* % Total Capacity
Grains (Corn, Wheat, 34 83.1
Barley, Milo)
Sugars (Sugarcane, Sweet 3 8.2
Sorghum, Sugar Beets,
Molasses, Sweet Pota-
toes, Cheese Whey)
Potatoes .2 0.4
Unknown 5 8.3
*Note: Some facilities plan to use more than one type of
feedstock.
22
-------
Table 2-4
ETHANOL-FOR-FUEL PLANTS UNDER CONSTRUCTION
(September 1985)*
State
Company
Capacity
(Thous. gal/yr)
Feedstock
Alaska
California
Iowa
Illinois
Indiana
Louisiana
Minnesota
N. Dakota
New Mexico
S. Carolina
Tennessee
Virginia
Diamond R
United Energy (Barrego)
United Energy (Yermo)
Archer Daniels Midland
Archer Daniels Midland
Agmont , Inc .
Solar Alcohol Energy, Inc.
Mississippi River Alcohol
Co.
Minnesota Dairy Tech.
Alchem Limited
Aurora Rresources, Inc.
Agripin
Tennol Energy Company
Newport News Energy Assn.
American Fuel Trading Co.
1,200
1,500
1,500
70,000
50,000
2,500
1,000
42,000
2,300
4,500
2,000
9,000
25,000
1,650
6,000
Barley
Corn,
Corn, molasses
Corn
Corn
Corn, wheat
Corn
Corn
Cheese whey
Barley, potato
Milo
Corn
Corn, Milo
Corn, Barley,
Milo
Hydrous
Ethanol
*Reference (37)
23
-------
Table 2-5
PROPOSED PLANTS
(1981)
Ethanol
Code No. Location Production Feedstock
D01
DO 2
D03
DO 4
DOS
D06
D07
DOS
D09
D10
Dll
D12
D13
D14
D15
D16
D17
D18
D19
IA
PA
IN
VA
LA
LA
IN
CO
ME
TN
TX
MI
MI
PA
SC
IN
IA
IA
LA
(gal/yr x 106)
216
63
50
50
40
40
36
30
25
25
22
20
20
20
20
20
20
20
20
Corn
Corn
Corn
Corn
Corn, Molasses
Sugar
Corn
Unknown
Corn
Corn
Milo
Corn
Corn
Corn
Corn
Grain
Corn
Corn
Sugar Cane,
Sorghum, Corn
Molasses
D20 SC 20 Unknown
24
-------
Table 2-5 (Continued)
PROPOSED PLANTS
(1981)
Ethanol
Code No. Location Production Feedstock
(gal/yr x 10°)
D21
D22
D23
D24
D25
D26
D27
D28
D29
D30
D31
D32
D33
D34
D35
D36
D37
D38
D39
D40
D41
D42
KS
MD
MN
NB
IL
KS
MT
IL
IL
KY
WA
MI
VA
MO
IA
ID
FL
MN
GA
CO
GA
NB
18
15
15
15
14.3
12.5
10.5
10.5.
10.5
10
10
10
10
10
10
5
5
4
2.5
2.5
2
1
25
Corn, Milo
Corn
Grain
Grain
Corn
Corn
Unknown
Unknown
Unknown
Corn
Corn
Corn
Grain
Corn
Corn
Wheat, Barley, Pota
toes
Corn, Milo
Barley, Wheat
Corn
Potatoes, Barley
Grain
Corn
-------
2.2.6 PROPOSED PLANTS (1985)
In 1985 there were 38 proposed ethanol-for-fuel plants in the
U.S. (37) These 38 plants represent a capacity of nearly 2.2
billion liters per year (593 million gallons per year).
Approximately one quarter of these plants are expected to enter
construction. The proposed plants (1985) are listed by state in
Table 2-6.
Another 36 ethanol-for-fuel projects are "on hold." These 36
plants represent over 1.9 billion liters per year (508 million
gallons per year) production. (37) The probability of any of
these facilities reaching construction is very low. (37)
2.2.7 PROJECTED PRODUCTION
A study conducted by the Department of Energy in 1979 estimated
the availability of surplus agricultural feedstocks and biomass
sources for conversion to ethanol. Based on this information,
the maximum amount of ethanol which can be produced from these
sources is presented in Table 2-7. To calculate these projec-
tions, the DOE study assumed the following percentages .of feed-
stocks to be available for conversion to ethanol: cheese whey,
80 percent; citrus wastes, 80 percent; corn, 80 percent; wheat,
80 percent; sugar cane, 100 percent; and sweet sorghum, 100 per-
cent. The study also considered sweet sorghum to be a better
feedstock than corn because it is cheaper, has a higher yield,
and requires less feedstock processing. Therefore, this study
assumed that 14 million acres of pastural or set-aside land
would be converted to sweet sorghum production by the year 2000,
allowing the elimination'of corn as a feedstock. In addition,
it should be noted that the projections for wood and agricul-
cultural residues depend on the development of appropriate
technology.
Geographic Distribution
Figure 2-1 presents the geographic distribution by EPA regions
of existing ethanol-for-fuel plants which were existing in 1981
or were under construction and proposed for construction. As
this figure shows, Regions 4, 5, 6, and 7 were projected to
contain 73 percent of the facilities and 83 percent of the total
capacity.
Figure 2-2 shows the same projected plants by state.
Thirty-three states were projected to have at least one
ethanol-for-fuel facility. Six states including Colorado, Iowa,
Illinois, Indiana, Louisiana, and Kentucky were projected to
have five or more facilities. Table 2-8 shows the 1985 status
by state, showing the number of existing plants and the number
of operating plants.
26
-------
Table 2-6
ETHANOL-FOR-FUEL PLANTS PROPOSED
(September 1985)
Capacity
State
Alabama
Florida
Iowa
Illinois
Kansas
Kentucky
Louisiana
Maine
Minnesota
Montana
North Carolina
Nebraska
Location
Decatur
Pensacola
Ames
Eddyville
Ethersville
Spencer
Argo
Piatt County
Liberal
Calvert City
Baton Rouge
Jonesville
New Iberia
New Orleans
Vidalia
Auburn
Appleton
Clarkf ield
Glenville
Mankato
Marshall
Billings
Hardin
Lumberton
Benkleman
Blair
Lincoln
Sidney
Winnebago
(Thous. gal/
25,000
3,000
23,000
6,000
6,000
10,000
135,000
6,500
6,000
20,000
10,000
5,000
49,000
35,000
12,000
15,000
3,150
5,000
10,000
20,000
10,000
4,000
10,000
1,500
30,000
16,500
12,000
18,000
10,000
yr) FeedstocK
Corn
Milo
Corn
Corn
Corn
Corn
Corn
Corn, Milo
Corn
Corn
Corn
Molasses,
Sugar
Sugar cane,
Sorghum
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Corn
Wheat
Barley
Corn
Corn, Milo
Corn
Corn
Wheat
Corn
27
-------
Table 2-6 (Continued)
ETHANOL-FOR-FUEL PLANTS PROPOSED
(September 1985)
State
Location
Capacity
(Thous. gal/yr)
Feedstock
New Jersey
New Mexico
Oregon
Texas
Utah
Virginia
Carney's Point
Las Cruces
Lovington
Klaraath
Hereford
Salt Lake City
Norfolk
Stony Creek
Taskey
10,000
10,000
12,000
10,000
7,000
2,000
10,000
10,000
5,000
Corn
Corn, Milo
Milo, Wheat
Corn
Corn
Wheat
Corn, Milo
Corn
28
-------
Table 2-7
PROJECTED MAXIMUM ETHANOL PRODUCTION
FROM U.S. BIOMASS RESOURCES
[Million Gallons Per Year]
Wood
Agricultural Residues
Grains:
Corn
Wheat
Grain Sorghum
Total Grains
Sugars :
Cane
Sweet Sorghum
1985
21,800
10,300
2,100
1,400
300
3,800
200
200
1990
20,200
11,300
900
1,600
300
2,800
700
3,000
2000
25,800
13,100
2,000
300
2,300
700
8,300
Cane
Sweet Sorghum
Total Sugars
Municipal Solid Waste
Food Processing Wastes:
Citrus
Cheese
All Other
200
200
400
2,300
200
100
300
700
3,000
3,700
2,500
300
100
300
700
8,300
. 9,000
2,900
400
200
300
Total Processing Wastes
600
700
900
TOTAL
39,200
41,200
54,000
Reference 3.
29
-------
CO
o e
>. ».
on
fa
A
II
rH 0PM
^g"
MCO
« H •
>-i fci O
3 «
toO l—l >-i
fa
COO
0
O
O
Ed
O
O
W
H
O
W
30
-------
W
En
g
i
i Hen
-------
Table 2-8
ETHANOL-FOR-FUEL PLANTS BY STATE
(September 1985)
Number of Plants
State
Alabama
Arkansas
California
Colorado
Florida
Georgia
Idaho
Illinois
Indiana
Iowa
Kansas
Kentucky
Louisiana i
Maryland
Michigan
Minnesota
Montana
North Dakota
Nebraska
New Jersey
New Mexico
Ohio
Oklahoma
Pennsylvania
South Dakota
Tennessee
Texas
Utah
Virginia
Washington
Wisconsin
Total
1
1
6
5
2
2
3
6
2
9
3
4
6
1
2
5
2
1
4
1
7
2
1
2
2
1
3
2
9
3
4
Operatina
n
\j
i
j.
0
i
J.
1
X
5
o
t*
i
J.
4
*±
0
•3
J
9
<<£
1
J.
9
£*
1
•3
O
•J
£,
1
X
1
X
0
1
J.
I
-L
1
J.
T
J.
2
TOTAL
Source: (37)
102
57
32
-------
Future Ethanol-for-Fuel Processes
In addition to the feedstocks in use in the ethanol- for-fuel
industry, it is projected that sugar cane, sweet sorghum, sugar
beets, cane molasses, citrus molasses, cellulose, cheese whey,
and potatoes may be used to provide ethanol for fuel. Despite
the feedstock used, all new ethanol-for-fuel plants constructed
in the near future are expected to use fermentation, distilla-
ation, and dehydration systems similar to those for existing
ethanol-for-fuel plants. This is due to the fact that all
feedstocks enter the fermenter as simple sugars regardless of
their original form. Nonfermentable matter (e.g., protein,
fiber, lignin) is routed to by-product processing, thus provid-
ing an ethanol/water feed to distillation and dehydration which
is independent of the feedstock.
Feedstock preparation techniques, on the other hand, will vary
depending on the type of biomass used for conversion. Over the
years, various methods of grinding, pulverizing, and mashing
have been specially developed for different feedstocks. Also,
by-product recovery systems, although analogous, will vary
according to the desired form (i.e., dry, moist, or liquid) and
marketability of the recovered by-product.
2.3 BTHANOL-FOR-FUEL PROCESS DESCRIPTION
In the United States, ethanol for beverage purposes must be
derived entirely from the fermentation of starch or sugar feed-
stocks. However, industrial- or fuel-grade ethanol can be made
via fermentation or synthesized from ethylene, a gas derived
from petroleum. Synthetic ethanol is not considered in this
document. Only those facilities producing ethanol which is
derived from renewable biomass feedstocks are defined as part of
this industry.
All fermentation ethanol plants employ four basic processes:
feedstock preparation, fermentation, distillation, and dehydra-
tion. A fifth process, by-product recovery, is also possible,
but not necessarily included in all ethanol-for-fuel plants.
Slight variations within each of the first four processes are
available; however, differences in fermentation, distillation,
and dehydration do not result in significant changes in the
quality or amount of emissions and effluents. Those steps which
may affect the characteristics of the wastes generated include
the feedstock preparation technique and the inclusion of the
fifth process, by-product recovery.
2.3.1 FEEDSTOCK PREPARATION
Feedstock preparation includes all steps in converting the raw
material (i.e., corn or wood chips) to a saccharified mash which
enters the fermenters. Depending on the feedstock, different
33
-------
methods of preparing a saccharified mash and for removing valu-
able by-products from the feedstocks, such as germ (protein) or
lignin (cellulosic material), are available. The feedstock
preparation techniques in use in the existing ethanol-for-fuel
industry include dry milling, wet milling, wood sugar
preparation, and cheese whey preparation.
Processing of Grain Feedstocks
The incoming grain contains considerable amounts of dirt and
extraneous matter such as stover, cobs, twigs, sand, tramp
metal, mold clumps, and stones. Therefore, the grain is first
cleaned and rough ground to remove the foreign matter. Large
amounts of particulate emissions occur from grain receiving,
cleaning, and conveying in addition to storage, milling, and
processing of the grain. The majority of the emissions are
fugitive and arise primarily from raw material handling. After
preliminary cleaning and grinding, two methods are available for
preparing the grain for fermentation: dry milling and wet
milling.
Dry Milling. In the dry milling process, the grain is bar
milled or hammer milled to form a fine meal. Milling breaks the
outer cellulosic wall around each kernel to expose more starch
surface to the action of cooking and conversion.
Water is added to the milled grain and the suspension is fed
into a cooker. Cooking may be carried out under pressurized or
atmospheric conditions in either batch or continuous processes.
Steam is injected during cooking to raise the temperature which
aids in solubilizing and gelatinizing the mash, thus forming a
more suitable substrate for enzymatic hydrolysis (biological
breakdown) of starches into sugars.
After cooking, the mash is cooled to about 63°C and ground
barley malt or fungal amylase is added to convert the
solubilized starches by enzyme action into component five and
six carbon sugars. This conversion may take place in a separate
vessel called a "converter" in order to free the cooker for the
next batch. The slurry, at this point called "mash," is further
cooled via vacuum or tubular heat exchangers to about 27°C and
then pumped to the fermenters.
Wastes from the mashing process consist of condensate from pres-
sure cookers and vacuum coolers in addition to residual material
from vessel cleanup. For plants operating in this mode, the
load comprises about 12 percent of the total plant waste. For
plants with atmospheric cookers and shell and tube mash coolers,
the load would be lower. =-.
Wet Milling. Another method of grain preparation used for corn
is referred to as wet milling. in this process, the corn is
34
-------
first steeped in a dilute aqueous solution of sulfur dioxide to
soften the kernels and cob (if whole corn is used) and to remove
soluble materials. The sulfur dioxide extract is collected and
concentrated to produce a product which is sold for fermentation
media and animal feed.
The softened kernels are then coarse-milled to loosen the oil-
containing germ, then washed and dried. After drying, the germ
is further processed by solvent extraction to yield the
desirable corn oil and a residual cake which is a valuable
animal feed material. The material remaining after removal of
the germ passes through successive milling, screening, and
washing to remove the hull fiber, which is dried and also used
in animal feed formulations.
At this point, a slurry which consists of a mixture of starch
and protein remains. This mixture is separated centrifugally to
produce the protein fraction that constitutes a valuable, high-
protein corn gluten by-product. The remaining fraction, which
is starch, is obtained from the centrifuges as a concentrated
slurry containing upwards of 40 percent solids.
The starch stream is then fed into a converter for enzymatic or
acid hydrolysis to fermentable sugars. Vacuum or tubular heat
exchangers may be used to cool the saccharified mash before
entering the fermenters.
The wastes generated from the corn wet milling process include
the water removed from the sulfur dioxide extract during concen-
tration, the numerous wash waters, and the condensate from the
vacuum coolers if this equipment is used.
In cases where corn wet milling is used in conjunction with
another process (e.g., corn sweetener), the wastes generated
from corn wet milling were not considered in ethanol-for-fuel
industry since corn wet milling will be covered as part of the
food industry.
Wood Sugar Preparation
It is possible to produce fermentable sugars from wood by treat-
ing it with sulfuric acid, lime rock, and caustic soda. This
process is one form of pulping in which the resulting fibrous
cellulosic material can be separated from a solution of calcium
lignosulfate and wood sugars by filtration or centrifugation.
The lignin/sugar solution is referred to as spent sulfite liquor
(SSL) and is usually concentrated in evaporators prior to
further processing. Nearly all pulp mills that employ this
technique either burn or recover the lignin from the SSL;
however, one pulp mill routes this SSL stream to an ethanol
35
-------
plant which removes the sugars (via fermentation) before
recovering the lignin.
The SSL stream is steam stripped to remove volatile sulfur com-
pounds and cooled using noncontact heat exchangers. The stream
is then neutralized to a pH of 4.3 and supplemented with aqueous
ammonia to satisfy the nutritional requirements of the yeast
prior to fermentation.
Excluding the wastes generated from pulping operations, the
wastes generated from this process include the evaporator
condensate and the overhead stripper condensate containing the
soluble sulfur compounds.
Cheese Whey Preparation
Cheese whey is currently being used at one plant to produce
96.5 percent ethanol. The ethanol is sold to another plant
which dehydrates the ethanol for its eventual use as a fuel.
The use of cheese whey as a feedstock has significantly reduced
the environmental impact of discharging cheese whey to the local
receiving water or wastewater treatment plant (4).
The preparation of cheese whey for use in ethanol production is
shown in Figure 2-3. The whey concentrate as received con-
tains 35 to 40 percent total solids and a lactose content of 35
to 38 percent (5). After pasteurization, the cheese whey enters
.a solid bowl centrifuge which removes the whey protein. The
whey protein is a valuable by-product used in food additives
such as casein. The supernatant, a 75 percent lactose stream,
enters the fermenters.
The necessity of maintaining high-purity surroundings for food
additive processing requires numerous system cleanings. This is
the only waste stream generated by this process.
2.3.2 FERMENTATION
The biological conversion of the saccharified mash by yeast for
the production of ethanol can be rendered in a continuous or
batch fermentation process. The grain and wood sugars are con-
verted into ethanol and carbon dioxide according to the
following chemical equation:
C6H1206 - - **2C2H50H + 2CC>2
yeast
Other reactions also occur producing small quantities of acetic
acid, aldehydes, and longer chain alcohols often referred to as
fusel oils. These processes are well documented in most
biochemistry text books.
36
-------
a
a
v e
n o
C
0)
O !-"
3.
13 y
C
-------
Continuous and batch fermentation processes require temperature
control, agitation, and pH adjustment. Fermentation is an exo-
thermic process, and external or internal 'cooling is usually
employed for temperature control. Related to this is the neces-
sity to agitate the fermenting mash to maintain homogenous
temperature and ethanol concentration gradients throughout the
vessel. To retard bacterial growth during fermentation, the pH
is controlled between 4.5 and 5.0; strains of yeast used have
been developed to tolerate these acidic conditions.
Depending on the choice of fermentation process (batch or con-
tinuous), the fermented mash will vary with respect to yeast
reclamation and recycle, fermentation vessel residence time,
live yeast concentration, and ethanol concentration. These four
parameters are closely interrelated and require special atten-
tion for the maintenance of steady-state operation in continuous
fermentation.
Batch Fermentation. Batch processes add predetermined amounts
of pure cultured yeast to each reactor vessel containing the
saccharified mash. The residence time of the mash varies from
60 to 72 hours, resulting in a final ethanol concentration of
approximately 10 percent by volume. The yeast may be removed by
centrifugation and sold as a protein by-product. The relative
ease of batch fermentation has led to its widespread use in the
beverage and ethanol-for-fuel industries.
Water usage in batch fermentation is limited to noncontact cool-
ing in the fermenters. The only source of wastewater is from
fermenter washing. The fermenters are washed after each batch
with steam and disinfectants to maintain sterile conditions.
Large quantities of carbon dioxide are produced during fermenta-
tion which contain small amounts of water vapor along with
traces of volatile organic compounds. Besides ethanol, these
organic compounds include acetaldehyde and furfural which are
by-products of the saccharification and fermentation reactions.
Continuous Fermentation. In continuous fermentation, the yeast
is separated from the fermented mash and recycled to the fermen-
ters. A portion of the recycle yeast stream is discharged or
recovered as a by-product to remove dead yeast and to prevent
contaminants from building up in the system. Although
concentrations of 10 to 12 percent ethanol are achievable, this
level of ethanol is toxic to yeast; therefore, the ethanol
concentration is generally kept below six percent to maintain a
high yeast population. The retention time for continuous
fermentation is much shorter than batch fermentation, usually
between eight and twenty-four hours. in addition, the yeast
population density is greater in a continuous process to enhance
the conversion of sugar to ethanol.
38
-------
Only two ethanol facilities in the United States currently use
continuous fermentation; these plants also provide anhydrous
ethanol for fuel. Plant A01 uses both batch fermenters and
continuous fermenters. Plant AO7 conducts a type of continuous
fermentation in which a series of well-mixed reaction vessels
are used with a total retention time of eight to ten hours.
As in batch fermentation, continuous fermentation produces large
quantities of carbon dioxide containing traces of organic com-
pounds and water usage in continuous fermentation is restricted
to noncontact cooling water. Unlike batch fermentation,
continuous fermenters are cleaned infrequently; this results in
a reduction of wastewater.
In both fermentation processes, the fermented mash, known as
"beer," is sent into a beer well en route to the beer still.
The beer well is a holding tank for the fermenters which ensures
continuous feed to the beer still and allows some settling of
solids out of the mash.
2.3.3 DISTILLATION
In distillation, the solids and most of the water is separated
from the ethanol. The process variations which occur at this
point are no longer a function of the feedstock but of the ulti-
mate product quality desired and age of the plant. For example,
those plants which produce potable ethanol as well as fuel-grade
ethanol include additional.purification steps in their distilla-
tion trains to remove nearly all impurities (e.g., fusel oils
and aldehydes). This type of distillation sequence is referred
to as a conventional system. A second type of distillation
train is used by former beverage alcohol producers who have
converted their facilities to produce only ethanol-for-fuel. In
these converted facilities, purification columns are eliminated
in response to relaxed purity requirements for fuel blends.
Finally, a third distillation scenario is depicted by grassroots
ethanol-for-fuel facilities that are designed to minimize energy
requirements and wastewater generation.
Conventional Distillation
Prior to entering the beer still, the fermented mash may enter a
degasser 'drum where the dissolved carbon dioxide is flashed off.
The amount of carbon dioxide released here is comparatively
small and is not recovered. The fermented mash, containing 10
to 12 percent ethanol, is then preheated by the beer still
overhead heat exchanger before entering the column. Once the
mash enters the beer still, the solids and much of the water are
separated from the ethanol.
Live steam is injected at the base of the column to strip the
ethanol from the fermented mash introduced near the top of the
39
-------
still. The vapor leaving the top of the still is condensed and
forms the product, an 80 percent ethanol solution containing
some impurities. The discharge from the base of the column
contains the soluble and suspended substances carried through
the process. Depending on the feedstock and its preparation
technique, the beer still bottom stream may contain many useful
by-products.
The purification columns following the beer still remove the
aldehydes, fusel oils, and water, while concentrating the
ethanol. Figure 2-4 illustrates a typical column arrangement.
The overhead beer still stream containing the ethanol enters a
solvent extractor which functions as an extractive distillation
column. The water injected into this column helps to separate
the fusel oils, and aldehydes from the ethanol and may be fresh
or recycled from another part of the plant. The water and
ethanol exit the bottom of the column with an ethanol concen-
tration of 10 to 20 percent. The more volatile aldehydes and
fusel oils leave the column at the top and just below the feed
tray, respectively.
The aldehyde stream from the solvent extractor is sent to the
aldehyde concentrating column along with the overhead stream
from the rectifier, which is also high in aldehydes concentra-
tion. The aldehydes exit the top of the concentrating column;
the bottom stream, containing some ethanol from the rectifier
and fusel oils from the solvent extractor, is recycled to the
solvent extraction column.
The fusel oil-rich stream removed from the solvent extractor
enters the fusel oil column where they are removed in a concen-
trated stream overhead. The water which enters the fusel oil
column leaves the bottom of the column and is pumped to the
wastewater treatment plant.
The rectifier receives the dilute ethanol stream (containing
small quantities of aldehydes) from the solvent extractor. The
aldehydes are removed from the top and sent to the aldehyde con-
centrating column, while the binary azeotrope of five percent
water and 95 percent ethanol is removed near the top of the
rectifying column. The ethanol stream from the rectifier is
then routed to the dehydration system. The rectifier bottoms,
which is relatively pure water, can be discharged to the
wastewater treatment system or recycled to the solvent
extractor.
Wastewaters from this multi-column process comprise two to four
percent of the total plant BOD load and fifteen to thirty per-
cent of the total wastewater volume, depending on whether or hot
the rectifier bottoms are recycled. This does not include the
wastewater from beer still bottoms which is routed to by-product
40
-------
-------
JCT
ril
J5-S
* 1
i.o s
•
a
M
I
-c*
s-1
t,
* s
§
M
I
-------
processing. Concentrated aldehydes may be discharged to the
wastewater treatment system or burned as fuel. Fusel oils,
which are less volatile than aldehydes, may be combined with the
ethanol product without affecting the performance of fuel
blends.
Vents on overhead condensers used to condense the distillation
column vapors are sources of volatile organic emissions such as
ethanol, aldehydes, and fusel oils (amyl alcohols). Although
these vent streams may have high concentrations of these com-
pounds, the total volume is very low.
Converted Beverage Plants
A high-purity product is not necessary if ethanol is to be used
for fuel; therefore, distillers who have converted their
beverage alcohol plants can eliminate the solvent extraction
column and the aldehyde concentration column as illustrated in
Figure 2-5. The removal of these columns from the distillation
train reduces the energy required to separate the ethanol from
water and also reduces the amount of wastewater generated.
In this method, the degasser drum and the beer still function in
the same manner as conventional distillation schemes with the
concentrated ethanol product sent overhead and the solids
removed from the bottoms. Instead of being routed to a solvent
extraction column, the top ethanol-rich stream now enters the
rectifier near the middle of the column. To prevent the
accumulation of fusel oils within the column, a sidestream rich
in fusel oils is removed from a plate near the top of the
column. The fusel oil sidestream contains ethanol as well as
water which is usually removed in a fusel oil concentrating
column. The concentrated fusel oils may be blended back into
the final product or used as a source of fuel for the distil-
lation columns. A 96 percent ethanol stream leaves the top of
the rectifier and is pumped to the dehydration system. The
rectifier bottoms are pumped to the wastewater treatment plant.
The wastewater generated in this distillation scheme is
estimated to comprise two to four percent of the total BOD plant
load and ten to fifteen percent of the total volume of
wastewater sent to the treatment system.
Current Designs
The widespread use of distillation in the oil industry has led
to technology advances in design techniques which are applicable
to the ethanol-for-fuel industry. Ethanol plants of the future
will utilize these advances to simplify the necessary separation
processes and reduce energy consumption.
42
-------
to
I
O*
(1)
3
W
O
W
H
W
o
u
CO
43
-------
Figure 2-6 illustrates the basic features of an ethanol-for-
fuel distillation design which might be found in a grassroots
facility. The system is similar to the two-column converted
beverage alcohol plant. However, the beer still no longer
receives its heat from live steam but from a reboiler. Also,
the second column, called a stripping column in this case,
receives a recycled stream from the dehydration system.
The beer still overhead stream enters the stripping column con-
taining approximately 50 percent ethanol. The ethanol/water
azeotrope occurs at a concentration of 95 to 96 percent ethanol.
This stream leaves the top of the column and is then condensed
and pumped to the dehydration column. A sidestream near the top
of the column enters a separator which removes the fusel oils
and recycles the remaining liquid to the stripping column. The
remaining input to the stripping column is an ethanol/water
stream from the dehydration system. Most of the dehydration
agent which enters the stripping column via the dehydration
recycle stream goes overhead with the ethanol and is sent back
to the dehydration system.
In this distillation scheme, all the wastewater from dehydration
is discharged through the distillation system, resulting in an
increase of less than one percent. On the other hand, the use
of reboilers in the beer still and rectifier rather than live
steam injection results in a 20 percent decrease in wastewater
generation for this system.
As in conventional distillation, the current distillation train
is a source of small amounts of volatile organic compounds which
are emitted from the vents on column condensers.
2.3.4 DEHYDRATION
When a mixture of ethanol and water is distilled at atmospheric
pressure, a minimum boiling point azeotrope is formed. It is at
this point (approximately 96 percent ethanol concentration) that
further separation of ethanol and water is impossible using sim-
ple distillation techniques. To produce anhydrous ethanol (pure
ethanol), a third compound (dehydration agent) can be added to
the mixture to alter the azeotrope and subsequently permit the
removal of all the water from the system. This sequence of
events is referred to as dehydration.
Currently,' there are two methods for dehydration in the ethanol-
for-fuel industry: one method consists of a self-contained
add-on unit and is used in beverage alcohol plants that have
been converted to produce anhydrous ethanol; the other is
designed as an integral part of the distillation system and is
used in ethanol-for-fuel facilities. A variety of dehydration
agents are available which are suitable for either system,
including benzene, hexane, ethyl ether, and gasoline.
44
-------
o
4J
S ca
•5 M
3
l-l
O
4J
2.
«
a.
cu
rH
0)
co
00
£
Cfl
g
§
§
s
i g
M -H
J-l 4J
CO 8 (8
O )-l
lU H T3
r-l IW >»
O J3
>>
CO
JJ
ca
•8
S-g
45
-------
The first system that is discussed uses a distillation column to
strip out the dehydration agent from the product ethanol stream;
this method is referred to as the solvent recovery method. The
second system allows a large amount of the dehydration agent to
remain in the ethanol and is referred to as dehydration without
solvent recovery.
Dehydration With Solvent Recovery
A typical solvent recovery scheme is shown in Figure 2-7. The
solvent currently used by three ethanol-for-fuel plants is ben-
zene. The addition of benzene, both fresh and recycled from the
benzene recovery column, produces a ternary azeotrope. In the
dehydration column, all of the water and benzene (along with
some ethanol) is taken off in the overhead stream. Ethanol,
present in excess, is withdrawn from the bottom of the column.
The overheads from the benzene dehydration column are cooled in
a separator and form two layers: a water/ethanol-rich bottom
layer containing some residual benzene and a benzene/ethanol-
rich top layer containing a small amount of water. The bottom
layer is sent to the benzene recovery column where all the
benzene and ethanol are stripped and recycled to the dehydration
column. The stream from the benzene recovery column bottom,
which is nearly all water, is sent to wastewater treatment. The
top layer from the separator is recirculated to the benzene
dehydration column.
The only wastewater stream from the dehydration system is the
bottom stream from the benzene recovery system. This stream is
very small (less than one percent of the total volume of process
wastewater), is low in BOD and total suspended solids, and may
contain trace amounts of benzene.
As with distillation column condensers, the vents on dehydration
column condensers are sources of small amounts of volatile
organics. Also, the vent on the two-phase separator is a source
of volatile organics. In addition to compounds such as ethanol
and fusel oils, dehydration agents (e.g., benzene) are also
emitted from these sources.
Dehydration Without Solvent Recovery
A flow diagram for a dehydration system that does not recover
the dehydration agent is presented in Figure 2-8. One ethanol-^
for-fuel plant uses unleaded gasoline as the dehydration agent
and, by leaving the gasoline in the ethanol, satisfies the re-
quirements set by the Bureau of Alcohol, Tobacco, and Firearms
(ATF) for denaturation. This scheme is more indicative of
future trends for the ethanol-for-fuel industry.
46
-------
ss-
SSI
e o
o> o
o
u
2
M—
a
Bu
I £ O 01
IT) 4J t-1 -H
ON U to O
47
-------
J.
rH. 3
O 0)
u s
II
4J
2
(8
CU
0)
OT
. B
h O
as
•H M
fe &
§
M
I
0) 09
§=1
Cu O
4J
U
48
-------
HH £ ? l^Vi?88 solvent recovery, the dehydration
n hhi« ? the dehydration column. Operating conditions
in this column are only severe enough to remove all of the water
(along with some gasoline and ethanol) ; a 50/50 blend of ethanol
and gasoline is withdrawn off the bottom of the column.
This system also sends the overhead stream from the dehydration
system to a separator which returns the upper gasoline-rich
phase to the dehydration column and the lower ethanol/water
Zu^^u Hhe ^ectifier used in distillation. Thus, water leaves
this dehydration system via the rectifier, and there is no
wastewater generated from the dehydration system proper.
Air emissions from this dehydration system are similar to those
emitted from dehydration systems with solvent recovery.
2.3.5 BY-PRODUCT PROCESSING
Depending on the feedstock and the preparation technique used,
the stillage from the bottom of the beer still may be recovered
as a marketable, high-protein by-product. Several variations
exist in the method of recovering whole spent stillage. Basi-
cally, all ethanol plants fall into two categories: (1) those
with no recovery of this material, and (2) those utilizing evap-
orators and dryers for complete recovery.
In some instances, the quantity of stillage does not warrant the
capital expenditure required for by-product recovery. This is
particularly true if feedstocks other than grain are used which
are deficient in protein content (e.g., sugars, cellulose). it
is more economical for these plants to dispose of wet stillaqe
to nearby farmers for cattle feed than to install a recovery
system. Those plants that do not recover stillage have a
substantially different wasteload since the by-product recovery
system is the major contributor to total distillery waste.
Figure 2-9 illustrates a typical process for a by-product
recovery system. Whole spent stillage is approximately five to
seven percent solids; thus, by-product recovery is essentially a
dewatering process. The first step consists of passing the
whole stillage over a screen. , The coarser solids are retained
and sent to a press for further removal of soluble solids. The
press cake, if dried separately on driers, becomes "distillers
light grain." The thin stillage liquid is normally centrifuaed
to remove suspended solids, then piped to multiple effect -
evaporators where it is concentrated to a syrup containing about
^b to 50 percent solids. These evaporated solubles may be
thermally dried to produce "distillers dried solubles," or more
commonly dried with press cake in rotary driers to produce
"distillers dark grains."
-------
I
Whole Stillagc
By-P roduct Exhaust
Dried Grain
With Solubles
T
W»stewater
Effluent
Figure 2-9
PROCESS FLOW DIAGRAM:
BY-PRODUCT RECOVERY
50
-------
One ethanol-for-fuel plant uses a cellulose based feedstock. in
this case, the lignin is recovered and concentrated as it too is
a valuable by-product. Evaporation lowers the moisture content
to approximately 50 percent before the lignin solution is pumped
to its own processing plant.
The 'high yeast concentration required in continuous fermentation
and the necessary separation of the yeast from the lignin/
ethanol solution before entering the beer still produces a
second by-product stream, dried yeast. After the last fermen-
tation vessel in the continuous fermentation train, centrifuges
are used to remove the yeast. A portion of the yeast is recy-
cled to the first reactor and the rest is pasteurized to kill
the yeast which can then be disposed of or sold as a by-product.
The major contribution to the ethanol-for-fuel plant wasteload
is from the by-product recovery system. It can account for as
much as 80 percent of the total plant waste. The most signifi-
cant source of wastewater within the feed recovery system is the
condensate from evaporators. Although most plants discard their
condensate, at least one grassroots plant recycles up to 95 per-
cent of the condensate to the mashing tank. This practice is
indicative of the new plants that will be coming on-line.
Finally, dust emanating from grain dryers may constitute another
source of wastewater if wet scrubbers are used. Many plants
eliminate this water through the use of cyclones and combine the
collected dust with by-product grains.
51
-------
SECTION 3
WASTE STREAM CHARACTERIZATION
3.1 DATA COLLECTION
An extensive literature search revealed that a limited amount of
information existed in the literature regarding water use and
wastewater quality for ethanol-for-fuel facilities. Consequently,
the Agency devised an extensive sampling program to characterize
the effluent streams from all ethanol-for-fuel plants and several
beverage alcohol plants. This program supplemented the data
provided by two other studies: an environmental characterization
of an ethanol-for-fuel facility sponsored by the Industrial
Environmental Research Laboratory in Cincinnati/ Ohio (lERL-Ci),
and a sampling program conducted by the Region IV EPA Surveil-
lance and Analysis Division (6) concerning effluents from three
rum distilleries.
In addition to these sampling programs, multimedia industry ques-
tionnaires were prepared and submitted under authority of Section
308 of the Clean Water Act, Sections 111 and 114 of the Clean Air
Act, and Section 3007 of the Resource Conservation and Recovery
Act of 1976. Also, National Pollutant Discharge Elimination Sys-
tem (NPDES) permit applications for ethanol plants were reviewed,
and EPA regional offices were contacted for pertinent effluent
data. The information gathered from these data collection
activities and sampling programs are summarized in Table 3-1.
This table also specifies whether the data were used in the
pollutant parameter treatability assessment.
3.1.1 MULTIMEDIA INDUSTRY QUESTIONNAIRE
A multimedia questionnaire was prepared and submitted to ethanol-
for-fuel and beverage alcohol facilities. This questionnaire
solicited information concerning water use; generation and con-
trol technology for wastewater, air emissions and solid wastes;
process configuration; internal stream routing; and chemical
application rates. Initially, the questionnaires were sent to
the eight ethanol plants scheduled for sampling and analysis.
Responses were obtained from plants A01, A03, A06, A07, A10, E02,
and EOS. A preliminary analysis of these responses demonstrated
a lack of data on the efficiency of the control and treatment
systems employed. Therefore, the questionnaires were revised to
obtain daily monitoring data on untreated and treated waste
streams and sent to six beverage alcohol plants. Responses were
obtained from plants E04, EOS, El2, El3, El7, and El8.
52
-------
Table 3-1
ETHANOL-FOR-FUEL DATA BASE SUMMARY
-Plant
Code
A01
A02
A03
A04
A05
A06
A07
A08
A10
BOX
E02
B03
•04
BOS
E06
B07
B08
B09
Ell
B12
B13
B14
BIS
E16
B17
El 8
819
B20
Type of Analytical Data
3 days, untreated effluent (C, N, P)
No data available
2 years, untreated and treated effluent
(C, N. P)
No data available
No data available
3 days, untreated effluent (C, N, P)
3 days, untreated and treated effluent
(C, N, P)
No data available
3 days, untreated effluent (C, N, P)
S days, untreated effluent (C, N, P)
3 days, untreated and treated effluent
(C, N, P) ,
5 days, untreated effluent (C, N, P)
Average diluted untreated effluent (C)
1 year, treated effluent, avg. untreated
effluent (C)
1 day, untreated and treated effluent;
treatability data
1 year, Monthly average (C)
6 days, untreated and treated effluent
(C, N, P)
3 days, untreated effluent (C, N, P)
1 year, average untreated and treated
effluent (C)
1 year, average untreated and treated
effluent (C)
1 year, treated effluent and treatabil-
ity data (C)
1 year, diluted treated effluent (C)
6 smiths, untreated and treated effluent (C)
1 year, diluted effluent only (C)
1 year, untreated and treated effluent (C)
2 aonths, untreated and treated effluent (C)
1 year, average untreated and treated
effluent (C)
5 days, untreated effluent (C, N, P)
Pollutant
Parameter
Treatabilitv
NO
Mo
Yes
No
No
No
No
No
NO
NO
Yes
No
No
Yes
Yes
Yes
Yes
No
Yes '
Yes
Yes
No
Yes
No
Yes
Yes
NO
No
C • Conventional Pollutant Data
N • Npneonventional Pollutant Data
P • Priority Pollutant Data
53
-------
3.1.2 NPDES PERMIT DATA
After the results from the sampling programs and questionnaire
responses were received, EPA regional offices were contacted to
obtain NPDES permit information on ethanol plants regarding
wastewater treatment systems and effluent monitoring data.
Information received from 14 direct dischargers including Plants
A03, E02f E05, E06, E07r E08f Ell, E12, E13, El5f E16, E17, E18,
and E19.
3.1.3 EPA REGION IV SURVEILLANCE AND ANALYSIS DIVISION (SAD)
PROGRAM
In 1978, the EPA initiated a study aimed at assessing the options
for disposal of rum distillery wastes and associated environmen-
tal consequences. Region IV EPA/SAD conducted sampling and
analyses at plants E01, E03, and E20 for five consecutive days.
Composite samples were taken of the undiluted beer still slops or
raosto stream and of the combined untreated effluent, where pos-
sible. Single grab samples were collected from each facility s
raw process water, fermentation tank, aldehyde column, and
rectifying column; flow rates of the waste streams were also
determined (6,7).
A statistical and engineering analysis demonstrated that the
effluent quality of the rum distilleries varied significantly
from the effluent of other beverage alcohol plants (as well as
from ethanol-for-fuel facilities). Furthermore, the industry
orofile reveals that there are no rum distilleries providing or
planning to provide ethanol-for-fuel. Thus, the effluent data
from the rum industry were; not presented in this evaluation,
however, the data have been included in Appendix E.
3.1.4 lERL-Ci SOURCE TEST EVALUATION
in anticipation of the rapidly developing et1?3^:^:^ *n".
dustry and subsequent environmental impact, in 1978 the IERL ci
sponsored a test program as part of its efforts to determine
sampling and analytical requirements for ethanol facilities.
This program included the monitoring of air emissions and sam-
plinq of solid wastes and wastewater effluents. Information con-
cerning the streams tested, sampling frequency, and analytical
parameters examined can be found in the EPA report entitled,
"Source Test and Evaluation Report: Alcohol Facility for Gasohol
Production" (8).
3.1.5 EPA MULTIMEDIA SAMPLING PROGRAM
In 1980, the Effluent Guidelines Division (EGD), the Office of
Solid Waste (OSW), and the Office of Air Quality Planning and
Standards (OAQPS) of the EPA sponsored a program to characterize
effluents, solid wastes, and air emissions from ethanol-for-fuel
54
-------
and beverage alcohol facilities. This multimedia program was
undertaken to provide the Agency with a basis for evaluating
regulatory aspects of wastewater,.solid wastes, and air emissions
from the ethanol-for-fuel industry;
Facility Selection
At the inception of the EPA multimedia sampling program, there
were only five ethanol plants producing ethanol-for-fuel; all of
these plants were selected for sampling. Data were also sought
from the beverage alcohol industry which was hypothesized to be
analogous to the ethanol-for-fuel industry in terms of the
quality and volume of wastewater generated. Three plants (E02,
EOS, and E09) were chosen from the beverage alcohol industry for
sampling and analysis. Statistical data evaluation showed the
effluent from beverage alcohol plants to be similar to effluent
from ethanol-for-fuel plants and justified the combination of the
effluent data from all ethanol facilities tested.
According to the industry profile, approximately 95 percent of
the ethanol-for-fuel plants constructed in the next five to ten
years were projected to use grain feedstocks. Therefore, plants
EOS and E09 (typical grain distilleries) were selected for test-
ting. Plant EOS treats its wastewater using aerated lagoons,
rotating biological contactors, and stabilization ponds while
plant E09 discharges its wastewaters to a municipal treatment
system.
Plant E02, which uses the second most common type of feedstock
(sugar cane and citrus molasses), was selected for comparison to
grain feedstock beverage alcohol plants and the rum facilities.
This facility produces products which range from 50 to 95 percent
ethanol. Its wastewater treatment system includes aeration
tanks, a clarifier, a polishing pond, and a sludge digester.
Wastewater Sampling
The combined raw wastewaters, treated effluent streams, and
several component raw wastewater sources were tested for con-
ventional and priority pollutants, as well as selected noncon-
ventional pollutant parameters and those pollutants listed in
Appendix C of the 1976 Consent Decree (Appendix C compounds).
All parameters selected for analysis are listed in Tables 3-2
through 3-4. The ethanol facilities, selected streams, and
analytical parameters evaluated in this program are summarized in
Table 3-5.
The primary EPA reference for sampling effluent streams is in
"Sampling and Analysis Procedures for Screening of Industrial
Effluents for Priority Pollutants," April 1979 (9). Additional
information is found in the June 14, 1979 and December 3, 1979
issues of the Federal Register (10,11). The sampling procedures
55
-------
Table 3-2
LIST OF 129 PRIORITY POLLUTANTS
Compound Name
1. acenaphthene
2. acrolein
3. acrylonitrile
4. benzene
5. benzidene
6. carbon tetrachloride (tetrachloromethane)
Chlorinated benzenes (other than dichlorobenzenes)
7. chlorobenzene
8. 1/2,4-trichlorobenzene
9. hexachlorobenzene
Chlorinated ethanes(including 1r2-dichloroethane,
1,1/1-trichloroethane and hexachloroethane)
10. 1,2-dichloroethane
11. 1,1,1-trichlorethane
12. hexachlorethane
13. 1,1-dichloroethane
14. Ir1,2-trichloroethane
15. 1,1,2,2-tetrachloroethane
16. chloroethane
Chloroalkyl ethers (chloromethyl, chloroethyl and
mixed ethers)
17. bis (chloromethyl) ether*
18. bis (2-chloroethyly) ether
19. 2-chloroethyl vinyl ether (mixed)
Chlorinated naphthalene
20. 2-chloronaphthalene
Chlorinated phenols (other than those listed elsewhere?
includes trichlorophenols and chlorinated cresols)
21. 2,4,6-trichlorophenol
22. parachlorometa cresol
23. chloroform (trichloromethane)
24. 2-chlorophenol
56
-------
Table 3-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
Dichlorobenzenes
25. 1,2-dichlorobenzene
26. 1,3-dichlorobenzene
27. 1,4-dichlorobenzene
Dichlorobenzidine_
28. 3,3'-dichlorobenzidine
Dichloroethylenes (I/1-dichloroethylene and
1,2-dichloroethylene)
29. lr1-dichloroethylene
30. 1,2-trans-dischloroethylene
31. 2,4-dichlorophenol
Dichloropropane and dichloropropene
32. 1,2-dichloropropane
33. 1,2-dichloropropylene (1,3-dichloropropene)
34. 2,4-dimenthylphenol
Dinitrotoluene
35. 2,4-dinitrotoluene
36. 2,6,-dinitrotoluene
37. 1,2-diphenylhydrazine
38. ethylbenzene
39. fluoranthene
Haloethers (other than those listed elsewhere)
40. 4-chlorophenyl phenyl ether
41. 4-bromophnyl phenyl ether
42. bis(2-chloroisopropyl) ether
43. bis(2-chloroethoxy) methane
Halomethanes (other than those listed elsewhere)
44. methylene chloride (dichloromethane)
45. methyl chloride (chloromethane)
46. methyl bromide (bromomethane)
47. bromoform (tribromomethane)
48. dichlorobromomethane
57
-------
Table 3-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
49. trichlorofluoromethane*
50. dichlorodifluoromethane*
51. chlorodibromomethane
52. hexachlorobutadiene
53. hexachlorocyclopentadiene
54. isophorone
55. naphthalene
56. nitrobenzene
Nitrophenols (including 2,4-dinitrophenol and dinitrocesol)
57. 2-nitrophenol
58. 4-nitrophenol
59. 2,4-dinitrophenol
60. 4,6-dinitro-o-cresol
Nitrosamines
61. N-nitrosodiraethylamine
62. N-nitrosodiphenylamine
63. N-nitrosodi-n-propylamine
64. pentachlorophenol
65. phenol
Phthalate esters
66. bis(2-ethylhexyl) phthalate
67. butyl benzyl phthalate
68. di-n-butyl phthalate
69. di-n-octyl phthalate
70. diethyl phthalate
71. dimethyl phthalate
Polynuclear aromatic hydrocarbons
72. benzo (a)anthracene (1,2-benzanthracene)
73. benzo (a)pyrene (3,4-benzopyrene)
74. 3,4-benzofluoranthene
75. benzo(k)fluoranthane (11,12-benzofluoranthene)
76. chrysene
77. acenaphthylene
78. anthracene
79. benzo(ghi)perylene (I,12-benzoperylene)
80. fluorene
81. phenathrene
58
-------
Table 3-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
82. dibenzo (a,h)anthracene (1,2,5,6-dibenzanthracene)
83. indeno (1,2,3-cd) pyrene (2,3,-o-phenylenepyrene)
84. pyrene
85. tetrachloroethylene
86. toluene
87. trichloroethylene
88. vinyl chloride (chloroethylene)
Pesticides and Metabolites
89. aldrin
90. dieldrin
91. chlordane (technical mixture and metabolites)
DDT and metabolites
92. 4,4'-DDT
93. 4,4'-DDE(p,p'DDX)
94. 4,4'-DDD(p,p'TDE)
endosulfan and metabolites
95. a-endosulfan-Alpha
96. b-endosulfan-Beta
97. endosulfan sulfate
endrin and metabolites
98. endrin
99. endrin aldehyde
heptachlor and metabolites
100. heptachlor
101. heptachlor epoxide
hexachlorocyclohexane (all isomers)
102. a-BHC-Alpha
103. b-BHC-Beta
104. r-BHC (lindane)-Gamma
105. g-BHC-Delta
59
-------
Table 3-2 (Continued)
LIST OF 129 PRIORITY POLLUTANTS
polychlorinated biphenyls (PCB's)
106.
107.
108.
109.
110.
111.
112.
PCB-1242
PCB-1254
PCB-1221
PCB-1232
PCB-1248
PCB-1260
PCB-1016
(Arochlor
(Arochlor
(Arochlor
(Arochlor
(Arochlor
(Arochlor
(Arochlor
1242)
1254)
1221)
1232)
1248)
1260)
1016)
Metals and Cyanide, and Asbestos
114. Antimony (Total)
115. Arsenic (Total)
116. Asbestos (Fibrous)
117. Beryllium (Total)
118. Cadmium (Total)
119. Chromium (Total)
120. Copper (Total)
121. Cyanide (Total)
122. Lead (Total)
123. Mercury (Total)
124. Nickel (Total)
125. Selenium (Total)
126. Silver (Total)
127. Thallium (Total)
128. Zinc (Total)
Other
113. Toxaphene
129. 2,3,7,8-tetra chlorodibenzo-p-dioxin (TCDD)
*Bis (chloromethyl) ether was deleted from this list on
February 4, 1984 (46 FR 10723); trichlorofluoromethane and
dichlorodifluoromethane were deleted on January 8f 1981 (46 FR
2266). However, testing for the ethanol-for-fuels industry was
performed prior to these deletions, so for the purposes of this
document, the list appears with all the original 129 priority
pollutants.
60
-------
Table 3-3
CONVENTIONAL POLLUTANTS
Biochemical Oxygen Demand (8005)
pH
Oil and Grease
Total Suspended Solids (TSS)
Fecal Coliform
61
-------
Table 3-4
•
NONCONVENTIONAL POLLUTANTS ANALYZED
Acidity
Alkalinity
Ammonia
Chemical Oxygen Demand (COD)
Dissolved Oxygen (DO)
Settleable Solids (SS)
Temperature
Total Kjeldahl Nitrogen
Total Organic Carbon (TOG)
Total Phenol (4AAP)
Total Phosphorus
Total Solids (TS)
Total Dissolved Solids (TDS)
Total Volatile Solids (TVS)
Aluminum
Barium
Bismuth
Boron
Calcium
Cobalt
Gold
Iron
Lithium
Magnesium
Manganese
Molybdenum
Palladium
Platinum
Sodium
Telurium
Tin
Titanium
Vanadium
Yttrium
62
-------
Table 3-4 (Continued)
NONCONVENTIONAL POLLUTANTS1 ANALYZED
Acetone Nitrites
n-Alkanes Styrene
Biphenyl Dimethyl amine
Chlorine Diethyl amine
Dimethyl ether Dibutyl amine
Diethyl ether Diphenyl amine
Dibenzofuran Camphor
Diphenyl ether Cumene
Methyl ethyl ketone -Terpineol
^Compounds presented in Appendix C of 1976 Consent Decree.
63
-------
o
§
P-4
m
I O
en 55
M
0) *1
*""* Pj
"5 3
H W
>4>
41 B
b 41
.3,3
bf"<
•> O
B.
1|
• O
<•«.»<
JS
41 e
C 0
? B
Ig
«
p"4
I
CO
01
b
41
en
41
g.g
S5
o» e
a a
m •>
O O
•SS 1 ii ii-Si^
bu u bb b b b b
» u ^ oca cacscsu
= =
1 i
0)U
41 B IW41 41 bT
m co B • we o e c ec ID
9 B B— 9 941 O B •
•M O Cu "O Q Uvl O
t) o.u e e t>9 a.4i
tl 0.41^1 41 U O « GU4I
u-To e e b bje o~< o
JbB4i «3 a B n b»
41 O bO O B > 41
en H HCO co9Hco
1 11
**« oTo o) oi oi t) at
41 41 41 41 41 U 41 41
W4«4v4 «4 »4»4«J»J
SO B B « tO ffl tO
O O O O O O O
bUUU U bbbOCJCJtJ
C5 C9 C9 C9
SXS £ SXSS
ill l 1 l l l
CM CM CM CM CM CM CM CM
X X
X ' X
XXXX X XXXXXXX
XXXX X XXXXXXX
« 41 f- X 0)
41 41 Q £ n 41
Q9QO^tfc* 01 JtfOlpNCMO
41T34l6tM 41^U*O GU41
«*B OIU B03B..S
nSCJCiJ-O UHUZZO3
O 01 OJ U 0)H 41 U 4!*bb41tfc<
b a Cw-l be) bXtoB.OIOIBU
g4iawHo> 30ia«x3tbu
o > e h of a > ui ai o
COHUM H 09 9 !H b] CO W <
«O
r- o
e 2
01 01 01
41 41 41
09 01 09
o o o
.D.D.O B'B'E"
o « o o o o
b b b O OCJ
esco . . .
i i i
•a-^-*
CM CM CM
X
X
"
XXX XXX
.
XXX XXX
41
i
1-4
(M
06 *W
Q) *p4 AJ
a o 41 01 o)
a o B 341
b BU ««-< OJ
01 0) 9>M 01
41 -O 41
-------
„!
0)
I
•U
a
o
o
m
w ««
X 0) '
B OX
g. "^
^••Sc
4J » O
BO
i t a
i-i CM a
O-D
JJ C
0
a
609<->
C-D
M X
CCM a
•D B
U Q)
O B a
BOO)
2B e.
0)
0> Jti 4J
> a o
03
b a j£
O 0) U
Uf 9
8 Q.b
b S U
|S &
65
-------
described briefly below and detailed in Appendix C are based on
these three references.
Each effluent water sample consists of a number of blank, grab,
and composite subsamples. Depending on which parameters are
determined at each site and on the effluent stream composition,
some of these subsamples were not collected. Additional param-
eters such as pH, temperature, and dissolved oxygen were to be
performed on-site.
For composite samples, compositing time is typically in the range
of 24 hours, with a constant minimum aliquot of 100 ml taken at
intervals of 15 to 30 minutes to give a minimum composite volume
of 5 liters. Samples were to be composited automatically,
utilizing ISCO Model 1580 Automatic Samplers.
Some of the parameters listed in Table 3-5 were collected as grab
samples. Grab samples were obtained at the midpoint of the com-
positing period in a turbulent, well-mixed section of the efflu-
uent stream. Grab sampling was conducted because of potential
rapid change in the parameter of interest (volatile organics,
phenolics, cyanides, etc.) or because of potential contamination
from the sampling operation (asbestos, fecal coliform).
The methodology of stream selection for wastewater sampling
included collecting a 24-hour composite on three consecutive days
for the total raw waste stream from the ethanol plant and any
major sources of wastewater that were accessible. Also, three
24-hour composite samples were collected of the effluent streams
from wastewater treatment systems to obtain information regarding
treatment system efficiency. Finally, raw makeup water samples
were collected to determine net discharge concentrations. The
characteristics of the makeup water did not change over a 24-hour
period; therefore, daily grab samples were obtained for this
stream.
Solid Waste Sampling
For solid waste sampling, all major sources of solid wastes and
by-products were collected for analyses. In addition, samples of
the feedstocks were collected and tested to determine if the raw
materials might be the source of toxic pollutants or contami-
nants. Various techniques were used to collect the solid
samples; a description of the sampling procedures used is pro-
vided in Appendix A.
The solid samples, as well as their acetic acid and distilled
water leachates were analyzed for pesticides, metals, and
selected nonconventionals according to procedures outlined in
RCRA. The parameters tested and analytical methods used are out-
lined in Appendix B. The analytical results of the solid waste
testing are presented in Appendix D. A detailed discussion of
66
-------
the solid wastes associated with ethanol production is provided
in Section 3.7.
Gas Phase Sampling
Whenever possible, the methods used to characterize the air emis-
sions from the ethanol plants were EPA-referenced methods. These
referenced methods are located in the Federal Register, Vol. 42,
No. 160, August 18, 1977 (12). In situations where an EPA-
referenced method does not exist for a particular parameter, a
proposed method was used. A detailed description of the sampling
procedures used at each site is given in Appendix A.
All major point sources of air emissions that were accessible
within the plant were examined for flow rates and concentrations
of suspected air pollutants. The accessibility of a source was
determined by its location and size, and the logistics of erect-
ing scaffolding, if necessary. Fugitive emissions (unintentional
discharges or leaks of volatile organic compounds from process
valves, process drains, open-ended lines, and flanges) were also
sampled at two facilities. The results of the air emissions
testing are presented in Appendix D. A detailed discussion of
the air emissions associated with ethanol production is provided
in Section 3.6.
Sample Point Selection
A ^resampling visit was made to each candidate ethanol facility
to assess the operation of the plant and the accessibility of the
air emission point sources and wastewater streams. The final
selection of the sample points and sample type based on the site
visits are summarized in Table 3-5 and discussed below.
Plant API. During the site visit, it was discovered that many
major sources of wastewater were inaccessible. The only streams
that were possible to test included the bottom stream from the
benzene recovery column, the makeup water, and the total ethanol
plant effluent stream. The wastewater treatment system pretreats
all plant A01 wastewaters before discharge to the municipal
wastewater treatment plant. The effluent stream from this treat-
ment system was not tested as the ethanol plant wastewaters com-
prise only a small fraction of the total load to the treatment
plant.
The vents for air emissions were located approximately 20 meters
from the ground and extended from the side of the ethanol plant
building. As such, the vents were inaccessible and no air sam-
pling was proposed.
This ethanol plant routes all solid wastes associated with etha-
nol production to a centralized feed house where wastes from
other processes are handled. The solid waste from the ethanol
67
-------
facility could not be sampled separately; thus, no solid waste
sampling was proposed for this facility.
Plant A03. This plant was sampled for air, water, and solid
wastes in a 1979 program sponsored by lERL-Ci (8). As a result,
only two streams were selected for additional testing for Appen-
dix C compounds and priority pollutants. For this study, grab
samples of the secondary biological treatment system effluent and
the source water were taken on two successive days. The lERL-Ci
study did not analyze solid wastes for metals; therefore, samples
were collected from the feedstock grain, by-product grains, and
biosludge streams for metal analyses.
Plant A06. This facility does not combine its waste streams or
treat its wastewater; therefore, only the major waste streams
(benzene stripping column bottoms, evaporator condensate, and
wash waters) were sampled. During the test effort, it was
determined that plant A06 was operating under start-up condi-
tions. Due to the unstable conditions of start-up operations,
grab samples were collected rather than composite samples.
The sources of air emissions that were selected include the vents
from fermenters, product storage, and the steam ejector used for
the vacuum system. Also, the outlet from the cyclone used to
control particulate emissions from the by-product grains dryer
and a CO2 degasser vent were chosen. These sources were hypo-
thesized to be the major sites for particulate, inorganic, and
hydrocarbon emissions.
No solid wastes were sampled from this facility.
Plant A07. In addition to the total raw waste stream from plant
A07, the evaporator condensate stream was selected since it con-
stitutes a major portion of the total raw waste. As in all other
plants, the makeup or source water stream was sampled to deter-
mine net values for pollutant concentrations.
Several wood pulping processes occur at plant A07 and the wastes
from these processes are combined with the effluent from the
ethanol plant. The ethanol plant contributes 40 to 65 percent of
the BODs load and 10 percent of the total wastewater volume.
Due to the high percentage BODs contribution from the ethanol
plant, the total plant raw wastewater and treated effluent from
plant A07's wastewater treatment system were selected for
sampling.
No air sampling was attempted at this facility due to the inac-
cessibility of sample points for air emissions. Also, the solid
wastes are routed to a lignin plant and were not selected for
sampling.
68
-------
Plant EOS. The wastewater sampling at this facility was confined
to the wastewater treatment system so that treatment system effi-
ciency data could be gathered. In addition to the total un- }
treated and treated effluent, samples were collected for six days
from the first aeration basin effluent, the rotating biological
contactors (RBC) effluent, and the influent to the air flotation
unit. A treatability study using a granular media filter was
also conducted for five days each on the first aeration basin
effluent and the RBC effluent (13).
The grain dust generated by the milling operation is collected by
a cyclone and baghouse in series. The duct from the baghouse to
the atmosphere was chosen for sampling. The by-product centri-
fuges decrease the water content of the distillers dried grains
(DDG). Vents from the centrifuges were easily accessible on the
dryer house roof and therefore were included for sampling. Also
accessible on the dryer house roof was the main dryer stack;
this stack was the primary point source that was sampled. The
vents on the cooker/cooler tanks, distillation system (beer still
and reboiler) and, ethanol storage tanks were all inaccessible
for sampling.
Both inlet grain and the DDG's were sampled from bulk storage
piles. Since the wastewater treatment system wastes no sludge,
the two streams mentioned above were the only solid streams
sampled.
Plant E09. This plant combines all of its wastewater, except
sanitary wastes and flash cooler condensate, into a receiving
tank called the distillery, waste basin. This distillery basin,
which is discharged to the local municipal treatment plant, was
selected for sampling. The mixing basin, which receives all
acidic and alkaline wastes for neutralization prior to being
routed to the distillery waste basin, was also identified for
sampling. Finally, the flash cooler condensate, which is
discharged directly to the river, was selected for sampling.
The condenser vents were located 30 meters from the ground and
were inaccessible. The dryer house stack was rectangular and
located on top of a roof which could not support scaffolding;
thus it was not chosen for sampling.
There are two solid waste streams from this plant: feedstock
grain and by-product grains. Both of these streams were chosen
for sampling and analysis.
Plant E02. In addition to total raw waste and treated effluent,
the evaporator condensate stream (which is the major contributor
to plant waste load) was chosen for sampling at this facility.
Also, since the treated effluent stream is diluted with noncon-
tact cooling water before being discharged to a local stream, the
69
-------
cooling water stream and diluted effluent were selected for
sampling. Both the noncontact cooling water and makeup water
were to be sampled as grabs since the quality of these streams
was not expected to change over a 24-hour period.
Air emission sources at plant E02 were inaccessible for sampling.
The types of solid samples that were proposed for collection at
this facility were all three feedstocks used, the by-products
produced, and the wasted biosludge from the bottom of the sludge
thickener. The feedstock samples included cane molasses, citrus
molasses, and the juice obtained from pressing orange peels
(pressed orange liquor). The by-product samples included the
beer still bottom stillage and the condensed molasses solubles.
Plant A10. Ethanol production at plant A10 is one of many pro-
cesses conducted at this facility. The wastes from the ethanol
plant and other production processes are routed to a common plant
sewer system. To properly characterize the ethanol plant, the
sewer line upstream and downstream of the ethanol plant was
selected for testing. Also, the evaporator condensate stream,
which is a major waste stream, was chosen for sampling. To
obtain treatment system efficiency information, the effluent from
the aeration pond was selected for analysis. Truck washings of
cheese whey and brewers' yeast, which are sent to the local
municipal treatment plant, were also identified for sampling.
As with many other ethanol facilities, the point sources for air
emissions proved to be inaccessible and were not considered in
the test effort. Solid waste streams chosen included by-product
condensed cheese whey solubles (CWS), core samples of land that
had been subjected to spray irrigation with treated effluent, and
samples of feedstock cheese whey and brewers' yeast.
3.2 STATISTICAL DATA EVALUATION
The ethanol-for fuel industry is a new industry for which limited
data are available concerning effluent quality and treatability.
To augment the data base, additional data were obtained from the
beverage alcohol industry which was hypothesized from an
engineering standpoint to be similar to the ethanol-for-fuel
industry in terms of effluent quality and volume of wastewater
generated. Thus, there are two objectives in this section. The
first is to determine if beverage alcohol plants and ethanol-for-
fuel plants differ significantly with respect to the amount or
quality of effluent generated. Beverage alcohol facilities which
are significantly different from ethanol-for-fuel plants are to
be excluded from the data base. The second objective is to
determine if there are factors which significantly differentiate
70
-------
groups within the ethanol-for-fuel industry (as represented by
the available ethanol-for-fuel plants and the statistically
similar beverage alcohol plants).
The results of an engineering and statistical analysis revealed
that the three rum facilities were significantly different from
the ethanol-for-fuel facilities and the other beverage alcohol
plants in terms of effluent quality. The rum facilities were
found to have significantly higher concentrations of TSS and
BODs because no recovery of by-product grains is practiced
(i.e., stillage is incorporated into total plant effluent). The
statistical analysis showed no significant differences in efflu-
ent quality between the ethanol-for-fuel facilities and the
remaining beverage alcohol plants. A detailed description of the
statistical methods used is provided in Appendix F.
AVAILABLE DATA
A statistical analysis was conducted using untreated effluent
quality data and flow rate data from 13 ethanol facilities (A03,
A06, A07f A10, E01r E02, E03, EOS, E09, E15f E17, E18, and E20).
These are the only facilities for which flow rate data and
untreated effluent quality data were available. These data were
derived from the following sources:
1. 1978 EPA/IERL study to characterize the waste streams of
an alcohol facility.
2. 1980 EPA/EGD screen sampling program for effluent guide-
lines development. ,
3. EPA Regional NPDES permit monitoring data.
4. EPA/EGD Industry Questionnaires.
5. 1978 Region IV EPA study of rum distillery wastewaters.
The analytical parameters that were evaluated in the statistical
analyses were total suspended solids (TSS)' and five-day biochemi-
cal oxygen demand (6005). These parameters were selected
because, historically, they have been used as indicators of water
quality in designing biological treatment systems and in monitor-
ing treatability. Sufficient data were not available on other
analytical parameters to use them- in the statistical analysis.
The BODs and TSS data available for performing these analyses
are summarized in Table 3-6. These data fit a lognormal dis-
tribution better than a normal distribution; therefore, natural
logarithms of the data were used in the statistical analysis.
71
-------
Table 3-6
DATA AVAILABLE FOR STATISTICAL ANALYSES
TSS
Facility Type
E thanol -For -Fuel
A03
A06
A07
A10
Beverage Alcohol
E01*
E02
E03*
E08
E09
E15
E17
E18
E20*
No. Of
Observations
66
3
3
2
5
3
5
7
3
5
165
54
5
NO. Of
Observations
152
3
3
2
5
3
5
7
3
5
25
23
5
*Rum producing facilities
72
-------
In addition to BODs and TSS, total plant flow rate as a func-
tion of ethanol production was evaluated in the statistical
analysis. Daily observations fbr plant flow rate and ethanol
production were not available for most plants. Therefore, the
analysis considered the ratio of average flow rate to average
ethanol production for each facility.
The approach that was taken to determine whether these facilities
differ with respect to average effluent quality consisted of
performing a single classification analysis of variance, with
facility as the classification variable. This was followed by a
multiple comparison procedure, which was used to classify facil-
ities into groups with similar average effluent quality. These
groups of facilities were then examined to determine which of
several potential factors may have been responsible for the
differences observed between groups.
To use the analysis of variance method, individual observations
are needed to account for daily variation within a facility.
However, daily observations for plant flow rate are not available
for most of the plants examined. Therefore, the approach taken
to evaluate flow rate was to classify the flow ratio (ratio of
average flow rate to average ethanol production) using the multi-
ple comparison procedure. If different groups result, they would
then be examined (as with effluent quality) to determine which
factors may have been responsible for the different groups. •,-
GROUPINGS BASED ON EFFLUENT QUALITY AND FLOW RATIO
The analysis of variance tested whether the 13 facilities differ
with respect to average effluent quality. This analysis indi-
cated that some of the 13 facilities tested had significantly
different average concentrations of TSS and 6005.
Duncan's multiple range test was then used to compare the average
concentrations of TSS or BODs for each pair of facilities.
Duncan's test classified those facilities with significantly dif-
ferent average concentrations of TSS or BODs into separate
groups, and those facilities with similar average- concentrations
into the same group. The procedure used to group facilities
takes into account the fact that the average concentrations of
TSS or BODs were more precisely estimated at those facilities
where more data were available.
' Table 3-7 presents the facilities within each group and the
average TSS and BODs concentration in the logarithm scale for
each facility. Within each group the parameters are listed in
descending order for average. TSS and BODs concentration. The
analyses shows two distinct groups for BODs and TSS. Both
73
-------
Table 3-7
GROUPING OF FACILITIES BASED ON UNTREATED EFFLUENT QUALITY
TSS
Low
E01 (16.2)
E20 (16.1)
E02
EOS
E09
E15
A03
EOS
A10
E17
A07
E18
A06
(13.
(13.
(13.
(12.
(12.
(11.
(11.
(11.
(11.
(11.
(10.
4
1
1
8
8
8
7
7
6
3
0
_BOD_5_
High
E20
E01
(17.4)
(17.3)
Low
EOS
A07
E02
A06
E09
A03
A10
E18
E15
E17
EOS
(14.
(14.
(14.
(14.
(14.
(14.
(13.
(13.
(13.
(13.
(13.
7
3
2
0
0
0
8
6
6
5
1
Notes: Groups were selected using Duncan's Multiple Range Test
Numbers in parentheses are facility means given in ug/1,
74
-------
plants in the high groups are rum facilities. Also, the third
rum facility (plant EOS) has the highest value in the low BODs
group and the second highest value in the low TSS group. There
is strong evidence from these statistical analyses that the rum
facilities differ from both beverage alcohol plants and ethanol-
for-fuel plants based on TSS and BODs. Th® rum facilities are
not part of the ethanol-for-fuel industry and are not considered
to be typical of future plants in the industry that will use
sugar feestocks. Therefore, data from the rum facilities are
excluded from the data base for the statistical analyses.
Disregarding the rum plants, Table 3-7 shows that the ethanol-
for-fuel facilities are interspersed with the beverage alcohol
facilities. This distribution indicates these plants cannot be
distinguished from one another on the basis of BODs or TSS.
Duncan's multiple range test was also used to compare the flow
ratios for each pair of facilities. The results of this test
indicate that all of the facilities fall into the same group.
ANALYSIS OF POTENTIAL FACTORS AFFECTING EFFLUENT QUALITY AND FLOW
RATIO
Based on the information presented in Sections 2 and 3, the
following factors were selected as having the greatest potential
to affect effluent quality and volume from an engineering
standpoint:
1. Process variations
s
2. Feedstocks
3. Final products
4. Plant age
5. Plant size
Tables 3-8, 3-9, and 3-10 show the relationship between these
factors and the facilities grouped in terms of 8005, TSS, and
flow ratio.
Process Variations
The five major processing steps associated with ethanol produc-
tion are feedstock preparation, fermentation, distillation, dehy-
dration, and by-product processing. As the data in Section 3
show, the only steps which might significantly affect effluent
quality are variations in feedstock preparation and by-product
processing.
75
-------
•a
3
eo
1
•o
1-4
o
a>
i
o
5
1
£
•rt
S
•o
i-4
o
CO
CO
ca u
o>
•o
S
•o
S
03
§.
EH
•o
o
U
O
o
09
£
•v4
S
|
a
i
a
i
•o
o
2
u
a
•o
i
e
aluation Factor
>
a
ocess Variation
u
04
11
&
§
By-Product Reco
No Recovery
edstock
£
'
u w
Grain-Derived {
Sugar-Derived 1
.nal Product
*n
Ob
_s
Sir
i-4 i-4
O O
e e
||
e e
a
u
a
£
o
S
a
b
11
in in
-H 1-1
V A
9
?
J
O —
N >-t
a^i
^5
SS
••4
Oi
W * J
g
-1=0
-4 ~« O»
i^i
a B<->
inoe"
M mm
1 1 A
O
G
•a
S
a
•V4
f-f
Facilities are
*
76
-------
col
o
ul
n
£
•o
3
(9
•o
3
CO
•o
t>4
o
u
•o
•*
o
co
^^
1
0)
JQ
(0
&^
CQ
M
M
S* o
H * g
J in o
5§ «
•< CQ *
fa J
|J O
0 fa
25
< CQ
93 «
O
Z <
63 fa
CQ
a z
£o
ta H
CO EH
*c
M J
03 <
CQ >
§H
M Q
S 2
< >•
m n
Ol QB
e 0
u >>
\0 09
O 0
< . ' >•
M n
e 0
u x
r> o
O 0
< S
<
X
O>
ft
X
JS
Ol
I
•o
s
•o
s
9
CO
•o
s
«o
3
•o
s
•o
s
CO
o
o
o
u
8
S
en
iH
n
18
O
o
e
to
o
09
03
0
O
o
§
18
> o
a z
0
£
tn
•an
* * ^
.?«•* o
U M 3
£2 3
i i i tn i J
10 .»,—.—
•o
o . . _
o eu ft. ^
4j -H A tf tf in in
tn looi"-* ®o *• •^l~l
•o u 3 «J "".*, c v ^
U co e V|A| n
Z a.
..a-'k'o e o «j
isjs a> -H 0-> oiBi-4
4J4J 0 ZO NrH
r! o
co e tn o o
a£ 7? A
c jj eo
<0 U (S
JJ
a
(0
ra
o
2
.77
-------
09
S
o>
o
z
O>
ft
•o
iH
o
oal
i
i
to
•o
3
CO
a
St-
•o
3
CO
CO
•o
fH
O
eal
<\
£
•*
33
o
z
I
CO
(I)
rt
JQ
m
(9
CO
•O
s
>
o
•*4
4J
a
8
EH ca
"I
<=
Cfl
a
£
co
i
•M
a
«
2
o
el
Cd|
o>
•o
s
b
4)
o
e
a
o
u
u
«
Oi
§
•4*
4J
Q
a
•H
«
a
e
ss Variatio
0
u
o
u
Oi
>
o
Product Rec
Recovery
>< o
a z
j^
0
jj
a
•o
^
z£
in in
1-4 >-l
V A
Ss
04
O-O
8 ®
a H
in o
M in
1 1
o m
C9
Dl
sted
2
«
a
o
•#4
JJ
•H
<-*
v4
U
A
Cu
78
-------
By-Product Processing
Two methods of by-product processing are in use in the industry:
1. Concentrating and drying stillage to produce by-product
animal feed.
2. Concentrating and routing the stillage stream to
another processing unit.
The first option is used by all the plants using a corn feedstock
(A03, E09, E15, E08, and E17) and the molasses and cheese whey
plants (E02 and E10, respectively). Plant A07 uses the second
option to process spent sulfite liquor and a by-product lignin
stream. There is no evidence to support that the condensate
discharged from by-product processing option 1 would be signifi-
cantly different from option 2 in terms of effluent quality or
volume.
The rum plants (E01, EOS, and E20), on the other hand, discharge
whole stillage (the major source of waste in an ethanol facility)
without processing. Although this does not affect the volume of
wastewater generated, it accounts for the high TSS and BODs
values observed for the rum facilities as indicated in Tables 3-8
and 3-9.
Feedstocks and Feedstock Preparation
Feedstock preparation techniques vary according to the type of
feedstock processed. The plants examined had two types of
feedstock: those requiring saccharification (grain-derived) and
those already containing high concentrations of fermentable
sugars (sugar-derived). The detailed preparation techniques for
each class of feedstock are outlined in Section 2, Industry
Profile.
As Tables 3-8 and 3-9 show, only sugar-derived feedstocks can be
found in the group with high TSS and high BOD§ values. How-
ever, plants using sugar-derived feedstocks are also interspersed
among the grain distilleries in the low TSS and BODs groups.
Also, Table 3-10 does not show that these factors affect flow
ratios. Therefore, no data are available to conclude that
feedstock type or feedstock preparation techniques significantly
affect waste streams from plants in the ethanol-for-fuel
industry.
Final Products
Most plants providing ethanol-for-fuel produce the same product:
anhydrous ethanol. In cases where the plant is a partially con-
verted beverage alcohol plant, 50 to 95 percent ethanol may also
79
-------
be sold as a product. Any difference in wastewater generation
between a 50 percent and a 100 percent product is due to the
addition of a rectification column and a dehydration unit. The
quantity of wastewater generated from these units would increase
the total plant effluent volume by less than 3 percent. Table
3-10 also indicates that the final product produced has no effect
on wastewater production. Furthermore/ the quality of the water
removed in rectification and dehydration is, in many cases/ bet-
ter than the intake water for most pollutant parameters. Thus,
in accordance with the information in Tables 3-8 and 3-9, the
type of product produced does not affect the quality or quantity
of the total plant effluent.
Plant Age
The effective age of a processing operation is usually difficult
if not impossible to define because there is often little corre-
lation between the age of a plant and the age of the equipment
used within the plant. A processor may constantly replace worn-
out equipment with new equipment, or, in some cases, install old
equipment in a new building. Tables 3-8 and 3-9 show that plants
of different age groups can be found in both high and low groups
of BODs and TSS. Also, Table 3-10 shows no relationship be-
tween plant age and flow ratio. Therefore, data are not avail-
able which would support distinct differences in waste generation
and effluent quality within the ethanol-for-fuel industry on the
basis of plant age.
Plant Size
In regard to plant size, the ethanol production capacity varied
from 17 cubic meters of anhydrous ethanol per day .at plant EOS to
230 cubic meters of anhydrous ethanol per day at plant E09.
Effluent quality is not a function of plant size as Tables 3-8
and 3-9 show; plants of different size groups can be found
interspersed in the high and low TSS and BODs groups. Further-
more, Table 3-10 shows that the wastewater generated to ethanol
produced ratio does not vary as a function of plant size.
3.3 WATER USE AND EFFLUENT SOURCE
As Figure 3-1 illustrates, the sources of wastewater from an
ethanol plant include flash cooler condensate from cooking and
cooling, rectifier bottoms and beer still bottoms from dis-
tillation, benzene stripping column bottoms from dehydration,
evaporator condensate from by-product processing, equipment wash
water, noncontact cooling water, boiler blowdown, and ash sluice
water. In most ethanol plants, the noncontact cooling water
stream is discharged directly without treatment and seldom com-
bined with ethanol plant wastes, although the noncontact cooling
water at plant E02 is combined with the treated effluent to
dilute the final discharged effluent. Because the noncontact
80
-------
BO
1
JJ
a
{
b
J
"So
'3,
o
u
t
i
jj
09
•o
01
01
u.
I
F*
0
o
D
— <
JJ
(8
CO
O.
01
u
fti
01
JJ
1
V)
01 01
1-1 JJ
J<8
09
— •• - oi
45-0
09 e
OS 0
ta
01
JJ
*~ JJ
09
lation
1-4
JJ
09
i-l
O
3-
o c
If
•Sfi
1
s
•r
Ji
0
]
J
t
1 JJ
> l-i
leu
t
i
j
i
i
?
!
i
•H
U-l
JJ
OS
T-4
1-1 -<
01 JJ
« M
k
H«e
09 O
01 O
£4 u
o a
CO *•* t
o '
1 p
O S5
60
CLO
O.JJ
1-4 JJ
V4 O
II
01
oa
0) CO
U 0 0
u o pa
"
0 ><
9 V4
•O 0)
, ° *
* fcl O
o. u
1 01
O (3
•g*
58
4 9
i! Hf3
j oi co
ell
0)
00
•H
Em
CO
I
I
81
-------
cooling water is not treated in the ethanol-for-fuel industry, it
is not addressed in this document. Also, boiler blowdown and ash
sluice water are not considered as there is no data available
from ethanol plants which use coal-fired boilers.
The extent to which each of the remaining wastewater sources con-
tributes to the total plant raw waste varies and is a function of
several design and process parameters, including the choice of
biomass feedstock, the form and extent of by-product recovery or
extraction, the reuse and recycle of water streams, and the pro-
duct quality desired. Table 3-11 presents the approximate per-
centages that each of these streams contributes to the total
plant wastewater volume for three grain distilleries.
3.3.1 COOKING AND COOLING
Depending on the type of equipment used in cooking and cooling of
the mash, a potential source of wastewater is the condensate from
flash coolers. A flash cooler is used to cool the cooked mash to
a temperature suitable for conversion. This is accomplished by
subjecting the mash to a partial vacuum? the subsequent evapora-
tion of liquid causes a loss of heat. The condensate from this
evaporated liquid amounts to 0.3 ,to 1.0 m3 per 1,000 kg of
grain processed (8,14).
Priority pollutant analyses conducted at plant A10 for the flash
cooler condensate stream revealed no toxic compounds present in
amounts greater than 10 ug/1. BODs values for plants A03, E09,
and E14 varied from 13 to 1,900 mg/1, with an average of about
900 mg/1. The BODs concentration of the flash cooler conden-
sate is related to the entrainment of dissolved organic sub-
stances in the flashed vapors. This entrainment is a function of
the type of equipment used and the efficiency achieved. Total
suspended solids were low, with mean values of 5 and 30 mg/1
obtained at plants A03 and EO9, respectively. The pH for plant
AO3 was 3.4, while a value of 7.2 was determined for plant EO9.
The high 8005 and low pH for plant AO3 suggests the presence of
organic acids in the condensate stream.
3.3.2 DISTILLATION
There are two significant sources of wastewater from the distil-
lation system: the beer still bottoms and rectifier bottoms.
The bottom stream from the beer still, referred to as stillage,
is routed to by-product recovery and, therefore, is discussed in
a later section.
The amount of wastewater generated by concentrating the ethanol
product ranges from 0.43 m3 per 1,000 kg of grain processed for
a grassroots ethanol-for-fuel facility (A06) to 1.4 m3 per
1,000 kg of grain processed for a conventional ethanol facility
such as A03 (308 Questionnaire, 198u). Plant A10 uses a cheese
82
-------
Table 3-11
PERCENT VOLUME OF TOTAL UNTREATED EFFLUENT
FOR GRAIN DISTILLERS WITH BY-PRODUCT RECOVERY
By-Product Recovery
Cooking/Mashing
Rectifying
Cleanup
Dehydration
Total
Plant E09(l)
77
11
10
2
100%
Plant E19(2)
50
36
7
7
100%
Plant A03(3)
66
14
28
1
1
100%
Sources: (1) ESE, 1974, Reference 14
(2) Middlebrooks, Reference 15
(3) Industry, Questionnaire Response
83
-------
whey feedstock and produces 0.58 m3 of wastewater per 1,000 kg
of feedstock (308 Questionnaire, 1980). The volume of rectifica-
tion wastewater is a function of the concentration of ethanol
entering the rectifier and the source of energy (heat) used to
separate the ethanol and water. When the rectifier feed is
derived from the beer still, a 60 to 80 percent ethanol stream is
concentrated to 95 percent in the rectifier. When purification
columns are used, the feed to the rectifier may be only 10 to 20
percent ethanol (the beer still product is diluted in purifying
columns) and likewise must be concentrated to 95 percent. Also,
it is estimated that the use of direct steam injection rather
than reboilers as a source of energy to accomplish the separation
of water and ethanol can increase the wastewater volume from
distillation by 20 percent (14).
Conventional analyses conducted for the rectifier bottom streams
exhibited BODs values for plants A03, A10, and E13 that were
Ir440, 277, and 300 mg/1, respectively. The total suspended
solids concentration for plants A03 and A10 were below the 1 mg/1
detection limit, while the pH values were 4.7 and 6.2, respec-
tively.
Priority pollutant analyses were conducted for the rectifying
columns at plants A10 and A06, which integrates the dehydration
and rectification processes. The priority organics detected at
values greater than 10 ug/1 were the same for both A06 and A10,
these included methylene chloride, bis(2-ethylhexyl) phthalate,
and phenolics (4AAP). The priority metals which were present at
levels above their detection limit for both A10 and A06 included
cadmium, copper, lead, and zinc. In addition, chromium and
nickel were found only at plant A06.
3.3.3 DEHYDRATION
In typical dehydration schemes, the remaining water is removed
from the 95 percent ethanol product via the bottom stream of the
solvent stripping column and/or dehydration column. These
streams are small, amounting to 0.002 m3 per 1,000 kg of grain
processed, and are independent of any processing variables (8).
The concentrations for 8005, TOC, TSS, pH, and phenolics for
the solvent stripping column bottoms from plants A01 and A03 are
presented in Table 3-12. The concentrations of these species in
the stripping column bottoms stream are quite low in these param-
eters. Additional priority pollutant analyses at plant A01
demonstrated the only organic compound present was methylene
chloride at 22 ug/1. The priority metals present at levels above
their detection limits included chromium, copper, and zinc at
4.0, 6.0, and 10.0 ug/1, respectively. An analysis for benzene
in the wastewater stream from the dehydration column and benzene
stripping column at plant A03 exhibited concentrations of 59.4
ug/1 and 5.7 ug/1, respectively (8).
84
-------
Table 3-12
SOLVENT STRIPPING COLUMN BOTTOMS FROM
DEHYDRATION SYSTEM
DISCHARGE VALUES (mg/1)
Plant API Plant A03
BOD5 26.0 16.0
TOG 15.0 8.0
TSS <1.0 1.0
pH 3.9 4.1
Phenolics <0.01 *
*Not analyzed.
85
-------
3.3.4 BY-PRODUCT RECOVERY
By-product recovery consists of concentrating the stillage from
the bottom of the beer still in the centrifuges and evaporators,
then drying the concentrated stillage in dryers. The evaporator
condensate from this process is a major source of wastewater. In
addition, the volume and quality of the condensate produced
varies greatly. As Table 3-11 illustrates, evaporator condensate
comprises 50 to 70 percent of the total volume of ethanol plant
wastewater. The flow for evaporator condensate varies between
2.2 and 4.1 m3 per 1,000 kg of grain processed. Alternate
feedstocks such as cheese whey or sulfite liquor generate 1.6
m3 per 1,000 kg of cheese whey and 0.78 m3 per 1,000 kg of
sulfite liquor, respectively (308 Questionnaire, 1980). Regard-
less of feedstock, this variation is a function of the stillage
concentration entering the evaporators and the percent of still-
age recycle to the cooker or conversion tank.
Another source of wastewater from by-product recovery is the
blowdown stream from wet scrubbers; these are used to remove
particulates from grain dryer exhaust gas. Plant E09 estimated
that the load from this source constituted 37 percent of the
total load from by-product recovery. Dry particulate collection
devices such as cyclones are in use at most plants to eliminate
this source of waste.
The sampling and analysis of evaporator condensate was done for
four plants which differed in feedstock. The conventional
parameter analyses demonstrated wide ranges for BODs and pH.
The BODs varied from 628 mg/1 for plant A06 (grain) to 4,835
mg/1 for plant A07 (sulfite liquor). The molasses and cheese
whey feedstock facilities had BODs's of approximately 2,550
mg/1. The pH ranged from 2.9 for plant A07 (sulfite liquor) to
7.95 for A10, the cheese whey facility. The high BODs concen-
trations and low pH values imply that the contributing substances
are primarily volatile organic acids.
A priority pollutant characterization of evaporator condensate
for the four plants mentioned above is presented in Table 3-13.
This table illustrates that few priority pollutant organic com-
pounds were present. All the organics listed except methylene
chloride, bis(2-ethylhexyl) phthalate, pentachlorophenol, phenol,
toluene, and di-N-butyl phthalate were observed only once. Most
of the priority metals were detected. All the metals except cad-
mium, chromium, copper, lead, nickel, and zinc were found only
once above their detection limit.
3.3.5 WASH WATER
The risk of contamination from bacteria and other biological or-
ganisms which compete with the yeast and lower the alcohol yield
have necessitated weekly cleanups and sterilization of the feed-
stock preparation vessels and fermenters. The amount of wash
86
-------
Table 3-1.3
EVAPORATOR CONDENSATE CHARACTERIZATION:
PRIORITY POLLUTANTS
Organics. A06
(ug/1) 1 {Grain)
aero le in
chlorobenzene
1,1,2-trichloro-
ethane
1,2-dichloro
propane
• thy 1 benzene
methylene chlor-
ide
pentachlorophenol
phenol
bis(2-ethylhexyl)
phthalate
toluene
cyanide
di-N -butyl phthalate
tetrachloroethylene
Metals (uK/l)2
antimony
arsenic
beryllium
cadmium
chromium
copper
lead
nickel
selenium
silver
zinc
11
—
...
..
--
34
—
—
6.0
—
i,~'
'—
16
—
1.0
9.7
17
862
160
168
.—
-.
36
(Sulfite
Liquor)
16
15
15
7.5
54
20.5
98
39
.10
20
--
—
2.3
1.3
—
13 '
17.7
15.7
79
45
1.7
1.3
74
A07
£02
17.5
13.5
10.5
1.5
1.0
9.5
13.5
17
26
A10
(Cheese
Whey)
150
74
80
118
1Priority pollutant organics with at least one maximum concen-
tration greater than 10 ug/1. Average concentrations are
listed.
^Priority metals with at least one analysis above the detection
limit for that element. Average concentrations are listed.
87
-------
water generated during sterilization and cleanup and the waste
load varies from plant to plant according to the final product
purity requirements, operating procedure, plant management
practices, types of equipment, and plant design. The amount of
wash water produced for the seven ethanol plants tested ranged
from 0.45 m^ per 1,000 kg of grain processed to less than
0.04m3 per 1,000 kg of grain processed of wash water at plant
A06.
Priority pollutant analyses of the wash waters from plants A06,
E09, and A10 yielded no toxic compounds present at concentrations
higher than 10 ug/1. Conventional pollutant analyses showed
BODs concentrations ranging from 48 to 1,760 mg/1, TSS concen-
trations ranging from 63 to 1,180 mg/1, and pH values ranging
from 4.0 to 12.0. Oil and grease was a significant pollutant
parameter at plant E09, with an average value of 137 mg/1.
Plants A06 and AlO had oil and grease values of less than 25
mg/1.
3.4 WASTEWATER CHARACTERIZATION
This section summarizes the analytical results obtained from the
sampling programs and data collection efforts for the total plant
untreated effluent. All the concentrations listed are absolute
concentrations of the raw wastewater; no adjustment has been made
for the species1 presence in the plant intake water. If a param-
eter was reported at "not detected" it was assigned a value of
zero for computational purposes. In cases where a parameter was
never detected in any analyses, a dot appears in each of the
columns to the right of the number of analyses.
Concentrations for metals were occasionally reported by the
analytical laboratory as "detected less than X," where X equals
some detection limit. In these cases, the exact concentration is
unknown and the parameter is reported as being detected, but at a
level less than the detection limit. For computational purposes,
the method that has been used in the past by the Agency for
quantifying the values reported as "detected less than X," where
X equals some detection limit, is to represent the value as
one-half of X.
Historically, the Agency has considered 10 ug/1 as a realistic
lower limit for detection of organic compounds. The total number
of samples where a detected value of greater than 10 ug/1 was
found is indicated since these concentrations are "quantifiable
levels." In regard to metals, the detection limit varies accord-
ing to parameter and the laboratory that conducts the analyses.
Therefore, the number of times a metal was detected above the
particular analytical laboratory's detection limit is indicated.
88
-------
The statistics used in this section include the minimum, median,
mean, and maximum reported concentrations. The statistical val-
ues for median, minimum, and maximum are based on all the analy-
ses performed. However, because the number of analyses performed
varied from plant to plant, the mean concentration reported for a
specific parameter is an average of the mean concentrations of
each plant. For the statistical analysis, if a parameter was not
detected in an analysis, it was given a concentration of zero and
if the reported species concentration was "less than X," it was
given a value of one-half of X.
The tables listing priority pollutant metals, cyanide, and asbes-
tos also include the 90 percent value (90 percent of the detected
values are below this concentration) and the standard deviation.
The tables presenting data on conventional parameter's include
the 95 and 99 percent values, as well as the standard deviation.
Statistical percentages such as the 95 percent level were not
calculated for priority pollutant organics and nonconventional
parameters which lacked a significant number of detections.
3.4.1 ETHANOL PLANT UNTREATED EFFLUENT
The analytical results for priority pollutant organics, priority
pollutant metals, conventional pollutants, and nonconventional
pollutants are summarised in this section. These results repre-
sent the total combined untreated effluent from ethanol plants
A01, A03, A06, A07, A10, E02, EOS, and E09.
It was not possible to sample a combined untreated effluent
stream at plant A06 or A10. For each parameter, the total raw
wastewater value was calculated by taking a weighted average
(flow rate basis) of the concentrations for each of the streams
contributing to the total plant effluent. The weighted values
were determined by flow ratios obtained from plant personnel in
their responses to the 308 questionnaire.
Priority Pollutants
The analytical results for priority pollutajnt organics listed in
micrograms per liter (ug/1) are presented in Table 3-14. Ten
organics were found with at least one maximum concentration above
10 ug/1. Only five of these ten were present at two or more
plants, these included bis(2-ethylhexyl) phthalate, chloroform,
methylene chloride, pentachlorophenol, and phenol. The mean
values for chloroform (27 ug/1) and phenol (33 ug/1) were
significantly influenced by the high concentrations found at A07
and E02, respectively. For the remaining five organics found at
levels above 10 ug/1, butyl benzyl phthalate, toluene, and
trichloroethylene were found only at plant E09. Benzene and
ethylbenzene were only present above the 10 ug/1 level at plants
A01 and E02, respectively.
89
-------
co g
COO
Ed PS'
COO
en
«a
OO
i:
St
SSA
rfgg
gi"
Big
O • • • -etg -O {S *® «
o • • • -em -o «e •« I*
B ^ » w
o . • • -O" -e « «o «
O • • • -OO -O O "O O
O * • • -On «O ••••«•••••• »^» «M • « • • •*
eo—oooooooooooowooooooojf
ICtCllCINnCltllMNMM
lUIZ'^Z Ul
:*£>fi So,
s:
w3o.ii.zu.g<
-------
«
«i
fi
§i
fcl
000
OMO
• e
n
ooe
ooo
:o A
M
.22
^nmooooinooopooveoeoooooooooooeo
^ ^* TJ
•^12 ?!
Sr'^ -'
JS
S5^^
g|l§
ssij u.gg?II
IM5A 2S^?S5
u. S£ Z
O u u ui *•*
Km Xuu
* - I I U Z Z Ml SB U IU •
• ZZZ ouiu oeueooooMuj
:~i5Z-^!!! ^s|gss^^ii -*s
ooooooaoiuwui
91
-------
•o
0)
i8
WH
W<
[d O
wen
>iO
1 11
U H
\>x EH 9
? 13
0) ><
r-4 WH
*§ aS
H blO
H H
«s
JSz
i!
ii
Si
o
1
n
rone GO .»••••<>«
CO ^
•OOOOOO -O • • • -O
>MI
ii!
o ci ei en « w c
O
CZ
u»ce
ui p
— — v — •— ' v v — — ---
w oo-j«J i-J *-«H J ^ ^ w
-------
is
CO M
^^k 52
•o to <
<
>! WH
to oS
H gg
^g
2
e
I
li
ii
s!
5!
Ml
I
• 8
I A
«e
• o • -o
ooooooo~oo«oooooooooooe
§ 2
ljgJ(Bfc-|
°J<551||1
:;fjjjiy;1jjB!;jil!!!!
IS^pS^i:
ISSl^Si
oau^z
F»"»»«»»
93
-------
All of the priority metals are listed in Table 3-15 and were
detected at levels above their detection limit. The cadmium and
lead analyses performed for the untreated effluent at plant EOS
have been omitted from the table as the detection limits of the
analytical laboratory-for plant EOS were significantly higher for
these compounds than those limits achievable at the other labora-
tories. Mercury was the only metal limited to a single facility,
EOS. The analyses for cyanide demonstrated only a single value
above the detection limit, 10.5 ug/1 at facility A10. The asbes-
tos testing was performed at plants A06, A07, and E09. No
chrysotile or fibrous asbestos greater than 5 micrometers was
found at any of these three facilities.
Conventional Pollutants
The concentrations of conventional pollutants, listed as milli-
grams per liter (mg/1), are summarized in Table 3-16. In
addition to the EPA Multimedia Sampling Program results, the
daily monitoring information obtained from the sampled facilities
as well as several other beverage alcohol plants (E06, E07, El5,
E17, and ElS) have been included. As mentioned earlier, the mean
value reported for a specific parameter was determined by finding
an average of all the plants' mean concentrations.
The BODs, total suspended solids (TSS), and oil and grease are
all present at average concentrations of 1,405; 406; and 186
ma/1, respectively, which are much higher than those for typical
domestic sewage. A wide range is evidenced for pH, which varies
from 3 to 13.
Nonconventional Pollutant Parameters
All parameters which were tested that are not classified as con-
ventional or priority pollutants are summarized in Tables 3-17
through 3-19 as nonconventional pollutants. The nonconventional
metali are listed in Table 3-17. All of these metals, except
bismuth, were detected one or more times above their detection
limit. However, palladium and tellurium were only found at plant
E09 while platinum was only present in the untreated effluent of
plant A07. The remaining nonconventional metals were found at
two or more facilities. Aluminum, calcium, magnesium, sodium,
iron, and phosphorus were found at levels above 1 mg/1 with
values of 1.2? 550; 38.5; 1,060; 5.4; and 63.9, respectively.
Table 3-18 presents the results of the analyses for those com-
pounds listed in Appendix C of the 1977 Consent Decree (Appendix
C Compounds). The compounds present at levels greater than 10
ug/1, at least once, included: acetone, diethyl ether, methyl
ethyl ketone, and the n-alkanes. The n-alkanes were found only
at plant EOS.
94
-------
ro
•8
H
V)
o
o>
a
M
O
I/I
«M«wo•--
^u» in w-
ocoeor»(c oocn »-o« « r- o
» o>
in
ifltoininmai
«-«•»-
o
ui CM
CM m
^or^MAvo^in^
»•» in t- *-«
n «
-wo
o»
o
-MO
o
e
•»•«
-on
»
-ou>
in
*xlfl
*g
IU<-
-» ws.
-------
10
rH
CO
I
to
53<
o
Ul
UI2
to<
•2!
j«
8
o
£
M
BUI
3 CB
»«r w •*•
omono
M Ul CD *• W
<• n
§«O«eo
iu5»-(D
5 w M
nnmor>
Sr~<0 •»
Oeo O
nOBCDin
So^ o
in n
•OOWrtf-
S^
CM NO] CO
g
(/>
Ul
8111 Z
M Ul
<*"uii/r«/>
M «-<
96
-------
MM
M
a
. 1
Ul H
^SJBS
felSSS
t-«/>-eo — O en eo N
i mm «-
00
n
*-«MeoNin
inn
ID
Sr-f»u>T-»-inc>'-
_M*-t*(0vC4 COO
in —i
— M COO N
in —
ID en
to
CO
o
in
COON
'<- »-o in
w 3~*
\< J gJ^
-------
00
CO
SCO
W frf
CO !H
ww
w>2
>•<
3 22
g:§
W £
QO
Cd U
5o
WK
MI:
Ii
E!
•8
• —o>«
<^«
iel
iui
ci-o
«s
1K
-------
'<- «> '*-
g
iH .H
in CM
oo in r* o? in
VO iH CM 3s rH
CM CO CM
i-l VO CM Q CM
8
co
CO
foco
OOCM
C«J
O
CO
0)
1
CN iHiHi-IOJ CM
CM CMrHrHfM CM
1
I
%$
•alt
8
a
-H
*• **. »±3 ^ **!
lilitg
CD to 0) mp
•ej -H T"i Q ffl -H
Q Q sfi 2 13 13
iH
I
99
-------
Table 3-19 presents the remaining nonconventional parameters
including those analyses conducted in the field. All the param-
eters listed had quantitative results reported except residual
and total chlorine, which were either not present or present at
levels below the detection limit of the analytical techniques.
The high mean values of chemical oxygen demand (COD) and total
organic carbon (TOG) at 2r618 mg/1 and 852 mg/1, respectively;
are consistent with the high BODs concentrations reported in
Table 3-16. Phenolics were found with a maximum concentration
above 10 ug/1 and were also present at two or more plants.
3.4.2 TREATED EFFLUENT
Three of the plants sampled in the EPA Multimedia Sampling
Program had wastewater treatment systems which could provide an
indication of the treatability of ethanol plant effluents, these
included plants A03, E02f and EOS. All three of these plants
were sampled for priority, conventional, and nonconventional
pollutants with a few exceptions. Appendix C compound analyses
were not conducted on the treated effluent of plant E02. Also,
one day's sampling for priority pollutant analyses at plant A03
is taken from the 1979 lERL-Ci study conducted by Radian
Corporation.
Priority Pollutants
Table 3-20 summarizes the priority pollutant organic analyses
conducted for ethanol plant treated effluent streams. The
compounds found at least once with a maximum concentration above
10 ug/1 include: bis(2-ethylhexyl) phthalate, chloroform,
methylene chloride, phenol, and 2,4-dimethyl phenol. Only
bis(2-ethylhexyl) phthalate and methylene chloride were present
more than once, the mean concentrations of these two compounds
were 40 ug/1 and 11 ug/1, respectively.
The priority metal analyses which are summarized in Table 3-21
demonstrate that 10 of the priority metals were present one or
more times above their analytical detection limit. As mentioned
earlier, the lead and cadmium analyses for EOS have been excluded
due to the much higher detection limit of the analytical labs for
these parameters at that1 particular facility. Four metals were
detected in the treated effluent at only one facility including
antimony, lead, mercury, and selenium. The remaining six
priority pollutant metals (arsenic, cadmium, nickel, chromium,
copper, and zinc) were found at levels above their detection
limit at two or more ethanol plants.
Conventional Pollutants
The analytical results for conventional parameters present in the
treated effluent are summarized in Table 3-22. In addition to
the data from plants A03, E02, and EOS, data on the BODs
100
-------
£
w
10
wq
tdOd
S "°
7 S&i
X u
uuiu P IU>£ uuiux£xXMMMMMa:5
-------
1
0}
!PM
I
§
o
I
tl-O
102
-------
2 W
~ IS
•o cos
d w q
c WP*
•3 WO
4J >"
C >JH
!O
Ck
0)
ff!
H QO
j;g&u,^^isgsssii| |
«%»^^^^ t>i ri ^« u IM w w ^ tar B lu K
liglBSBBSSHlH&HHE
103
-------
0)
I
4J
O
u
o
•M
i ' . . . i i i i i -iii
z "w »€>i««M«
-------
o
u
W!
4J
I
n
•s-
H
i|
ii
5
S
z
ooooooo
105
-------
oj
I
ctf
H
wo
a
Ul
N
•:
01
s
a
Q
HI
Ul
M
Kill
IM
HZM
^1 ^ w
(0 C4 t
»-o —inowoooo —in
?isi?s5 iigsg^
OH>-KO«IH''^H«SO2Pj
•» 1.0,6
-------
Ol/> U
-------
(total), fecal coliform, oil and grease, total suspended solids
(TSS) concentrations, and pH values for this table were obtained
from the 308 Questionnaire responses that were received from the
seven beverage alcohol facilities (plants EOS, E06, E07, E13,
E15, E17, and E18).
Both the BODs and total suspended solids concentrations have
demonstrated significant improvement over the untreated effluent
concentration, with mean values of 26 mg/1 for 8005 and 49 mg/1
for TSS. The pH values for the treated effluent are all within
the range of 6 to 9.
Nonconventional Pollutant Parameters
Tables 3-23 through 3-25 present the analytical results for non-
conventional pollutant parameters in the treated effluent from
plants E02 and EOS. The nonconventional metals (Table 3-23)
which were not present at concentration levels above their ana-
lytical detection limit were bismuth, palladium, platinum, and
tellurium. Also, four of the nonconventional metals were found
only at plant E02; these metals included molybdenum, tin, vanad-
ium, and yttrium. Aluminum, calcium, magnesium, sodium, and iron
were found at levels above 1 mg/1 with values of 2.9, 165, 3.7,
50.2, and 2.6 mg/1, respectively.
The Appendix C compounds for plant E02 are summarized in Table
3-24. The only compound found above 10 ug/1 was acetone at a
concentration of 43 ug/1.
Finally, the remaining nonconventional parameters are summarized
in Table 3-25. The average values for COD and TOC were reduced
from 2,618 mg/1 and 852 mg/1 in the untreated effluent to 460
mg/1 and 182 mg/1, respectively.
3.5 WASTEWATER POLLUTANTS OF CONCERN
The Agency has studied ethanol-for-fuel wastewaters to determine
the presence or absence of toxic, conventional, and selected
nonconventional pollutants.
One hundred and twenty-nine toxic pollutants (known as the 129
priority pollutants) were studied pursuant to the requirements of
the Clean Water Act of 1977 (CWA). These pollutant parameters,
which were listed in Table 3-2, are members of the 65 classes of
toxic pollutants referred to as Table 1 in Section 307(a)(l) of
the CWA. The five conventional pollutants identified in Section
304(a) of the CWA were listed in Table 3-3. The nonconventional
parameters which were presented in Table 3-4 include, but are not
limited to, a group of Agency-selected nontoxic metals and the
species listed in Appendix C of the 1976 Consent Decree.
108
-------
fO
CN
I
n
o.
IU
« g
111 H
_1_IU1UH-
<0.>IUM
slsss
HWXQJ
o:12
^ui^
(
«• CM<
CM
in
mo*mooeoinoe)CMO^o
r-CMincono oocooin
«~ *" CM r» *• *~
S
"
s
t ^ v in ^ o> o>
5 CM
CM
«om«mmcino««inno
j M <» w w w in inoinMinvmo oe> in
in o> M *-o> n r»o>
w GO n
ID *• ^
w
in
CM CO
CO!DO<*CD«CM~COCDCMOOCO O CM t CO CM CM «
COCOrMCOCOCOMMCOCOCOCMCMCOCMCOCOCOCMCOCD
109
-------
&
I W
H
0)
!-4
I
CO
Ml
CO'
>ii
H25
Sao
H M
j z
ws
QS
"5
^i
§1
si
I
Ul
(HO
Moooeoooooooctoo
> Z »>
Z J«Z
(•uDoaeoooa
-H
izm
110
-------
co
8
IT)
I
govooor-ii-Hi-HOomococpocg
COCOOOCDCOvOvDVOiHOOr^CO VO CO
ooooaooooooovoaNcoaor^covocom
rH
%
I
tn to
01 to
"i P _ «5 J"«5 -3 O
«
«
CO
fl
-------
A review of environmental regulations reveals that no federal
regulations specifically apply to. the effluents from either
ethanol-for-fuel facilities or beverage alcohol facilities. In
?he absence of effluent guidelines, National Pollutant Discharge
Elimination System (NPDES) permits have been issued to Distillers
based on "best professional judgment," under authority of Section
402(a)(l) of the Federal Water Pollution Control Act.
The EPA regional offices and state agencies have typically
regulated suspended solids (TSS) r biological oxygen demand
(BODc) and pH for beverage alcohol facilities based on best
professional judgment. From this study these parameters have
Ilso been selected as those potentially requiring reduction or
control before discharge based on amount of discharge, treata-
bility, costs and- treatment technology.
Total Suspended Solids
Total suspended solids is a measure of the suspended material
that cJn *e removed from the wastewater by laboratory filtration,
but does not include coarse or floating matter than,cano°e.
readily screened or settled out. Generally, suspended solids
include both organic and inorganic materials. The inorganic
exponents include sand, silt, and clay. ™e organic .£«*ion
includes such materials as grease, oil, fibers, and various
materials from sewers.
The suspended solids from an ethanol facility would most likely
be oraanic in nature such as entrained fibers and insoluble
Biochemical Oxygen Demand
Biochemical oxygen demand is a measure of the oxygen consuming
capabilities of organic matter. Materials which may contribute
to BOD include: carbonaceous organic materials usable as a food
source by aerobic organisms; oxidizable nitrogen derived from
nitrites* ammonia, and organic nitrogen compounds which serve as
food for specific bacteria; and certain chemically oxidizable
materials such as ferrous iron, sulfides, sulfite, etc. , which
will react with dissolved oxygen or which are metabolized by
bacteria.
The raw wastewater from an ethanol facility has^a mean -
concentration (total) of 1,405 mg/1. Approximately 80 Percent of
this loading is dissolved organic materials. The high concen-
tration of BOD5' approximately seven times normal domestic
sewage? requirls that this parameter be reduced before
discharge.
112
-------
pH
Although not a specific pollutant, pH is related to the acidity
or alkalinity of a wastewater stream. It is not a linear or
direct measure of either; however, it may be properly used to
control both excess acidity and excess alkalinity in water. The
term pH describes the hydrogen ion-hydroxyl ion balance in
water.
Data from the sampling program indicate a pH range of 3 to 13.
Because extremes of pH or rapid pH changes can stress secondary
biological treatment systems or kill aquatic life, this
parameter must be controlled.
Other Pollutants
The Settlement Agreement in Natural Resources Defense Council,
Incorporated vs. Train, 8 ERG 2120 (D.D.C. 1976), modified March
1979, which precedes the CWA, provides for the exclusion of
particular pollutants, categories, and subcategories. The
ethanol-for-fuel industry is not one of the 21 industries
included in the Settlement Agreement and the provisions of this
agreement do not necessarily pertain to the ethanol-for-fuel
industry. However, the pollutant exclusion criteria developed
are logical and reasonable means for determining whether
parameters should be omitted from regulation. Therefore while
EPA is not developing regulations for this industry, these
criteria (summarized in Table 3-26) will be considered along
with other criteria in the determination of pollutants of
concern for the eJbhanol-for-fuel industry.
\
All of the priority pollutants and nonconventional pollutant
parameters are not among the pollutants of concern for this
industry for reasons discussed below. In addition, two
conventional pollutants (fecal coliform and oil and grease) have
been excluded as they are process and plant specific.
Exclusion of Priority Organics
Pollutants Not Detected by Approved Analytical Methods
Historically, the Agency has determined the detection limit for
organic priority pollutants to be 10 ug/1. This level is the
minimum concentration at which the signal-to-noise ratio was of
sufficient magnitude to give a quantifiable value for the specie
concentration. Therefore, pollutants that are detected concen-
trations equal to or less than 10 ug/1 as well as pollutants not
detected in any stream can be eliminated from regulation (Crite-
rion 3). The compounds detected at values greater than 10 ug/1
in the untreated effluent are presented in Table 3-27.
113
-------
Table 3-26
SETTLEMENT AGREEMENT EXCLUSION CRITERIA
1. Equal or more stringent protection is already provided
by EPA's guidelines and standards under the Act.
2. The pollutant is present in the effluent discharge
solely as a result of its presence in the intake water
to the production .process.
3. The pollutant i.s not detectable in the effluent within
the category by approved analytical methods or methods
representing the state-of-the-art capabilities. This
includes cases in which the pollutant is present solely
as a result of contamination during sampling and analy-
sis. (Contamination is determined by the species
presence in the method and control blanks.)
4. The pollutant is detected in only a small number of
sources within the category and is uniquely related to
only those sources.
5. The pollutant is present only in trace amounts and is
neither causing nor likely to cause toxic effects.
6. The pollutant is present in amounts too small to be
effectively reduced by known technologies.
7. The pollutant is effectively controlled by the tech-
nologies upon which other effluent limitations and
guidelines are based.
114
-------
Table 3-27
TOXIC ORGANIC POLLUTANTS FOUND IN UNTREATED EFFLUENT
FROM ETHANOL PLANTS (ug/1)
Pollutant
benzene
bis phthalate
butyl benzyl phthalate
chloroform
ethylbenzene
methylene chloride
pentachlorophenol ,
phenol
toluene
trichloroethylene
Total
Number
Samples
23
23
23
23
23
23
23
23
23
23
Total
Number
Detects
16
18
6
14
4
20
4
16
20
6
Mean
65
18
13
27
1
30
4
33
10
7 •
Max
1,000
72
220
390
11
99
47
190
94
92
115
-------
Pollutants Present Due to Contamination
It is known that during sample collection, automatic composite
samplers were equipped with polyvinyl chloride (Tygon) tubing or
original manufacturer-supplied tubing. Phthalates are widely
used as plasticizers to ensure that the Tygon tubing remains
soft and flexible . (16,17). These compounds, added during
manufacturing, have a tendency to migrate to the surface of the
tubing and leach into water passing through the sampler tubing.
Laboratory experiments have been performed to determine if
phthalates and other priority pollutants could be leached from
tubing used on composite samplers (18). The types of tubing
used in these experiments were clear tubing supplied with the
sampler at the time of purchase.and Tygon S-50-HL, Class VI.
Results of the analyses of the extracts representing the
original and replacement Tygon tubing are summarized in Table
3-28. The data indicate that both types contain bis phthalate,
and the original tubing leachate also had high concentrations of
phenol.
To verify the actual presence of toxic pollutants in the ethanol
facility effluent streams, an analysis of field and lab contami-
nation was conducted. This was accomplished by the collection
of method and control blanks. The results of these analyses are
presented in Table 3-29. The method and control blank analyses
demonstrate high concentrations (maximum = 190 ug/1) of bis
phthalate; however, phenol was not detected in any of the other
26 samples. Therefore, bis phthalate is excluded on the basis
of contamination, while phenol is not.
\
Two volatile organic compounds were detected as a result of the
analyses of grab samples: methylene chloride and ethylbenzene.
The volatile nature of these compounds suggests contamination as
a possible source, especially considering the relatively low
concentrations detected in the samples (mean values of 6 ug/1
and 1 ug/1 for methylene chloride and ethylbenzene,
respectively). Also, these compounds may be found in the
laboratory as solvents, extraction agents, or aerosol
propellants. Thus, the presence and/or use of the compounds in
the laboratory may be responsible for sample contamination.
This type of contamination has been previously addressed in
another study (19). In a review of a set of volatile organic
blank analytical data from this study, inadvertent contamination
was shown to have occurred; the prominent compounds being
raethylene chloride and ethylbenzene. On the basis of this
study, methylene chloride and ethylbenzene were attributed to
contamination and not selected for regulation.
116
-------
Table 3-28
TUBING LEACHING ANALYSIS RESULTS
Microqrams/Liter
Component Original ISCO Tygon
Bis (2-ethylhexyl) Phthalate
Acid Extract 915 N.D.
Base-Neutral Extract 2,070 885
Phenol
Acid Extract 19,650 N.D.
Base-Neutral Extract N.D. N.D.
N.D. - Not Detected
117
-------
g
CO
38
co ptf
t*JO
CT» *5
7 S
n o
0) ~
3
OiJ
N O
M P<
«r:
is
gs
SpLl
ii
Ifl^.
S5S
iSo
ZOA
,£S
Emu
K!2
_IUI -I
?li
• OIION
n
o • •«• -oo -o
•MMM
•»OO
"OO —OWDO'-OOOOOOOOOOOOW'-'-OOOOOO'-
_ (- z uj3o.u.lu._, -
»ZM u z—^-.«~ *"•ZX
-------
!§
!SA
tn
~s
_IIU.
ir1
01 CO
8
• Mini--
M
M
• •OMB • •'•
• ininn • ••«-«
oo
• oo« • -oo
~
?2uixiJt-uJOOOQ:n:>ooi-t-'
i m OOuiiu x SB Eg o±5a aa : - = -- . -
MHMMMMMMZZZZZf>«J_IUJUUIUIUI(IZV»>ltllUll I r <
OaOOOOOOUIUUIUIIUUIU.IfeZXXXXX<-iMKZSZZZZ
119
-------
to
w
CO
SHW
J u
<3 M
^CJ ^ti ^ti
0) O
i S3
1 I*
I "I
^ §§
er\ §3
N Ro
I Hfe
0) OH
»Q JM
OCA
(£&<
8
• m
• o • • .-o
OOOOOOOOOONOOOnOOPlOOOVOOOOOOOO
B(00Q(0(DOfO(D(D(DI0(0coco(D60C0600nGOflOttOtDflOGOt0GOCD
(OCKilCIMCIMCICIMMNMCINnCllMMCINMCimCIMCilNNCil
"nn ft in a
-IO WM CMN N«
I
Ul
s
u
• u
!iu ZHU
; o in u M iu M iu
U.L! z-.K^SSIiSgSS
SlJlpSjjSl&gp*'
>O U Ul I
iSfe!
=1
JIUDZXSS SS I I .MMHMK I M
~at mm ^-Siuaca & 55>i? ?*1N.C>1.???? "T".1?
sl££ggggaS£££ISggSH5lC-Zv*'r
120
-------
OiJ
s
!l
si
ini
in
IB
3u«-
ZO A
.S6
555
Q.
§.
111
2J
S v
uuuoz
UIZIU OOO-IZXZiiUJX
^>< . ^Ilsslssg0-
£XU -IK-IIU _l
&xooom_i>:_i
! a o -J a. t =J t o v S o
_ ! a x
'i xuiMMKMXaoa
O
§
121
-------
Pollutants Detected in a Small Number of Sources and Uniquely
Related to Those Sources
Benzene was found only at plant A01 at concentrations above its
detection limit (10 ug/1). The source of benzene at this facil-
ity is the dehydration unit where it is used as the dehydration
solvent. (The maximum concentration of .benzene from the
dehydration column was 1,000 ug/1.) Since a variety of solvents
are in use today, permit authorities should consider the
establishment of a limitation for benzene if it is used at a
particular facility.
Exclusion of the Remaining Priority Organic Pollutants
Data on treated effluent are available from three ethanol
facilities (A03, E02, and EOS). As Table 3-30 shows, the
maximum concentrations of toluene, trichloroethylene,
pentachlorophenol, and butyl benzyl phthalate are below their
detection limit at every facility tested. These parameters are
excluded as they are present in the treated effluent at levels
too low to be reduced further by existing treatment
technologies.
Data on Untreated and treated effluent for phenol and chloroform
are presented in Table 3-31. As this table shows, phenol was
detected in the treated effluent at only one facility and this
value is suspect since it is higher than the level detected in
the untreated effluent. Chloroform was not detected in the
treated effluent at plant EOS; the presence of chloroform in the
treated effluent at plant E02 is suspect as it was not detected
in the influent stream to the treatment system. The concentra-
tions of these pollutants in the treated effluent are too small
to be quantified by approved analytical methods. Therefore,
these pollutants are excluded also.
Exclusion of Priority Metals
Pollutants Present in Amounts Too Small to be Effectively
Reduced by Known Technologies
The concentrations for priority pollutant metals found in the
untreated effluent from ethanol facilities are presented in
Table 3-32. All of these metals except copper, nickel, lead,
and zinc are present in the untreated effluent at maximum
concentrations so low that further reductions cannot be
accurately quantified.
Pollutants Detected at a Small Number of Sources and Uniquely
Related to Those Sources
The values for copper, nickel, and zinc present in the untreated
effluent for each plant are presented in Table 3-33. As this
122
-------
Table 3-30
CONCENTRATIONS OF TOXIC ORGANIC POLLUTANTS FOUND
IN TREATED EFFLUENT FROM ETHANOL PLANTS (ug/1)
Pollutant
benzene
chloroform
phenol
toluene
trichloroethylene
Total
Number
Samples
11
11
11
11
11
Total
Number
Detects
3
2
1
2
0
Max
1
42
15
5
0
123
-------
*J O
e -H
0) 4J
u u
iJ 3
0) -O
*£
o
o
J
o
25
Ed
£w
z u
X il
52=. c£
OH
b V3
O <4
O* S
o
3B Z
ftaj
b 04
^ O
HZ
»j as
1^ • »^j
CD U
«C M
U
fl£ H
p*4 21
U
J CO
«c m
u EC
M Oi
C5
Q
*J
o
M
CD
0)
3
l"l
«4
ta
•0
4J
m
0)
H
y
^J
*^n
(0 OI
^^
IS
X 3
* ._
Q 01 g
z ^ z
Jl
i 5 i
^
01 V.
4J OI
4JO
A
01
fH
fH
IM
IM
CO
•o
*J
(8
Q>
4J
e
a
5?
04 U
vo
^CJ1 ***
f»» N °°
° ° H
•Sfi ™
in
*-< CM
t- ® 2
ifi "V
in
m CM
oo
4J
c
Q>
3
14J
•o
Q)
4J
(Q
C
•o
0)
4J
o
0)
JJ
0)
•c
4J
o
01
5
i
m
o
•H
01
O
a>
a
n
3
01
01
3
01
124
-------
Table 3-32
PRIORITY METALS PRESENT IN UNTREATED ETHANOL
PLANT EFFLUENT (ug/1)
lead (total)
mercury (tot
nickel (tota
selenium (tc
silver (tote
thallium (tc
zinc (total)
Compound
total)
.otal)
(total)
.otal)
total)
»tal)
:otal)-
il)
:otal)
>tal) ]
; total)
)tal)
[total)
il)
[chrysotile) (>5 urn)
[fibrous) (>5 urn)
[ chrvsotile-f ibers/
Total
Number
Samples
23
23
23
17
23
23
23
17
23
23
23
23
23
23
3
3
3
Total
Samples
Above
Detection
Limit
6
9
5
12
18
21
1
10
5
11
9
5
4
22
0
0
1
Mean
4
3
2
6
17
342
9
54
<1
71
5
1
11
164
1
Max
10
8
8
17
36
1210
11
189
1
270
43
3
48
590
2
liter/10E5)
asbestos (total-fibers/liter/
10E5)
243
690
125
-------
Table 3-33
PRIORITY POLLUTANT METALS PRESENT IN UNTREATED
EFFLUENT FROM ETHANOL PLANTS
Copper
Plant
Code
A01
A08
A06
A07
A10
E02
£08
B09
A01
A03
A06
A07
A10
E02
EOS
E09
Total
No. of
Samples
3
1
3
3
2
2
6
3
3
1
3
3
2
2
6
3
No. Samples
> Detection
Limit
1
1
3
3
2
2
6
3
Nickel
0
1
3
3
0
2
0
2
Mean
(ug/1)
19
950
158
25
559
71
210
762
25*
4
195
46
50*
261
30*
6
Max
(ug/1)
48
950
227
32
1065
71
250
1210
25*
4
264
50
50*
270
30*
8
*Detection Limit.
126
-------
Table 3-33 (Continued)
PRIORITY POLLUTANT METALS PRESENT IN UNTREATED
EFFLUENT FROM ETHANOL PLANTS
Zinc
Plant
Code
A01
A08
A06
A07
A10
E02
E08
E09
Total
No. of
Samples
3
1
3
3
2
2
6
3
No. Samples
> Detection
Limit
2
1
3
3
2
2
6
3
Mean
(ug/1)
357
270
138
110
114
133
64
153
Max
(ug/1)
590
270
164
128
121
142
119
182
127
-------
table shows, relatively high levels of copper were found in the
treated effluent only at plants A03f A10, and E09. Likewise,
only plants A06 and E02 had relatively high levels of nickel,
and only plant A01 had a relatively high concentration of zinc.
For the remaining facilities, the levels of these parameters are
too low to be reduced further by known technologies. Permit
authorities should consider the establishment of a limitation .
for copper, nickel, or zinc for a particular facility if these
parameters are present at levels that can be treated.
Exclusion of the Remaining Priority Metals
The detection limit for lead varied from 5 ug/1 to 200 ug/1 for
different analytical laboratories. When analytical values were
reported such as <200 ug/1, a value of 100 ug/1 was used to
calculate the mean. The maximum and mean concentrations of lead
in the untreated effluent were 189 and 54, respectively. This
parameter was excluded as it was present at levels too low to
quantify by approved analytical methods.
The Agency has determined that background levels for total
asbestos fibers may be lQ5 to 10? fibers per liter of
sample. Although the concentration values for the samples
analyzed fall within this background range, further quantitative
standards are to be promulgated in the near future. Therefore,
consideration of this parameter will be deferred until such
standards are set.
Exclusion of Conventional Parameters
"he fecal coliforms present in the effluent from ethanol plants
do not originate in the ethanol production process. The source
of this parameter is the. sanitary waste which is mixed with the
ethanol plant effluent at some facilities. Currently fecal
coliforra levels are regulated under the NPDES permit program for
those ethanol plants which treat their sanitary wastes rather
than sending them to municipal treatment systems. Therefore,
fecal coliform is excluded since it is uniquely related to a
small number of sources within the industry.
The oil and grease parameter is a measure of the hydrocarbons,
• esters, oils, fats, waxes, and high-molecular weight fatty acids
that are dissolved by extracting the aqueous sample with hexane
or trichlorotrifluroethane (Freon). Oil and grease concentra-
tions ranged from 3 mg/1 to 1,560 mg/1. An analysis of the con-
centrations for individual plants reveals that the oil and
grease contribution from an ethanol facility is process and
plant specific. Therefore, permit authorities should consider
the establishment of a limitation for oil and grease for
facilities where this parameter is determined to be a concern.
128
-------
Exclusion of Nonconventional Parameters
The analytical results for nonconventional metals in the un-
treated and treated effluent were presented in Tables 3-17 and
3-23, respectively. Maximum concentrations for six of these
metals were found at levels above 1 ppm in both the treated and
untreated effluent. These metals include aluminum, calcium,
magnesium, sodium, iron, and phosphorus with maximum values of
1.2, 550, 38.5, 1,060, 5.4, and 63.9 mg/1, respectively, in the
untreated effluent. There is no data available which suggests
that these metals would be an environmental problem at the
levels detected, therefore they are excluded.
Tables 3-18 and 3-24 presented the results for Appendix C com-
pounds in the untreated and treated effluent. The only compound
with a maximum concentration greater than 0.05 mg/1 was diethyl
ether with a maximum value of 0.8 mg/1 in the untreated efflu-
ent. Diethyl ether is a common laboratory solvent and may be
present as a contaminant at this low level. The Appendix C
compounds are excluded as they are present at levels too low to
be reduced further by known technologies.
The analytical results for the remaining nonconventional param-
eters analyzed in the treated and untreated effluent were pre-
sented in Tables 3-19 and 3-25, respectively. Very high values
of total organic carbon (TOG), chemical oxygen demand (COD),
total dissolved solids (TDS), total solids (TS), and temperature
were measured' for the untreated effluent. The data show that
secondary biological treatment which reduces 8005 and TSS is
also effective in reducing TOG, COD, TDS, and TS. Therefore,
since 8005 and TSS have been selected for regulation; TOC,
COD, TDS, and TS are excluded.
The concentration of total phenolics was present above the
detection limit in the untreated effluents; however, its
concentration was below the detection limit for the treated
effluents for every facility tested. It is therefore excluded
because it is present in the treated effluent at levels too low
to be reduced further by existing treatment technologies.
In addition, the data show a reduction in the temperature of
untreated effluent from an average value of 35°C (maximum of
44°C) to a value of 22°C (maximum of 30°C) for the treated
effluent. These data do not indicate a need to regulate tem-
perature for treated effluent from the average ethanol facility.
However, permit authorities should consider the establishment of
standards for temperature if this is determined to be a problem
for a particular facility.
While the presence of the pollutants was insignificant in the
facilities studied, they may be present in significant quanti-
ties at any specific facility and perhaps should be considered
by permitting authorities if evidence indicates a concern.
129
-------
3.6 AIR EMISSIONS
The Clean Air Act and its amendments created a comprehensive
program to protect and enhance the Nation's air quality and a
regulatory scheme for the control of air pollution. The
cornerstone of the Act is the development of uniform national
ambient air quality standards (NAAQSK Responsibility for
limiting emissions to meet the ambient standards lies with the
states. The Act required each State to develop state
implementation plans (SIPs) which provide for implementing,
maintaining, and enforcing the ambient standards.
The Act also requires the United States Environmental Protection
Agency to establish three sets of nationally uniform emission
limitations: new source performance standards (NSPS), hazardous
pollution emission standards, and motor vehicle emission stan-
dards. NSPS requires the application of "best demonstrated
technology" to new and modified stationary sources considering
costs and health, energy and environmental impacts. The Act
allows the States to require more stringent emission limita-
tions than those developed for NSPS.
Part C of the Act, prevention.of significant deterioration of
air quality, provides EPA a means to regulate any pollutant from
any major emitting facility which may adversely affect the
public health and welfare. A major emitting facility for the
ethanol- for-fuel industry would be any source which releases to
the atmosphere or has the potential to release 227 metric
tons/year (250 tons/year) or more of any pollutant.
In considering the air emissions associated with ethanol
production, available emission data were used to (1) determine
the magnitude of emissions and (2) assess the impact of State
and Federal regulations on the ethanol-for-fuel industry.
A review of existing NSPS reveals that there are no regulations
which specifically address the emissions from the ethanol-for-
fuel industry. Proposed regulations that will apply to impact
the industry include (1) NSPS for emissions from volatile
organic liquid storage tanks that would have application to the
industry's storage facilities and (2) NSPS for volatile organic
compound (VOC) fugitive emissions in the synthetic organic
chemical manufacturing industry that would specifically deal
with fugitive VOC emissions from the industry.
VOC emissions from storage tanks were estimated and the cost of
compliance to proposed regulations were calculated based on the
work presented in the Background Information Document (BID) for
VOC Emissions from Volatile Organic Liquid Storage Tanks. Simi-
lar tasks were performed for VOC fugitive emissions based on the
BID for Fugitive Emissions from the Synthetic Organic Chemical
Manufacturing Industry (SOCMI). It was found that there would
130
-------
be little or no cost to the industry, (or even a savings by
preventing loss of product) from compliance to these proposed
standards.
The assessment of the total projected emissions for ethanol
plants and their source specific emissions indicates that
sufficient regulatory activity exists to potentially control
emissions without initiating additional regulatory efforts.
3.6.1 EMISSION SOURCES
Figure 3-2 illustrates the major sources of air emissions from a
typical ethanol-for-fuel facility. These air emissions consist
of particulate and volatile organic compounds (VOC), both point
and fugitive sources. As Figure 3-2 shows, the sources for air
emissions for a particular ethanol facility depend on the feed-
stock and by-product processing. Air emissions from ancillary
processes, such as steam generation, are beyond the scope of
this document and are not included.
Regardless of feedstock type or by-product processing, all
ethanol-for-fuel facilities have air emissions from fermenter
vents as well as condenser vents on distillation columns (e.g.,
the beer still and the dehydration column). Volatile organic
compounds (VOC) such as ethanol, by-product fusel oils (pri-
marily amyl alcohols), low molecular weight aldehydes
(acetaldehyde, and formaldehyde), and dehydration agents
(gasoline, benzene, or hexane) may be emitted from these
sources. In addition, fugitive VOC emissions occur throughout
the plant at valves, pumps, flanges, open-ended lines, and
storage tanks. !
By-product processing usually involves three steps: (1) centri-
fugation of the screened solids from the beer still, (2) concen-
tration in evaporators, and (3) final drying in either direct-
contact dryers or indirect steam heated dryers. VOC emissions
occur from the condenser vents on evaporators. Indirect grain
dryers are sources of particulates- and VOC emissions. Direct-
contact dryers often use boiler flue gases to dry the by-product
grains; therefore, CO, SOX, and NOX occur in addition to
particulate and VOC emissions.
Table 3-34 summarizes the major sources of air emissions for an
ethanol-for-fuel facility which uses grain as a feedstock and
practices by-product processing. The utilization of grain
rather than sugar feedstocks for ethanol production results in
the generation of additional particulate emissions. In the
feedstock preparation step, fugitive particulate emissions occur
during the unloading, loading, conveying, rough grinding,
screening, cleaning (with shakers), and fine milling of the
grain. If area ventilation is used to collect these emissions
and then vented to the atmosphere, this becomes another point
source emission.
131
-------
t
•
I-*—
•
*4
£^
w
«
J h
DUtilUtioa
ColUKlB
1 1
L
!**"
!
•M
••4
«4
M
u
gp
V
2
|
I
j
9
n- i
w
si 1
• C ** v
rf1*" *
i3
^ k
|
H
1 B
1 d
* S
* ^
HI
o
M
«v«
§
M
5:
!IU —
M **
ba ««
•
1
^ 2
•
V si .
g
Enxyac
Coiiviril
j i
-g
!«
"i 2.
*£
•k
CO
O
CO
i
•
'
" t
5
5
132
-------
Table 3-34
MAJOR SOURCES OF AIR EMISSIONS FROM
AN ETHANOL-FOR-FUEL PLANT*
Grain Handling and Milling
Fermenter Vents
Condenser Vents on
Distillation Columns,
Dehydration Columns, and
Evaporators
Ejector Vent on Flash Cooler
Direct-Contact Dryer Exhaust
Indirect-Contact Dryer Exhaust
Valves, Pump Seals, Open-Ended
Lines, Flanges, Storage Tanks
Particulates
Volatile Organic
Compounds
Volatile Organic
Compounds
Volatile Organic
Compounds
Particulates, CO, SOXf
NOX, and Volatile
Organic Compounds
Particulates, Volatile
Organic Compounds
Fugitive Volatile Organic
Compounds
*Based on a facility which uses grain and processes by-product
grains.
133
-------
Finally, grain feedstocks must be cooked to solubilize the
starch portion in preparation for enzyme conversion of the
starch to sugar. If the cooked grain is flash cooled, VOC
emissions result from steam ejectors used to provide vacuum for
the process.
3.6.2 EMISSION CHARACTERIZATION
To characterize emissions from ethanol-for-fuel plants, a sam-
pling and analysis program was conducted at three facilities:
two plants producing ethanol-for-fuel and one plant producing
beverage alcohol. The test program was intended to give pre-
liminary information on the type and magnitude of emissions from
the industry.
A multimedia test programi was conducted at plant A03 which
included a screening of all the sources of air emissions. The
sources tested and the analytical results are discussed below
and presented in Tables 3-35, 3-36, and 3-37. Data are
presented in standard conditions unless otherwise specified.
Plant A03 has a capacity of 61,000 m3/year (16 x 106 gal-
lons/year); approximately 11,000 m3/year (3 x 106 gallons/
year) is fuel grade ethanol. The plant feedstock consists of
starch from a protein extraction unit as well as milled whole
grain. The cooked mash is cooled in a flash cooler and then
routed to the fermenter. The remaining process steps are
similar to those shown in Figure 3-2; benzene is used as the
dehydration agent.
VOC emissions were sampled at the fermenter vent, beer still
condenser vent, solvent extractor condenser vent, fusel oil
column condenser vent, dehydration column condenser vent, and
the grain dryer cyclone outlet. The VOC emissions from the
dryer would not be appreciably affected by the cyclone since it
operates dry. The results (Table 3-35) indicate that the grain
dryer had the greatest VOC emissions with 2.04 kg/hr (4.50
Ib/hr). Total VOC emissions were 6.07 kg/hr (2.75 Ibs/hr) or
0.41 Ibs/ton on a production basis.
An OVA Century 108 hydrogen flame ionization detector was used
to measure VOC emissions. The detector is sensitive to the
specific type of compound being measured. Correction factors
have been determined for several organic compounds that can be
applied to determine the correct readings. However, a
methodology has not been developed to adequately correct
readings for a mixture of organic compounds. Therefore, for
this study, the "worst" case was determined by applying the
largest correction factor for those compounds believed to be
present. In addition, the largest molecular compound present
was used to determine the mass of the emissions. These methods,
therefore, are quite conservative and actual emissions may be
in the order of a magnitude less than those calculated.
134
-------
hi
^ JS
0)^ —
e m
OJQ
tfl
r-
o
in
1-1
•
o
r»
o
ve
o
o
•
o
o
•
o
eo t-
voo
oo
pH ro
(*> O
o o
00 00 04
ao coo
in in <-«
• • •
o oo
o
in
4)
4)
(0
JJ
4)
(0
4)
I O
o 10 a
hi a
> a>
< u
in
en
en
O
m
in
r-
en
o o
o o
eno
% «
en p»
o oo
ooo
•a
o
in m c*
in in in
m u
ro Z
I 03
f) N
Z
4). U
f-4 CO
m
in
o
en
O
•O
4>
m
f) -Q
vo
•o
m
n ><
o
o
00
o
en
v
in
ci
o
ve
in
in
09
0)
m
JJ
&
hi
4)
JJ
I
JJ
J>
rH hi
•* 4)
jj n
to e
hi rj X
4) C H
4> o
CO CJ
hi
O
JJ
U JJ
« e
z$
M
U hi
4)
JJ 0)
e e
"* e i
o o
CO U
c
hi 4)
4>!>
•rt 4)
JJ 0}
u e
4) 4>
os-o
Column
Vent
M4 4)
O n
r-l 4) O
0) -O I
n c H
£8
e
o
•H hi 4)
jj 4> e
10 m 4>
hi C N
•p 4>y e
L
-» e
38
Ol hi 4)
ea> e
•H m 0
SSo o c
•Z?£HS
JJ O
en u
4J
e
4) 4>
c >
r-4 Q X
S,cH
cj o
•O 0)
4) U
U C
U 4>
4> iJ
U 4)
4)
OS
135
-------
Table 3-36
PARTICULATE MATTER ANALYSIS AND SAMPLING DATA
FOR PLANT A03/CYCLONE ON DIRECT-CONTACT
BY-PRODUCT DRYER
Particulate Particulate
Sample tl Sample »2
Average Flue Gas Velocity (m/s) 14.0 14.1
Average Flue-Gas Temp. (°C) 98.9 88.3
Stack Pressure (kPa) 102 102
Flue Gas Composition
H20 19.2 20.4
c°2 5.0 5.1
°2 6.5 0.5
CO 0 0.6
N2 69.3 73.4
Flue Gas Total Flow (Actual m3) 1,670 1,670
(ra3/hour) 63,390 64,240
Flue Gas Grain Loading (grams/m3) 0.04 0.02
Particulate Flow Rate (kg/hour) 2.8 1.6
Sample Percent Isokinetic 110.9 108.9
136
-------
^
CO
1
CO
0)
«H
•Q
fQ
H
^^
CO
o
H
Z
«tf
iH OS
^* S
OS OS
O 0
fe
EH
CO CJ
*^ MB?
CO Q
» o
•J5
< On
Z 1
CD
ta
QH
M CJ
X <
O H
z
z o
U CJ
OS CJ
H BJ
M OS
Z M
Q°
38
63 Cd
Q z
M O
X J
OCJ
W ^4
Qcj
OS
3
Cb
tj
o
CO
o
m
c —
O »4
•H .c
MX
to c
"s^
u
o
•
o
V
Q>
4J "^
(0 ^
CO OS £
O SCO
o e
fH *-
0
vo
ON
•»
VO
1 C
c o
33-
co flj S
«J 0) U Q
cj co 4J o
IQ C *••*
£ 0>
PJ O
CO
o
V
•o
10 fl)
•H jj
(8 O •»* O *"•
*» 0 « C3I
O » CD fH 3
S CO O
o
fH
o
in
VO
V
,
T3
» 0)
rH »^ ^"^
o or>
> se
«J «-
CO
VO
CO
o
14
0 >
C (Q i>4
0 4J Q
c
0) O *»
C CJ 0
0 1 3
•H 4J -O
0 0 O
>sC0 14
cj i4 eu
*f4 i
Q >
CO
fH
&
CO
o
in
o
•
o
V
0
VO
ON
»
VO
CO
o
V
fH
o
in
VO
V
VO
r-
o
CN
=*•
CN
o
CO
CN CN
CN CO 00 CN
^« m in P*
• • . • •
fH O O fH
0000
VO VO VO VO
ON ON ON ON
«*»»•*
VO VO VO VO
fH I*" CO P*
VO O CO CN
CN •"+ CO
m •* ON fH
f"» ON fH ON
VO
jyh ^| ff* f^*
rl fH fH fH
o o o o
o o o o
o o o o*
fH CN CO ^J"
4t> *• * *
X X X X
o o o o
z z z z
JJ .
fl CN
E O
•H Z
3 °
5 i
W JC
CN
137
-------
The dehydration column and benzene stripping column were also
tested for benzene which is used as a dehydration agent at this
facility. The benzene emissions detected at the condenser vents
on the stripping column and dehydration column were 0.10 kg/hr
(0.22 lb/hr) and 0.03 kg/hr (0.07 Ib/hr), respectively.
Particulate sampling was conducted on the cyclone which was used
to remove particulate matter from the grain dryer exhaust. The
inlet to the cyclone was inaccessible and therefore only the
outlet was sampled. As Table 3-36 indicates, the emissions from
the cyclone outlet averaged 2.2 kg/hr (4.7 lb/hr). Based on a
conservative removal rate of 80 percent for the cyclone
performance and estimated grain particle size distribution, the
uncontrolled particulate emissions would be approximately 10.a
kg/hr (23.7 lb/hr). On a production weight basis emissions are
0.73 Ibs/ton.
The flue gases from the gas-fired boiler were used in the by-
product grain dryer, therefore, the cyclone outlet was also
tested for SOX and NOX. Table 3-37 presents the results of
this testing. The SOX concentration (measured as SO2) was
below the detection limit. Nitrogen oxide concentrations were
below 35 ppm which corresponds to an emissions less tnan ±.»
kg/hr (4.0 lb/hr).
After testing was completed at plant A03, two additional plants
(A06 and EOS) were selected for testing to provide further
information on the magnitude of emissions from ethanol-for-fuel
plants. These facilities were tested for fugitive emission
sources as well as point sources. A beverage alcohol plant was
included in the test effort since these plants were determined
to be similar to the ethanol-for-fuel plants in volume and
composition of air emissions. Data obtained at plant A03 were
considered in determining which point sources were the major
contributors. The final selection of sources and types of
emissions for plants A06 and E06 are summarized in Table 3-38.
A description of the sampling procedures used at each site is
given in Appendix A.
Plant A06. Plant A06 is a new grassroots ethanol-for-fuel
plant. The processes employed are similar to those shown in
Figure 3-2. Benzene is also used in this plant as the
dehydration agent. The plant has a production capacity of
11,360 rnVyr (3 x 10° gallons/year).
Particulate sampling was conducted only on the by-product grain
dryer which was equipped with a cyclone. The inlet to the
cyclone was inaccessible and therefore not sampled. Particulate
emissions from this source were 0.15 kg/hr (0.33 lb/hr) which is
much less than the cyclone emissions for plant A03. The differ-
ence may be due to the difference in sampling methods. Assuming
again an 80 percent efficient cyclone, the uncontrolled
emissions would be approximately 0.75 kg/hr (1.65 lb/hr).
138
-------
Table 3-38
1980 EPA SAMPLING PROGRAM/AIR EMISSIONS
TESTING OF ETHANOL PLANTS
Plant
Code
A06
Stream Sampled
Stream Ejector Vent
Fermenter Vent
By-Product Dryer
VOC
X
X
X
Particulates
X
Fugitive
VOC Emissions
Cyclone Outlet
Valves, Pump Seals,
Flanges, Open-Ended
Lines, Storage
Tanks
EOS Corn Mill Vent -
Baghouse Outlet
Centrifuge Vent X
Conveyor Vents X
Grain Dryer Cyclone X
Outlet
Valves, Pump Seals,
Flanges, Open Ended
Lines, Storage
Tanks
139
-------
VOC sampling was conducted on the cooker/cooler at the steam
ejector discharge, the fermenter vent, and the cyclone exhaust
on the by-product grain dryer. VOC emissions were greatest for
the dryer, just as they were at plant A03. The average VOC
emissions from the dryer were 9.6 kg/hr (21.1 Ib/hr). This is
much larger than the value for plant A03 which was 2.04 kg/hr.
The differences could not be accounted for as sampling error but
may be due to operational differences. On a production basis,
the uncontrolled emissions are 0.66 g/kg (1.32 Ib/ton) and 8.5
g/kg (16.9 Ibs/ton), respectively, for particulate and VOC
emissions.
Fugitive VOC emissions were measured from flanges, open ended
lines, agitator seals, valves and pumps. Over 95 percent of
these sources were screened using a portable Century System
model OVA-108 portable hydrocarbon detector. The total VOC
emissions were measured at 17.7 kg/day (39.0 Ibs/day) as shown
in Table 3-39. The VOC mass emissions were estimated from VOC
emission factors developed by the Agency on petroleum
refineries.
Plant EOS. Plant EOS is a beverage alcohol plant with a ca-
pacity of 34,065 m^/yr (9 x 10^ gallons/yr). The processes
employed are basically the same as those shown in Figure 3-2,
although additional distillation columns are used to produce
beverage grade ethanol.
Particulate sampling was performed on the corn mill vent and
dryer. The corn mill is a hammer-type and is equipped with a
baghouse. The inlet to the baghouse could not to be tested;
therefore, only the outlet was sampled. As in plants A06 and
A03, the dryer is equipped with a cyclone and again, the inlet
was inaccessible.
Particulate results measured 0.55 kg/hr (1.22 Ib/hr) and 0.02
kg/hr (0.05 Ib/hr) of particulate from the dryer and corn mill,
respectively. Assuming an efficiency of 99 percent, for the
baghouse and 80 percent to the cyclone, uncontrolled emissions
.from the dryer and corn mill are approximately 2.76 kg/hr (6.1
Ib/hr) and 2 kg/hr (4.4 Ib/hr), respectively.
VOC sampling was performed on the centrifuge, conveyor vents,
and dryer. VOC emissions were 0.04 and 0.07 kg/hr (0.02 and
0.03 Ibs/hr), respectively, for the centrifuge and conveyor
vents and 41.6 kg/hr (91.8 Ib/hr) for the dryer. This is larger
than the other plants measured and may be due to the presence of
an oil aerosol in the exhaust stream during testing. On a pro-
duction basis, uncontrolled emissions from the dryer are 0.81
g/kg (1.76 Ib/ton) for particulate and 12.3 g/kg (24.6 Ib/ton)
for VOC emissions. VOC emissions would not be appreciably
affected by the cyclone.
140
-------
X
4J
Cf-*
W
E
B
el
32
JC
58
a *J
a o
« a
3o
"So
• d
a*
o oi
CM
e>
s
d
^ CM O
fM f» -I
rt d o
o
»
s
m
mo o o o
-4 d •«
r* O O
a
• it
-) 0
(5 U
s
oo
• •
OO
i-t m
<*» m i-t
^5 C? '^
eoo
a
v
•8 .
aw
?«
g>S<
» 0
-* C
OU
a. a
o
8*5 "S
a e «
E «
Z v
o
1
co
Flanges
OlA
3
g
cr1
» a oo
> O-l
r-
<-i r*
OS
i
•o
«
•o
&
1 c
1 s.
eu o
0
a
M
CO
Agitator
US 0
«4 U h
h «
01 .o)
£ u a
O.-O 01
2?.°*
,
g
o
a
a
i
2
o
H
4J a a
< 9-0
s u
U4 0
o -fa
u e
u «
c • u
-------
Fugitive emissions were measured at flanges, valvesr pumps, open
ended lines, and agitator seals within the plant. Approximately
95 percent of these sources were tested. The total fugitive VOC
emissions were determined as 6.7 kg/day (14.9 Ibs/day) as shown
in Table 3-40. Mass VOC emissions were estimated using VOC
emission factors developed by the Agency on petroleum
refineries.
3.6.3 NATIONAL EMISSIONS
The total particulate and VOC emissions were estimated for the
current and projected ethanol-for-fuel industry using the data
from plants A03, A06, and A08. The data from plant A03 include
all major point sources of emissions from a typical ethanol-for-
fuel plant and therefore are used to calculate national point
source emissions. Fugitive VOC emissions were estimated from an
average of fugitive emissions from plants A06 and EOS: 12.2
kg/day (26.9 Ibs/day) per plant, regardless of production
capacity.
Table 3-41 presents the particulate and VOC emissions calculated
for the current and 1985 projected ethanol-for-fuel industry.
Based on a 1981 estimated production capacity of 6.2 x 105
cubic meters per year (1.6 x 108 gallons per year) from the
industry, national particulate and VOC emissions are approxi-
mately 175 metric tons and 165 metric tons, respectively. If
all the plants under construction and half of the plants pro-
posed for construction are in operation by 1985, the * projected
production capacity from the resulting 71 plants would be 5.1 x
106 cubic meters per year (1.4 x 109 gallons per year).
Projected particulate and VOC emission for 1985 are 1,500 metric
tons and 1,130 metric tons, respectively.
3.6.4 EMISSION REGULATIONS
A review of existing NSPS reveals that there are no regulations
which specifically address the emissions from the ethanol-for-
fuel industry. Part C of the Act, prevention of significant
deterioration of air quality, provides EPA a means to regulate
any pollutant from any major emitting facility which may ad-
versely affect the public health and welfare. A major emitting
facility for the ethanol-for-fuel industry would be any source
which releases to the atmosphere or has the potential to release
227 metric tons/year (250 tons/year) or more of any pollutant.
Based on continuous operation this limit can be expressed as
28.6 kg/hr (63.1 Ibs/hr). Reviewing the emission data gathered,
only one test, at plant EOS's dryer, resulted in emissions
greater than 28.6 kg/hr and it is suspect. Otherwise, no data
were available that demonstrate ethanol plants to be major
emitting facilities.
142
-------
o
t*
0)
1-4
,£>
«
H
OO
O
w
H
25
*S
CD
as
g
CO
H
g
CO
w
OS
S
O
M
03
C/3
0
g
w
H
M
O
£
*?
•c
o a
5C
»4
3|
"S
•JG
2 2> •» «
O O CN vo
S 2 S S
0^
o M «« m
o \oo odd
*
gu
*•< o
a w
.38
J*
C0«
O «A
o tno o o o
• • • • • •
O «CCM «H O — t
•H •><
°id a
oi a
«-< a. B IS
« f-*O«J § 0) »4
£ 5 11^
tn
i h
S? 33
•
2 tVo
0)
•* «o
i^ ea^
• *w
5S
•o
B -
aw
e «^
•co oo
3 —
I * "
13 .S-i
> •»!
See3
5° .
•5 B 6
41 W-H
oi eo
—1 B£
O W 4J
M*B O
•
g"O ^
h b
«
f u m
9~»ee
5 ««"
^5*2
U4 0
o ••«
U B
4J «
B • 4J
B fl) ^ to
§ I"*™
*<^ 09 U C
0 Sv4 «
•*< B eo
B < • sT
U 2 O v4
O B
•S 8 «! S
V O (•< Q
4J b 41—1
O bt .u ft,
H *
143
-------
Table 3-41
ESTIMATED PARTICULATE AND VOC EMISSIONS FROM THE
CURRENT AND PROJECTED ETHANOL-FOR-FUEL INDUSTRY
Current . Projected*
Industry Industry
(1981) (1985)
Total Number of Plants 15 71
Ethanol Capacity (M3/Year) 0,62 x 106 5.1 x 106
Particulate Emissions
(Metric Tons/Year) 175 1,500
VOC Emissions (Metric Tons/Year) 165 1,130
-Point Source 99 850
-Fugitive 66 280
*Includes all plants currently in operation and all plants
currently under construction as well as 50 percent of the plants
proposed for construction.
144
-------
However, the ethanol-for-fuels industry should consider limiting
the use of benzene as a dehydration agent in order to avoid
emissions of benzene from the condenser vents of the dehydration
columns and separators. Justifications for limiting the use of
benzene are 1) an alternative dehydration agent that is less
toxic, such as hexane or gasoline, is available and 2) benzene
is listed by EPA as a hazardous air pollutant.
In addition, the Office of Air Quality Planning and Standards
(OAQPS), United States Environmental Protection Agency (EPA) is
presently developing background data for the support of
regulations for volatile organic storage tanks and VOC fugitive
emissions in the synthetic organic chemical manufacturing
industry. NSPS for emissions from volatile organic liquid •
storage tanks would have application to the ethanol-for-fuel
industry's storage facilities. NSPS for VOC fugitive emissions
in the synthetic organic chemical manufacturing industry will
specifically deal with fugitive VOC emissions from the industry.
Although impact of these proposed regulations on the ethanol-
for-fuel industry cannot be quantified until the regulations are
promulgated, the impact may be estimated.* The background
information document (BID) for VOC Emissions from Volatile
Organic Liquid Storage Tanks (EPA, a, 1980) evaluated several
alternative methods to reduce or control VOC emissions.
Alternative III, contact internal floating roof with primary
seals only, was the second most cost effective alternative
evaluated and had the lowest impact on product price, actually
enabling product price to decrease as a result of applying the
alternative. Cost impacts were projected assuming this
alternative will be chosen to promulgate NSPS.
Emissions from ethanol storage facilities are not available,
however; the BID for storage tanks developed equations to
estimate VOC emissions. These equations were used to estimate
both baseline and controlled emissions (EPA, a, 1980). The
*Impacts of these "proposed" air pollution regulations were
estimated in 1980. At the time this document was published in
1986, the status of these regulations was as follows: A)
Standards regulating volatile organic liquid storage vessels
were proposed on July 23, 1984 (49FR 29698). The BID was
updated and is listed in Reference 38. (B) Standards regulating
VOC fugitive emissions were promulgated on October 18, 1983
(48FR 48328). The BID was updated and is listed in Reference
39. For both regulations, the BID alternatives used in the
ethanol-for-fuels cost analyses are not significantly different
from the alternatives found in the updated BIDs. Thus, updated
cost analyses were not performed just prior to publication of
this document.
145
-------
baseline emissions were estimated at 0.48 Mg/year of VOC for an
average plant of 7.1 x 104 m3/year. The controlled
emissions were estimated at 0.16 Mg/year, a reduction in VOC
emissions of 67 percent. The annualized costs of the control
technique per plant is estimated at $86. The annualized costs
for the entire industry in 1985 would be only $7,000 (20).
The BID for VOC Fugitive Emissions in Synthetic Organic Chemi-
cals Manufacturing Industry (21) evaluated several alternatives
to reduce VOC fugitive emissions. Alternative II was the most
cost effective alternative evaluated and also produced the
lowest impact on product price, actually allowing a decrease in
product price. This alternative would require leak detection
and repair methods be implemented. Leak detection is accom-
plished by use of a portable VOC detection instrument. Air near
the potential leak area is sampled and analyzed. If VOC emis-
sions are greater than 10,000 ppm, then equipment repair would
be required. Cost impacts were estimated assuming this alter-
native is chosen as a basis for promulgating NSPS. The esti-
mated VOC fugitive emissions for the industry in 1985 are 280
Mg/year. The total annualized costs without recovery credits
for the industry to control these emissions are estimated to be
$80,000; if recovery credits are included, a net annual savings
of $22,000 would result (20).
There would be no or very little cost impact of these proposed
standards on the ethanol-for-fuel industry. Furthermore, these
proposed standards could actually result in savings to the
industry by preventing the loss of product.
3.7 SOLID WASTES
The Resource Conservation and Recovery Act (RCRA) was passed in
1976xto provide for more uniform solid waste control.. The pur-
pose of RCRA is three-fold: (1) regulation of hazardous waste
management; (2) provide technical and financial assistance for
the safe disposal of wastes; and (3) provide technical and
financial assistance for developing facilities and plans to
recover energy and other resources from discarded materials.
RCRA was designed with the following principal features:
regulation of certain wastes, defined or characterized as
hazardous, are to be the responsibility of the federal
government; and regulation of nonhazardous wastes is to be a
state responsibility, in conformance with federal guidelines.
However, under RCRA Section 3006, states are authorized and
encouraged by EPA to develop and carry out their own hazardous
waste programs in lieu of a federally administered program.
Authorization for state run programs must be granted by EPA and
is being initially administered through an "interim status"
program. "Final authorization" will be possible after Section
3004, Part 264 requirements are promulgated.
146
-------
To determine if industry-specific regulations are needed and
their subsequent impact,- the prevailing factor is whether the
waste is considered hazardous or nonhazardous under the Resource
Conservation and Recovery Act. If one or more of the solid
waste streams generated by ethanol-for-fuel facilities are
considered to be hazardous, the Administrator has the authority
to "list" such streams. When this occurs the generators,
transporters, and disposers of these wastes must comply with all
appropriate Subtitle C regulations of the Resource Conservation
and Recovery Act (RCRA 3000 Series). Wastes which are not
hazardous are subject to Subtitle D regulations (RCRA 4000
Series).
3.7.1 SOLID WASTE SOURCES
Data on solid waste streams from ethanol facilities were
obtained during a sampling and analysis program. Details on site
selection, waste stream selection, parameters analyzed, and test
methods are presented in this section.
It was determined that none of the solid waste streams from
ethanol-for-fuel plants exhibit the characteristics of ignita-
bility, corrosivity, reactivity, or EP toxicity. Thus the solid
waste streams would not be considered hazardous under RCRA.
Since the ethanol production solid wastes are nonhazardous, no
industry-specific- regulations are required. Existing federal
guidelines which pertain to nonhazardous wastes are sufficient
at this time.
The two major solid waste streams at an ethanol-for-fuel plant
are the by-product stream and the biosludge stream that results
from secondary treatment of process wastewater. Since the by-
products have a significant market value they are most often
recovered and sold. Ultimate disposal of the biosludge is
therefore the only factor which will effect total plant
treatment costs.
In order to present a conservative or "worst" case cost
analysis, the cost of gravity thickening, aerobic digestion,
centrifugation, and contract hauling were estimated since these
methods are capital intensive. The production of biosludge is a
direct result of wastewater treatment and therefore, the costs
associated with biosludge treatment and disposal are included in
Section 6 under the cost of direct discharge wastewater treat-
ment options. In addition, the economic impact and cost/benefit
aspects of biosludge treatment and disposal or management are
discussed in the wastewater treatment section of this document.
In order to evaluate the impact of solid waste regulations on
the ethanol-for-fuel industry, an assessment was made of the
solid waste streams generated by the ethanol production process,
air emission controls, and wastewater treatment. Solid wastes
147
-------
from ancillary processes such as steam generation are beyond the
scope of this document.
Figure 3-3 presents a generic diagram of an ethanol production
process. One solid waste stream from an ethanol-for-fuel facil-
ity is grain dust collected from particulate controls (e.gef
cyclones) associated with grain milling and by-product drying.
In most cases, particulates collected in grain milling are sent
to the cooker and particulates from by-product drying are recy-
cled to the dryer. Therefore, these wastes are not considered
further in this analysis. Other solid waste streams are
stillage from the beer still, if not processed into by-products,
and the processed by-products, if they cannot be sold.
Figure 3-4 presents a diagram of the solid waste streams from
process wastewater treatment. The solid waste streams are the
treated wastewater if it is land applied and biosludge from
secondary wastewater treatment which may be land applied, land-
filled or hauled away by a contractor.
All of the waste streams identified above are actually potential
waste streams. It is possible, although not probable, that an
ethanol-for-fuel facility might produce no solid wastes. This
would occur if the grain dust were recycled, the beer stillage
was either sold wet or processed into by-products which were
then sold, and the process wastewater was indirectly discharged
to a publicly owned treatment works (POTW). However, an actual
facility will most likely have at least one solid waste stream.
3.7.2 EVALUATION OF SOLID WASTE STREAMS
In 1980, the EPA conducted a test program to characterize the
solid wastes and potential solid wastes from ethanol-for-fuel
facilities. At the inception of. this test program, there were
five ethanol plants producing ethanol-for-fuel; all five plants
were considered for solid waste sampling. To increase the data
base, several beverage alcohol plants were also considered for
testing, as this industry was determined from an engineering
standpoint to be analogous to the ethanol-for-fuel industry in
terms of the characteristics and volume of solid wastes gen-
erated. Three ethanol-for-fuel and two beverage alcohol
facilities were chosen for sampling in order to include
processes which use different feedstocks and produce various
by-products.
A presampling visit was made to each candidate ethanol facility
to assess the operation of the plant and the accessibility of
the solid waste streams. The final selection of the sample
points and sample type based on the site visits is summarized in
Table 3-42 and discussed further below. A description of the
techniques used to collect the solid samples is provided in
Appendix A.
148
-------
e
o
S r
52
SI
.ol lee ted
w
r
„
u
L
e
0
•
1
b
w
^
j
a
u
J
|
a
1
i
15
0
a
•o
91
i
Jt
U
2
•3
91
09
k
k
1
S
(Sacclmr
L
§
S
1
a.
k
i
A
L
i
<
i
i
(
:
t
t
<
*
i
«*
4
*
i
1
1
1
V
1
4i
1
J
1
!
^
u
:
3
j
?
k
rt
i
K
a
k
»
L u
< 91
1 IW
|H
i
1
^
t
:
i
7
1
a
91
hi
U
en
|
4
1
k
I
||
•« M
•* U
1 '
i
s s
2 a
I "I
1
*
2 •
1 1
V ft*
» *•
i
a
•w
»4
e
09 , a
J
1
|i
£!
i
i
i
PROCESSING
g
t
149
-------
•g
ca
i-l
a.
§
•rl
4J
a
u
u
60
•a
o
•H
«
sis
o Irt
CO
150
-------
§refyTFVhhiSi 6tha"01 ?lant r°UteS a11 solid waste* associ-
ated with ethanol production to a centralized feed house where
thS e?hfnSl ?l??iri ?r°CeSSe; KrS handled' The solid waste from
the ethanol facility cannot be sampled separately; thus, no
solid waste sampling was proposed for this facility.
Plant A03. In 1979, this plant was sampled for air, water and
solid wastes in a program conducted by EPA/IERL-Ci. Solid waste
samples of by-product grains and biological sludge were collect-
™°r-me*ai analyses (which hac3 not blen addressed in the
— LI study) .
N° S°*id, WaStSS were samPled from this facility as
^ were similar to those collected from plants A03 and
0?' The solid wastes from this plant are routed to a
plant and were not selected for sampling.
Plant Alp. solid waste streams chosen included by-product con-
densed cheese whey solubles (CWS) and core samples of land that
had been subjected to spray irrigation with treated effluent?
Plant E02. The types of solid samples that were proposed for
?h^ ™.10H ^ fc?X; fa;nity were the by-products produced and
the wasted biosludge from the bottom of the sludge thickener
JnH ^'Product samples included the beer still bottom stillage
and the condensed molasses solubles.
f^fh33?!!' /eedstoc:k 9rain a"d the by-product DDGs were sampled
from bulk storage piles.: Also, a sample of sludge was collected
from the bottom of the wastewater treatment aera?Jd iSgoon.
Tl?6re are tw° solid waste streams from this plant:
f
wJJf r?o grain and brProduct Stains. Both of these stams
were chosen for sampling and analysis.
?~ addltu°n t0 the streams listed in Table 3-42, samples of the
feedstocks were collected to determine if the raw materials used
bfdetecteTin6,^ tO"iC P°llutants or contaminants^? mighf
oe detected in the waste streams.
3.7.3 RCRA RELATED ANALYTICAL PARAMETERS AND TEST METHODS
According to the criteria outlined in RCRA, a solid waste can be
^n???-^ hazardous.if it exhibits any of the characteristics
identified as corrosivity, ignitability, reactivity, and extrac-
tion procedure (EP) toxicity. At the inception of the solid
waste test program (April 1980), a comparison was made of the
solid waste from ethanol plants and the proposed methods of
determining corrosivity, ignitability, and reactivity. Based on
this comparison, it was ascertained that ethanol-for-f uel solid
151
-------
Table 3-42
FACILITIES AND SOLID WASTE STREAMS TESTED
Facility
A03
A10
E02
EOS
E09
Solid Waste Stream Tested
Biosludge
Distillers Dried Grains
Condensed Whey Solubles
Core Samples
Beer Still Bottom Stillage
Condensed Molasses Solubles
Biosludge
Biosludge
Distillers Dried Grains
Distillers Dried Grains
152
-------
wastes would not be considered hazardous using these criteria.
Therefore, EP toxicity was the only hazardous- property evaluated
further in this study.
To determine if a solid waste exhibits the characteristic of EP
toxicity, RCRA requires that the wastes be extracted with
(1) acetic acid and (2) distilled water and that these extracts
(or leachate samples) be analyzed for compounds listed as toxic
contaminants. Table 3-43 presents a list of the toxic pollu-
tants which must be analyzed to determine EP-toxicityf as well
as their detection limits and maximum allowable concentrations.
According to the 19 May 1980 issue of the Federal Register
(Volume 45, Number 98, page 33122) (22), a waste can be con-
sidered to exhibit the characteristic of EP toxicity if the
extract from the waste contains any of the contaminants listed
in Table 3-43 at a concentration equal to or greater than the
respective value given in that table.
The results of the test program for RCRA related solid wastes
are presented in Table 3-44. Of the 14 compounds listed in
Table 3-43, only two were found at levels above their detection
limits: barium and chromium. Barium levels ranged from 25 to
1,300 ppb and chromium varied from 1 to 35 ppb. These levels
are well below those designated as rendering a'waste hazardous.
Therefore, the solid wastes from ethanol-for-fuel facilities
examined in this document are classified as nonhazardous
according to EP toxicity criteria.
In addition to leachate analysis, the'solid waste samples were
also analyzed to determine if the solid wastes, rather than
contamination, were the source of any toxic pollutant found in
the leachate analyses. The results from the solid digestion
analyses are presented in Appendix D. Since no toxic pollutants
were detected above the maximum allowable concentrations in the
leachate analyses, no further analysis of the solid digestion
data is required at this time.
Other analytical parameters which were evaluated are presented
in Table 3-45. The analytical methods used for all the
parameters identified are discussed in Appendix B. The results
for the leachate analysis and the solid digestion analyses are
•presented in Appendix D. The Agency has determined that none of
these other pollutants were present at levels which are
considered to be hazardous at this time.
All of the RCRA related parameters (Table 3-43) as well as the
other parameters (Table 3-45) were tested for on samples of the
ethanol plant feedstocks. The results of the leachate analysis
and the solid digestion analyses are presented in Appendix D.
None of the pollutants were detected at levels which are
considered to be hazardous at this time.
153
-------
Table 3-43
POLLUTANT PARAMETERS ANALYZED TO DETERMINE
RCRA EP-TOXICITY
Toxic Metals
Arsenic
Barium
Cadmium
Chromium
Lead
%
Mercury
Selenium
Silver
Pesticides
2-4 D
2,4,5 TP Silvex
BHC (Lindane)-Gamma
Endrin
Methoxychlor
Toxaphene
Detection Limit (ppb)
Max imum
Allowable
Concentration
(ppb)l
^Source:
p. 33122 (22).
2
1
42
5
2
0.2
2
10
\
0.8
0.3
0.2
2
2
100
Federal Register, Volume 45,
5,000
100,000
1,000
5,000
5,000
200
1,000
5,000
10,000
1,000
400
. 20
10,000
500
Number 9
154
-------
rr
1
m
l)
S
H
l»
^C
n
D
CO
CO
1
I*
. -s( 00
aojal « t ^| *cf ^* in "•* •<
ab.S1 O o S
c ol i ! S 5- ' i
\jjrf.s3 o o rf ^ S
f» CM CO 01 <
<^ OJ |H
S _
.J £
M a-4 U
HsS
3 a u-3
z a a
ene
£ j
3
eg n rt f-i m *4 p-t m ut
!?!,«,
sJ s
A§
(4 C9-4 4J
"S'aSJ
Zw^
O r- O O -• -1
i£
i-! a
oci
H
c>j tn K « m m
1 Botton Stillage
•ri
1*4
CO
u
01
aa
09
e
•§
f-4
a
o
-4
a
i
0)
14
a u
4) CO
«M
1
3
so
s
o
u
1 Bottom Stillage
s Dried Grains
i*4 4)
CO r*
(4 M
a a
a
«-i
X
i
"8
a
e
9)
C
3
Molasses Soluble,
"S
a
e
9)
•a
e
3
so
"§
a
O
pa
a
9)
t~<
a.
8
a
en
u
3
155
-------
Table 3-45
ANALYTICAL PARAMETERS ANALYZED FOR SOLID WASTE TESTING
Metals
Aluminum
Beryllium
Bismuth
Boron
Calcium
Cobalt
Copper
Gold
Indium
Iron
Lithium
Magnesium
Manganese
Molybdenum
Detection
Limit (ppb)
50
2
250
45
40
30
5
48
280
8
2
500
6
10
Metals
Nickel
Phosphorus
Platinum
Potassium
Silicon
Sodium
Strontium
Tellurium
Tin
Titanium
Uranium
Vanadium
Wolfram
Yttrium
Zinc
Detection
Limit (ppb)
15
180
600 .
40
16
11
2
520
600
25
320
15
90
9
15
Anions*
Chloride
Nitrate
Sulfate
Total Organic Carbon
Detection Limit (ppb)
600
1,000
*Distilled water leachate samples were not analyzed for anions,
156
-------
SECTION 4
WASTEWATER TREATMENT AND CONTROL TECHNOLOGY
4.1 BACKGROUND
Applicable technologies effective in reducing or eliminating
pollutants present in wastewater from ethanol-for-fuel plants
include in-plant source control methods for wastewater reduc-
tion, such as plant management practices and production process
modifications; preliminary, primary, secondary, and tertiary
wastewater treatment technologies; disinfection and sludge
handling. The pollutant parameters of concern are 8005, TSS,
and pH as discussed in Section 3.5.
The quantity and characteristics of untreated effluent generated
by beverage alcohol.facilities are not significantly different
from that generated by ethanol-for-fuel facilities. This is
strong evidence that the control and treatment technologies used
by beverage alcohol plants are not only applicable to ethanol-
for-fuel. facilities, but should also result in similar perform-
ance and reduction of pollutant parameters. Hence, treatability
data from both industries are presented in this section.
A survey of the ethanol-for-fuel industry in 1981, which in-
cludes data on 15 facilities, reveals that 12 facilities (80
percent) were indirect dischargers (or facilities discharging
into publicly owned treatment works). This high percentage is
attributed to the fact that most existing ethanol-for-fuel
facilities are small; two-thirds of existing ethanol-for-fuel
plants have capacities less than three million gallons of
ethanol per year. Combining these data with the available data
from 16 beverage alcohol plants, the indirect dischargers then
comprise about 50 percent of the industry. All of the beverage
alcohol plants considered have capacities larger than three
million gallons of ethanol per year. In addition to size, plant
location also influences whether a particular facility is a
direct or indirect discharger. In 1981 there were three large
facilities, with capacities greater than 15 million gallons per
year, located in urban areas which were also indirect dis-
chargers.
In regard to level of technology practiced, all beverage alcohol
and ethanol-for-fuel plants which were direct dischargers use
secondary biological treatment systems. Many of these treatment
systems also incorporated some form of preliminary treatment
157
-------
(e.g., neutralization, bar screening) and/or primary treatment
e.g. coarse screens, primary sedimentation). In addition, 60
percent of the indirect dischargers from the ethanol-for-f uel
industry (44 percent of the indirect dischargers from both
ethanol industries) use secondary biological treatment before
discharging their effluent to a municipal treatment plant.
The most common methods of secondary treatment in use at ethanol
plants were aerated lagoons, stabilization or °5ldajlon P°£d^'
activated sludge systems, trickling filters, and rotating bio-
logical contactors (in that order). Data were1availa^d°" the
trlatability of BOD5 and TSS from 12 ethanol Pja^ secondary
treatment systems; these data are summarized in Table 4 1. As
this table shows, BODs reduction varies from 87. b to ye./
percent and TSS reduction varies from 25.2 to 96.3 percent. The
low TSS Deduction associated with plant E18 is due to a problem
with algal growth in the stabilization pond.
No tertiary treatment was in use at ethanol-for-f uel
however, one beverage alcohol plant had a polishing pond and
another used an air flotation unit. No data was available which
quantifies treatability of BOD5 or TSS from these tertiary
methods of treatment when used on ethanol plant wastewaters.
Finally, all plants which combine their domestic wastes with
process wastes (25 percent of the plants surveyed) use
chlorination for disinfection. The ef fectiveness of dis-
infection by chlorination for bacteria (e.g., fecal col i form) is
nearly 100 percent if proper dosage rates and sufficient contact
times are used.
4.2 IN-PLANT SOURCE CONTROL FOR WASTEWATER REDUCTION
The generation of wastewater from facilities that
ethaLl via fermentation can vary from as much as f-5 gallons of
wastewater per gallon of ethanol for plant A06 to 33.7 gallons
of wastewater per gallon of ethanol for plant E09 (see Table
6-sT? The widfrange in these ratios is a result of the former
plant's efforts to minimize wastewater generation by improved
plant management practices and production process changes.
These practices can only be effective in con3 unction with
increased management awareness of the importance of in-plant
control.
4.2.1 PLANT MANAGEMENT PRACTICES
The primary plant management practices for wastewater reduction
inllude proper spill disposal, washwater control, and water con-
servation.
158
-------
Table 4-1
BODs AND TSS REDUCTION ACHIEVED BY ETHANOL PLANT
WASTEWATER TREATMENT SYSTEMS
Plant
Code
A03
E02
EOS
E06
E07
EOS
E12
E13
E15
E17
E18
E21
Wastewater Percent BODs
Treatment System Reduction
Activated Sludge
Aerated Lagoon with
Stabilization Pond
Aerated Lagoon with
Stabilization Pond
Activated Sludge with
Stabilization Pond
Aerated Lagoon with
Rotating Biological
Contactor
Aerated Lagoon with
Rotating Biological
Contactor
Trickling Filter with
Stabilization Pond
i
Aerated Lagoon with
Stabilization Pond
Aerated Lagoon with
Stabilization Pond
Aerated Lagoon with
Trickling Filter
Aerated Lagoon with
Stabilization Pond
Activated Sludge
Averaae of Treatment
98.7
87.6
96.5
91.9
93.3
97.0
96.4
94.5
98.3
97.2
98.2
98.6
95.7
Percent TSS
Reduction
95.0
55.6
77.5
82.9
73.8
73.0
92.9
82.5
84.4
76.1
25.2
96.3
80.7*
Systems' Performance
*Average does not include value for plant E18,
159
-------
Spill Disposal
Spills from ethanol-for-fuel facilities may result from tank
overflows, the loss of heating or cooling in the distillation
columns, pumping equipment malfunctions, or operator error. The
containment and disposal of these spills can be facilitated by
the use of a process centralized sump or a spill lagoon*
Plant A01 has a centrally located sump in its distillation
building. The spill disposal system has been designed such
that, depending on the liquid in the sump, the spill can be
recycled to the distillation columns for ethanol recovery or
pumped to the wastewater treatment facility.
Spill lagoons, such as the ones maintained by plant E02 and E15,
function in a similar fashion, but they are larger and not
designed to recycle the spilled liquid back to the ethanol pro-
duction process. The spill lagoon liquid is gradually added to
the wastewater treatment system to prevent upsets in the second-
ary biological treatment operation which may result from a fluc-
tuating wastewater strength.
Washwater Control
The quantity of washwater generated at an ethanol-for-fuel
facility is less than that produced by beverage alcohol plants
because of the lower purity requirements of the former industry.
However, certain'washes, such as those for the fermenters, are
still required to avoid bacterial contamination. Common
in-plant controls which may be employed to reduce waste
generation include:
1. Install central cleanup systems such as clean-in-place
(CIP) units (valved or triggered hoses). These systems generate
a controlled-pressure supply of hot or warm water containing a
detergent and reportedly clean better with less water (ESE,
1974). Plants E09 and ElO use CIP units to clean the fermenters
and feedstock delivery trucks, respectively.
2. Eliminate practices of unnecessary washwater use.
Many plants operate water valves wide open, regardless of actual
need. The installation of ball valves in water lines after globe
valves reduces water usage since the ball valve functions as a
volume adjustment and the globe valve as an on/off controller.
Water Conservation
Techniques that are available for wastewater reduction by water
conservation include:
1. Install automatic shutoff valves. Water hoses equip-
ped with these valves can save up to 60 gallons per minute when
employees forget to shut off hoses (14).
160
-------
2. Install low-volume, high-pressure systems on all water
sprays which cannot be eliminated.
3. Recirculate water for reuse in feedstock preparation
(e.g., washing, mashing) or, if applicable, extractive distil-
lation.
4. Parallel product purity with water purity by introduc-
ing the fresh water in the latter stages of production and then
reusing it in earlier stages of the process. This technique
reduces the input of fresh water.
5. Recycle of noncontact waters from mash cooling and the
distillation column condenser, and any noncontact streams of
suitable quality for other in-plant uses.
4.2.2 BEST MANAGEMENT PRACTICES
Plant management practices can be required in NPDES permits as
Best Management Practices (BMPs). BMPs are broad and may
include processes, procedures, human actions, or construction
requirements. Pursuant to Sections 304 and 402 of the Clean
Water Act, BMPs may be incorporated into permit conditions
supplemental to numerical effluent llimits.
BMPs in NPDES Permits
BMPs are placed in permits in two basic ways: BMP plans and
site- or pollution-specific BMPs. Site-specific BMPs may be
imposed as specific conditions of the BMP plan or as independent
provisions of the permit. BMP plans are usually kept on-site
and made available to the permitting authority on request. The
normal compliance schedule is to require preparation of the plan
within six months, and implementation within twelve months, of
permit issuance. Nine specific requirements have been
identified as a basis for developing BMP plans in the NPDES
program. Site-specific or pollutant-specific BMPs are left to
the discretion of the permit writer and are highly dependent
upon a careful review of the circumstances at a particular
facility. The minimum requirements of a BMP plan are presented
below.
Minimum Requirements of a BMP Plan
1. General Requirements
o Name and location of facility
o Statement of BMP policy and objective
o Review by plant manager
161
-------
2. Specific Requirements
o BMP committee
o Risk identification and asssessment
o Reporting of BMP incidents
o Materials compatibility
o Good housekeeping
o Preventive maintenance
o Inspections and records
o Security
o Employee training.
BMP Committee
The BMP committee is that group of individuals within the plant
organization which is responsible for developing the BMP plan
and assisting the plant management in its implementation,
maintenance, and updating. Thus, the committee's functions are
similar to those of a plant fire prevention or safety committee.
Plant management, not the committee, has overall responsibility
and accountability for the quality of the BMP plan.
The scope of activities and responsibilities of the BMP
committee should include all aspects of the facility's BMP plan,
such as identification of toxic and hazardous materials
addressed in the plan; identification of potential spill
sources; BMP inspections and records procedures, review of
environmental incidents to determine and implement necessary
changes to the BMP plan; coordination of incident notification,
response, and clean-up procedures; establishment of BMP training
programs for plant personnel; and aiding interdepartmental
coordination in carrying out the BMP plan.
Risk Identification and Assessment
The areas of the plant subject to BMP requirements should be
identified by the BMP committee, plant engineering group,
environmental engineer, or others in the plant. Each such area
should be examined for the potential risks of discharges to
receiving waters of toxic pollutants or hazardous substances
from ancillary sources. Any existing physical means (dikes,
diversion ditches, etc.) of controlling such discharges also
should be identified.
A hazardous substances and toxic chemicals inventory (materials
inventory) should be developed as part of the risk
identification and assessment. The details of the materials
inventory should be proportionate to the quantity of toxic
pollutants and hazardous substances on site and their potential
for reaching the receiving waters.
162
-------
Reporting of BMP Incidents
A BMP incident reporting system is used to keep records of
incidents such as spills, leaks, runoff, and other improper
discharges for the purpose of minimizing recurrence, expediting
mitigation or cleanup activities, and complying with legal
requirements. Reporting procedures defined by the BMP committee
should include: notification of a discharge to appropriate
plant personnel to begin immediate action; formal written
reports for review and evaluation by management of the BMP
incident and revisions to the BMP plan; and notification, as
required by law, of government and environmental agencies.
Materials Compatibility
Materials compatibility includes the consideration of:
compatibility of the chemicals being stored with the container
materials; compatibility of different chemicals upon mixing in a
container; and compatibility of the container with its
environment. The BMP plan should provide procedures to address
these three aspects in the design and operation of the equipment
used for the storage or transfer of toxic and hazardous
materials.
Incompatible materials can cause equipment failure resulting
from currosion, fire, or explosion. Equipment failure can be
prevented by ensuring that the hazardous substances or toxic
pollutants are compatible with the container contents and the
surrounding environment.
Good Housekeeping
Good housekeeping is the maintenance of a clean, orderly work
environment and contributes to the overall facility pollution
control effort. Periodic training of employees in housekeeping
techniques for those plant areas where the potential exists for
BMP incidents reduces the possibility of mishandling of
chemicals or equipment.
Examples of good housekeeping include neat and orderly storaage
of bags, drums, and piles of chemicals; prompt cleanup of
spilled liquids to prevent significant runoff to surface waters;
sweeping, vacuuming, or other cleanup of accumulations of dry
chemicals as necessary to prevent them from reaching receiving
waters; and provision for storage of containers or drums to keep
them from protruding into open walkways or pathways.
Preventive Maintenance
An effective preventive maintenance (PM) program is important to
prevent environmental incidents. A PM program involves
inspection and testing of plant equipment and systems to uncover
163
-------
conditions that could cause breakdowns or failures, with
resultant significant discharges of chemicals to surface waters.
The program should prevent breakdowns and failures by adjust-
ment, repair, or replacement of items.
A PM program should include a suitable records system for
scheduling tests and inspections, recording test results, and
facilitating corrective action. Most plants have PM programs
that provide a degree of environmental protection. A BMP plan
should not require the development of a redundant PM program.
Instead, the plan should reinforce the objective to have
qualified plant personnel (e.g., BMP committee, maintenance
foreman, or environmental engineer) evaluate the existing plant
PM program and recommend to management those changes, if any,
needed to address BMP requirements.
A good PM program includes identification of equipment or
systems to which the PM program should apply; periodic
inspections or tests of identified equipment and systems;
appropriate adjustment, repair, or replacement of items; and
maintenance of complete PM records on the applicable equipment
and systems.
Inspections and Records
An inspection and records system detects and documents actual or
potential BMP incidents. The BMP plan should include written
inspection procedures and optimum intervals between inspections.
Records to show the completion date and results of each
inspection should be signed by the appropriate supervisor and
maintained for a period of three years. A tracking or follow-up
procedure should be instituted to ensure that adequate response
and corrective action have been taken. The record keeping
portion of this system can be combined with the existing spill
reporting system in the plant.
The inspection and records system should include those equipment
and plant areas having the potential for significant discharges.
To determine the inspection frequency and inspection procedures,
experienced personnel should evaluate the causes of previous
incidents, the likelihood of future incidents, and assess the
probable risks for incident occurrence or recurrence. Con-
sideration should be given to the nature of chemicals handled,
materisls of construction, and site-specific factors including
age, inspection techniques, and cost effectiveness of BMPs
employed.
Security
A security system prevents accidental or intentional entry to a
plant which might result in vandalism, theft, sabotage, or other
improper or illegal use of plant facilities that possibly could
164
-------
cause a BMP incident. Most plants have security systems to
prevent unauthorized entry.
The BMP plan should describe those portions of the existing
security system and any improvements that are necessary to
ensure toxic chemicals are not discharged to receiving waters in
significant quantities as a result of unauthorized entry. Doc-
umentation of the security system may require separate filing
from the BMP plan to prevent unauthorized individuals from
gaining access to sensitive or confidential information.
Employee Training
Employee training programs should install in personnel, at all
levels of responsibility, a complete understanding of the BMP
plan. Training should address the processes and materials on
the plant site, the safety hazards, the practices for
preventing discharges, and the procedures for responding
properly and rapidly to toxic and hazardous materials incidents.
Meetings should be conducted at least annually to assure
adequate understanding of the objectives of the BMP plan and the
individual responsiblities of each employee. Typically, these
could be a part of routine employee meetings for safety or fire
protection. Such meetings should highlight previous spill
events or failures, malfunctioning equipment, and new or
modified BMPs.
Training sessions should review the BMP plan and associated
procedures. Just as fire drills are used to improve an
employee's reaction to a; fire emergency, spill or environmental
incident drills may serve to improve the employee's reactions to
BMP-related incidents. Plants are encouraged to conduct spill
drills on a quarterly or semi-annual basis. Spill or incident
drills serve to evaluate the employee's knowledge of BMP-related
procedures and are a fundamental part of employee training.
Site-Specific or Pollutant-Specific BMPs
Site-specific and pollutant-specific BMPs are those designed to
address conditions peculiar to a facility or pollutant. The
need for specific BMPs at a facility often will be discovered in
conjunction with other permit-related activities, such as
compliance inspections. Poor housekeeping or a history of
spills, for example, indicate a need for site-specific BMPs to
supplement the quantitative effluent limits on specific
pollutants in the permit. These "situation-specific" BMPs may
be conventional, such as secondary containment around a storage
tank, or innovative, such as siting containers so that a spill
caused by a careless forklift operator will not flow into the
river. Other examples of site-specific BMPs are contained in
recent NPDES permits.
165
-------
4.2.3 PRODUCTION PROCESS MODIFICATIONS
A wide range of values for the quantity of wastewater generated
per gallon of ethanol produced is not only linked to plant
management practices, but also to equipment selection. The
following process changes can be implemented to reduce
wastewater generation:
1. The addition of instrumentation for the automatic con-
trol of evaporator operation at optimum levels of liquid/solid
separation. Evaporator performance below the optimum operating
conditions can increase entrainment by stillage flashing upon
entering the evaporator or foaming. Entrained solids signifi-
cantly increase the BOD and TSS of the evaporator condensate
sent to wastewater treatment.
2. The replacement of barometric condenser systems used
in mash cookers, mash coolers, and evaporators with surface
(noncontact) condensers. The cooling water added to the
condensate increases the hydraulic load requirements of the
wastewater treatment system. The barometric condensate can
amount to as much as 28 percent of the total BOD load (14).
3. The use of reboilers rather than live steam for
heating the distillation columns can reduce wastewaters from the
column bottoms by 20 to 30 percent (14).
4. The removal of the purifying columns from beverage
plants planning to convert to ethanol-for-fuel production
indirectly reduces wastewatergenerated by lowering steam and
cooling requirements.
4.3 PRELIMINARY TREATMENT TECHNOLOGIES
In order to allow downstream operations to perform effectively,
the influent to the wastewater treatment system is often
subjected to preliminary treatment such as bar screening,
comminuting, equalization, and neutralization. The use of bar
screens and communitors protects pumps and other equipment
downstream from damage by large solids. An equalization basin
provides the necessary flow rate control, while a neutralization
system provides pH control. Biological treatment tolerates only
a small pH range; thus, control of the influent stream is
required to prevent pH shock.
4.3.1 BAR SCREENING
Screening, as a method for removing large suspended particles,
is commonly used in wastewater treatment plants. The ethanol-
for-fuel plants using screening are A01, A03, and A07. Bar
screens or bar racks are considered to be a preliminary treat-
166
-------
ment option and can be used to protect plant equipment against
large solids which can cause physical damage. A bar screen is
made of vertical steel bars spaced at equal intervals across a
channel through which the wastewater flows. Openings between
the bars range from 50 to 150 mm (two to six inches), thus
preventing large, heavy objects from entering the treatment
plant and damaging pumps or other downstream equipment (23).
The screen is automatically cleaned by a traveling rake. Bar
screens are used ahead of raw wastewater pumps, flow meters,
grit chambers, and primary sedimentation tanks.
4.3.2 COMMINUTORS
Comminutors are cutting devices that cut influent waste
materials to six to nineteen mm in length (0.25 to 0.75 inch)
without removing material from the flow (23). They serve the
same basic function as bar screens by reducing the size of
solids entering the treatment plant. These devices are
currently being used by several beverage alcohol plants.
4.3.3 GRIT REMOVAL
Wastewater grit materials are characterized as nonbiodegradable,
having a subsiding velocity substantially greater than that of
organic biodegradable solids, and they are generally discrete
rather than flocculent in nature. Materials falling into these
categories are particles of sand, gravel, and other minute
pieces of mineral matter. Grit is removed from a wastewater
system to protect moving mechanical equipment from abrasion and
abnormal wear; reduce conduit clogging; and prevent loading of
treatment works with inert matter that may interfere with the
operation (e.g., siltation of anaerobic digestors or aeration
tanks). Grit removal devices are currently classified as either
horizontal flow or aerated.
The quantities of grit removed via mechanical cleaning in a
horizontal flow device or in the hoppers of an aeration device
can vary greatly. Values separated range from 3.1 m3 per
million liters to 225 m3 per million liters for municipal
treatment systems. Aeration tank grit removal devices can
achieve, with proper adjustment, greater than 99 percent grit
removal.
The choice of grit removal method is usually determined from
factors such as head loss requirements, space requirements,
types of equipment used elsewhere in the plant, and the costs of
each of the three alternatives. Aerated grit removal offers the
advantages of minimal head loss through the grit chamber, low
biodegradable solids removal, and simultaneous grease removal by
surface skimming. In addition, the wastewater may undergo some
BOD5 reduction because of the contact with air. Aerated grit
167
-------
chambers can also be used for chemical addition prior to
settling (23).
The grit that is stored in hoppers is usually disposed of by
truck hauling to a landfill for large installations. For
individual wastewater treatment systems encountered at ethanol
plants, the amount of this material which would be collected is
relatively small compared to other solid waste streams. Only
one plant, EOS, was reported to use grit removal as part of a
primary treatment scenario.
4.3.4 EQUALIZATION ' '
A common problem in ethanol-for-fuel wastewater treatment plants
is rapidly changing influent wastewater flow rate and BODs
concentration. A decrease in flow rate can reduce settler
overflow rates while an increase in flow rate can decrease
solids removal efficiency. Changes in influent wastewater
concentration can result in process overloadings and ultimately
bring about decreases in effluent quality. Equalization acts
to control fluctuation in both flow rate and concentration.
An equalization basin is simply a basin to which the influent
wastewater is pumped at varying flow rates; wastewater is simul-
taneously pumped out of the equalization basin at a constant (or
near constant) flow rate and fed to the downstream treatment
units. Wastewater in the equalization basin is mixed, either by
mechanical mixing or by air sparging. The mixing results in
less variation in the BODs concentration of the wastewater
pumped from the equalization basin and prevents solids from
settling and accumulating on the bottom of the basin.
Typical schematic flow diagrams of equalization basins are shown
in Figure 4-1. As illustrated by the figure, there are basi-
cally two different equalization flow schemes: in-line equali-
zation and side-line equalization (24). In-line equalization
has been found to provide the greatest flow rate and concen-
tration damping, as well as minimizing the effects of, toxic
shock loads and providing some pH stabilization. In-line
equalization is practiced at ethanol-for-fuel plant A01 as well .
as beverage alcohol plants E04 and E21. Thus, in-line
equalization is recommended when biological treatment is being
used (24).
4.3.5 NEUTRALIZATION
In a study of the beverage alcohol industry. Environmental
Science Engineering found that the pH of the combined process
effluent may vary from a value of four to eleven over a 24-hour
period (13). Also, the data presented in Section 3 of this
document reveal a pH fluctuation of three to 13 for raw
wastewaters from this industry. Generally, Publicly Owned
168
-------
Stw
U4
s
«CJ<
a)
M
d
bO
i
j
fe
u
M
H
W
U
CO
cs
(U
o
o
03
169
-------
Treatment Works (POTWs) require any wastewater being discharged
into their system to have a pH between 6.0 and 9.0. The optimum
pH for biological wastewater treatment is in the range of 6.5 to
8.5 (25). Thus, the effluent from ethanol-for-fuel plants will
require pH control whether the wastewater is discharged to a
POTW or to an on-site biological treatment system.
The conventional name for pH adjustment in wastewater treatment
applications is neutralization. In the ethanol-for-fuel and
beverage alcohol industries, a common practice is to combine
alkaline washwaters with acidic process wastewater. Plants A01,
A03, and A07 use this method of neutralization. Occasionally,
further neutralization consisting-of acid or base addition is
required when sufficient quantities of alkaline or acidic
wastewater are not available. •
A variety of alkaline substances can be used. Lime is usually
the least expensive alkali source, although both sodium
hydroxide (NaOH) and sodium carbonate (Na2CO3) have been
used. Pebble quicklime, which is simply high calcium quicklime
in pebble form, is easier to handle and creates fewer dust
problems than other forms of lime (24). Quicklime is fed into a
lime slaking tank, where the solid quicklime (CaO) is reacted
with water to form a calcium hydrate (Ca(OH)2) slurry. The
lime slurry is then pumped into a holding tank, where it is
mixed to maintain the lime in suspension and is fed by a
metering pump into the neutralization reaction tank.
In general, either sulfuric acid or hydrochloric acid is used as
an acid for neutralization. Both acids are handled as liquids
from delivery to application. The acid is stored on-site in a
storage tank and pumped to the neutralization reaction tank.
A neutralization reaction tank is used to provide for proper
mixing and contact time for the complete neutralization of the
wastewater. Wastewater enters the tank, mixes with the acid or
base reagent, and exits after adequate reaction time has been
provided. Depending on the pH of the raw influent wastewater,
the tank may be constructed of a variety of corrosion resistant
materials (e.g., stainless steel or concrete).
An integral part of any neutralization system is the control
system which usually consists of one or more continuous pH
probes which are connected to a microprocessor or other
controller. Based on the signal received from the pH probes,
either base or acid is added to the wastewater. If pH
fluctuations are not too rapid, a manually operated control
system may suffice. However, systems which use automatic
control have been found to be more reliable than manually
controlled systems.
170
-------
4.4 PRIMARY TREATMENT TECHNOLOGIES
The removal of suspended- solids by physical means (e.g.,
settling or flotation) is usually considered to be primary
treatment technology. Currently, the most widely used primary
treatment operations in the ethanol industry are coarse screen-
ing and sedimentation. The reduction of solids in primary
treatment reduces the oxygen requirements of downstream bio-
logical units and reduces the solids loading to the secondary
sedimentation tank.
Untreated effluent from ethanol-for-fuel facilities had a median
total suspended solids (TSS) concentration of 380 miligrams per
liter (mg/1) with a maximum concentration of 2,680 mg/1. Typi-
cal raw domestic sewage has TSS concentrations in the range of
100 to 350 mg/1 (26). Thus, wastewaters from ethanol-for-fuel
facilities may have concentrations of suspended solids many
times higher than domestic sewage. If discharged to a POTW,
these solids could result in overloading of the POTWs primary
sedimentation tanks depending on the ratio of ethanol-for-fuel
wastewater flow to domestic sewage flow. Such high suspended
solids concentrations can bring about problems in secondary
treatment systems. If the solids are biodegradable, the
secondary treatment system (e.g., activated sludge system,
aerated lagoon) might be overloaded.
4.4.1 COARSE SCREENING
As a method of primary treatment, coarse screening may be used
to prepare,,,wastewater high in suspended solids for either dis-
charge to a POTW or discharge to further on-site treatment such
as an activated sludge system or an aerated lagoon. The sus-
pended solids present in wastewaters from ethanol-for-fuel
facilities are, for the most part, readily biodegradable.
Removal of suspended solids in a preliminary treatment step may
offer a significant cost savings for plants with complete
on-site wastewater treatment systems. This cost savings is
possible because removal of biodegradable solids in primary
treatment can result in a reduction in the aeration basin volume
and air supply capacity of the secondary treatment system.
Coarse screens are used in the beverage alcohol industry and
are used in ethanol-for-fuel plant A03. -
Coarse woven-wire media screens'are used after bar screens to
remove material prior to introducing wastewater to biological
filters or gravity sand filters. Screens of this type were
developed in the mid-1960's for use in dewatering pulp slurries
in the pulp and paper industry (27). They have also been
applied for the treatment of raw domestic sewage where TSS
removals in the range of five to twenty-five percent have been
achieved (27).
171
-------
A rotating wedge wire screen has also been developed that has
the advantage of being self-cleaning and has been found useful
where grease binding problems were encountered with stationary
wedge wire screens. Rotating screens are also reported to
require less maintenance, they have a lower head loss, and they
require less space than stationary screens. They also produce a
sludge with a higher solids concentration. However, rotating
screens have a higher capital cost (27).
4.4.2 SEDIMENTATION/COAGULATION
Sedimentation is the removal of solid particles from a suspen-
sion by gravitational settling. Sedimentation basins are often
referred to as clarifiers. Plants A07, Ell, and E12 have
primary sedimentation basins for suspended solids reduction.
The settling characteristics of suspended particles are a func-
tion of the nature of the particles, their concentration, and
conditions in the settling device. There are no data available
concerning removal efficiency for ethanol plant wastewater;
however, the literature suggests that a properly designed and
operated primary sedimentation tank can remove 50 to 70 percent
of the suspended solids and 25 to 40 percent of the BOD from
domestic sewage (26).
In addition to providing for effective removal of suspended
solids from its effluent, a clarifier must have an adequate
sludge removal capacity and provide sufficient reduction in
sludge volume to facilitate sludge handling and processing. The
clarifier may also be equipped with a skimming device to collect
scum that floats to the surface.
In the event that the particulate impurities in wastewater are
too small for gravitational settling alone to be an effective
removal process, chemical agents can be added to induce an
aggregation of these small particles into readily settleable
agglomerates which can be removed by some other method (e.g.,
sedimentation, air flotation, or filtration). This process is
referred to as coagulation.
There are many types of chemical agents (coagulants or coagulant
aids) available, including lime, aluminum and iron salts, syn-
thetic organic polymers, and activated silica. The type and
dosage of coagulants cannot be determined without some experi-
mentation; the performance of a coagulant is most often evalu-
ated using a jar test. The removal efficiency in coagulation
depends upon the particles in the wastewater to be treated,
other chemical characteristics of the solution, and the
coagulant aid which is used.
172
-------
4.5 SECONDARY TREATMENT TECHNOLOGIES
The term secondary treatment refers to the removal of dissolved
organics that cannot be removed in primary screening or settling
processes. Dissolved organics consist of many different
chemical compounds and are usually measured in terms of the
generalized parameter biochemical oxygen demand (BOD). In
addition to BOD removal, some total suspended solids (TSS) is
also removed.
Based on ethanol-for-fuel industry questionnaire responses and
data gathered by ESE (14) on the beverage alcohol industry, the
following distribution of secondary wastewater treatment methods
were found to be applied at existing plants:
of % Plants Using Technology to Treat
Secondary Treatment at Least Part of their Wastewater
Aerated Lagoon 65
Stabilization Ponds 30
Activated Sludge - 20
Trickling Filter 15
Rotating Biological 10
Contactors
NOTE: Some ethanol plants employ more than one of the above
treatment technologies; thus, the total does not sum to
100 percent (sample population of 24 plants).
Four ethanol-for-fuel plants have wastewater treatment systems.
Plants A06 and A07 use aerated lagoons for treatment, plant A03
uses an activated sludge system and discharges directly to a
river, while plant A01 pretreats with an activated sludge system
then discharges to a POTW. In addition, trickling filters and
rotating biological contactors are also applicable to the
ethanol-for-fuel industry. ESE determined in its study of the
beverage alcohol industry that ethanol plant wastewaters are
typically low in the nutrients nitrogen and phosphorus, which
are essential for proper growth of the activated sludge
microorganisms (14). The data in Section 3 indicate that
nutrient addition is also necessary for the proper operation
ofsecondary treatment technologies when treating wastewaters
from ethanol-for-fuel facilities.
4.5.1 NUTRIENT ADDITION
In order to maintain optimum efficiency in biological systems,
minimum quantities of nitrogen and phosphorus are required for
173
-------
cell synthesis. Without a proper nutritional balance, soluble
BODs reduction and liquid-solid separations are impaired.
A summary of typical influent wastewater characteristics for
grain distilleries based on the data presented in Section 3 is
shown in Table 4-2. As this table indicates, the wastewaters
are deficient in both nitrogen and phosphorus. To maintain
proper cell growth, nitrogen and phosphorus must be added to the
wastewater. Nitrogen is usually provided by the addition of
ammonia; phosphorus is provided by the addition of phosphoric
acid. Both of these chemicals can be stored on-site in steel
storage tanks and pumped into the aeration basin at an
appropriate rate.
4.5.2 AERATED LAGOONS
Aerated lagoons are basins in which aeration is accomplished by
either mechanical aerators (usually by fixed or floating surface
aerators) or by diffused air piping systems. The BOD removal
rate is waste specific and temperature sensitive and must be
determined by laboratory or pilot unit testing. Therefore, for
a specific waste and temperature, the BOD removal is only a
function of detention time (assuming a completely mixed aerobic
system). A single cell aerated lagoon can obtain good removal
of soluble BOD, but the effluent will contain suspended solids
in the same concentrations as the mixed liquor. A greatly
improved effluent can usually be achieved by following the
aerated lagoon with a second unmixed polishing lagoon where
suspended solids are allowed to settle.
There are two common designs in use: the completely mixed basin
in which all solids are kept in suspension (aerobic lagoons) and
the partially mixed aerated lagoon in which the heavier solids
settle to the bottom of the basin .(facultative lagoon). In the
former design, stabilization of organics is entirely aerobic.
In the latter, the settled solids undergo anaerobic biological
decomposition while suspended and dissolved organics undergo
aerobic biological decomposition.
Aerobic lagoons have a shorter retention time than facultative
lagoons to achieve the equivalent soluble BOD removal. However,
a greater mixing requirement and therefore more power input is
necessary for the aerated lagoon. Several aerators are needed
to ensure complete mixing in the aerobic lagoon. These aerators
provide oxygen and keep the solids in suspension. Diffused
aeration (used at plant A07) generates coarse bubbles and is
recommended where severe winter conditions can render surface
aerators ineffective. The effluent from an aerobic lagoon is
high in BODs caused by unsettled microbial solids. In order
to remove these suspended solids, some designers of aerobic
lagoons include baffled sections which provide for solids
settling before discharge.
174
-------
Table 4-2
TYPICAL INFLUENT WASTEWATER CHARACTERISTICS
AT GRAIN DISTILLERIES
„ ^ Untreated Wastewater
Wastewater Parameter Grain Distilleries
BOD5
Total Nitrogen (mg/1) 21
Total Phosphorus (mg/1) 2
BOD:N:P* 100:1.4:0.13
*Recommended value of the BOD:N:P ratio is 100:5:1 (28)
175
-------
In facultative lagoons, aeration is only required to disperse
oxygen. The solids are allowed to settle to the bottom of the
lagoon where anaerobic biological degradation of the organic
matter takes place. Surface aerators are commonly used; in
climates with severe winters diffused aeration may be required.
Figure 4-2 shows the wastewater treatment system in use at Plant
E13 which contains an aerated lagoon. Also, part of the system
is a stabilization pond which is used to reduce solids and a
chlorinator for disinfection (sanitary wastes are mixed with
ethanol plant wastes). This plant has a BODs reduction of
94.5 percent and a TSS reduction of 82.5 percent (14).
4.5.3 STABILIZATION PONDS
A stabilization pond is a relatively shallow body of water con-
tained in an earthen basin which utilizes no induced aeration.
These ponds are designed to treat wastewater in the following
manner: (1) settling of solids; (2) equalization and control of
wastewater flow; and (3) stabilization of organic matter by aer-
obic and facultative microorganisms, and also by algae.
Stabilization ponds are usually classified by the biological
activity occurring as aerobic, anaerobic, or aerobic-anaerobic.
Aerobic-anaerobic stabilization ponds are the second most widely
used biological treatment option by ethanol facilities and are
only found as the final stage in biological treatment following
other methods of secondary treatment. Large ponds allow plants
to store wastewaters during periods of high flow in the re-
ceiving body of water or for irrigation purposes in the summer.
Stabilization ponds are common in rural areas where land is
available and relatively inexpensive.
Stabilization ponds are usually one to two meters deep and have
hydraulic retention times of one to six months. In^these rela-
tively deep ponds, the wastewater near the bottom may be void of
dissolved oxygen. Therefore, settled solids may be decomposed
by aerobic, anaerobic, or facultative organisms, depending upon
lagoon conditions. It is essential to maintain aerobic con-
ditions in the top layer of the pond since aerobic micro-
organisms effect the most complete removal of organic matter.
Disadvantages of stabilization ponds include their reduced
effectiveness during winter months which may require supple-
mental aeration, increased design capacity, and possible
provisions for no discharge during long periods of time (winter
months). Also, stabilization ponds require a relatively large
amount of land. Algal growth may lead to high suspended solids
in the effluent. Odor may also become a problem if the pond
becomes anaerobic (e.g., if covered with ice during winter).
176
-------
Gi .
0)
t-4
U-l
%
J3r
4-1
Oi
&
§
177
-------
No data is available concerning the effectiveness of stabiliza-
tion ponds alone on the effluent from ethanol plants. In other
industries, stabilization ponds can achieve 8005 removals up
to 95 percent; however, the pond effluent contains a high con-
centration of bacteria and algae that may exert a higher 8005
than the original waste (26). There are several methods avail-
able for removing algal cells from lagoon effluents, including
coarse-medium filtration (developed primarily for this purpose)
and algal harvesters.
4.5.4 ACTIVATED SLUDGE
The activated sludge system is one of the most frequently ap-
plied methods of biological wastewater treatment. The process
has shown itself to be capable of high BOD removal efficiency
(85 to 99 percent) and can be adapted to almost any type of
biological waste treatment problem. This flexibility has led to
numerous modifications of the "conventional" activated sludge
process. The most common type of activated sludge process in
use today in the beverage alcohol and ethanol-for-fuel industry
is extended aeration.
Extended aeration differs from a conventional activated sludge
process in that it is operated with relatively long hydraulic
residence times and a high sludge age. Oxygen requirements may
be twice that of a conventional activated sludge unit. The
extended aeration process is used iri the ethanol-for-fuel and
beverage alcohol industries due to its ability to handle shock
loadings. Extended aeration activated sludge is used at plants
A01r A03, E06, and E21.
Figure 4-3 illustrates the extended aeration activated sludge
system used at Plant A03. This process consists of an aeration
tank, a secondary clarifier, pumps, and a sludge recycle line.
Also in this system, the wasted sludge is centrifuged from the
clarifier; the cake is sent to by-product processing at the
ethanol plant and the supernatant is recycled to preliminary
wastewater treatment. Mixing is accomplished by mechanical
aerators as the sludge flows through the length of the basin.
Adsorption, flocculation, and oxidation of the organic matter
take place during aeration. The solids are settled in the
secondary clarifier and the resulting sludge, a mixture of these
solids and wastewater, is withdrawn from the bottom of the
clarifier. A portion of the settled sludge is recycled to the
head of the aeration basin and the excess is sent to a centri-
fuge for concentration. Effluent from the secondary clarifier
is generally low in 8005 and TSS. As Table 4-1 indicates,
this facility obtains an average reduction in 8005 and TSS of
98.7 and 95.0 percent, respectively.
Few operating problems are encountered in the activated sludge
processes when the characteristics of the wastewater are ,consis-
178
-------
tM
E
oo
II
IB
4)
U
I
8S
H
CO
H
179
-------
tent.. However, the performance of the process can be adversely
affected by significant changes in temperature, pH, and, depend-
ing on the type of activated sludge process, the organic concen-
tration and volumetric flow rate. The microorganism concentra-
tion in the tank must also be carefully controlled by adjusting
the recycle stream and the amount of sludge wasted. The concen-
tration of nutrients such as nitrogen and phosphorus must also
be carefully controlled.
4.5.5 TRICKLING FILTER
The trickling filter is a type of attached growth, biological
process for wastewater treatment. It is used by three beverage
alcohol plants and is applicable to the treatment of wastewater
from ethanol-for-fuel facilities. Trickling filters are often
used in series, with the effluent of one filter becoming the
influent of the following filter. A portion of the effluent
from the last filter is often recycled to the initial filter.
There are two types of trickling filters: standard and high
rate. These trickling filters differ in the distribution and
flow rate per unit surface area of the wastewater over the
filter media.
The trickling filter media has relatively small openings and
must be preceded by primary treatment to remove gross solids and
debris to avoid clogging. A settling tank equipped with scum-
and grease-collecting devices are adequate for this function.
The trickling filter is comprised of a wastewater distribution
system, a vessel containing the filter media, an underdrainage
collector, and a partial recirculation system. The suspended
solids not removed by the filter and those generated by the
sloughing of the microbial layer are removed in a final
sedimentation tank.
The operation and maintenance problems associated with the
trickling filter are few and can be minimized by proper design
considerations. The filter media may be stone or some type of
synthetic material such as polyethylene saddles which provide a
high surface area per unit volume, a high void space per unit
volume, durability, and a resistance to clogging.
Figure 4-4 illustrates the wastewater treatment system used at
plant E17 which incorporates two trickling filters in series
that follow an aerated lagoon. This system also uses two
polishing lagoons (the first aerated and the second not aerated)
to achieve an effluent with a BOD5 reduction of 97.2 percent
and a TSS reduction of 76.1 percent (14).
4.5.6 ROTATING BIOLOGICAL CONTACTORS (RBC)
An RBC provides a secondary wastewater treatment technique
effected by attached biological growth. RBCs are used at two
180
-------
i
=
9
I
I
e
I
III
s .
17
181
-------
beverage alcohol facilities and are applicable to the treatment
of wastewaters from ethanol-for-fuel facilities.
The RBC treatment process is often preceded and followed by
clarifiers for solids removal. The closely spaced, molded
polystyrene disks that are three to four meters in diameter are
mounted on a common shaft. The set of disks -is partially (40
percent) submerged in a cylindrically bottomed tank. A series
of these tanks with the shafts parallel are positioned between
the two clarifiers; no recirculation of sludge is required.
After a biological film on the surface of each disk has grown,
the rotating action of the disks (one to two rpm) shears off -
excess microbial growth, keeps solids in the tank in suspension,
and provides oxygen thereby reducing aeration requirements.- The
attached suspended microorganisms adsorb and assimilate the
organic wastes. The thin layer of water that adheres to the
surface of the disk as it rotates and the large surface area
covered by the biofilm provide a high microorganism to food
ratio, and a high degree of oxidation can be carried out
quickly; contact times are generally less than one hour. The
high degree of oxidation eliminates the necessity of recir-
culating part of the effluent and therefore pumping requirements
are minimal. The sloughed biomass has good settling charac-
teristics and can be easily separated from the waste stream in
the final settling tank.
The operating and maintenance problems associated with the RBC
process are fewer than those of trickling filters, but startup
problems can occur in establishing the biofilm. However, once
the system is established, power outages or downtimes of a day
or two require only a few hours to bring the system back to
equilibrium. The RBC treatment system is usually enclosed to
avoid freeze up.
Figure 4-5 shows the wastewater treatment system for Plant EOS
which features three RBCs in series. The first RBC receives the
effluent from an aerated lagoon and the third RBC discharges to
a second aerated lagoon which is followed by three ponds used to
settle solids. Finally, the last pond discharges to an air flo-
tation unit used to remove algae and other solids which are
difficult to settle. This system achieves BODs and TSS
reductions of 97 and 73 percent, respectively. BODs and TSS
removals of 50 and 10 percent, respectively, are achieved by the
RBC units alone (14).
4.6 TERTIARY TREATMENT
In an ethanol-for-fuel wastewater treatment facility, tertiary
treatment would receive the effluent from the secondary treat-
ment system. Based on treated effluent data this secondary
effluent typically contains 40 mg/1 TSS as biological floe, with
182
-------
s
S §
0) G
0)
VI
o
u
S
S u
g „
o
s
3
eg
u
S
a
2
co
><
CO
in
l
-------
peaks of perhaps 120 mg/1. The effectiveness of tertiary
treatment is affected by the origin of the wastewater. Three
tertiary treatment systems which are considered applicable to
the ethanol-for-fuel industry are granular-media filtration, air
flotation, and land application.
4.6.1 GRANULAR-MEDIA FILTRATION
This process consists of passing wastewater through a packed bed
of granular material of a depth on the order of one meter or
more, wi.th resulting deposition of solids in the granular mate-
rial. Deposition occurs by a combination of physical mechanisms
(i.e., mechanical straining, chance-contact straining, sedimen-
tation, impaction, interception, diffusion, and adhesion) which
are discussed by Metcalf and Eddy (26) and Weber (29). The
wastewater is diverted from a filter unit, and the unit is taken
off line when (1) effluent quality reaches an unacceptable level
due to the inability for the given bed depth to hold the solids
(breakthrough), (2) a limiting headloss occurs across the bed
due to accumulated solids (terminal headloss), or (3) the fil-
ters are backwashed oh a time cycle basis. After the units are
taken off line, the bed is backwashed by passing water upward
through the bed to expand it, allowing the shearing action of
the water to remove the deposited solids. Backwash is often
supplemented by internal or surface water jets or air scouring.
The backwash wastewater can be recycled to primary sedimentation
or to the biological treatment unit.
Options for flow direction include downflow (conventional),
upflow, and biflow. Historically, downflow systems have
predominated (27) since they have the advantage of supplied
hydrodynamic head. A discussion of the less frequently used
upflow and biflow systems can be found in (27).
Particle size and size distribution of the media have major
effects on filter performance. Finer media particles possess
greater removal abilities than do coarser particles, but they
also result in greater headloss per amount of solids removed
(27) due to premature bed clogging. The problem of particle
size gradation can be alleviated with the use of two or more
media. By layering a coarser, less dense medium over a finer,
denser one (e.g., coal over sand), a downflow configuration can
be combined with a coarse-to-fine gradation in the direction of
flow. A further refinement involves multi-media (three media:
typically coal over sand over garnet). The gradation can also
be eliminated with the use of uniformly sized particles.
As a tertiary treatment technology, granular-media filtration
can be expected to reduce levels of 30 mg/1 TSS in the influent
stream to concentrations of 10 mg/1 (27). Supplemental removal
of particulate BOD remaining after biological or chemical treat-
ment is achieved by filtration.
184
-------
Pilot-plant studies for filtration are required to ensure proper
G iT S~CS the characteristics of the influent LI- P
1?8 ^ ^ Perf otraance. Although granular-media
has been extensively used in treating the effluent of
ni«n ^reatment Processes at domestic wastewater treatment
eth±i' ^ r n0t bSen USSd f°r tertiary treatment purposes in
ethanol plant wastewater treatment systems.
4.6.2 AIR FLOTATION
?hJ Ji™at*°n i? a techni<3ue which removes suspended solids in
the form of a floating sludge, it can be either purely physical
° Phvsical/chemical With the ^ition of chemica? coagufants
Uni1?s.9enerate air bubbles, and the buoylncy of
8 riS1?9 throu9h the wastewater lifts suspended
eSUrfaCe- ^ fl°at
ei^no?h airf10tati°n is not widely used in the treatment of
ethanol plant wastewater, it is being used by plant E15 to
remove algae and suspended solids from its aerated lagoon
effluent. This facility employes a dispersed air flotation
system which uses diff users to form air bubbles.
^a?lA£3 reports thf? the effluent from its activated sludge
unit Wha?hP°°r Sf^in? <=ha^cteristics. An air flotation
unit, which is relatively compact in size and produces a fairlv
°°at?d Slud9e' m^ *e a viable alternative to a secondar?
removal of suspended solids from secondary treat-
s such
n , s rom seconary treat
ment systems such as activated sludge. However, air flotation
and may produoe
4.6.3 LAND APPLICATION OP WASTEWATER
J
In the land application of wastewater, filtration of solids and
biological decomposition are provided by vegetation, the soil
ndl ' eoo
land application of wastewater are slow rate, rapid infiltra-
tion, and overland flow. Less widely used methods
wetlands and subsurface application (30).
Slow rate treatment is also known as spray irrigation- however
in this case the irrigational effect is secondary to the ?relt-
ment of wastewater. In slow rate treatment, waJtewater is
SrrnooS"1 3 fe8frYolr and ^Plied to the soil via a sprinkler
H^?H \ S I 9 techni(3ue- The disposition of the water is
divided between percolation and vegetative uptake and, there-
fore, both the soil and vegetation are critical in managing the
wastewater and its constituents. Organics are reduced by
biological oxidation within the top few inches of the soil
Suspended solids can be removed to a level of one mg/1 or less
185
-------
by filtration. Volatile solids are biologically oxidized, while
mineral solids become a part of the soil matrix. The slow rate
process is applicable to agricultural land, grasslands, forest
land, and public land such as parks and golf courses.
Rapid infiltration (also known as infiltration-percolation)
involves application of the wastewater to a highly permeable
soil via sprinklers or flooding basins at a greater rate and
upon a smaller area than in slow rate treatment. In rapid
infiltration, the soil serves essentially as a filter medium.
The water percolates to underdrains, wells, or groundwater;
little evaporation or vegetative uptake occurs. Removal o£
suspended solids and BOD by filtration and straining is nearly
complete (30).
Overland flow involves the application of wastewater to the
upper areas of a sloped terrain which possesses a low
permeability soil or a subsurface barrier to percolation. The
wastewater flows down the vegetated surface as a film and is
collected at the base for either reuse or discharge. Organics
and suspended solids are removed by biological oxidation,
sedimentation, and grass filtration (30).
Of the three types of land application processes, the slow rate
method is most compatible with crop cultivation. Furthermore,
whereas rapid infiltration requires,a highly permeable soil and
overland flow requires a soil of low permeability, slow' rate
operates within a wider and more moderate range. Finally, the
slow rate process produces effluent of the highest quality.
One ethanol-for-fuel facility in the United States (plant A01)
currently practices land application of wastewater; however,
this facility is constructing an activated sludge system which
will then discharge to a POTW. There is also one beverage
alcohol facility (plant E21) which practices land application.
Both of these facilities employ the slow rate process; neither
overland flow nor rapid infiltration is employed by the ethanol
industry.
4.7 DISINFECTION
Disinfection is the elimination of selected disease-causing
organisms. This selective elimination differs from
sterilization, a process which kills all organisms. Dis-
infection is necessary if sanitary wastes are sent to the
wastewater treatment system. Currently, chlorination is the
only practiced means of disinfection.
Chlorination is used for final wastewater disinfection primarily
bv those plants that combine sanitary wastes with raw wastewater
effluents (plants A04, EOS, EOS, Ell, and E12). Disinfection
effectiveness generally has been measured by the concentration
186
-------
of the coliform bacteria indicator group that remains after
disinfection has taken place. Alternatively, chlorination
utilizes a more indirect measure of residual chlorine, which "
provides presumptive evidence that adequate disinfection was
achieved.
Chlorine is highly corrosive when wet; thus, the gas is stored
dry, under pressure. It is mixed with water to form an aqueous
solution prior to injection to the wastewater stream. The aque-
ous chlorine solution is mixed with the wastewater in a dif-
fusion chamber; the wastewater plus chlorine then enters a
chlorine contact tank, which provides the appropriate detention
time before discharge to the receiving water. The chlorine
dosage required for disinfection will vary with the quality of
the effluent to be treated. To ensure proper disinfection,
™*i ? K? ?rinS mUSt be added to force the formation of free
residual chlorine. The presence of free residual chlorine can
easily be monitored to check if adequate chlorine has been
added.
One disadvantage of chlorination for disinfection is that it
reacts with organic compounds. Groups are formed which often
™™* Vf f5?M?hlorine. residuals; they possess little or no
germicidal ability and give an overestimate of the free residual
present. Also, many undesirable chlorinated organics formed
during chlorination are suspected to be carcinogenic.
The germicidal effect of chlorine is believed to be due to the
reaction of chlorine compounds with the cell membrane of the
bacterial cell, thereby stopping the metabolic process. Viruses
are also affected, but not in the same correlative, quantifiable
way as with bacteria. Among the conditions which affect the
germicidal effectiveness are contact time, chlorine concentra-
tion, NH3-N concentration, intensity of light, temperature,
pH, number and types of organisms, and the nature of the
suspending liquid. In a well-designed contact chamber, the
reduction of coliform content should exceed 99 percent, with
minimal residual chlorine (less than one mg/1).
4.8 SLUDGE HANDLING
The biological treatment of wastewaters results in the
generation of excess biological solids which must somehow be
disposed. A portion of the waste material present in the raw
wastewater has been concentrated in the form of biological
solids; thus, by cleaning the water, a potential solid waste
problem is created. This problem has been a recognized area of
concern since the advent of biological wastewater treatment, and
numerous technologies are available to dewater, stabilize, and
recover waste biological sludge.
187
-------
One typical scenario that is evaluated in this section is shown
in Figure 4-6. Waste sludge from the secondary settler is sent
to a gravity thickener, where further settling increases the
sludge concentration. Concentrated sludge is sent to an aerobic
digester, where a portion of the cell matter is oxidized to
carbon dioxide. This brings about a reduction in the net mass
of waste sludge. The effluent from the aerobic digester is sent
to a solids centrifuge, where additional water is removed,
resulting in a semi-solid sludge with a solids concentration of
up to 20 percent. This sludge can then be trucked to a sanitary
landfill for final-disposal. Ultimate disposal methods for
dewatered and stabilized biosludge as well as for other solid
wastes from ethanol facilities are discussed in Section 5 of
this document.
.4.8.1 GRAVITY SLUDGE THICKENING
A gravity sludge thickener is essentially the same piece of
equipment as a secondary settler except that the feed, effluent,
and underflow solids concentrations typically found in a sludge
thickener are much higher than those found in a secondary set-
tler. There may also be slight differences in the torque
rating, sludge rake designs, and effluent weirs.
Influent sludge enters a gravity sludge thickener at concentra-
tions of 5,000 to 25,000 mg/1. The underflow solids concen-
tration in gravity thickeners treating waste activated sludge
ranges from 15,000 to 40,000 mg/1. The overflow from the
gravity thickener has a suspended solids content of 100 to 350
mg/1 and a BODs of 60 to 40° m9/:L (26)< Due to lts high
solids and BOD5 content, the thickener overflow is usually
sent back to the aeration basin for further treatment.
4.8.2 SLUDGE DIGESTION
Aerobic digestion can be used to stabilize biological sludge,
primary sludge, or a combination. Plant A10 uses separate
aerobic digestors for the stabilization of mixtures of excess
activated and primary sludges. The digestion process involves
oxidation of sludge in either a surface-aerated or a diffused
air basin. The major components of an aerobic digester system
include a tank, an aeration system, a thickener, and sludge
pumps.
Compared to other methods of sludge stabilization (particularly
anaerobic digestion) aerobic digestion produces a biologically
stable, odorless end product and a supernatant liquor with a
lower BOD content than that from anaerobic digestion; this is
important in recycling supernatant to avoid overloading the
treatment system (Benefield and Randall, 1980). Also, the
capital cost of aerobic digestion is generally lower than that
for anaerobic digestion and fewer operational problems will
188
-------
c
•H
co
CO
S3
o*^ —
•r4
4J
CO
<
o
Return
*
^
i
CO
0)
^4
4J
03
•o
i 1
f-l
i-4
r^ i-(
CO
4
00
C
1-1
(4
0)
CO
3
Q
C
^
.
O
**H
4J
CO
N
' i-l
f— «
•H
J3
«
i t
3 i k OT
5
•^^
J
X 0)
4J
-------
occur than with anaerobic digestion; therefore, maintenance and
labor costs may be reduced. Finally, aerobically digested
sludges have a higher fertilizer value than do those from
anaerobic digestion. Disadvantages of aerobic digestion include
high power requirements for oxygen supply, and the fact that
aerobically digested sludge is often difficult to dewater
resulting in a supernatant from subsequent thickening that is
high in suspended solids.
4.8.3 SLUDGE DEWATERING
Two methods of sludge dewatering which are used in the beverage
alcohol industry and are applicable to the treatment of waste-
waters from the ethanol-for-fuel industry are solids centrifuge
and sludge drying lagoons.
Solids Centrifuge
The influent to the solids .centrifuge enters at a typical con-
centration of 30,000 mg/1. Solids are forced to the inside wall
of the rotating bowl and collected by the rotating conveyor.
Liquid centrate passes out the other end of the centrifuge. The
centrate will have a TSS concentration in the range of 2,000 to
15,000 mg/1 and a BODs concentration between 1,000 and 10,000
mg/1. Thus, this stream is generally sent back to the aeration
basin for further treatment. Since the flow rate is so small,
no modification of the aeration basin design is required.
Solids leave the centrifuge at 10 to 35 percent solids. Sludge
at this concentration is semi-solid and can easily be trucked to
a landfill for final disposal.
Sludge Drying Lagoons
Sludge drying lagoons provide a nonmechanical means of de-
watering the waste sludge produced during biological wastewater
treatment. Before the sludge is pumped into the lagoon, it must
be digested for stabilization and reduction of odor emissions.
Although the sludge lagoon itself may provide additional stabi-
lization, the primary function is dewatering. Lagooning is not
capital intensive and does not require significant maintenance;
however, it is a land-intensive operation, and odor may be a
problem.
In a sludge drying lagoon, the digested sludge is pumped into
the bottom of the lagoon and left to dry. Evaporation is the
primary mechanism by which dewatering occurs, with supernatant
removal and permeation of the fill lining contributing minor
amounts to dewatering. Any supernatant which exceeds the
overflow level is pumped back to the treatment plant.
Depending on the design of the sludge drying lagoon, a high (>30
percent solids) or low concentration of suspended solids in the
190
-------
dewatered sludge can be achieved prior to removal. A high
solids concentration sludge is mechanically removed from the
lagoon by a front-end loader, and can be used as a soil con-
ditioner or fertilizer. A liquid product with a low concentra-
tion of solids can be pumped from the lagoon into tank trucks
and land applied.
Residence times for dewatering depend on the sludge depth in the
lagoon. After sludge removal, it is recommended that a six-
month rest separate emptying and refilling. Therefore, at least
two sludge lagoons should be present at any location.
4.8.4 RECOVERY
Grain alcohol producers who recover stillage can also recover
the wastewater treatment sludge by incorporating this sludge
into by-product grains. In the by-product grain recovery
system, thestillage is first screened; the screened solids are
concentrated in centrifuges, evaporators, and dryers. The thin
liquids from screening are recycled to the ethanol process or
sent to wastewater treatment. The sludge produced in wastewater
treatment can be dewatered and mixed with the stillage in the
dryers, then sold as a by-product cattle feed if sanitary waste
from the plant is not sent to the wastewater treatment system.
Thus, the recycle of sludge, which has been practiced for many
years by the grain alcohol industry, is the preferred option for
ethanol-for-fuel producers using grain.
Previous studies of the beverage alcohol industry show that fer-
mentation of sugar feedstocks (cane molasses, citrus molasaes,
and sugar cane) produces: a stillage low in protein content which
is not as nutritional as grain stillage. Therefore, the common
practice with this low-protein stillage is treatment and/or
disposal.
191
-------
-------
SECTION 5
SOLID WASTE TREATMENT AND DISPOSAL TECHNOLOGIES
For many ethanol-for-fuel producers that process grainr it will
be profitable to recycle and reuse or recover for sale as
by-products all wastes associated with ethanol production.
However, if the wastes are not recovered, the distiller must
comply with Subtitle D (RCRA 4000 Series) regulations which
require nonhazardous solid wastes to be disposed of by sanitary
landfill. Application of this waste to land used for growing
food chain crops is acceptable because excessive levels of heavy
metals (lead, cadmium) are not found in the waste. Although no
analysis for PCB's was performed, those compounds are not
expected to be present based on best engineering judgment.
Table 5-1 presents the treatment and disposal technologies for
solid waste currently used in the fermentation ethanol industry.
These technologies are used in many industries and are adequate
to effectively treat ethanol process wastes.
5.1 RECYCLE/REUSE
Ethanol-for-fuel producers who recover stillage can also recover
the wastewater treatment biosludge by incorporating this sludge
into by-product grains. However, the sludge may be reclaimed
only if sanitary wastes have not been incorporated into the
wastewater treatment system.
In the by-product grain recovery system, the stillage is first
screened? the screened solids are then concentrated in centri-
fuges, evaporators, and dryers. The dewatered, stabilized bio-
sludge can be mixed with the stillage in the dryers, then sold
as a by-product cattle feed.
The recycle of sludge, which has been practiced for many years
by several beverage alcohol producers, is the preferred option
for ethanol-for-fuel producers using grain. The cost of sludge
recovery is offset by the sale of the recovered sludge as
by-product. Also, sludge recovery would require little capital
cost since the equipment used is already installed for
by-product processing.
Previous studies of the beverage alcohol industry show that
fermentation of sugar feedstocks (cane molasses, citrus
molasses, and sugar cane) produces a stillage low in protein
192
-------
-------
in
CD
OS
£
CO
u
H Q
M
J J
< O
CO CQ
O
eu H
co z
22
1
•O 01
JJ
c
2
e
CD
Ol CO
10 CD
C 0
(0 -H
£ JJ
X O
tH (0
10 i-l
co CM
o
Oi
CO
•I-l
Q
c c
5in
X 3
C (0
O OS
•H
JJ JJ
(0 O
U (0
•M U
iH JJ
a c
f% O
*^s o
X
*O *"^
C f-f
(B -rt
.J Mj
1
TJ Oi
C C
10 -H
J iH
X 3
C Q
0 3C
•1-4
JJ JJ
10 U
O (0
•p>4 £4
>H JJ
ac
a o
< o
X
•a -4
C f-4
(O-H
hJ It)
CO
JJ
o
3
•O
2
cu
^
CQ
C — •
•H OI
C
c •«•<
O E
co
<
•o
1
I"
•a
0)
(D
b
(0
i?
10 -H
X 3
C (0
O X
4J JJ
(0 O
U (0
C -f4
CO
(0
1%
$8
•O
fH C
O <0 -H
CO
C
o
•H
JJ
?
iH
O
c
£
u
CD
H
JJ
C
JJ
|Q
CD
H
C JJ
< (0
IiJ
It ^^J
0 C
CD
U O
•* C
£ O
00
CD *
< c
0
CT-U
e co
•H CD
Aa Ol
jj a
(0
5 0
Mk 1
c
o
•H
JJ
CO
CD
O»
•i-l
Q
O
!o
o
CD
o> 01
e 01 c
•H C 'ft
CD *C CD
JJ O JJ
Oi
•H
Jj
CD
JJ
<0
o-
O) JJ
c co
•H CD
^i Ol
^j »»^
Q a
% °
O -H
•o
n
OS
a>
a
o
JJ
c
CD
U
I
CD
<0
C
h
o
o
14
CD
C
o
JJ
CO
CD
Ol
U
•H
£
O
CD
i
O JJ O
•fH O CD
M Q) OS
a u
%'
CO
C CD
•O M O
C O
tit Ij I [
M O 04
(0
•o
c
o
u
CD
CO
a!
I a
CQ
0)
JJ
CO
10
o
CO
JJ
c
Q)
JJ
Q)
Ol
•O
iH
CQ
O
•H
CD
•H
JJ
CO
0)
Q)
OQ
O
U
U-l
0)
Oi
(0
JJ
CQ
CD
JJ
JJ
CO
CO
CO
0)
o
o
193
-------
content which is not as nutritional as grain s tillage. There-
for eTthe common practice with this low-protein stillage is
treatment and/or disposal.
5.2 TREATMENT TECHNOLOGIES
qolid wastes which contain large amounts of water (up to 95 per
volume of the waste. The concentrated waste is then digested
Teller aerobically or anaerobically) to produce a stabilized
solid waste.
5.2.1 DEWATERING
Three methods of dewatering which are used in the beverage
concentration
the ranae of 2,000 to 15,000 mg/1 and a BOD5 concentration
treatment.
Solids leave the centrifuge at 10 to 35
applied.
194
-------
sludge lagoon itself may provide additional stabilization, the
primary function is dewatering. Lagooning is not capital inten-
sive and does not require significant maintenance; however, it
is a land intensive operation and odor is a continuing problem.
In a sludge drying lagoon, the digested sludge is pumped into
the bottom of the lagoon and left to dry. Evaporation is the
primary mechanism by which dewatering occurs, with supernatant
removal and permetation of the fill lining contributing minor
amounts to dewatering. Any supernatant which exceeds the
overflow level is pumped back to the treatment plant.
Depending on the design of the sludge drying lagoon, a high or
low concentration of suspended solids in the dewatered sludge
can be achieved prior to removal. A high solids concentration
sludge, which is typically 30 percent or more, is mechanically
removed from the lagoon by a front end loader, and used as a
soil conditioner or fertilizer. A liquid stream with a solids
concentration of 3 to 6 percent is pumped from the lagoon into
tank trucks and land applied.
Residence times for dewatering depend on the sludge depth in the
lagoon. After sludge removal, it is recommended that a six-
month rest separate emptying and refilling. Therefore, at least
two sludge lagoons should be present at any location.
Gravity Thickening. A gravity sludge thickener is essentially
the same piece of equipment as a secondary settler except that
the feed, effluent, and underflow solids concentrations typi-
cally found in a sludge thickener are much higher than those
found in a secondary settler. There may also be slight dif-
ferences in the sludge rakes and effluent weirs.
Typically, influent sludge enters the gravity sludge thickener
at concentrations of 5,000 to 25,000 gTSS/m3. The underflow
solids concentration in gravity thickeners treating waste acti-
vated sludge ranges from 15,000 to 40,000 gTSS/m3. The over-
flow from the gravity thickener has a suspended solids content
of 100 to 350 gTSS/m-s and a BOD5 of 60 to 400 gBODs/m3
(26). Due to its high solids and BODs content, the thickener
overflow is usually sent back to the aeration basin for further
treatment.
5.2.2 STABILIZATION
Solid wastes are stabilized in order to: reduce pathogens,
eliminate offensive odors, and inhibit, reduce, or eliminate the
potential for decomposition of organic matter (26). The two
most widely used means of stabilization for the ethanol industry
are aerobic and anaerobic digestion. These methods biologically
reduce the volatile content of the solid waste, thereby reducing
the survival of pathogens, release of odors, and decay of
organic matter.
195
-------
Aerobic Digestion. Aerobic digestion can be used to stabilize
logical sludge, primary sludge, or other solid wastes. Plant
A10 uses separate aerobic digesters for the stabilization of
mixtures of excess activated and primary sludges. The digestion
nrocess involves oxidation of the solid waste in either a
lurllcf-aerated or a diffused air basin. The ma3or components
of an aerobic digester system include a tank, an aeration
system, a thickener, and sludge pumps.
Compared to other methods of sludge stabilization (particularly
anaerobic digestion) aerobic digestion produce.s a biologically
stable, odorless end product and a supernatant liquor with a
lower BOD content than that from anaerobic digestion; this is
important in recycling supernatant to avoid overloading the
treatment system (28). Also, the capital cost of aerobic
digestion is, generally lower than that for anaerobic digestion
and fewer operational problems will occur than with anaerobic
digestion; therefore, maintenance and labor costs may be
reduced. Finally, aerobically digested sludges have a higher
fertilizer value than do those from anaerobic digestion.
DiladvanSges of aerobic digestion include high power ^quire-
ments for oxygen supply, and the fact that aerobically digested
sludge is often difficult to dewater resulting *"/ supernatant
from subsequent thickening that is high in suspended solids.
Anaerobic Digestion. Anaerobic digestion of secondary waste-
water treatment sludges is a very sensitive process. *requent
upsets have led to the use of aerobic digestion (28). Unless
all solid wastes from the ethanol production process are con-
solidated and fed to the anaerobic digester, as with the
A^AMM® process, the value of the methane generated is minimal
in offsetting the cost of digestion. Two of the beverage
alcohol plants surveyed currently use anaerobic digestion.
5.3 DISPOSAL AND MANAGEMENT PRACTICES
Solids which cannot be sold or recycled as well as treated,
stabilized sludge must be disposed of safely. Two methods for
ulSimaie disposl! of solid wastes are practiced by the beverage
alcohol and ethanol-for-fuel industries-, contract hauling to a
landfill and land application.
Contract Hauling to a Landfill. Options for solid waste
al by landfill for wastes which have been stabilized to reduce
odor and sufficiently dewatered for handling Purposes (> 20 per-
cent solids) (31) include handling and disposal by the ethanol
Sroducinq facility on-site, contract hauling and placement
^n-si?e?9anrcontract hauling to a landfill site not owned by by
the ethanol facility. The common practice to date for beverage
SSohS JlinS whicS produce a secondary treatment sludge is to
hire a contractor to remove and dispose of the solid waste.
196
-------
The economics of the disposal of industrial wastes by contract
methods are a function of location, method of disposal, and the
distance from the plant to the disposal site. Sanitary landfill
of a solid waste represents a relatively inexpensive form of
disposal (32).
Land Application* Stabilized sludge may be land applied in
either liquid or semi-solid form. If applied as a liquid, the
sludge contains 90 to 97 percent water. If applied as a semi-
solid, the sludge contains 60 to 80 percent water. Currently,
only one ethanol-for-fuel plant in operation uses land
application as a means of sludge disposal.
According to Gulp (33), there are two approaches for land
application of sludge: (1) apply the sludge to land used for
growing agricultural products or other vegetation, or (2) dedi-
cate an area to sludge disposal with no attempt to grow crops.
The advantages of using farmland for disposal are the use of
nutrients in the sludge such as nitrogen and phosphorus. Care
must be taken, however, to avoid pollution of the ground water
or heavy metals buildup in the soil and food chain. Heavy
metals buildup can be controlled by monitoring the loading rate
at which the sludge is applied and periodically testing the soil
for heavy metals buildup. The sludge loading rate can then be
adjusted, as required to comply with development of the regula-
tions. Although application of sludge to forest or agricultural
land poses possible health, safety, and odor problems, it might
be the most feasible method of ultimate sludge disposal/
management from an economic as well as environmental point of
view.
197
-------
-------
SECTION 6
COST, ENERGY, AND NONWATER QUALITY ASPECTS
OP WASTEWATER TREATMENT
In order to as-sess the overall economic impact of pollution
control on the ethanol-for-fuel industry, an engineering an-
alysis was conducted to determine: (1) the typical wastewater
Shn^t-Pr°b/tI!lS.2f thS industrv' <2) the applicable treatment
technoloies
hn-/. ' e rea
technologies, (3) the cost and energy requirements of these
technologies, (4) the effectiveness of these technologies in
reducing pollutant discharges from the industry, and (5) the
nonwater quality impact from the proposed regulations.
An economic impact analysis was also performed to investigate
5?? ™^*Y °f i^ust^Y to pay the cost of wastewater treatment.
The results of this analysis for the ethanol-for-fuel industry
are beyond the scope of this document and are presented in a
separate EPA document (34).
6.1 MODEL PLANT COSTING
6.1.1 MODEL PLANT CONCEPT
In order to conduct an economic impact analysis of an industry,
model plants are developed. A model plant is an engineering
concept useful in attempting to assess overall industry costs
from technologies which must be designed on a plant-specific
basis. Rather than calculate the individual cost of installina
wastewater treatment systems at each plant in the industry and
summing these costs, the Agency bre.aks the plants down into
groups and lets each group of plants be represented by a model
plant.
To calculate the total industry cost of installing a particular
technology using the model plant concept, the cost of installing
the technology at each of the model plants is first estimated.
Since the model plants cover the same general range of produc-
tion capacities as the real plants, any economies-of-scale or
other size-related effects on the cost of the technology are
incorporated in the cost estimates. The total cost to the
industry is calculated by multiplying the cost of a given
technology for a model plant by the number of real plants that
the model plant represents.
198
-------
-------
6.1.2 SIZE DISTRIBUTION OF ETHANOL-FOR-FUEL MODEL PLANTS
The existing ethanol-for-fuel industry and future growth trends
were described in Section 2, Industry Profile. For this study
which was performed in 1981, it was assumed that a very substan-
tial increase in the number of ethanol plants was expected in
the next 10 years, with a wide range of production capacities.
The plants were classified as new or existing plants. Existing
plants include those which are in operation as well as those
under construction. The new plants include those for which
construction is initiated after this study. The proposed
facilities discussed in the industry profile were used to
characterize the new plants.
After a thorough -review of all the available information on new
and existing plants, five model plant production capacities were
selected as indicated in Table 6-1. These sizes were selected
because they covered the full range of expected plant sizes and
best represent the distribution of plants. The number of plants
of each size for each plant type is shown in Table 6-1. In 1981
there were 15 currently operating ethanol-for-fuel facilities
and 35 under construction; there were 42 proposed plants in some
stage of discussion or planning.
6.1.3 MODEL PLANT WASTEWATER CHARACTERISTICS
Typical characteristics of the raw wastewater produced by an
ethanol-for-fuel plant are presented in Table 6-2. These char-
acteristics were used to represent the untreated effluent in all
of the treatment system design work presented here. Table 6-2
was prepared by analyzing all the available data on ethanol-
for-fuel untreated effluent including: (1) long-term data (six
months or more) available from four ethanol plants, (2) EPA's
sampling data as discussed in Section 3, and (3) various sources
from the literature (14,25,35,36).
The available data for the facilities examined indicate wide
variation in wastewater characteristics;.influent BODs ranges
from 500 to 2,400 mg/1 with an industry mean of 1,406 mg/1. As
indicated in Table 6-2, a value of 1,500 mg/1 was selected to
represent the untreated effluent BODs concentration for the
model plants. Values for influent TSS and the other parameters
listed in Table 6-2 were selected in a similar manner.
There was no information available which indicated that waste-
water concentration varied as a function of size. Thus, the raw
wastewater composition shown in Table 6-2 has been assumed to
describe the wastewater at all five model plants.
6.1.4 MODEL PLANT FLOW RATES
A wastewater treatment plant design is based on both the raw
wastewater concentration and flow rate. To assign a wastewater
199
-------
.1
vo
a)
r-4
•8
H
o
in
«•>©
«
u
•
a
«
§
eo «
e o.
•So
m
e
o
4,1
£
•8
g.
o
•200
-------
Table 6-2
UNTREATED EFFLUENT CHARACTERISTICS
USED IN THE DESIGN AND COSTING OF WASTEWATER
TREATMENT SYSTEMS FOR ETHANOL-FOR-FUEL PLANTS
Total
Dissolved
Total Suspended Solids (TSS)
Total Kjeldahl Nitrogen (TKN)
Ammonia (NH4-N)
Total Phosphorus
pH range
Concentration
(mg/1)
1,500
1,100
500
3
0
7
4-11
201
-------
flow rate to each of the five model plants, a general relation-
ship between wastewater flow rate and plant production capacity
was developed. The data available for the development of model
plant flow rates are presented in Table 6-3. As shown in Table
6-3 the data consist of average wastewater flow rate and
average ethanol production for a total of 18 facilities,
including both ethanol-for-fuel plants and beverage alcohol
plants. Also shown in this table is the ratio of wastewater
flow rate to ethanol production.
The ratios of wastewater generated to ethanol produced are shown
plotted versus plant capacity in Figure 6-1. These data indi-
cate that the wastewater-to-ethanol ratio varies from 6.9 to
33.7 and does not increase or decrease as a function of plant
size. This indicates that the wastewater flow rate varies
linearly with plant production capacity. The median was se-
leeted to be used in relating model plant capacity to wastewater
flow. Thus, since the median has a value of 16, each model
plant has a wastewater flow rate equal to 16 times the model
plant ethanol production capacity.
6.1.5 MODEL PLANTS SUMMARY
A summary of the characteristics of the model plants is presen-
ted in Table 6-4. Grain consumption was calculated by assuming
that 1,000 kilograms of corn can produce 0.37 cubic meters of
ethanol. This is equivalent to assuming 2.5 gallons of ethanol
per bushel of corn, where a bushel of corn weighs 56 pounds.
Plants were assumed to be producing alcohol only 330 days per
year; the remaining 35 days are devoted to equipment cleaning
and shut-down for maintenance and repairs. Thus, in calculating
daily wastewater flow from yearly ethanol production, it was
assumed that the entire yearly production of ethanol was Pro-
duced in only 330 days. On the other hand, wastewater treatment
O&M costs were calculated on the basis of 365 days per year.
This assumes wastewater flow continues even during periods of no
ethanol production (e.g., during plant cleanups).
The wastewater flow rate for each of the model Plants was calcu-
lated by assuming a wastewater-to-ethanol ratio of 16, as dis-
cussed in the section on the flow prediction. These flow rates,
along with the concentration values given in Table 6-2, were
used as the basis for the treatment systems costs presented in
the following sections.
in 1981, all beverage alcohol and ethanol-for-fuel producers
sold the beer still bottom stillage, either as wet or dried
by-products, for animal feed because of a viable market for
these high-protein by-products. Further, the market for these
bv-products was projected to double by 1985 to 1986 28).
Therefore, no cost for treatment or disposal is considered in
the cost analyses for the stillage or by-product processing.
202
-------
Table 6-3
PRODUCTION AND WASTEWATER GENERATION DATA FOR
BEVERAGE AND ETHANOL-FOR-FUEL PLANTS
Ethanol
Wastewater
Ratio of Wastewater
Production to Ethanol
Plant
Code
A03
A06
A07
A10
E02
E04
EOS
E06
E07
EOS
E09
Ell
E12
E13
E15
E17
E18
E19
Production
(m3/day)
200
24
70
21
30
25
52
43
47
32
230
45
44
90
23
23
23
118
Production
(mVday)
2,650
170
1,290
340
760
400
830
610
570
610
7,650
1,100
820
1,320
380
380
350
1,550
Production
(Dimensionless)
13.3
6.9
18.5
16.2
25.0
15.7
16.0
14.2
12.0
19.1
33.7
24.4
18.6
14.7
16.2
16.5
15.3
13.1
203
-------
o
o
13
KQ
taB
00
o
gaS
?5 O
11
siw
0
o
H
H
32
30
28
26
24
22
20
13
16
14
12
10
8
6
EC
Se\i
_
_
©
- ' E°2Efl
•
'
""" ' .
•
E°8 ° °
PI 9 A07
.^AM <2?E15_0 f_i^LZ_ , , ;
©E04 E05
© ©
E18 © E13
"" E06
O ©
_ E19
E07
—
_
0
£Q6 1 1 1 f II II I I
20 40' 60 80 100 120 140 160. 130 200 220
ETHANOL PRODUCTION (m3/day)
Figure g-i
RATIO OF WASTEWATER GENERATED TO ETHANOL
PRODUCED VERSUS ETHANOL PRODUCTION
204
-------
T
VO
Q)
JQ
to
£H
CO
u
M
EH
'Ji
06
H
*^
o:
t^
3!
U
£4
z
g
i«4
Da
a
o
X
b
O
a:
f^
•£
JE
CO
Q>
i
0
Cb
Q)
4J
10
»
0)
4J
(0
10
^^
>
•c
e
oooo
VO VO Ol fH
in co i^. <^
fH en e^
^
03
^
fH
<0
CT
o
^J
^^
u> en oo vo
fH ^* 9* ^
o o o fs
o
JJ
0
3
O
ft
0
(0
JC
M
i4
\
g
^^>
oooo
o o o o
TT CM f- 0
-JJ" r~ m os
,U E t- oo
*^
^
^
(0
D
O
fH
«•"
m 2 S S
^
O
fH
4J
Q
e
3
0)
C
o
c
•fH
j cr» t^ o
o? o -H m
CO VO "">
^
^
<0
^
0)
o
4J
id
fH.ua>
» c ja
•o •*
0
0
fc
(M
O
in
0
0
o
in
o
o
{*)
pa
0
-0-
in
205
-------
The characteristics of the biosludge and the amount produced at
each facility were based on the model plant wastewater treatment
system design. The biosludge from the secondary clarifier has a
solids concentration of 10,000 gTSS per cubic meter (one percent
solids). Table 6-5 indicates the estimated sludge production
from the clarifier for the wastewater treatment options
developed for the five model plants.
6.2 TREATMENT OPTIONS FOR COST EVALUATION
6.2.1 WASTEWATER TREATMENT OPTIONS
There are a wide variety of treatment technologies which are
appropriate for the wastewaters produced by an ethanol-for-fuel
plant. Technologies differ with respect to cost and final
effluent quality. Four different direct discharge treatment'
options were selected for detailed economic evaluation:
Option 1 - Use of aerated lagoons for secondary treatment.
Option 2 - Use of activated sludge for secondary treatment.
Option 3 - Use of aerated lagoons for secondary treatment,
followed by granular media filtration.
Option 4 - Use of activated sludge for secondary treatment,
followed by granular media filtration.
Aerated lagoons and activated sludge are both widely used in the
beverage alcohol and ethanol-for-fuel industries. Granular
media filtration can follow either aerated lagoons or activated
sludge and will bring about significant additional suspended
solids removal (40 to 50 percent).
No treatment options have been considered for indirect dis-
chargers (those who discharge their wastewaters to publicly
owned treatment works). Based on the analytical data presented
in Section 3, no pollutants are present in ethanol-for-fuel
wastewaters which would upset or interfere with the operation of
a publicly owned treatment work. However, developers of an
ethanol-for-fuel plant should consult the general pretreatment
requirements contained in 40 CFR, Part 403 to ensure that such
standards are met.
6.2.2 SOLID WASTE TREATMENT OPTIONS
As identified in Section 5.3, there were four methods practiced
by the ethanol-for-fuel industry to treat and dispose of
biosludge in 1981.
1 Dewatering, stabilization, further dewatering; and
either contract hauling, landfilling, or land application.
206
-------
Table 6-5
BIOSLUDGE PRODUCED DURING WASTEWATER
TREATMENT FOR ETHANOL FACILITIES
Model Plant Alcohol
Production Capacity
(10 qal/yr)
11,400 (3)
37,900 (10)
75,700 (20)
189,000 (50)
454,000 (120)
Sludge Produced
m3/Year
8,180
27,380
54,750
138,700
328,500
Treated Sludge
to Landfill
(1,000 kq/yr)
139
462
945
2,355
5,640
207
-------
2 Dewatering, stabilization, lagooning; and either
extract hauling, landfilling, or land application.
3. Dewatering, inclusion in by-products.
4. Dewatering, land application.-
For the purpose of performing the cost analysis, the ff«fc
^rLtment and disposal option is selected since it is the most
cIpSrin?ens?vIPoptionPand would provide the most conservative
or "worse case" impact.
actual treatment train used in the cost analysis consists of
$66 per metric ton of sludge.
6.3 CAPITAL AND OPERATION AND MAINTENANCE COSTS
6.3.1 WASTEWATER TREATMENT COSTS
Capital costs of wastewater treatment for all four treatment
the site of an existing ethanol-for-fuel plant.
SS 2 rgSSE
.
posal! The annualized cost of capital is not included.
all costs are in March 1980 dollars. Adjustments for inflation
can be mfde using tSe EPA SCCT cost index which had a value of
162.2 in March 1980.
A schematic flow diagram for treatment Options 1 and 3 is shown.
tn Piaure 6-2 The aerated lagoon system (Option 1) includes
and a centrifuge for solids dewatering. The Option 3 system is
?Sen?icIl to the Option 1 system except that the effluent from
t£rseconda?y clarifier receives additional treatment by
granular media filtration.
208
-------
Table 6-6
ASSUMPTIONS USED IN THE DESIGN OF THE SOLID WASTE
HANDLING SYSTEM
Gravity Thickener (22)
Solids Loading Rate (SLR): 20,000 g TSS/m2/day
Underflow Concentration: 30,000 g TSS/m-*
Aerobic Digester
Reduction in Volatile Suspended Solids: 35 percent
Centrifuge
Solids Capture: 80 percent
209
-------
s
1
CO
H
CO
o
" ^
w SI
J w 2
5jH 3
SS 1
V • ^1
P^ •J M
0
0 300
JITJOi-l
W U^K
Bum
•^ f*%
r*» ^^
(M
C >i»^
§ So^o
«C *O O *H
AJ O C7^
1 '"'oiiNr *
I me
u a
I r1 '
e 5-^
l^il
lit!
w u •
OM «*•* !
1-1
P
rn g s s
f*» ** O "^
• • * ^
^ 4. •« -»
s °
i i- • °1
'- «N «
^
»
1
1 S S S g
« « « 2-
; — ~ — ^
<
•>
•S H
«
.
<
S "S | |» « 55
i^ 2 5 S.|B |-lc
u Sz '4^ 9
•S-g
H §
9*4
•«i|
U2L
CO
0) CU
M •
CJ>«4
4J 4J
^S-0
a S
1 0
r4 U
82
tri
4J
M "
= S
4J O
o oo
•rf e.
Ou fl>
e
0 0
h b
^4 Of
*00
•o^
CO 4J
Sm
Sij
ta
« 0
X u
•S*«
2^.
u
n a
0 «
CJ 4)
^d U
«e 5
••
«
4J
1
-------
00
vo
4 M
OX
W
g
^gg
s
^^
CO
h
u»»
-JTi"
O JJ vo
0 3 O f
5"§^> M
u £«^
a. mo
•«* w
•*
1
i § §
oo to 0<
^ o^ o
M i-t CM
O^ 9
O JJ
£-DO —
jj 5 •
o«S **
— o
ut
O
1 • 1
X
B X»H
ajj. a
S^uTi M
u so
9 300
JJ Oh*"
^ICo
e- iT 7
XM
o^» a
e u vo
g 300
.ciaoi-)
W M -X
f* O
o o e
vo ir> vo
O
i - !
. tjl
g^^J
"O^TB S
0 3 O^C
js-aoo
jj osr>-i
fal b «
BUM X
•M
000
CM |M jj •>*
9 ** a -o
b jj u e a
« U « 3S B
^ < <>^ o
M O.fc~4
E O E<-4 9
BO B60 BO3U
OO O*O OOBJJ
•^ 60 •* 3 «^ OCOJ-N
H &.J e.09 eu«J u fa.
O O o
§
O
CM
§
o"
o
vO
irt
S
f^
0
tM
^
Q)
M
1 5
tjjjzg
-» « jj
C 60*3 2
5-§gi
JJi-* hi w4
o09
^3
J
4J
o
3
14
e
B •
0-0
O V
n
ll
JJ B.
a
V 43
UJI
e
M"O
o 5
•§.
wri j_b
^^ **
If
jj a
ai
• jj
I*
o to
U B
31
^k 5i
If
B
52
* 0)
«-« a.
*«'
OO
O 0
OO JJ
£ «
* M B
« o
^6 W
5*3
sS
« Q
y
CO
vU (U
e a
O t)
ss
<5
• 9
«l
JJ
§
211
-------
»
u
1
VO
ojc/a
Sw
M
H
W H
MnJ
CO M
OO
U»»•«
i 3C50
jj or*
U b -X
CM
b
"-jsr*
*o4jTi M
CO NO
0 900
U b°ix
b >
^J^s
1 *Ti a
« §00
fooe
"1511
t-<
j
£
c
4
c
i.
1
1
o o o o
CM VO !•«• •-<
-< GO i-^ 0^
«»> CM W CM
go
f>
i n vo vo f<>
,
o *o
1 P» 1 OO
i m i m
-3- ON "I ' O
m m vo i*«
^ CM ** «M
1 "S
•O *J "O •"
t) « «i a a a
7J ^ ^ «^ ^ ^4
B —4 « 13 M tJ
S u Com jj a a)
S 0 0)9X0 U9SC
4* < < i-* O C ** 9 01^4 s)
co ceo eo9b c M9 b
OO O-O OOBJJ OT3 C 4J
•4«0 •»49 —4 00 0) 1-1 — 1 3 OJf-4
I U B Ui-4 U B f^— 1 4Ji-4 W-4
i a.>3 e»ca a. J C9 u. Q.W 13 b
000 0
U 0
12
1.
u m
§!H
4)
«i e
*:
u o
O M
1-4-O
5§
oL§"
9
U
fc.
SB
5-3
u
0«4
b O.
« «
O
a
4J Cl
gg «
9 «
"
|
212
-------
3
£
£
U
u
1
§7
•w4 ^
8.8-
I °
I £ -i-1
^
-r21 S£
sSji
s
s
I
U
5
!
ii
A u 5T
| WO
w g
« • •-
* -
ji
en
i
vo
-------
Options 2 and 4 are illustrated in Figure 6-3. Treatment up to
the aeration basin is identical with Options 1 and 3. An
activated sludge system differs from an aerated lagoon due to
the use of sludge recycle which allows higher biomass concen-
trltions to be maintained in the aeration basin Waste sludge
is sent to a gravity thickener and aerobic digester before
dewatering by9a solids centrifuge. The Option 4 system differs
from the Option 2 system only in the use of flranular media
filtration for additional solids removal before discharge.
Cost estimates were developed using standard design techniques
and published cost data or direct vendor quotes. Assumptions
used in the system design are presented in Table 6-10. Cost
estimation assumptions are presented in Table 6-11. Note that
all capital costs presented in this document exclude interest
during construction. The cost of interest during construction
variei as a function of interest rate and is discussed in the
economic impact study (31). For an interest rate of 10 percent
and an amortization period of 30 years, the cost of interest
during conduction will add an additional 5 to 10 percent to the
capital costs presented here.
6.3.2 SOLID WASTE TREATMENT COSTS
Capital costs for sludge handling for new and existing faci-
lities are presented in Table 6-12. Annual operation and
maintenance costs as well as energy requirements for the treat
ment and disposal of solid waste are also presented. Table 6-5
presented thl amount of treated sludge in metric tons per year
which must be hauled for landfill.
The only solid waste which has an economic imPac V°Vn
production facility is the biosludge from wastewater treatment.
Therefore, the costs associated with solid waste handling have
been included in the wastewater treatment costs.
6.4 NON-WATER QUALITY ASPECTS
The nonwater quality aspects of the presented treatment options
inclCde any solid waste disposal, air pollution, or energy con-
sumption problems that might be associated with the treatment
ootions The Agency gives consideration to nonwater quality
ilsues in order lo minimize cross-media conflicts; for example,
creatinq an air pollution problem while solving a water pol-
lllion IroSlem. Energy conservation is also a national Priority
and the Agency examines the energy requirements of each treat-
ment option to determine if a significant increase in energy
required per pound of product would result.
Solid Waste Disposal. All four of the wastewater treatment
options previously presented will produce significant quantities
of biological sludge. This sludge has been determined to be
214
-------
g
4*
*
* g
J • -S
« "«^ 4J
I1
j:
.0
CM
i
CO
S3
£ H
toO &4
0
en
S
6
2
215
-------
Table 6-10
ASSUMPTIONS USED IN SYSTEM DESIGN
Preliminary treatment consists of bar screening, grit removal,
and fTS measurement. These units were sized based on maximum
flow rate.
p.v, wastewater pumping capacity was set to provide a firm pumping
capacity equal to tne maximum flow.
Eaualization basin volume is set equal to 20 percent of total
dai?y llow volume.' In the activated sludge system a concrete
basin was used. The aerated lagoon system uses a lined earthen
basin.
na lim f system are included. Average chemical doses over
a 24-hour period are 200 mg/1 CaO and 47 mg/1 H2SO4.
Nutrient addition is necessary because wastewater is high in
and low in both nitrogen and phosphorus. Required chemi-
dosaoes are calculated on the basis of cell growth by assum-
^^^^
coefficient equals 0.45 mg VSS per mg
kind often sttles porly. As an aid to settling, secondary
ciaririer i! dosel w?th 17 mg/1 of ferric sulfate (^2804).
Ae?aJion system was designed by considering oxygen demand and
mixing Requirements. A diffused aeration system was selected and
75 cubic meters of air were applied for each kilogram of BOD5
removed.
Aerated lagoon system was designed using a first order
model with a kinetic constant value of 2 day A. This
in a hydraulic residence time of 25 days. The aerated lagoon
consists of a lined earthen basin with surface aerators. A
cemlnf circufar clarifier is used after the lagoon for suspended
soTiSs removal. Aerators transfer 2.1 pounds oxygen per
horsepower-hour .
216
-------
Table 6-10 (Continued)
ASSUMPTIONS USED IN SYSTEM DESIGN
Sludge handling system consists of sludge thickener, aerobic
digester, and solids centrifuge for the activated sludge system.
Sludge thickener size for solids loading of 20 kilograms of TSS
per square meter per day. Aerobic digester achieves 35 percent
volatile suspended solids reduction. Centrifuge has 80 percent
solids capture and produces a final sludge with 20 percent
solids.
Granular media filtration used filtration rate of 2 to 5 gallons
per minute per square foot.
217
-------
Table 6-11
ASSUMPTIONS USED IN COST ESTIMATION
1. Date basis for all costs is March 1980 at which time the EPA
SCCT Cost Index had a value of 162.2.
2. Cost estimates were developed from direct vendor quotes,
material take-off calculations, and the following published
data sources: Benjes, 1980; Conway and Ross, 1980; Gulp,
1980; EPA a, 1975; Gumerman et. al., 1979; and Patterson and
Banker, 1971.
3. Yardwork is 14 percent of total installed unit process
costs.
4. Engineering and contingency are each 10 percent of the total
direct construction cost.
5. Land cost was assumed to be $15,000 per acre for aerated
lagoons and $30,000 per acre for activated sludge.
6. Working capital was assumed to be 20 percent of annual O&M
cost.
7. Labor wage is $11.00 per hour direct plus 15 percent for
indirect costs (medical, insurance). Net rate is $12.65 per
hour.
8. Electricity costs $0.035 per kilowatt-hour.
9. Chemical costs are as follows:
Chemical
Lime (pebble quicklime)
Sulfuric Acid
Phosphoric Acid (75% solution)
Ammonia (Aqua-ammonia, 30%
Ferric Sulfate, 94%
$ 65/ton
$ 70/ton
$ 460/ton
$ 225/ton
$ 146/ton
All costs above include shipping to the plant site.
10. Sludge disposal costs $60/ton including hauling from plant
site to landfill.
218
-------
>t
Jj — '
0 >
4J.C
0 S
a> us
o
CM
m
r-
o
ft
o
o
CO
_
^*
fl
O
o
00
CM
CM
O
o
VO
00
^*
p*
o
o
o
0
*H
M.
O
0)
£ to
«« O' .
O Ow-
O
tn
r-
m
o
o
ts
co
O
z
z
<
X
ta
H
CO
I
a) 2
•H
JD a
(0 M
co
Cu
O
CO
o
U
4J
to
0
u
ft
(0
'a
IQ
u
n
0)
•1-1
4J
•H
u
(0
ba
O
•H
4J
(0
•rH
M
U
o o o o
o o o o
Tp O ••* CTt
^> oo ve co
^H CO ft fl
m vo OT\ PO
ft
to-
to
Q>
•1-1
4J
•H
ft
•I-l
u
fl
Cu
0)
Z
0)
M —
•H >
co a
C £
(Q £
o o o o
o o o o
c-» ft oo en
en* en CM en
o ^* PO m
^« m r- o
i— t
CO-
PO O O O
ft CM m
o
o
%
00
r-
CM
O
O
°1
m
en
^j
^^
o
o
*"*
e
o>
•d
CO
0)
•o
4J
C
i
4J
(0
0)
f
4J
(U
4J
(0
0)
4J
to
(0
Q>
4J
•O
«)
•o
•H
> •
O (0
U 0>
a-*
o»
e o
(I) iH
4J nj
C Q)
U
•i-4 Q)
<44 4J
«W tO
3 flJ
CO »
•K
219
-------
nonhazardous and, in some cases, can be recovered and sold with
the by-product grains. If this sludge is not recovered, it is
usually dewatered and stabilized before contract hauling to a
landfill. No further wastes are generated by sludge treatment.
Wastewater overflows from the gravity thlc*en*%and solids cen-
trifuge used to dewater the sludge are sent to the aeration
basin lor treatment. Also, stabilization of the sludge reduces
any odors emitted from the thickened sludge. Section 3.-7 pre-
sented a detailed discussion of solid wastes associated with
ethanol-for-fuel production and methods of recovery, treatment,
and disposal.
Air Pollution. No serious air pollution problems are -antici-
pated as a result of implementing any of the control techno-
logies evaluated in this cost analysis. Potential odor P^lems
could be encountered in operating secondary biological treatment
Systems, but this should not be a serious problem when systems
arl operated properly. Section 3.6 presented a detailed dis-
cussion of air pollution problems associated with ethanol-
for-fuel production.
Energy Requirements. Table 6-13 presents energy requirements
for treatment options 1 through 4. Although energy ^u^ents
constitute a major portion of the O&M costs of the treatment
system, none of these treatment systems would result in a signi-
filant increase in the overall energy requirements of a typical
ethanol-for-fuel plant.
220
-------
H
CO
is
s
Sco
^S ^
l_^ 5** ^^
11 1
Qr^J «^
S* 1
OS .1
>» B3 •*
095 ,
p"* u
ca |
H H
•< CO
&M
Sx
H W
CO
)
fc^^1
C ^S^^
o-^. «
f4 *<")fO Ct(
0 4J •
B a xo
Jg 300
JJ Of^"1*
"£So
5 1. -S 1
o* 53* -T o"
<-• — f-t ^<
SI
h*%*
-If"
O *J •
£ Sj _*
5-88-
W b «X
?l Ift
b
B X-£
f-«
Bu« X
^^
B
0
S o i»
»-• <-4 CM <-T
3 2
v * "« « « a
4J ^ ^ ^4 S ^2
g ^ « «o 5 ?
b JJ bOBW 4J CO W
Jl ^ ^5S§ ^5si
"B "*« "B^? ^^J"
co coo eosh e S"D u
O O O T3 O 0 C 4J O *O C fcl
*J S? £— Scfb^ i5 S52
221
-------
GLOSSARY
absolute ethanol: Dehydrated ethyl alcohol of the highest proof
obtainable (200° proof), also called anhydrous ethanol.
absorption: The taking up of one substance into the body of
another.
acid hydrolysis: A kind of cellulose-to-sugar conversion
process which uses acid (sulfurous acid) to break down the
cellulose. Urban waste and vegetable residues can be
turned into ethanol by this process.
activated sludge: Sludge floe produced in raw or settled
wastewater by the growth of zoogleal bacteria and other
organisms in the presence of dissolved oxygen and accumu-
lated in sufficient concentration by returning floe
previously formed.
activated sludge process: A biological wastewater treatment
process in which a mixture of wastewater and activated
sludge is agitated and aerated. The sludge is subsequently
separated from the treated wastewater (mixed liquor) by
sedimentation and wasted or returned to the process as
needed.
adsorption: The adherence of a gas, liquid, or dissolved
material on the surface of a material.
aerated lagoon: A natural or artificial wastewater treatment
pond in which mechanical or diffused-air aeration is used
to supplement the oxygen supply.
aerobic: A condition in which free, elemental oxygen is
present.
alcohol: A class of organic chemicals composed of carbon,
hydrogen, and oxygen which include methanol, ethanol, and
other alcohols; most all alcohols will produce a flame when
ignited in air.
aldehyde (Webster): Any of various highly reactive compounds
typified by acetaldehyde and characterized by the group
CHO. A volatile fluid obtained by the oxidation of
alcohol.
alkalinity: Alkalinity is a measure of the capacity of water to
neutralize an acid.
anaerobic: A condition in which free, elemental oxygen is
absent.
222
-------
anaerobic fermentation: The process whereby chemicals (espe-
cially starches and sugars contained in many agricultural
crops) are broken down by bacteria and yeasts in the
absence of free oxygen to produce alcohols.
anhydrous: Means "without water." The ethanol contained in
gasohol is usually anhydrous; even very small amounts of
water in ethanol may cause separation of the ethanol
gasoline mixture.
apparent proof: The equivalent'of proof for ethyl alcohol
solutions containing ingredients other than water.
ATF (Bureau of Alcohol, Tobacco and Firearms): Federal agency
responsible for the licensing and regulation of alcohol
production and sales. A division of the Department of
Treasury.
backwashing: The operation of cleaning a filter by reversing
the flow of liquid through it and washing out matter
previously captured in it.
bar rack: A screen composed of parallel bars, either vertical
or inclined, placed in a waterway to catch debris.
barometric condenser: See condenser, barometric.
basin: A natural or artificially created space or structure
which has a shape and character of confining material that
enables it to hold water.
beer: The liquid containing mash which has been fermented in an
ethanol-for-fuel plant. It contains 10 to 12 percent
ethanol.
beer still: A distillation column in which the beer is stripped
of the ethanol, producing an 80 percent ethanol product.
benzene recovery column: A column in which the benzene and
ethanol are stripped from an ethanol/water rich inlet. The
benzene and ethanol are recycled to the dehydration column
while the residual water is sent to the waste treatment
plant.
biochemical: Pertaining to chemical change resulting from
biological action.
bio-degrade: To biologically reduce the complexity of a chemi-
cal compound or substance by splitting off one or more
groups or large component parts; decompose.
223
-------
bio-dearadability: The destruction or mineralization of either
natural or synthetic organic materials by microorganisms.
biological filter: A bed of stone or other medium through which
wastewater flows or trickles that depends on biological
action for its effectiveness.
biological wastewater treatment: Forms of wastewater treatment
in which bacterial or biochemical action is intensified to
stabilize, oxidize, and nitrify the unstable organic matter
present. Intermittent sand filter, contact beds, trickling
filters, and activated sludge processes are examples.
biomass: Living matter, vegetation or any plant material, now
in a state of decay, including animal and human waste, that
may be used to produce energy.
BOD (Biochemical Oxygen Demand): A semiquantitative measure of
bioloqical decomposition of organic matter in a water
sample. It is determined by measuring the oxygen required
by microorganisms to oxidize the contaminants of a water
sample undlr standard laboratory conditions. The standard
conditions include incubation for five days at 20 C.
BOD load: The BOD content, usually expressed in mass or weight
per unit time, of wastewater.
boiler blowdown: Discharge from a boiler system designed to
prevent a buildup of dissolved solids.
boiler feedwater: Water used to generate steam in a boiler.
This water is usually condensate, except during boiler
startup, when treated fresh water is normally used.
brine: Concentrated salt solution remaining after removal of
distilled product.
brix: A reading on a hydrometer scale which represents weight
percentage of sugar in solution at a specified temprature.
bulking sludge: An activated sludge that settles poorly because
of a low density floe.
bushel: The weight of grain contained in a bushel varies by
industry as follows: (a) Barley = 22 kg (48 Ib)
(b) Malt = 15 kg (45 Ib) (c) Distillers Grain = 25 kg
(56 Ib).
capital costs: Costs which result in the acquisition of, or the
addition to, fixed assets.
224
-------
cellulosic: Refers to chemicals contained in crop stalks,
forest residues, and substantial portions of urban wastes;
treatment of cellulosic materials with acids or enzymes
will yield fermentable sugars which can be converted to
alcohols.
clarification: Removing undissolved materials from a liquid by
settling, filtration, or flotation.
clarifier: A unit of which the primary purpose is to reduce the
amount of suspended matter in a liquid.
coagulation: In water and wastewater treatment, the destabili-
zation and initial aggregation of colloidal and finely
divided suspended matter by the addition of a floe-forming
chemical or by biological processes.
COD (Chemical Oxygen Demand): Its determination provides a
measure of the oxygen demand equivalent to that portion of
matter in a sample which is susceptible to oxidation by
strong chemical oxidant.
column bottoms: The less volatile component in a distillat/ion
column comes off the bottom while the more volatile
component is vaporized and comes off the top. The less
volatile component makes up the column bottoms.
comminute: To reduce to minute particles or fine powder; to
brealc up, chip, or grind; to pulverize.
composite sample: A combination of samples taken at selected
intervals to minimize the effect of the variability of
individual samples and are proportional to the flow at time
of sampling.
concentration: The amount of a given substance in a unit
volume. For wastewater, normally expressed as milligrams
per liter (mg/1).
condensate: Water resulting from the condensation of vapor, as
in an evaporator.
condenser: A heat exchange device used for condensation.
barometric: Condenser in which the cooling water and the
vapors are in physical contact; the condensate
is mixed in the cooling water.
surface: Condenser in which heat is transferred through a
barrier that separates the cooling water and the
vapor. The condensate can be recovered sepa-
rately.
225
-------
continuous fermentation: A fermentation process in which the
yeast is separated from the fermented mash and recycled to
the fermenters.
conversion ratios:
1. 1 bushel of corn yields 2.73 gallons of 190 proof ethanol.
2. 1 bushel of corn yields 2.55 gallons of 200 proof ethanol.
3. 1 barrel = 42 gallons.
4. 1 bushel of corn weighs 56 pounds.
5. 1 gallon of ethanol weighs 6.6 pounds.
6. 1 ton of crop residue contains .8 tons of fermentable sugar,,
7. 1 ton of fermentable sugar yields .5 tons of 200 proof
ethanol.
i
cooling tower blowdown: Discharge from a cooling tower system
designed to prevent a buildup of dissolved solids.
decanting: Separation of liquid from solids by drawing off the
upper layer after the heavier material has settled.
dehydration: The removal of all water from the ethanol. This
process must be accomplished by altering the azeotrope by
the addition of a third compound.
dehydration agent: That compound used to alter the water/
ethanol azeotrope to permit the dehydration of the
ethanol.
denaturant: A material added to ethanol to destroy its
character as beverage.
denatured ethanol: Ethanol which has been denatured pursuant to
completely denatured ethanol formulas prescribed by federal
regulations. Unfit for human consumption.
digestion: See sludge digestion.
dissolved solids: See solids.
distillate: Condensed vapors from the solution which form the
product of distilling.
Distiller's Dried Grains (DDG): A high protein (25 to 30
percent) by-product of the grain fermentation process which
is used for animal feed; large scale ethanol production
would substantially increase DDG by-products.
distillation: .A process of evaporation and recondensation used
for separating liquids into various fractions according to
their boiling points or boiling ranges.
226
-------
D.O. (Dissolved Oxygen): A measure of the amount of free oxygen
in a water sample. It is dependent on the physical, chemi-
cal, and biochemical activities of the water sample.
DOE: Department of Energy.
DOI: Department of Interior.
doubling: Redistilling spirits to improve strength and flavor.
"effect": In systems where evaporators are -operated in series
of several units, each evaporator is known as an effect.
EGD: Effluent Guidelines Division
energy economy: Heat release; Btu's per gallon; often expressed
in miles/100,000 Btu's.
entrainment: The entrapment of liquid droplets in the water
vapor produced by evaporation.
enzyme: Catalytic chemical substances responsible for alcoholic
fermentation.
enzyme hydrolysis: A technology which uses enzymes in yeast and
mildew to break down cellulose to sugar.
EPA: United States Environmental Protection Agency.
equalization basin: A holding basin in which variations in flow
and composition of a liquid are averaged. Such basins are
used to provide a flow of reasonably uniform volume and
composition to a treatment unit.
ethanol (ethyl alcohol): The common name for the hydroxyl deri-
vative of the hydrocarbon ethane which is also known as
carbinol, ethyl hydroxide, grain alcohol, fermentation
alcohol, cologne spirits, and spirits of wine.
ethanol-for-fuel plant: Those commercial-size (greater than one
million gallons per year) facilities that convert biomass
(via fermentation-)- to ethanol for use as a fuel.
evaporator: A closed vessel heated by steam and placed under a
vacuum. The basic principle is that syrup enters the
evaporator at a temperature higher than its boiling point
under the reduced pressure, or is heated to that tempera-
ture. The result is flash evaporation of a portion of the
liquid.
227
-------
excise tax exemption (gasoline)s P.O. 95-618 exempts gasoline
used for blending with alcohol from 4 cents Federal excise
tax. Many states have similar exemptions.
experimental permit: ATF temporary permit which allows experi-
mentation or development of materials for the production of
distilled spirits, processes for the production or distil-
lation of distilled spirits or industrial use of distilled
spirits. Ethanol produced cannot be sold or given away.
feedstock preparation: The process by which the raw material is
converted to a saccharified mash which can be fermented.
The process varies according to the feedstock used.
feed wort: A mixture of cane and beet molasses that is diluted
with water, clarified, sterilized, and pH adjusted, and
used to provide carbon, sugar, and other nutrients
necessary for yeast growth.
fermentation: The production of ethanol and carbon dioxide from
fermentable carbohydrates by the action of yeast.
fermentation ethanol: Ethanol obtained by the fermentation of
renewable biomass feedstocks.
FGD: Flue Gas Desulfurization.
filter: A device or structure from removing solid or colloidal
matter from a liquid. The filtering medium consists of a
granular material, finely woven cloth, unglazed porcelain,
or specially prepared paper.
filter press: In the past the most common type of filter used
to separate solids from sludge. It consists of a simple
and efficient plate and frame filter.
fixed beds: A filter or adsorption bed where the entire media
is exhausted before any of the media is cleaned.
flocculant: A substance that induces or promotes fine particles
in a colloidal suspension to aggregate into small lumps,
.which are more easily removed.
flotation: The raising of suspended matter to the surface of
the liquid in a tank as scum - by aeration, the evolution
of gas, chemicals, electrolysis, heat, or bacterial de-
composition - and the subsequent removal of the scum by
skimming.
fusel oil: An inclusive term for heavier, pungent-tasting
alcohols, principally anyl and butyl alcohols, removed
through rectification.
228
-------
Gasohol: A registered trademark held by the State of Nebraska
for a fuel mixture of 10 percent anhydrous ethanol and 90
percent unleaded gasoline; it is often used to mean any
mixture of alcohol and gasoline to be used for motor fuel.
germicidal treatment: Any treatment involving killing of micro-
organisms through the use of disinfecting chemicals.
GPD: Gallons per day.
GPM: Gallons per minute.
granular media filtration: A filtration process which consists
of passing wastewater through a packed bed of granular
material with the solids in the wastewater depositing onto
the granular media.
heads: A distillate containing a high percentage of low-boiling
.components such as aldehydes.
hydrolysis: The chemical splitting of a bond which results in a
new compound and water.
hygroscopic: Tending to absorb moisture from the atmosphere.
impoundment: A pond, lake, tank, basin, or other space which is
used for storage of wastewater.
industrial wastes: The liquid wastes from industrial processes,
as distinguished from sanitary wastes.
industrial wastewater: Wastewater in which industrial wastes
predominate.
ion exchange: A chemical process in which ions from different
molecules are exchanged.
ion exchange resins: Resins consisting of three-dimensional
hydrocarbon networks to which are attached ionizable
groups.
ketone (Webster): An organic compound with a carbonyl group
attached to two carbon atoms.
Kraus Process: A modification of the activated sludge process
in which aerobically conditioned supernatant liquor from
anaerobic digesters is added to activated sludge aeration
tanks to improve the settling characteristics of the sludge
and to add an oxygen resource in the form of nitrates.
lagoon: A pond containing raw or partially treated wastewater
in which aerobic and anaerobic stabilization occurs.
229
-------
lean fuel mixture: An excess of air in the air/fuel ratio.
Gasohol has a leaning effect over gasoline because the
ethanol adds oxygen to the system.
mash: Grain which has been steeped in hot water. During the
mashing process, the starch in grain is converted to
fermentable sugars.
mashing: The process involving cooking, gelatinization of
starch, and conversion, changing starch into grain sugar.
membrane technology: Works by a process of osmosis. In a
highly simplified explanation, the membranes act as a
screen or filter, only allowing certain substances to pass
through. A membrane would allow ethanol to pass through
while stopping stillage, sugars, and water. The final
result of membrane technology is two hundred proof ethanol
which is less expensive to produce.
metabolism: The sum of the processes concerned in the building
up of protoplasm and its destruction incidental to life;
the chemical changes in living cells by which energy is
provided for the vital processes and activities and new
material is assimilated to repair the waste.
raethanol (methyl alcohol): An alcohol which can be produced by
destructive distillation of wood or urban wastes and used
as a gasoline extender; most of the methanol used today is
produced from natural gas; coal may also be converted into
methanol; also known as wood alcohol or methyl alcohol;
methanol when mixed with gasoline, tends to separate from
the gasoline under certain conditions; methanol will also
enhance gasoline octane.
ug/1: Micrograms per liter (equals parts per billion (ppb) when
the specific gravity is unity).
MGD: Million gallons per day.
rag/1: Milligrams per liter (equals parts per million (ppm) when
the specific gravity is unity).
mixed liquor: A mixture of activated sludge and organic matter
undergoing activated sludge treatment in the aeration tank.
mixed media filtration: A combination of different materials
through which a wastewater or other liquid is passed for
the purpose of purification treatment, or conditioning.
moisture: Loss in weight due to drying under specified condi-
tions, expressed as percentage of total weight.
moisture content: The quantity of water present in a sludge
expressed in percentage of net weight.
230
-------
molassess A dark-colored syrup containing sugar produced as a
by-product in cane, citrus, and beet sugar processing and
in the production of citrus concentrates.
mostos: The stillage produced by cane and citrus molasses
distillers which has less nutritional value than grain
stillage.
multiple effect evaporation: The operation of evaporators in a
series.
municipal sewage: The spent water of a community. See waste-
water.
MSW (Municipal Solid Waste): In regard to this document the
term refers to waste with potential for conversion to
methanol.,
net BOD: The amount of BOD added by a process; the difference
between the BOD load of a plant's discharge and its intake.
neutralization: The process of pH adjustment which results in a
final solution pH of 7. Depending on the influent solu-
tion's pH, either acid or base is added to achieve a
neutral solution.
noncontact wastewaters: Those wastewaters such as spent cooling
water which are independent of the manufacturing process
and contain no pollutants attributable to the process.
NOX: Nitrogen Oxides.
NPDES: National Pollutant Discharge Elimination System.
NSPS: New Source Performance Standards.
nutrients: The nutrients in contaminated water are routinely
analyzed to characterize the food available for micro-
organisms to promote organic decomposition. They are:.
Ammonia Nitrogen (NH3), mg/1 as N Kjeldahl Nitrogen
(ON), mg/1 as N Nitrate Nitrogen (NOs), mg/1 as N;
Total Phosphate (TP), mg/1 as P Ortho Phosphate (OP),
mg/1 as P
O&G (Oil and grease): Wastewater parameter measuring nonsoluble
organic fraction.
Operating Permit for Distilled Spirits Plant: ATF permit
required if the distilled spirits plant will produce
ethanol only for nonbeverage industrial use (e.g., a
Gasohol plant).
231
-------
osmotic pressure: The pressure associated with the diffusion of
substances through a semi-permeable membrane, such as a
cell membrane. The osmotic pressure is related to the
molar concentration of the medium and the absolute
temperature.
OSW: Office of Solid Waste (EPA).
ozonation: The saturation of a solution with ozone, resulting
in disinfection of the solution.
PCTM: Pollution Control Technical Manual.
pH: pH is a measure of the negative log of hydrogen ion
concentration.
pitching: Adding yeast to a solution to cause fermentation.
PNA: Polynuclear Aromatics.
polluted wastewaters: Those wastewaters containing measurable
quantities of substances that are judged to be detrimental
to receiving waters and that are attributable to the
process.
polyelectrolytess Usage of this term in a document refers to a
coagulant aid consisting of long chained organic molecules.
POTW: Publically Owned Treatment Works.
ppb: parts per billion. See micrograms/liter.
ppm: parts per million* See milligrams/liter.
precoat filter: A type of filter in which the media is applied
to an existing surface prior to filtration.
preliminary filter: A filter used in a water treatment plant
for the partial removal of turbidity before final
filtration.
preliminary treatment: Those processes used to protect or opti-
mize the performance of downstream units at a wastewater
treatment facility. Preliminary treatment provides no
pollutant removal; it is a control system to ensure effec-
tive operation. The processes used are bar screening,
equalization, and neutralization.
primary treatment: The removal of suspended solids by physical
means. The processes used are coarse screening and sedi-
mentation, which remove approximately 10 percent of the
influent suspended solids*
232
-------
proof: Alcoholic content of a liquid at 16°C (60°F), stated as
twice the percentage of ethanol by volume (United States
definition).
proof gallon: A standard U.S. gallon containing 50 percent
ethanol by volume.
raw wastewater: Wastewater prior to treatment.
reboiler: A kettle used to heat the bottoms of a column which
will be recycled to the column inlet.
rectification: Usually referring to the redistillation of
certain goods for the purpose of increasing purity,
concentration, or quality.
returned sludge: Settled activated sludge returned to mix with
incoming wastewater.
rich fuel mixture: An excess of fuel in the air/fuel ratio.
ridge and furrow irrigation: A method of irrigation by which
water is allowed to flow along the surface of fields.
rotary vacuum filter: A rotating drum filter which utilizes
suction to separate solids from the sludge produced by
clarification.
rotating biological contactor (RBC): A set of molded disks that
have a thin biological film growing on the surface. These
disks are partially submerged in a cylindrical tank and are
rotated. RBC's are used for secondary treatment.
roughing filter: (1) A wastewater filter of relatively coarse
material operated at a high rate to afford preliminary
treatment, (2) For water treatment, see preliminary filter.
sanitary sewage, sanitary wastewater: Liquid wastes from
residences or commercial establishments, as distinguished
from industrial wastes.
secondary wastewater treatment: The treatment of sanitary
sewage by biological methods after primary treatment by
sedimentation, usually considered to remove 90 percent or
more of the influent BOD.
settleable solids: See solids.
settlings: The material which collects in the bottom portion of
a clarifier.
233
-------
settling pond: See clarifier.
sewerage: System of piping, with appurtenances, for collecting
and conveying wastewater from source to discharge.
skimming: The process of removing floating grease or scum from
the surface of wastewater.
sludge: The accumulated solids separated from wastewater during
treatment.
sludge cake: Sludge that has been dewatered to a moisture
content of 60 to 85 percent.
sludge dewatering: The process of removing the moisture content
of a sludge to such an extent that the sludge is spadable.
sludge digestion: The process by which organic or volatile
matter in sludge is gasified, liquefied, mineralized, or
converted to a more stable organic matter through the
activities of either anerobic or aerobic organisms.
sludge drying: The process of removing a large percentage of
moisture from sludge by drainage or evaporation.
sludge thickening: The process of increasing the solids
concentration of a sludge, but not to such an extent that
the sludge is spadable.
sludge handling: The transport, storage, treatment, and
disposal of sludge.
slurry: A watery mixture or suspension of insoluble matter.
solids: Various types of solids are commonly determined on
water samples. These types of solids are:
Total Solids (TS): The material left after evaporation and
drying of a sample at 100° to 105°C.
Dissolved Solids (TDS): The difference between suspended
solids and total solids.
Volatile Suspended Solids (VSS): Organic matter which is
lost when the sample is
heated to 550°C.
Settleable Solids (SS): The materials which settle in an
Imhoff cone in one hour.
234
-------
Total Suspended Solids (TSS): The material removed from a
sample filtered through a
standard glass fiber filter
and dried at 103° to 105°C.
solvent extraction: The stripping of a component of a solution
by use of a solvent.
SOX: Sulfur Oxides.
spadable sludge: Sludge that can be readily forked or shoveled,
ordinarily under 75 percent moisture.
spent beer: Residual nutrients separated from harvested yeast
by centrifugal separation.
spent grains: Residual grains following their utilization in
the processing of ethanol. These by-products are usually
marketed as animal feeds.
spent sulfite liquor (SSL): The lignins/sugar solution
separated from the fibrous cellulosic material in wood
preparation.
spray evaporation: A method of wastewater disposal in which
water is sprayed into the air to expedite evaporation.
spray irrigation: A method of irrigation by which water is
sprayed.
stillage (or still slops): The waste dealcoholized liquid from
the beer stills.
synthetic ethanol: Ethanol produced from ethylene as opposed to
fermentation ethanol, which is obtained from the fermenta-
ation of renewable biomass sources.
tax-free alcohol: Pure ethyl alcohol withdrawn free of tax for
government, for science or for humanitarian reasons. It
cannot be used in foods or beverages. All purchases out-
side of the government must obtain permits, post bonds, and
exert controls upon storage and use of tax-free alcohol.
tax-paid alcohol: Pure ethyl alcohol which has been released
from Federal bond by payment of the Federal tax of $21.00
per gallon at 200 proof or $19.95 per gallon at 190 proof.
tertiary treatment: The processes which follow secondary treat-
ment in a wastewater treatment facility. These processes
provide further removal of pollutants and are granular
media filtration, land application, and air flotation.
235
-------
TOG: Total Organic Carbon.
TSP: Total Suspended Particulates.
TSS: Total Suspended Solids.
VOC: Volatile Organic Carbon.
volumetric fuel economy: Miles per gallon.
whey: The water part of milk separated from the curd in the
process of making cheese; it is a by-product produced
commercially in large quantities and can be used as a
fertilizer, animal feed or in the production of ethanol.
yeast: Microscopic unicellular organism responsible for
alcoholic fermentation.
236
-------
REFERENCES
1. Potter, F. L., U.S. Alcohol Fuels Industry Data Base,
Information Resources Incorporated, Washington, DC, (1984).
2. Cheremisinoff. Gasohol for Energy Production. Ann Arbor
Science, Ann Arbor, Michigan, (1979).
3. U.S. DOE. First Annual Report to Congress on the Use of
Alcohol in Motor Fuels. Office of Alcohol Fuels.
Washington, D.C., April 1, 1980.
4. U.S. DOE. The Report of the Alcohol Fuels Policy Review.
Washington, D.C., DOE/PE-0012, June 1979.
5. Burnstein. Protein Production from Acid Whey via
Fermentation. EPA, Office of Research and Development.
Washington, D.C., (1974).
6. Caribbean Rum Study; Effects of Distillery Wastes on the
Marine Environment. Office of Research and Development.
Washington, D.C., April 1979.
7. Study of Rum Distillery Waste Treatment and By-Product
Recovery Technologies. SCS Engineers, Long Beach,
California for Industrial Pollution Control Division
IERL/EPA, (1978).
8. Scarberry. Source Test and Evaluation Report; Alcohol
Synthesis Facility for Gasohol Production. Radian
Corporation, McLean, Virginia, 1980.
9. EPA, Sampling and Analysis Procedures for Screening of
Industrial Effluents for Priority Pollutants, April 1979.
10. Federal Register, Vol. 44, No. 116, June 14, 1979.
11. Federal Register, Vol. 44, No. 233, December 3, 1979.
12. Federal Register, Vol. 42, No. 160, August 18, 1977.
13. Hydrotechnic Corporation. U.S. EPA Testing of Ethanol
Plant Wastewater Treatment by Sedimentation and Dual,
Granular Media, High Rate Filtration. Prepared for the
U.S. EPA/EGD, December 1980.
14. Draft Development Document for Effluent Limitations
Guidelines and New Source Performance Standards for the
Beverages Segment of the Miscellaneous Foods and Beverages
Point Source Category. Environmental Science Engineering.
Internal Draft of the U.S. Environmental Protection Agency.
237
-------
15. Middlebrooks. Industrial Pollution Control, Vol. It
Agro-Industries. John Wiley and Sons, New York, (1979).
16. Froth Flotation in 1975. Advance Summary of Mineral
Industry Surveys, Bureau of Mines, U.S. Department of the
Interior, Washington, 1976.
17. Hawley, J. R. The Use, Characteristics and Toxicity of
Mine-Mill Reagents in the Province of Ontario. Ontario
(Canada) Ministry of the Environment, Ottawa, 1972.
18. Mining Chemicals Handbook. Mineral Dressing Notes No. 26,
American Cyanamid Company, Wayne, New Jersey, 1976.
19. Seminar for Analytical Methods for Priority Pollutants.
U.S. Environmental Protection Agency, Office of Water
Programs, May 23-24, 1978.
20. Rader, R. D. Memo to File "Impact of Possible Air
Standards on VOC Emissions." September 22, 1981.
21. United States Environmental Protection Agency, Office of
Air Quality Planning and Standards. VOC Fugitive Emission
in Synthetic Organic Chemicals Manufacturing Industry -
Background Information for Proposed Standards. Draft,
August 1980.
22. Federal Register, Vol. 45, No. 98, May 19, 1980.
23* Wastewater Treatment Plant Design. Water Pollution Control
Federation. Washington, D.C., (1977).
24. Process Design Manual for Upgrading Existing Wastewater
Treatment Plants. U.S. EPA, Washington, D.C., (1975).
25. Process Design Techniques for Industrial Waste Treatment.
Associated Water and Air Resources Engineers, Inc., Enviro
Press, Nashville, Tennessee, (1974).
26. Metcalf and Eddy, Inc. Wastewater Engineering.
McGraw-Hill, New York, New York, (1979).
27. Process Design Manual for Suspended Solids Removal. U.S.
Environmental Protection Agency, Technology Transfer,
January 1975.
28. Benefield, L. D. and C.1 W. Randall. Biological Process
Design for Wastewater Treatment^. Prentice-Hall, Inc.,
Englewood Cliffs, New Jersey, (1980).
29. Weber, W. J. Physicochemical Processes for Water Quality
Control. Wiley-Interscience. New York, (1972).
238
-------
30' Process Design Manual for Land Treatment of Municipal
31. Process Design Manual, Sludge Treatment and Disposal. U S
Environmental Protection Agency, Municipal Environmental '
Research Laboratory, September 1979.
32. Conway, R. A. and R. D. Ross. Handbook of Industrial waste
Disposal. Van Nostrand Reinhold Company, New York, New
York, (1980).
33. Gulp, G. L. Handbook of Sludge Processes. Garland STPM
Press, New York, New York, (1979).
34• An Assessment of the Economic Impacts of Wastewater
Treatment Requirements on the Ethanol-For-Fuel Industry
For EPA Office of Analysis and Evaluation.Washington,
D.C., May 1981.
35. Burkhead, et. al. "Pollution Abatement of a Distillery
Waste." Water and Wastes Eng. Vol. 6, No. 5, (1969).
36. Paulette. "A Pollution Abatement Program for Distilling
Wastes." J. Water Pollution Control F^ri. . vol. 42, No. 7,
i j.y /u).
37> u's* A3-conol Fuels Industry Data Base. Information
Resources, Inc. Washington, D.C., 1985.
38. United States Environmental Protection Agency, Office of
Air Quality Planning and Standards. VOC Emissions from
Volatile Organic Liguid Stoarag Tanks - Background
Information for Proposed Standards.Draft EIS, July 1984,
EPA—450/3—81—033a.
39. United States Environmental Protection Agency, Office of
Air Quality Planning and Standards. Benzene Fugitive
Emissions—Background Information for~pFomulqated
Standards. EIS, June 1982, EPA-450/3-80-032b.
239
-------
-------
BIBLIOGRAPHY
"Alcohol Plants - Operating & Announced." List obtained from
the National Gasohol Commission, Educational Services Division,
Lincoln, Nebraska. August 1980.
Alcohol Week, June 1, 1981.
Alcohol Week, June 15, 1981.
Alcohol Week, July 20, 1981.
Alcohol Week, July 27, 1981.
Behr, Peter (1980). "$20 Billion Plan on Synfuel Signed," The
Washington Post. July 1, 1980.
Benjes, H. H. (1980). Handbook of Biological Wastewater
Treatment. Garland STPM Press, New York, New York.
Bradley, P. R., and J. Y. Oldshire (1972). The Role of Mixing
in Equalization. Presented at the 45th Annual Conference of the
Water Pollution Control Federation, Atlanta, Georgia, 1972.
Chemical Engineering, (1979). "Ethanol-from-biomass plant set
for Louisiana." Volume 86 (26).
Chemical Engineering, a(1980). "Chementator." Volume 87 (2),
page 62 (1980).
Chemical Engineering, b(1980). August 25.
Chemical Engineering, c(1980). "The ethanol race: Waiting for
the Government plan." Volume 87 (5), pages 80-85.
Chemical Engineering, April 20, 1981.
Chemical Week, "Diamond Shamrock Joins Amstar in an Ethanol
Plan." Volume 127 (8), page 17, (1980).
"CPI News Briefs." Chemical Engineering. Volume 87 (16), page
45 (1980).
Culp, Russell L., et. al., (1978). Handbook of Advanced
Wastewater Treatment, 2nd Edition. Van Nonstrand Reinhold
Company, New York, New York.
"Current Ethanol Producers/Buyers." List obtained from the
National Alcohol Fuels Information Center, Golden, Colorado.
August 1980.
240
-------
Davy McKee (1980). Fuel Alcohol/Report and Analysis of Plant
Conversion Potential to Fuel Alcohol Production. Davy McKee
Corporation for U.S. National Alcohol Fuels Commission.
Washington, D.C. September 1980.
Dickr R. I. (1970). "Role of Activated Sludge Final Settling
Tanks." Journ. San. Eng. Div., Amer. Soc. Civil Eng., 96, SA2,
423.
Earth Energy (1980). Publication of the National Alcohol Fuel
Producers Association, July.
Ethanol: Farm and Fuel Issues. Schnittker Associates for U.S.
National Alcohol Fuels Commission. Washington, D.C., August
1980.
Proceedings of the Environmental Evaluation/ Gasohol Production
and Health Effects Seminar. EPA Region VII and lERL-Ci. Kansas
City, Missouri.October 1979.
United States Environmental Protection Agency, Office of Air
Quality Planning and Standards. VOC Emissions from Volatile
Organic Liquid Storage Tanks - Background Information for
Proposed Standards. Draft. November 1980.
Federal Register, Vol. 43, No. 123, June 26, 1978.
Gasohol U.S.A. Volume 1 (7). December 1979.
Gasohol U.S.A. Volume 2 (1). January 1980.
Gasohol U.S.A. Volume 2 (2). February 198Oe
Gasohol U.S.A. Volume 2 (3). March 1980.
Gasohol U.S.A. Volume 2 (4). April 1980.
Gasohol U.S.A. Volume 2 (5). May 1980.
Gasohol U.S.A. Volume 2 (6). June 1980.
Gasohol U.S.A. -Volume 2 (7). July 1980.
Gasohol U.S.A. Volume 3 (3). March 1981.
Gasohol U.S.A. Volume 3 (4). April 1981.
Gasohol U.S.A. Volume. 3 (5). May 1981.
Gasohol U.S.A. Volume 3 (6). June 1981.
Gasohol U.S.A. Volume 3 (7). July 1981.
241
-------
Gasohol U.S.A. Volume 3 (8). August 1981.
Recommended Standards for Sewage Works. Great Lakes - Upper
Mississippi River Board of State Sanitary Engineers. Health
Education Service, Inc., Albany, New York, (1978K
Gonzalez, et. al. Biological Effects of Rum Slops in 'the Marine
Environment. Environmental Research Laboratory, Office of
Research and Development. Narragansett, Rhode Island. 1979.
Gumerraan, R. C., et. al. Estimating Water Treatment Costs,
Vols. 1-4. Prepared by Culp/Wesner/Culp Consulting Engineers
for the U.S. Environmental Protection Agency, Municipal
Environmental Research Laboratory. August 1979.
Hagler, Bailly and Company. Alternative Fuels Monitor; Ethanol
from Biomass. Energy Process Division EPA, Washington, D.C.,
(1980).
Inside DOE (1980). "DOE's Alcohol Office Sees 10-Billion
Gallons of Alcohol Output by 1985." June 27. Page 7.
Inside DOE. "TVA Considering Using Waste Heat from Watts Bar to
Power Ethanol Plant.* McGraw-Hill publication, page 6,
May 2, 1980.
Irvine. "Sugar-Based Fermentation for Fuel Alcohol." The First
Interamerican Conference on Renewable Sources of Energy. New
Orleans, Louisiana, (1979).
*
Jelen, F. C. Cost and Optimization Engineering. McGraw-Hill
Book Company, New York, New York, (1970).
Ladisch. Cellulosic Residues (Biomass) as a Renewable Source of
Fuels. Chicago, Illinois, (1980).
Kuby, et. al. Testing and Evaluation of Two Farm Alcohol
Production Facilities. Acurex for EPA/IERL-Ci, (1980).
Lyons, Richard L. "Senate Votes $20 Billion Plan to Produce
Synthetic Fuels." The Washington Post. June 20, 1980.
McCombs, Phil. "Gasohol Proves Popular in Area and Nationwide."
The Washington Post. June 6, 1980.
Metcalf and Eddy, Inc. Wastewater Engineering. McGraw-Hill,
New York, New York, (1972).
Monod, J. "La technique de Culture Continue - Theorie et
applications." Ann. Inst. Pasteur (Lille), 79, 390, (1950).
242
-------
Murphy, 1 through 11. "A Set of Notes and Calculatxons for
Sludge Lagoons and Land Application of Sludge." Prepared for
the U.S. Environmental Protection Agency by Radian Corporation,
McLean, Virginia, July 1980.
Paterson, R. B. "Computer-Aided Design and Control of an
Activated Sludge Process." Masters Thesis, University of
Delaware, Department of Chemical Engineering, Newark, Delaware,
(1980).
Paterson, R. B. "A Set of Notes and Calculations for Costing
Primary and Secondary Wastewater Treatment Systems." Prepared
for the U.S. Environmental Protection Agency by Radian
Corporation, McLean, Virginia, June 1980.
Patterson, W. L. and R. F. Banker. Estimating Costs and
Manpower Requirements for Conventional Wastewater Treatment
facilities. Water Poll. Control Res. Ser. No. 17090DAN10/71,
U.S. EPA, Washington, D.C., (1971).
Peters, M. S. and K. D. Timmerhaus. Plant Design and Economics
for Chemical Engineers. McGraw-Hill Book Company, New York, New
York, (1968).
Pound, Charles E., Ronald W. Crites, Douglas A. Griffes. Cost
of Wastewater Treatment by Land Application. Prepared for U.S»
EPA, Office of Water Program Operations, Washington, D.C. June
1975.
Radian Corporation, "Fugitive Emissions Results for James Beam
Distillery," December 1980.
Radian Corporation, "Fugitive Emissions Results for White Flame
Fuels, Inc.," October 1980.
Radian Corporation, "Generic Air Sampling Plan for a
Conventional Alcohol Facility," July 1980.
Radian Corporation, "Generic Sampling Plan for the Fuel Alcohol
Point Source Category," July 1980.
Radian Corporation, "Site-Specific Sampling Plan, Archer Daniels
Midland Plant," June 1980.
Radian Corporation, "Site-Specific Sampling Plan, Georgia
Pacific," June 1980.
Radian Corporation, "Site-Specific Sampling Plan, Hiram Walker
Distillery," June 1980.
Radian Corporation, "Site-Specific Sampling Plan; Jacquins'
Florida Distillery," June 1980.
243
-------
Radian Corporation, "Site-Specific Sampling Plan, James Beam
Distillery," October 1980.
Radian Corporation, "Site-Specific Sampling Plan, Midwest
Solvents," June 1980.
Radian Corporation, "Site-Specific Sampling Plan, Milbrew
Incorporated," May 1980.
Radian Corporation, "Site-Specific Sampling Plan, White Flame
Fuels, Inc.," August 1980.
Radian Corporation. Frequency of Leak Occurrence for Fittings
in Synthetic Organic Chemical Plant Process Units, Final Report.
Austin, Texas, 1980.~~~~
Radian Corporation. The Assessment of Atmospheric Emissions
from Petroleum Refining, Appendix B; Detailed Results. Austin,
Texas, 1980. . ;—
Radian Corporation. Technical Feasibility, Resource Availabil-
ity, Market Analysis, and Cost Analysis for the AMFES Fuel
Alcohol Facility in Ames, Iowa. McLean, Virginia. 1981.
Ramalho, R. S. Introduction to Wastewater Treatment Processes.
Academic Press, New York, New York, (1977).:
Rolz, C. A New Technology to Ferment Sugar Cane Directly; The
Ex-Perm Process. Central American Research Institute for
Industry. Guatemala, (1979).
"Sampling and Analysis Procedures for Screening of Industrial
Effluents for Priority Pollutants." April 1, 1979. Federal
Register, June 14, 1979 and December 3, 1979.
Schmit, F. L., et. al. "The Effect of Tank Dimensions and
Diffuser Placement on Oxygen Transfer." J. Water Poll. Control
Fed., £0, 1750, (1978). ~~
Schroeder, E. D. Water and Wastewater Treatment. McGraw-Hill
Book Company, New York, New York, (1977).
Smith, J. M., et. al. Upgrading Existing Wastewater Treatment
Plans. Technology Transfer Design Seminar presented at
Vanderbilt University, September 18, 1972.
Smith, R., et. al. Design and Simulation of Equalization Basin.
U.S. Environmental Protection Agency, Internal Publication,
February 1973.
Sundstrom, D. W. and H. E. Klei. Wastewater Treatment.
Prentice-Hall, Inc., Englewood Cliffs, New Jersey, (1979).
244
-------
"Synfuel Man, Planning Large Gasohol Plant." The New York
Times. July 31, 1980.
Synfuels. McGraw-Hill publication. March 21, 1980.
Synfuels. McGraw-Hill publication. April 4, 1980.
Synfuels. McGraw-Hill publication. April 11, 1980.
Synfuels. McGraw-Hill publication. April 25, 1980.
Svnfuels. McGraw-Hill publication. May 9, 1980.
Svnfuels. McGraw-Hill publication. May 16, 1980.
Synfuels. McGraw-Hill publication. June 6, 1980.
Svnfuels. McGraw-Hill publication. June 13, 1980.
Svnfuels. McGraw-Hill publication. June 20, 1980.
Svnfuels. McGraw-Hill publication. July 4, 1980.
Svnfuels. McGraw-Hill publication. July 11, 1980.
Synfuels. McGraw-Hill publication. July 14, 1980.
Synfuels. McGraw-Hill publication. August 15, 1980.
Tucker, W. G. "Recommended Approach to Cost Estimating for
Synfuels PCGDS." Internal EPA Memo, April 22, 1980.
Tyteca, D., et. al. "Mathematical Modeling and Economic
Optimization of Wastewater Treatment Plants." CRC Critical
Reviews in Environmental Control, December 1977.
U.S. DOE. Alcohol Fermentation Plant/Environmental
Characterization Information Report. U.S. DOE Office of
Environmental Assessments. June 1981.
U.S. NAFC. Fuel Alcohol; An Energy Alternative for the 1980's,
Final Report. U.S. National Alcohol Fuels Commission.
Washington, D.C., (1981).
Viessman, W., Jr., et. al. Introduction to Hydrology. Intext
Educational Publishers, New York, New York, (1972).
Wallace, A. T. "Analysis of Equalization Basins." Journal of
the Sanitary Engineering Division, American Society of Civil
Engineers, SAG, pp. 1161-1171, (1968).
Wang, et. al. Fermentation and Enzyme Technology. John Wiley
and Sons. New York, (1979).
245
------- |