TLEAI
WATER POLLUTION CONTROL RESEARCH SERIES • 12120 EUR 11/71
Information Resource:
Water Pollution Control
in the Water Utility Industry
U.S. ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUnON CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the
results and progress in the control and abatement of pollution
in our Nation's waters. They provide a central source of
information on the- research, development and demonstration
activities in the Environmental Protection Agency, through
inhouse research and grants and contracts with Federal, State,
and local agencies, research institutions, and industrial
organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should "be directed to the Chief, Publications Branch
(Water), Research Information Division, R&M, Environmental
Protection Agency, Washington, B.C. 20460.
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INFORMATION RESOURCE:
WATER POLLUTION CONTROL
IN THE
WATER UTILITY INDUSTRY
by
American Water Works Association Research Foundation
2 Park Avenue
New York, N.Y. 10016
for the
ENVIRONMENTAL PROTECTION AGENCY
Program Number 12120 EUR
November, 1971
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E!PA Review Notice
This report has been reviewed by the Environmental
Protection Agency and approved for publication.
Approval does not signify that the contents necessarily
refle.ct the views and policies of the Environmental
Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommen-
dation for use.
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.50
ii
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ABSTRACT
This report describes the accomplishments of a program conducted to org-
anize, coordinate, and disseminate information on new or modified sludge
treatment technology for water treatment plant wastes. The reliable
control of these potential pollutants is of increasing importance with
the enactment and enforcement of more stringent pollution control leg-
islation. The report contains information on research, engineering,
plant operation, and regulatory aspects of the problem. A Project Ad-
visory Committee provided recommendations for developmer of information
resources, and assisted the Research Foundation in structuring an infc-
formation clearing-house. The report describes current research act-
ivities and new approaches for characterizing and reducing water treat-
ment plant waste volumes. A program was initiated to evaluate the
applicability of polymers as primary coagulants, coagulant aids, and
sludge conditioning agents . A Sub-Committee was established to prepare
uniform sampling, analysis, and categorization techniques for water
utility sludges. Each program is in progress. Surveys were distributed
to water utilities and regulatory agencies to provide information on
sludge treatment methods and requirements. The AWWA Research Foundation
plans the continuation and expansion of this centralized information
resource program.
This report was submitted in fulfillment of Program (Project) Number
12120 EUR, under the partial sponsorship of the Water Quality Office,
Environmental Protection Agency.
iii
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CONTENTS
Section Page
I Conclusions 1
II Recommendations 3
III Introduction 7
IV Advisory Committee Recommendations 15
V Information Resources Available 23
VI Technology Transfer Results 33
VII Survey of Regulatory Agencies 57
VIII Water Utility Survey 81
IX New Technological Developments 101
X Reference Abstracts 129
XI Information Resource Developments 141
XII Acknowledgments 145
XIII References 149
XIV Appendices 157
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FIGURES
PAGE
1. PRIMARY COAGULANTS AND COAGULANT AIDS HO
2. INTERFACE LEVEL VS. TIME 111
3. SLUDGE CONDITIONER DATA SHEET 119
4. EQUIPMENT FOR STANDARD FILTER COLUMN TEST 121
5. FILTER COLUMN DATA SHEET 123
vi
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TABLES
No. Page
1. Processes for Treatment, Disposal, and By-Product 9
Recovery of Water Treatment Plant Wastes
2. Utilization of Waste Treatment Parameters 53
3. Acceptability of Sludge Disposal Methods 55
4. Acceptability of Liquid Waste Disposal Methods ji
5. Waste Production and Monitoring 72
6. Major Contributors to Support Research 74
7. Major Conductors of Research Effort 75
8. Acceptability of Discharging Reduced Wastes to a 77
Watercourse
9. Categorization of Survey Data Parameters go
10. Concentration of Basin Sludge 87
11. Concentration of Filter Washwater 88
12. Disposal Techniques for Basin and Filter Washwater 90
Solids, and Liquid Wastes
13. Techniques Employed for Final Disposal of Solid and 9^
Liquid Wastes
14. Basin Sludge Concentration Data 93
15. Filter Washwater Sludge Concentration Data 94
16. Chemical Analysis of Basin Sludge 95
17. Chemical Analysis of Filter Washwater 96
18. Chemical and Biochemical Oxygen Demand Character of 97
Purification Plant Wastes
19. Chemical and Biochemical Oxygen Demand Character of 98
Softening Plant Wastes
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SECTION I
CONCLUSIONS
1. The problem of controlling pollution caused by wastes from water treat-
ment plants becomes a practical consideration when the discharge of
of untreated wastes to a watercourse conflicts with the state and/or
federal legislation prohibiting such action.
2. The reclamation and reuse of filter washwater has been demonstrated
at several water treatment plants. The effects of settling this waste,
and recovering and recirculating the supernatant must be examined at
individual plants. Factors to be investigated in the recovery and
reuse of washwater should include: the effects on the bacteriological
quality of the finished water; on the other system variables and over-
all treatment efficiency, and on the capital, operating, and mainte-
nance costs.
3. The utility of calcining softening sludges to recover lime for reuse
or resale has been demonstrated. Individual evaluations are required
to determine whether the reduction (minimi?.?>*-ion) of wastes for dispos-
al and the recovery of lime outweigh the costs and operation consid-
erations for such a waste treatment facility. Among the important
considerations are: operation, maintenance, and capital costs for a
recalcining plant; the level of operation sophistication; the extent
of impure and inert material to be separated and disposed of prior to
calcining; the market for excess lime produced; the recovery of carbon
dioxide from the kiln for the carbonation of the product water or the
carbonation of the sludge; the need to minimize air pollution in the
calcining operation; and reduced main plant operating costs.
4. The possibility of recovering alum from coagulant sludges has been
demonstrated. The recovery process requires careful control and oper-
ation. The recovery appears economically attractive in plants treating
flows of 100 mgd or greater. Individual testing is needed to determine
the value of alum recovery at specific locations.
5. Physical and chemical liquid-solid separation processes for sludge
disposal require laboratory and pilot plant applications before a
system can be selected.
6. Laboratory, pilot, and plant scale testing provides the basis for
selecting the most efficient and economical sludge dewatering and/or
recovery process.
7. The development of uniform reports on sampling, analysis, and cate-
gorization for the evaluation of wastes from all types of water treat-
ment plants has been initiated. Standardized reporting procedures are
needed for comparing data from water treatment plants. The accumulat-
ed data may illustrate seasonal variations in waste character that
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are important in the orderly progression of laboratory or pilot unit
testing.
8. A standard methodology to evaluate the suitability of polymers as
primary coagulants, coagulant aids, and sludge conditioning agents
will assist in solving the waste treatment problem. Work has been
initiated to determine the utility of polymers to assist in reducing
waste volume.
9. The recovery of by-products from sludge for reuse or marketing should
be further investigated as an alternative to lagooning or landfill.
10. Coagulants such as MgC03, polymers, or other chemicals should be more
intensively investigated. They may be suitable to replace alum, pro-
duce properly treated waters, and leave easily dewatered or treated
sludges.
11. The type and amount of sludge produced in water treatment plants
depends upon the raw water quality, treatment processes, and treatment
efficiency. The control of these variables should be directed to
maximizing waste concentration and thus minimizing of waste volume.
12. The majority of authorized regulatory agencies will require that
waste effluents from water treatment plants meet existing effluent
requirements and/or stream classification water quality standards
before wastes can be discharged to a watercourse.
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SECTION II
RECOMMENDATIONS
The development of standard testing procedures to sample, analyze, and
categorize wastes from all types of water treatment plants is in progress.
Following completion and evaluation, the methodology is to be submitted to
an appropriate Standard Methods Sub-Committee for review and modification.
It is intended that these procedures will be published in future editions
of Standard Methods for the Examination of Water and Wastewater.
With the establishment of uiiform reporting formats, water treatment plants
should undertake the examination of their wastes as a routine operation.
Records of waste quantity and quality should be accumulated and correlated
to system variables such as raw water quality, treatment efficiency, temper-
ature, and other parameters. The collection of this data is an important
first step in selecting sludge dewatering or by-product recovery technol-
ogy for laboratory or pilot scale evaluation.
The utility of polymers or some universal coagulant to favorably alter
waste character and minimize waste volume should be demonstrated at specif-
ic treatment plants. The suitability of polymers to replace or reduce
alum or ferric salts in the production of potable water and to make sludges
more amenable to dewatering must be fully resolved. A methodology is under
development to systematically evaluate and choose effective polymers.
The results of research and demonstration projects on techniques to recover
and reuse filter washwater, to recover solid wastes for reuse or market-
ing, and to utilize new or modified liquid-solid separation processes
should be collected by the AWWA Research Foundation. The need for water
utility oriented organizations to provide reports of individual research
is evident for the success of a central information resource. As a clear-
ing-house, the Foundation will organize, coordinate, and transfer reports
on research and new technological developments, such as the use of magne-
sium carbonate to remove color and turbidity from water and the rotary
precoat vacuum filtration of alum sludge, to the water utility industry.
The design of new or modified water treatment facilities should' incorporate
integrated water and waste treatment processes having the flexibility to
adjust to changes in the sludge character.
Laboratory, pilot, and plant scale investigations are invaluable in deter-
mining the most suitable sludge treatment sequences at specific utilities.
The most economically justifiable sludge treatment alternative must provide
the basis for the final process selection. It is expected that heavily
populated areas will require the investigation of by-product recovery or
dewatering procedures utilizing minimum area requirements for ultimate
disposal. Areas not heavily populated may still use sedimentation or
lagooning procedures to treat wastes. The record of chemical constituents
in particular sludges may justify the use of recovery processes.
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Each water utility must consider the effects of recycling highly treated
washwater to the intake line of the treatment facility. Bacteriolog-
ical and other quality and treatment efficiency evaluations must be made.
The recovery of this water may lower plant operating costs and reduce
pollution caused by the discharge of this waste to a watercourse.
The climatological conditions of a specific geographic area must be
fully exploited in waste treatment. The natural freezing and thawing
of purification sludges in lagoons' will reduce the solids to a coffee
ground formation that settles well and occupies a minimum volume. These
settled solids can be used as the first step in alum recovery operations.
Other possibilities such as the use of solar evaporation ponds in arid
regions to treat concentrated brine wastes, must be part of an overall
treatment sequence.
The selection and operation of water treatment processes affects the
nature of the waste. Processes must be chosen that make wastes amenable
to handling and treatment.
Some water treatment facilities do not presently have sludge disposal
problems. It is expected that these utilities will plan future treat-
ment alternatives that can alleviate or lessen the problems when they
become real. For instance, two raw water supplies may be available for
development. One source may require significant pumping before reach-
ing the plant. The second source may be nearby. The first source may
be relatively higher in quality than the second source. If the source
further away will produce considerably less waste, the cost of pumping
this water and treating this waste should be compared with the cost of
pumping the closer raw water supply and treating its waste before a
selection is made.
The true effects of discharging softening and purification wastes to
sewage treatment systems must be fully explored. The effect of sludges
on settling efficiency in primary settling tanks and removing phosphate
in activated sludge processes is relatively unknown. These solid wastes
will increase digester requirements. The efficiency of a digester should
be tested with varying amounts of water plant sludge added to the basic-
ally organic sewage wastes.
Sludge incinerators, with adequate particulate emmission removal systems
which minimize air pollution, must be investigated. The residue from
incineration can be used as a landfill and may demonstrate utility as
an aggregate for concrete.
The hydraulics of transporting purification and softening sludges in
pipelines needs reasearch. Pumping, head loss, and floe disintegration
must be included in this area of study.
Modifications to new or existing processes available from other indus-
tries should be developed. The Metroplitan Water District of Southern
"California modified the alum recovery operation used in Tokyo by
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incorporating filter pressing to separate the recovered alum sulphate
solution from the acidified inert sludge*
Research on the recovery and treatment of concentrated brine solutions
must be considered so that the use o£ ion-exchange and desalination
processes will be possible without Violating state and federal pollu-
tion control requirements.
The effect of regionalizing treatment systems for producing potable
water and handling wastes in contiquoUs operations must be considered.
Several basin commissions have been formed to determine legitimate water
utilization and water pollution control measures. The regional approach
applied to water treatment plants might require more sophisticated oper-
ation and management.
In large water treatment plants where the recovery of alum may be prac-
ticable, special personnel may be requited to operate the recovery
facilities. Chemical suppliers might be interested in operating this
facility. The recovery process may hot be economically lucrative
when first compared to the price of new aluttij but alum recovery mini-
mizes the amount of waste for ultimate disposal.
Water utilities must keep abreast of state and federal legislation,
such as the Harbors and Rivers Act of 1899, that may require each treat-
ment plant to file discharge permits with the U.S* Army Corps of Engi-
neers .
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SECTION III
INTRODUCTION
The need to successfully handle and dispose of wastes from water treat-
ment plants has attained increased importance. More stringent pollu-
tion abatement legislation is being enacted to deal with wastes from
all types of industrial sources. Public awareness of controlling pollu-
tion caused by municipal and industrial discharge of waste streams
to watercourses is emphasized in the various communication media. The
wastes from water utilities are classified as industrial in character.
There is an opportunity for the water treatment industry to be the first
major industry to control their wastes on a national scale.
The AWWA Research Foundation, in 1969, published a state-of-the-art
report on the "Disposal of Wastes from Water Treatment Plants." This
study was supported in part by a grant from the FWPCA. It presented
known treatment technology, cost data, and suggestions for future needs.
Tha- report recommended the establishment of a central information
clearing-house to organize, coordinate, and disseminate information on
new or modified treatment technology and promote its application by
the water utility industry.
The Research Foundation, in 1970-71, conducted an expanded program
titled "Information Resource on Water Pollution Control in the Water
Utility Industry." This study was supported by a grant from the Water
Quality Office, EPA, and by matching funds from 30 water utilities.
Implementation of the project has developed activities for the trans-
fer of technology among researchers and water utilities, and has defined
gap areas of treatment technology requiring further investigation.
A Project Advisory Committee, composed of experts involved in the
research, engineering, plant operation, and regulatory aspects of the
sludge disposal problem, was assembled for a two day meeting. The
purpose of the meeting was for Committee members to exchange ideas and
present recommendations to aid the Research Foundation in organizing
an information service. The preparation of two surveys and the pre-
sentation of several reports on aspects of the sludge treatment problem
were undertaken.
The need was recognized for an information clearing-house to initiate
laboratory or pilot scale investigations of sludge dewatering and by-
product recovery processes. The accumulation and dissemination of
current research information is a valuable step in providing criteria
for solution of specific problems at individual water utilities. The
report is intended to aquaint the water utility industry with references
to past, present, and proposed work as bases for the adoption of waste
treatment programs.
Research and development activities were identified through governmen-
tal agencies, literature searches, and personal correspondence with
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water research institutions. Technical articles were abstracted in
accordance with Water Resources Science Information Center specifi-
cations for inclusion into their computerized storage and retrieval
system. Abstracts in section 5 of this report are capsule summaries
of new material acquired since the 1969 Research Foundation report.
Section 9 summarizes information from historical articles tracing the
development of presently utilized sludge disposal techniques.
Surveys were distributed to authorized regulatory agencies and water
treatment plants. The results reported in regulatory surveys provide
new information on the parameters to be considered for treatment re-
quirements; acceptability of sludge disposal methods; maintenance and
reporting of waste production records, and the support and conduct of
research. The water utility surveys demonstrate the need for standard
documents to sample, analysis, and categorize basic waste quantitative
and qualitative data.
Several new approaches have been developed to establish means of:
comparing data from water utilities; reducine waste volume and increas-
ing waste concentration; and inventorying the equipment available for
treating waste sludges. A project Sub-Committee is actively involved
in developing standard sampling and analysis documents for wastes
from all types of water treatment plants. A polymer evaluation pro-
gram has been initiated to determine the applicability of polymers as
primary coagulants, coagulant aids, and sludge conditioning agents.
The publication of new information should further stimulate the direc-
tion and support of research into areas of needed investigation.
There is no universal solution for the treatment of water purification
and softening sludges but, rather, a variety of alternative methods.
Treatment alternatives will require evaluation based on local situa-
tions, and will involve studies of efficiency, operation and mainte-
nance requirements, and economics.
Process Development and Applicability
Several major sludge treatment processes were suggested by the Project
Advisory Committee and the Research Foundation to be incorporated into
the manual Research & Development system. These treatment alternatives
are arranged alphabetically in Table 1 titled "Processes for Treatment,
Disposal, and By-product Recovery of Water Treatment Plant Wastes." The
state of development and applicability of each process are identified
on the basis of the references utilized. This listing is not intended to
be all inclusive, but to summarize the information accumulated in this
specific study.
The utility of conducting laboratory, pilot, and plant scale evaluations
of new or established sludge treatment technology cannot be overemphasized.
Waste character can vary significantly from treatment facility to treat-
ment facility. The study of new or modified technology on laboratory
or pilot scale aids in the development of physical and chemical design
parameters. The systematic evaluation of alternative treatment methods
is an important step in avoiding major deficiencies in the design and
construction of plant scale facilities.
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TABLE 1
PROCESSES FOR TREATMENT, DISPOSAL, AND BY-PRODUCT
RECOVERY OF WATER TREATMENT PLANT WASTES
Process
Alum Recovery
Centrifugation
Chemical & Polymer
Conditioning
Drying Beds
Filter Pressing
Freezing
Lagooning
Lime Recovery
Magnesium Carbonate
Recovery
Recycling
State o£ Development
Laboratory, Pilot,
and Plant Scale
Pilot and Plant Scale
Laboratory, Pilot,
and Plant Scale
Pilot and Plant Scale
Pilot and Plant Scale
Laboratory, Pilot,
and Plant Scale
Pilot and Plant Scale
Pilot and Plant Scale
Laboratory, Pilot,
and Plant Scale
Pilot and Plant Scale
Applicability
Alum Sludge
Lime and Lime-Soda Sludge
Alum Sludge
Polymer Conditioned Sludge
Filter Washwater Sludge
Alum Sludge
Lime and Lime-Soda Sludge
Filter Washwater
Alum Sludge
Lime and Lime-Soda Sludge
Polymer Sludge
Filter Washwater Sludge
Alum Sludge
Lime and Lime-Soda Sludge
Polymer Conditioned Sludge
Filter Washwater Sludge
Alum Sludge
Alum Sludge
Lime and Lime-Soda Sludge
Polymer Conditioned Sludge
Ferric Hydroxide Sludge
Filter Washwater Sludge
Lime and Lime-Soda Sludge
Lime and Lime-Soda Sludge
Alum Sludge
Lime and Lime-Soda Sludge
Polymer Conditioned Sludge
Filter Washwater
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TABLE 1 (continued)
Process
Recycling
Sedimentation
State of Development
Pilot and Plant Scale
Pilot and Plant Scale
Vacuum Filtration
Miscellaneous
Neutralization and
Precoat Filtration
Thickening-Dewatering
Evaporation Ponds
Brine By-Product
Recovery
Evaporation-Well
Disposal
Sewage Treatment
Coagulant
Laboratory, Pilot,
and Plant Scale
Applicability
Alum Sludge
Lime and Lime-Soda Sludge
Polymer Conditioned Sludge
Filter Washwater
Alum Sludge
Lime and Lime-Soda Sludge
Polymer Conditioned Sludge
Ferric Hydroxide Sludge
Filter Washwater
Alum Sludge with
Conditioning or Precoat
Lime and Lime-Soda Sludge
Evaluation-Pilot Scale Acid Mine Drainage Waste
Detailed Study
Laboratory and Pilot
Scale
Conceptual Design
Developmental
Laboratory and Plant
Scale
Acid Mine Drainage Waste
Desalting Concentrated
Brine Streams
Desalting Concentrated
Brine Streams
Zeolite Softener Brines
Lime and Lime-Soda Sludge
Section XIII of this report contains the references used in the develop-
ment of the information resource program. The references .are arranged
alphabetically by author and numbered consecutively. The following
processes and references provide a basis for individual investigation.
Alum Recovery
The recovery of an aluminum sulfate coagulant from purification wastes
containing appreciable aluminum content has been utilized on a plant scale
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basis both in France and Japan. The acidification of a basically
aluminum hydroxide waste produces a soluble reuseable coagulant and
inert material. The process can substantially reduce the waste volume
for final disposal, but requires a more sophisticated operation and manage-
ment than physical thickening processes. Other important considerations
in this technology are the efficient separation of recovered alum solution
from the inert material unaffected by acidulation and the minimization of
impurities such as iron and manganese building up in the recovered solution.
The following reference numbers apply to the investigation of- alum recovery
on laboratory, pilot, or plant scale level: 9, 15, 22, 27, 33, 38, 39,
and 92.
Centrifugation
The centrifugation of waste sludges from purification or softening facili-
ties physically changes the solids concentration of the feed stream.
Centrifugation can be employed as a major process to produce a waste concen-
trate suitable for landfill or can be one unit process in a sequence to
prepare the waste for by-product or additional dewatering. The use of polymer-
ic or inorganic conditioners appears to be beneficial in the centrifugation of
purification waste. Pilot and plant scale activities of centrifugation
investigations have been identified. The reference numbers include: 1, 9,
14, 20, 25, 28, 33, 54, 57, 58, 69, 72, 88, 92, 95, and 98.
Chemical and Polymer Conditioning
The conditioning of wastes by the application of inorganic or organic
materials can assist in increasing the dewaterability rate and additionally
concentrating waste solids. Conditioning agents can be applied to waste
streams to prepare these streams for dewatering by physical separation
techniques such as centrifugation, drying beds, filter presses, and vacuum
filtration. Some polymers have demonstrated suitability, in specific
instances, of replacing the inorganic coagulant to produce a concentrated
waste amenable to dewatering. Development at laboratory, pilot and plant
scale levels is still needed in this area. The references applying to
the conditioning of waste volumes include numbers: 1, 9, 13, 17, 18, 46,
53, 68, and 97.
Drying Beds
The successful dewatering of waste sludges on drying beds is in part
dependent on the climatological conditions of the region and the character
of the waste sludge. The use of polymers to form a bridge between floe
particles from alum coagulation processes may enhance the dewaterability
of these difficult to treat sludges in this process. The efficiency of
drying beds to produce a concentrated waste for final disposal should be
developed carefully to determine the specific design parameters applicable
at each water utility. Literature reference to drying beds include numbers:
7, 9, 18, 50, 52, 56, 57, 83, 92, and 96.
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Filter Pressing
The use of filter presses to dewater wastes from purification and softening
processes has been developed on plant scale bases in England and other
parts of Europe. Plant scale presses are under construction in both Atlanta,
Georgia, and Little Falls, New Jersey. Detailed laboratory and pilot plant
testing of filter pressing determines parameters for final design. Some
manufacturers of filter pressing equipment for sewage treatment plant
waste have informed the Research Foundation that experimental work is
underway to determine the suitability of this equipment for dewatering water
utility wastes. Literature references to filter presses include numbers:
5, 9, 12, 13, 17, 25, 26, 33, 35, 46, 57, and 94.
Freezing
The natural freezing of aluminum hydroxide sludge has been utilized by
the Copenhagen Water Department on a plant scale level. Natural and
artificial freezing has undergone detailed development in England. The
freezing and thawing process physically alters the character of aluminum
hydroxide wastes. A continuous slow freeze of these waters aids in
releasing the water of hydration from purification wastes. The solids
settle rapidly upon thawing, assuming a coffee ground type of consistency.
Work in the United States is in laboratory and pilot stages both for artificia
and natural freezing processes. Literature references to freezing include
numbers: 9, 14, 15, 17, 19, 25, 26, 27, 33, 34, 39, and 57.
Lagooning
The separation of solid wastes from the supernatant waste can be accomplished
in a well designed and operated lagoon. The settling of purification and s
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Magnesium Carbonate Recovery
The recovery of lime from softening sludge is a major technology that can
alleviate the solids disposal problem existing at lime or lime-soda soften-
ing plants. To achieve a high grade lime product, impurities such as
magnesium must be removed. Carbonation of softening sludge containing
appreciable magnesium hydroxide can dissolve the insoluble magnesium salt.
The soluble magnesium carbonate can be physically separated from the
calcium carbonate precipitate. The utility of magnesium carbonate as a
purification plant coagulant to replace alum is being evaluated at the
Montgomery, Alabama, water treatment plant. Literature references for
magnesium carbonate recovery include numbers: 16 and 28.
Recycling
The recycling of waste supernatant from filter washwater operations may
be economically justifiable on the basis of the recovered water and the
pollution control need. The suspended solids in filter washwater may
provide sites for initiating the coagulation and the agglomeration of
floe particles. High rate clarification units also may utilize a recycled
sludge to provide nuclei for floe formation. Literature references for
recycling include numbers: 9, 37, 44, 48, 59, 81, 86, 90, 92, and 97.
Sedimentation
The settling of wastes from filter washing and sedimentation tank cleaning
may provide a good approach to additional thickening of the sludge and
the recovery of the supernatant. Sedimentation can be accomplished in
basins constructed of various material. Literature references for sedimen-
tation include numbers: 9, 23, 24, 37, 39, 50, 55, 63, 78, and 81.
Vacuum Filtration
The dewatering of both purification and softening wastes has been accom-
plished through vacuum filtration. Softening wastes require little or
no conditioning prior to dewatering on the vacuum drum. Alum wastes
may require preconditioning with various materials. Pilot work is under-
way using a rotary precoated vacuum filter to dewater alum sludge. Litera-
ture references to vacuum filtration include: 1, 4, 5, 8, 9, 11, 14, 17,
23, 25, 31, 33, 39, 47, 48, 55, 56, 57, 62, 69, 92, and 96.
Miscellaneous
Studies dealing with the treatment of acid mine drainage, desalting plant
brines, zeolite softener brines, and the use of lime and lime-soda sludges
as sewage treatment coagulants have been identified in this study. Reference
numbers 62 and 69 deal with the neutralization and precoat filtration and
thickening of acid mine wastes respectively. Literature dealing with the
evaporation and by-product recovery from desalting brines include reference
numbers 29, 30, 36, 40, 42, 60, 66, 80, and 91. Reference numbers 7 and
75 consider the evaporation well disposal of zeolite exchange softening
brines. Reference numbers 6 and 75 consider the use of softening wastes
as coagulants for sewage treatment plant use.
13
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SECTION IV
ADVISORY COMMITTEE RECOMMENDATIONS
Introductory Statement
The AWWA Research Foundation conducted a study in 1968-1969 on the "Dis-
posal of Wastes from Water Treatment Plants." The comprehensive report
was published under that title as Water Pollution Control Series, ORD-2,
by the Federal Water Pollution Control Administration, U.S. Department
of the Interior. The report was also published serially in four issues
of the AWWA Journal.
The Foundation's study was comprised of four status reports on research,
engineering, plant operations, and regulatory aspects, and a review of
current technology and costs. The final report recommended that "substan-
tially expanded programs of research and demonstration be undertaken" and
included lists of specific problems in need of investigation to develop
effective and economical technology.
The Project Advisory Committee for that study recommended the establish-
ment of a central service to promote the planning of research and develop-
ment, and to implement new programs. The service was proposed to organize,
coordinate, and disseminate information on new or modified treatment tech-
nology to control pollution from water treatment plants. The transfer of
this technology is needed to promote its application by the water utility
industry of the United States.
A central information service has been established. The program, titled
"Information Resource on Water Pollution Control in the Water Utility
Industry," is jointly funded by the Water Quality Office of the Environ-
mental Protection Agency and by matching funds contributed by 30 U.S.
water utilities. The contributions from water utilities to support the
development of new and important technical information represents an
expression of confidence in the usefulness of the program.
Project Advisory Committee
The Research Foundation assembled'individuals concerned with various as-
pects of the water utility industry to advise and guide the Foundation in
its information resource program. Members of the Committee were selected
to include the Chairmen of two AWWA Committees: the Water Quality
Division Committee on Water Treatment Plant Waste Disposal, and the Re-
search Committee on Sludge Disposal. The Committee also included four
members who served in the project on "Disposal of Wastes from Water Treat-
ment Plants," and four new members.
The Advisory Committee provided the expertise to assist the Research Foun-
dation in defining the dimensions and directions of the study to collect,
evaluate, and distribute the information required.
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Status reports on the activities of the two AWWA Committees were presented.
The Foundation staff summarized the goals of the information resource pro-
gram. The research plans were prepared under three principal areas: the
organization, coordination, and communication of information.
Research Foundation Goals
The Research Foundation assisted by the Advisory Committee planned to:
1. Publicize current regulatory, research, engineering, and operat-
ing practice procedures and to encourage the submittal of infor-
mation trom manufacturers of equipment and supplies applicable
to the study. Also, to encourage questions by water utility
manufacturers that provide the basis for additional research
and/or development.
2. Present to research, engineering, operating practice groups,
and manufacturers, those sludge treatment and disposal tech-
niques requiring further development.
3. Encourage initiative among the various water utility trade organ-
izations to develop novel approaches for sludge treatment and dis-
posal.
The critical analysis of information prepared by the Foundation,and methods
to improve the analysis and translation of information into a useable form,
is an essential Advisory Committee function. Disseminated information
should be designed for use at all levels of operation.
Recommendations for additional information to supplement existing infor-
mation and the presentation of problems existing in current operations
and possible solutions by the Advisory Committee will provide direction
for the Foundation's study.
Experience in Organization of Information
The Research Foundation, as a central information resource, planned the
identification and inventory of research and demonstration projects.
Several sources were searched to obtain information on projects completed,
in-progress, or projected. The sources included: Science Information
Exchange; Water Quality Office of the E.P.A.; Office of Saline Water,
USDI; municipal water utilities; educational institutions; manufacturers
of equipment and supplies; engineers; and foreign institutions.
The status of research and demonstration projects identified through each
of these sources was developed by correspondence with principal researchers.
Available publications and reports collected are classified in accordance
with a manual Research & Development Information Storage & Retrieval System.
A copy of this system is contained in the report appendix.
A basic data survey was prepared by members of the operating practice group
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of the Advisory Committee. The purpose of this survey was to inventory
basic data on the quality and quantity characteristics of wastes from water
treatment processes, and on their pollutional effects. A copy of this sur-
vey, prepared for distribution to water utilities, is included in the re-
port appendix.
Additional information sources included the AWWA Research Committee on
Sludge Disposal and the Water Quality Division Committee on Water Plant
Waste Disposal, other committees performing related work, and development
needs identified by others.
Various processing industries were suggested as having waste disposal prob-
lems whose methods could be converted into the water utility field. The
results of research from manufacturing organizations may provide new or
modified approaches to waste treatment technology.
The sections of the AWWA were recommended as a source of information on
research and demonstration projects. Although few sections have research
committees, the publicity of the information resource program at the section
level could stimulate the submittal of information on research activities.
Members of the regulatory group prepared a survey to be distributed to
state regulatory agencies. The purpose of this survey was to provide infor-
mation on statistical, research, and regulatory aspects of the waste treat-
ment process. A copy of the regulatory survey is included in the report
appendix.
The Advisory Committee recommended the development of uniform sampling, anal-
ysis, and categorization techniques for water treatment plant wastes as
an immediate priority. The orderly development of reliable waste quantity
and quality data is dependent on standard test procedures. Variations, in
a recent survey, have proven significant due to the sampling and/or analy-
sis methods.
The Committee recommended the future funding of pilot and plant scale dem-
onstration facilities. The project conducted by the Research Foundation
will allow better justification for providing funds in this area. The
priority need must be demonstrated before these projects are federally
supported. Demonstration on pilot plant scale is a definite need since,
if there is much more delay in funding research, plant scale processes
will be built. Meaningful suggestions for priority research will illustrate
the need for increased funds to be made available for treating water plant
wastes.
Coordination of Information
The program is dynamic in nature. Practical applications of waste disposal
technology must be presented to scientists, engineers, and administrators
in a useable form. Data must constantly be analyzed, translated, and supple-
mented to facilitate its application in research and demonstration projects.
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The exchange of information between those who develop and those who apply
new information often requires translation. Through the development of a
central information resource for pollution control in the water utility
industry, the Research Foundation plans to stimulate communication between
research organizations and water utilities to develop the required technol-
ogy.
Prime emphasis in this study was given to the development of treatment pro-
cess modifications. These modifications may result in wastes of different
quantity or quality characteristics, thus affecting waste volumes and treat-
ability. Pollution control processes and procedures must be established
to meet the constantly changing stringent requirements of federal and state
regulatory agencies.
Communication of Information
Communication of information is essential to a diverse cross-section of
individuals and organizations. The water utility industry can benefit by
learning the newest developments in waste treatment practices. Research
workers will find important direction in investigating water utility waste
problems while learning of current research programs.
In this way, duplication of programs can be avoided and money and time
channeled into new programs. Consulting engineers will have the needed data
to design water treatment plant waste control units. Manufacturers will
have avenues to develop products that will be immediately needed, and incen-
tive and direction to develop new process equipment and supplies.
The Foundation planned assistance for the design of research and demonstra-
tion projects to assure the wide applicability of all types of information
developed. Reports defining specific research topics will be published.
Basic and applied research results must be reported with the degree of their
applicability.
Special Reports by Advisory Committee Members
Report of AWWA Committee Activities. The Water Treatment Plant Waste Disposal
Committee (AWWA Water Quality Division) activities were reported by Lee
Streicher, Chairman.
This Committee was formed with a scope to study and report the problems and
methods of disposal of water treatment plant wastes considering:
a. Disposal of filter washwater and sludges
b. Disposal of brines
The Committee was originally composed of 10 members, including the Chairman,
and was divided into 5 different subject sections as follows:
1. Disposal of Filter Washwater
2. Disposal of Lime-Soda Sludge
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3. Disposal of Alum Sludge
4. Disposal of Other Coagulant Sludge
5. Disposal of Brines
The preliminary report of this Committee stresses certain objectives that
must be considered. Initially, the amount of waste produced should be
reduced by the careful selection of an appropriate treatment method. After
waste reduction is acheived, concentrated efforts should be directed to
finding an easier sludge disposal form. As an example, it is suggested
that polyelectrolytes replace alum as a coagulant. The polyelectrolyte
sludge is more easily dewatered.
Mr. Streicher is presently dealing with Colorado River water that has re-
quired only intermittent coagulation. A new plant is under construction
to process a different supply source which will require continuous coagu-
lation with alum. Without adequate lagooning area, other alum sludge dis-
posal means must be considered.
Other treatment alternatives entertained were alum recovery, discharge to
quarries, and discharge to sanitary sewers. The discharge of sludge to
sanitary sewers was initially rejected by the Bureau of Sanitation. After
some thought, the Bureau reconsidered this proposal since the sludge trans-
port water would enhance the quality of their source water from sewage
treatment plants. Further study by the Bureau showed that the water treat-
ment plant sludge would add significant bulk to their own sludge and also
make the sewage sludge harder to dewater. Digester capacity would have to
be increased, and the water utility would have to pay for the resulting
increases in the water reclamation plant digestion units due to the pre-
sence of the alum sludge.
The development of by-products from waste sludges was also presented. Lime
and alum recovery were cited as reclamation processes. Reference was made
to Peter Doe's paper on lime sludge reclamation, and the possibility was
raised of developing uses for lime or alum.
If by-products cannot be recovered, the methods of final disposal should
be improved. Efficient dewatering and sludge incineration techniques should
receive further investigation.
There is a great need for the standardization of sampling, analysis, and
categorization techniques for sludges at water treatment plants. To make
any data meaningful and applicable, standardization is essential.
Finally, Mr. Streicher discussed the contribution such a Committee would
make to resolving the sludge disposal problem. Rather than enumerate or
reference sludge treatment and disposal processes, this Committee would
discuss processes such as the handling of lime or alum sludges or the
recovery of products from sludges. This would provide concerned individ-
uals with methods of handling different problems in a step-by-step fashion.
Discussion of Committee Report. Several points were made regarding the
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report on water treatment plant waste disposal. The control of waste quan-
tity was questioned. The concentration of the material produced was suggest-
ed as being under control of the water plant operator.
The amount of wastes produced is under control if the coagulant is a poly-
electrolyte and not alum. Not only is the waste concentrated, but its na-
ture is changed. Studies have shown that 1.0 to 1.25 ppm of polymer is
equivalent to 20 to 25 ppm of alum.
Total control of sludge volume and quantity is not always possible. These
values cannot be controlled when softening water to a certain residual
hardness and removing turbidity to predetermined finished water levels.
The softening process produces calcium carbonate and removes suspended ma-
terial from water. These solids cannot be reduced. A change of chemicals
in the clarification system may aid in changing the volume produced.
The Committee report refers to a plant which softens Colorado River water
by ion exchange. The new supply being developed at this utility will re-
quire clarification only.
The question of taste and odor problems arose concerning the.waters in ques-
tion. Carbon is not used, although there were infrequent taste and odor
problems with the Colorado River water. Taste and odor are generally small
in magnitude. A system has been developed to control taste and odor and
bacteria. Due to bird droppings, the bacterial count of water going to the
filters was several times higher than the count of the raw water. A three-
step chlorination process was developed and odors were controlled. The
new supply source will introduce a color problem. Among the experimental
methods being studied for color removal is the use of ozone. Ozone reduces
color effectively and does a fine job of preliminary sterilization. In-
stead of prechlorination, an ozonation step could possibly be used. The
reduction of waste volume should be a primary goal if possible.
The treatment facility mentioned in the Committee report has successfully
utilized Catfloc and Nalcolyte 607. These polymers produce a fine but
suitable floe. However, the floe required a nonionic to produce weight
for settling. A dosage of 0.20 to 0.25 ppm of Magnifloc 985 along with
Ippm of Catfloc or Nalcolyte 607 does a good job. The need for investi-
gation of polymers to reduce waste volumes is evident.
Report of Research Activities. Research activities were reported by R.N.
Kinman. Most of the work I am aware of now deals with the recovery of
useable material from lime-soda sludges and the conditioning of alum sludges
through the use of polymers.
Dr. Black has in progress at the City of Dayton, the University of Florida
at Gainesville, and Montgomery, Alabama, projects dealing with the recovery
of magnesium from water softening plant sludges. The process plans to
recover magnesium, which in turn, can be recycled as a coagulant. A patent
is involved with this particular research. It is also proposed to study
use of the magnesium recovered at Dayton as a coagulant at the local sewage
treatment plant for phosphorus removal.
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At Virginia Polytechnic Institute work is being done on the conditioning
of alum sludge with polymers. Nonionics of relatively high dosages ap-
pear to be most effective.
Several water treatment plants are experimenting with their sludges attempt-
ing to make them more amenable to dewatering. Research work is being done
with sludge trom the Cincinnati Water Treatment Plant at the plant and at
the University of Cincinnati. Investigators have shown that polymer addi-
tion to this sludge has increased the dewaterability characteristics of
the sludge.
A number of priorities should be established under research needs. The
foremost need is to develop a standardization of sampling, analysis, and
categorization techniques for sludge. With the development of a standard
method, there would be a basis for comparison of sludge wastes. It was
pointed out that several plants do not presently recycle filter washwater
and that such recycling could decrease the volume of wastes produced. The
reduction of waste volume is an important consideration. Polymers may
applicable in reducing waste volume, although they are sensitive. There
is no universal polymer available at this time. Laboratory methods should
be carefully considered, since detergents contain anionic surfactants
that neutralize the polymers. Polymers should also be fresh and stored
in glassware that must be aged. Finally, in recovering or reusing pro-
ducts from sludge, a market is needed to make the operation meaningful.
The City of Dayton has a market survey underway to determine buyers and
the price of recovered magnesium.
Discussion of Research Activities Report. If there are interfering sub-
stances in the water due to detergents or other contaminants,methods to
destroy these interfering substances economically should be explored
before searching for the right polymer.
Polymers are quite expensive. The turbidity of an average water, how-
ever, can be removed with parts per billion of polymer as opposed to
parts per million of alum. Polymers have a variable price range. The
Catfloc ranges in price from 40 to 50 cents per pound. The Nalcolyte
ranges in price from 30 cents per pound for tank car lots to 40 cents
per pound for small quantities.
Polymer prices may go down in time. There are not many water treat-
ment plants using polymers at this time. There is experimentation in
progress and a large numbers of polymers have been approved by the
Public Health Service for water treatment plant use. Few water treat-
ment plants have the time to investigate all the approved polymers.
Quality control in polymer production was mentioned. Polymers must
be purified and consistencies insured before approval can be granted.
The elimination of trace byproducts and consistent production quality
are essential.
It appears that the more polymers are used, the lower will be the cost
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and more consistent the product. Manufacturers will have experience
in producing polymers. It was recommended to use polymers wherever
they fit into the treatment process.
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SECTION V
INFORMATION RESOURCES AVAILABLE
The Project Advisory Committee was requested to recommend specific infor-
mation needs and resources. The Committee members were assigned topics
dealing with research, engineering, regulatory, and plant operating prac-
tice aspects of this problem.
Research Needs - R.N. Klnman
A review of the first report, "Disposal of Wastes from Water Treatment
Plants", showed what was known. The Research needs were spelled out in
the AWWA Conference report. These needs were grouped under four headings.
The headings were: Nature of Wastes, with 4 problem areas; Treatment of
Water Plant Wastes, with 15 problem areas; Ultimate disposal of Wastes,
with 7 problem areas; and Future Water Treatment and Waste Management
Technology, with 5 problem areas.
Several projects have been proposed or are in progress to obtain infor-
mation related to the solution of these problem areas enumerated in the
Conference report.
The following agencies or individuals should be contacted to obtain as
a full report as possible on what is known at the present time and the
specific objectives of each project. The list is as follows:
a. A.P. Black, University of Florida at Gainesville
b. Walton Farr, City of Dayton, Ohio
c. George Webster, Water Quality Office of EPA
d. City of Atlanta, Howard Peters
e. Clifford Randall Virginia Polytechnic Institute
f. Paul King, Virginia Polytechnic Institute
g. Office of Water Resources Research
h. Sharpies Centifuge Company
i. Bird Centrifuge Company
j. Rex Chainbelt Company
k. Ralph Evans, Illinois State Water Survey
1. Lee Streicher, Metropolitan Water District of Southern Califor-
nia. '
When information is reviewed, it should be reported to the industry in
Willing Water, the AWWA Journal, and in a Research Foundation publication.
When information is reported, its relation to the whole or partial solu-
tion of one of the problems should be indicated along with the research
needs still to be met. This procedure would keep Everyone abreast of what
is known and at the same time call attention to the work remaining to be
done.
Since much of the usefulness of the data developed by the Research Founda-
tion depends on basic data concerning the first grouping, Nature of Wastes,
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which has been generated by performing standardized analyses for the same
parameters, on wastes from different plants, it is essential that this
Committee develop and promulgate standard methods of analysis for water
treatment plant wastes. After these have been evaluated and approved, the
methods should be furnished to the water utility industry with the basic
data questionnaire attached. Then data would be generated that could be
compared in a meaningful way.
The priorities in research are as follows:
1. Uniform sampling procedures and standard methods of analysis.
2. Recycle of waste waters.
3. Reduction of waste volumes.
4. Recovery of valuable materials from waste either for reuse or
sale.
Discussion of Research Needs
The need for the development of basic data on waste quantity and quality
was emphasized. Standardized sampling, analysis, and categorization tech-
niques should be developed to effectively compare data from water treat-
ment plants.
The ultimate goal will be to have these uniform techniques submitted to the
appropriate Standard Methods Sub-Committee for review. The Standard Methods
Sub-Committee may suggest additional techniques and consider the incorpo-
ration of this work into their publication. The final methods may result
from modification to existing approved methods that have been successfully
utilized for agricultural, soils, or other analysis fields.
A Sub-Committee composed of Messrs. Herbert Hartung, Kenneth Shull, Ralph
Evans, and Riley Kinman was organized to suggest appropriate modifications
to existing sampling and analysis techniques that would then be applicable
to water treatment plant wastes. The Research Foundation is to coordinate
the exchange of information. Each member is to suggest standards for lime
softening and alum sludges that could be exchanged for review and comments.
Standards should be considered for brine sampling and analysis procedures.
This program has been implemented.
Engineering Needs - G.P. Fulton
The role of the engineer is to translate scientific data into a form that
is both useable and practical. The research needs of the engineer are
consistent with those outlined earlier by Riley Kinman. We are planning
to develop future data, but the time for the engineer is now. The states
have arbitrary standards at present for treating water treatment plant
wastes. Metcalf and Eddy has 1 plant in construction, 2 in the design
stage, and 1 going into design with waste treatment facilities.
We have been studying treatment plants ranging in size from 100 mgd to
2000 mgd that would operate on a regional basis. Those familar with the
problems of the New York City water supply will realize that plants of this
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magnitude will be required in the next 25 years. Plants of this magni-
tude will require significant waste treatment facilities.
We have been handicapped by the lack of basic data. The most elemental
data, that would necessarily require the development of a standard method
to obtain, is the suspended solids. Turbidity has been a common handle
for water treatment plant operation. When we talk about wastes, we are
talking about solids that we must handle. Most plants keep accurate re-
cords on chemical usage, based on coagulant and coagulant aid usage. From
the chemicals being used, we are able to determine the amount of precipi-
tates being formed; but it is very difficult to figure out the amount of
solids being separated trom the raw watei.. There are more things common
in a sewage waste than in a water treatment influent water.
Fortunately, suspended solids data was available for design consideration
in our larger plants. In the future most water treatment plants will have
waste disposal problems that must be solved. It makes a great difference
in solids generation whether the water contains 20 or 50 ppm of suspended
solids. The time to collect such data is now, without necessarily wait-
ing to establish a standard method.
The problem in the Northeast is not sediment, but the organics in the source
water. The state is promoMn^ more sophisticated analyses since they real-
ize organics and not turbidity is the problem. i'he determination of amor-
phous matter and volatile solids would be important considerations. These
parameters are reflected in seasonal variations. Analyses should be fre-
quent enough to display seasonal trends for a water treatment system. This
is an important design factor.
The reduction of wastes is a most important factor. Preventive action is
more effective than taking care of the waste disposal problem once it is
created. As mentioned earlier, organics are the major problem in the
Northeast. In New York, we are faced with using the 10 States Standards
that have been designed to treat Mississippi River water. 90 per cent of
the Northeast supply is impounded water, and you can never find a brown
color in the Hudson River. There has to be a strong effort, in those parts
of the country where sediment is not the problem, to eliminate the use of
alum. New York has shown that if you can prove that coagulants are not
needed, they will accept a design that does not employ them.
Metcalf and Eddy has adopted 2 waste disposal methods, lagooning and natural
freezing, based on economics. A settling lagoon 10 feet deep could hold 5
feet of sludge, and 2 separate freezing lagoons could be provided. The
sludge can be spilled or sprayed on the bed. Johnson Well Screen type
strainers are being installed in all the lagoons to permit decantation of
water. A considerable area is required for waste treatment. The magni-
tude of the waste facilities is proportional to the size of the plant
and will increase directly with the amount of wastes produced.
Plants of 100 mgd or greater will present formidable waste disposal pro-
blems. In the Hudson River study, a maximum of 20 ppm of solids was
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considered and a coagulant dosage of a grain of alum. In this case, a
reduction of wastes is the most important factor. The reduction may be
either on the preventive or treatment side. For the 100 mgd or greater
plants, alum recovery has been determined to be the best method. The
limitation of alum recovery is that such a plant requires more sophisti-
cated operators and operations.
A plant of 280 mgd, utilizing alum recovery, was discussed. The waste
area facilities have been tremendously reduced. This leaves many plants
in the 5 to 100 mgd range that have problems with no economically avail-
able solutions. A possible solution for these smaller plants might be the
development of a package alum recovery system. The alum recovery, includ-
ing ultimate disposal, on the 100 mgd plants and greater adds $5 to $7 per
million gallons of treatment. The cost of mechanical equipment for lagoons
is nominal, but the land cost is great.
Some studies have been made on the type of ice-making equipment that would
be available for the artificial freezing operation. Most equipment would
be applicable for small.plant operation. The package type units would be
the mosfe logical choice based on the operating personnel experience level.
The Hackensack Water Company has stored sludge since 1926. The company
has not run out of area yet, but they are getting worried. The fill site
is similar to sites in Florida where wastes from phosphates or phosphoric
acid operations are dumped.
Engineering Needs - P.W. Doe
There are several examples where plant research is needed to provide valu-
able information. Sludge pumping is one variable that must be considered
in sludge handling. The viscosity of the sludge changes with the varia-
tion of solids concentration. The standard head loss equation, hL=fL V ,
D 2g
ceases to apply after a certain point. An illustration of the difficulty
of hand ling sludge is evident in this example. Sludge was pumped by
Moyno pumps to a tank 30 feet high. The sludge from this tank had to flow
through a 12X) feet of line to a freezing plant. Polyelectrolytes were used
in the sedimentation basins and increased the sludge solids content from
about 3 to 5 per cent. The result was that the 25 percent grade on which
the pipe was laid was not sufficient for gravity flow. The line had to
be broken and another Moyno pump inserted to pump into the freezing tanks.
Handling of low and high concentration sludges also presents problems.
Alum sludge, which is thixotropic, will settle in a pipeline when it is
pumped at high solids concentrations. Some provision should be made for
draining the pipeline while the sludge is fluid to avoid settling duririg
intermittent operation. When the sludge reaches a higher solids concen-
trations, a different solids handling mechanism, such as a screw conveyor,
might be used. If raw sludge or water contacts the cakes, the sludge can
revert to its fluid form. The screw conveyor then will grind the cakes
back into a slurry. The end product is important. Whatever the solids
concentration of the cake, there must be a means of finally disposing it.
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Operating data and experience would be greatly appreciated in this area.
The methods of sludge withdrawal from sedimentation basins is an important
consideration since it may affect the concentration and quantity of waste.
Using Moyno or other pumps to desludge the basins on a continuous or inter-
mittent basis could provide needed data. The goal of withdrawal would be
to produce a sludge of minimum volume and maximum concentration.
There may be some other ideas to be examined in final disposal. Can sludge
be disposed of in underground aquifers? If the sludge is pumped to gravel
beds, the interstices of the gravel bed will fill with sludge and a super-
natant will be displaced from the top. Filter press cakes may be disposed
of on a sanitary landfill. These cakes generally do not revert, but break
down into smaller pieces. The interstices of a sanitary landfill could be
filled with this material.
There is little information on the effect of alum sludge on activated sludge,
trickling filters, and digesters other than some economics. A research
program could investigate the effect of increasing alum sludge in incre-
ments from 1 percent to 8 percent, etc in such units. This disposal method
would be very cheap and should be investigated.
The use of incineration to further reduce combustible components of sludge
should be examined. The level of dryness should be determined to see
where combustion is self-supporting. Existing incinerators could be used
with increased amounts of pressed cakes to develop data. The incineration
of polyelectrolyte sludge could be examined to show advantages and disadvan-
tages of the incineration process.
The long term storage of sludge should be investigated. Personal experience
has indicated that sludge will turn purple, undergo anaerobic digestion,
and produce methane after a 14 day storage period or thereabouts.
The lagooning of sludges presents problems of maintenance, safety, and
liability. A quarry should be fenced to prevent access by children who
might inadvertently attempt to walk over a seemingly stable sludge crust.
A fence will last 10 years but may then require maintenance. In the case
of accidents or death resulting from people falling into lagoons, the
legal liability is tremendous.
Practical experience on the use of polyelectrolytes should be collected
by the Foundation. This information would provide direction and guidance
for developers, designers, and operators.
A list of plants that have waste treatment disposal facilities was reported:
1. Stocks plant, Fylde Water Board (England) - freezing
2. Daer Water Board, Scotland - alum recovery and freezing
3. United Kingdom Atomic Energy Commission - Freezing of phosphate
sludge.
4. Tokyo - alum recovery
5. Stocks Treatment Plant - 2 filter presses
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6.' 'Broughton Treatment Plant - 1 filter press
7. Manchester Corporation Waterworks - 2 filter presses
8. City of Atlanta - 1 filter press
9. Passaic Valley Commission - 2 presses
It may be possible, at selected plants, to make weekly logs of raw water
suspended solids, chemical dosages, and sludge produced, so that chemical
balance could be attempted.
If the information is not available, small joint ventures might be under-
taken to develop needed data. Abstracts from pilot operations could be
publicized by the Foundation.
Research instrumentation could be included in engineering design. At the
Passaic Valley plant, sludge will be pumped through some 1000 feet. By
installing pressure gages and other instrumentation, head loss curves could
be developed for sludge at different flows and concentrations. This field
of research is easy to do and write up.
Chlorinated rubber base paints provide good protection against corrosion
in sludge storage tanks. Epoxy paints, on the other hand, sometimes tend
to strip. The report of effective materials for corrosion resistance is
another important consideration. PVC pipe is also very resistant to the
corrosive nature of alum sludge.
A bibliography of information should be developed for ready reference and
as a complete file of sludge disposal literature. The Foundation should
have as a complete reference as possible to be a true clearing-house.
Discussion of Engineering Needs
Waste reduction was considered important. Polymers might be used to re-
place alum. If efficient incineration processes could be developed without
producing air pollution, only small residues of non-combustible material
would be produced. Only a bare minimum of material would be produced for
ultimate disposal.
Alum recovery studies, conducted by the Metropolitan Water District of
Southern California, have shown that the higher the ratio of aluminum hy-
droxide to other materials, the higher the percentage of alum recovery.
Tokyo claims to get 80 percent recovery of alum. Small scale studies,
both laboratory and pilot plant stages, indicate that it is useless to
recover alum on sludges having a 5 percent aluminum content. The Metro-
politan Water District studies have shown recoveries of from 80 to 93 per-
cent. When the organic content is increased to 50 percent in the waste,
recovery of alum is from 80 to 85 percent.
The Metropolitan Water District has modified the Japanese alum recovery
procedure to gain higher efficiency. Instead of decanting the aluminum
sulphate solutions and leaving the remainder of the insoluble material,
the sludge is treated with acid and passed through a filter press.
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Tliis squeezes out the soluble alum and leaves a cake of 50 percent solids
with some residual alum. The Japanese attempted to increase recovery effi-
ciency through elutriation, but diluted the recovered solution too much.
Metcalf and Eddy has considered the lagooning and natural freezing of
sludge as a treatment method. In the design of a sludge treatment and dis-
posal facility for a 5mgd water utility, several points were raised. The
major problem in the northern part of the U.S. is snow. The effect of 18
inches of snow covering partially frozen sludge is unknown. The design
provides flexibility by allowing spilling or spraying of the sludge on the
bed.
Metcalf and Eddy is considering 60 percent recovery for alum reclaiming
operations. The raw water source is the Hudson River, containing a 20ppm
maximum solids concentration. The waste sludge will contain a large amount
of aluminum hydroxide. In alum recovery, aluminum hydroxide is converted
into aluminum sulfate through treatment with sulfuric acid. Some alumi-
num sulfate must be contained in the final waste. With a low recovery
and a pH of 2, the waste must be neutralized with lime. Wastes contain-
ing a high percentage of alum, due to poor recovery operation, will form
aluminum hydroxide. The recovery method, in this case, is very inefficient
and expensive if recovery factors are not reasonable. A 1 to 2 percent
solution of recovered liquid alum would be good.
Metcalf and Eddy has also done studies of vacuum filtration of water sludges
with sewage sludges. Adding extra lime to the mixture improved the filtra-
tion. This operation is not suitable when sludge transmission is required.
If the sludge is discharged to sewers, digestor capacity would have to be
increased, creating economic problems.
The applicability of nuclear sludge density meters for the control of
water treatment sludges, similar to the meters used for the control of sew-
age sludge, was considered. This unit may provide means to operate at an
optimum sludge density at all times. These meters eliminate the need for
starting a pump to sample the sludge density. Sewage treatment plants
sometimes use these meters for primary sludge density control. The unit
is a continuous metering device mounted in-line. The meter is produced
by Industrial Nucleonics of Columbus, Ohio.
The utility of this meter for controlling alum or softening sludges is
unknown. Sewage sludge solids have a different density than alum sludge.
Densities of alum sludge and water are so close that a high solids concen-
tration is required to give a measureable difference.
The Metropolitan Water District of Southern California is using a nuclear
sludge density meter at a washwater reclamation facility treating filter
backwash water. The meter appears to be an effective measuring device
in the 4 to 5 percent density range. The meter results have been correlated
with laboratory tests.
The availability of equipment to treat sludge from water treatment plants
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should be explored. The cooperation ofcraanufacturers in providing infor-
mation on other products would help water utilities and designers in
building pilot and plant scale sludge treatment systems.
Regulatory Needs - R. Boes. R. Evans
The need was pointed out for a questionnaire that would establish a clear
"picture of what is being done and what must be done in the future", regard-
ing waste discharges from water treatment plants as viewed by regulatory
agencies.
A review was made of the responses to a previous questionnaire (1968) includ-
ed in the Foundation's first report concerning Regulatory Aspects. Al-
though a large majority of regulatory agencies considered wastes from water
treatment plants a definite source of pollution, and had established regu-
lations governing discharges, only 5 of 53 responding "had data on the
characteristics and quantities of these wastes. This is not unusual since
regulatory agencies generally are not involved in conducting or supporting
research at least at the state level.
It seemed pertinent to find out what these agencies consider major sources
of pollution from water treatment processes as well as their views upon
acceptable treatment, particularly since decisions are being made in spite
of the lack of basic data and research findings. There is need for a new
questionnaire that would define some areas, for the Foundation's study,
as well as provide some insight on the regulatory agencies activities re-
garding treatment requirements and fundings.
Discussion of Regulatory Needs
Relating to the 1953 survey by Dean and to the 1968 survey by the Research
Foundation, a marked change is evident in regulatory agency attitudes.- The
policy in most states is that new water treatmert plants will require waste
handling facilities. The 1968 survey replies that existing plants will
not be required to develop waste handling facilities unless their waste
discharges cause definite problems. If an existing plant is modified or
expanded, appropriate waste handling facilities will be required. Pressure
may require even existing plants to treat wastes.
The most evident problem is visible wastes. In Cincinnati, the filter back-
wash water contains considerable carbon that is visible when it is dis-
charged to the Miami River. This causes complaints. If the same waste
was discharged to the Ohio River through a diffuser, it would not be
visible. Aesthetic problems caused by visible wastes arouse the public.
In Illinois, the Division of Water Treatment acts as a breaking force between
water utilities and the Bureau of Stream Pollution. This Division is
most cognizant of the water treatment waste disposal problem. Good coop-
eration exists between water utility superintendents and regulatory agencies.
These agencies can provide good advice to the stream pollution personnel.
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Regulatory agencies adopt increasing controls on water utilities when com-
plaints of visible wastes are reported. The Columbus, Ohio,water treat-
ment plant has been a softening facility since 1910. Softening sludge was
discharged from this plant to the river below a dam. The spring floods
washed the sludge away. Complaints were received for 60 years. In the
last 4 or 5 years so much pressure was applied that this disposal method
was eliminated. A commercial lime plant, supplying this facility, was
located next to the plant. It had several large holes that could serve
as permanent lagoons. The lime company studied the reprocessing of the
lime sludge from the water treatment plant by burning, and found that it
was possible to develop a high purity lime. The costs for hauling and
thickening lime sludges and competition from a nearby lime supplier out-
weighed the market potential of the proposed recalcination process.
For waste disposal requirements, some states use effluent standards and
others use treatment standards based on stream quality criteria. States
using the stream quality criteria generally contain clauses in their per-
mits specifying what must be done to meet treatment requirements in 6 to
12 month periods. The permit amounts to being an effluent standard al-
though it, is not classified as such officially. The states not using
effluent standards inform designers engaged in water treatment and sewage
treatment plant work of their criteria, so that designers work in terms
of effluent wastB standards.
It was suggested that effluent standards are established to facilitate
the administration of water pollution abatement measures. Some regulatory
agencies may have knowledge of the assimilative capacity of the stream.
With this knowledge, criteria may be provided for a waste treatment set-
ting waste effluent levels at 80 ppm suspended solids at a certain mile
point on a river. For instance, at critical flows in the Cincinnati
River, 15 tons of material are requieed to change the river concentration
of this material 1 mg/1. The use of the assimilative capacity of rivers
and streams in many cases would require complex analses.
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SECTION VI
TECHNOLOGY TRANSFER RESULTS
Introduction
The AWWA Research Foundation, as a central information resource, identi-
fies and inventories research and demonstration studies dealing with the
treatment and disposal of wastes from water treatment plants. Several
sources have been searched to determine the type, extent, and status of
research activities both in the United States and several foreign research
organizations.
In its first year of operation as an information clearinghouse, the Research
Foundation has collected and organized information on research and demonstra-
tion studies from a variety of sources. These sources include: Science
Information Exchange of the Smithsonian Institution; Water Quality Office
of the Environmental Protection Agency; Office of Saline Water, U.S. Depart-
ment of the Interior; personal correspondence with principal research
investigators; members of the Fylde Water Board, Blackpool, Lancashire,
England; and reports discovered through literature searches. Several new
research reports have been published since the publication of the first
AWWA Research Foundation report titled "Disposal of Wastes from Water Treat-
ment Plants."
The material following represents the research activity identified for the
treatment and disposal of wastes from both conventional and desalting water
treatment facilities. This information defines new or modified waste treat-
ment technology. Accumulated information is classified and stored in the
Research Foundation's Research & Development Information Storage and Retriev-
al System.
News of research activity is valuable to the water utility industry. The
Research Foundation plans to continue and expand the organization, coordi-
nation and dissemination of information on the waste disposal problem.
Additional research and demonstration projects dealing with this subject
area, submitted to or discovered by the Research Foundation will be reviewed
and incorporated into this expanding study.
Science Information Exchange
The mission of the Science Information Exchange (SIE) is described as:
"to facilitate effective planning and management of scientific research
activities supported by the U.S. agencies and non-Federal institutions...."
The Research Foundation utilized the services of this organization to
define research activity for the subject area titled "treatment and dispos-
al of sludge from water treatment plants-all types- of water treatment
plants including desalination plants."
The SIE was able to provide copies of Notices of Research Projects that
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they have received from Federal and state department agencies, educa-
tional institutions, and various commercial organizations. These Notices
are provided with the understanding that they may not be utilized for
publication or publication reference without the permission of the princi-
pal investigators involved.
The Research Foundation contacted those investigators having information
on treatment technology applicable for the control of pollution caused by
wastes from water treatment plants. The researchers were informed of the
Foundation's principal activities, the collection and exchange of data
on laboratory, pilot plant, and full scale studies. ,
Each investigator was asked to permit the Research Foundation to include
the Notice of Research Project in its Research & Development Information
Storage & Retrieval "System, and to inform the Research Foundation of the
availability of reports describing progress in the study.
The following summary reports illustrate studies conducted by individuals
or organizations that have granted permission to the Foundation to include
their work in the information resource.
These Notices of Research Projects are listed alphabetically by the support-
ing agency for each study. These agencies are the Business and Defense
Services Administration; City Government of Decatur, Illinois; Federal Water
Quality Administration; Office of Saline Water; Office of Water Resources
Research; State Government of Illinois; and the University of.Illinois.
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Supporting Agency: Commerce Department, Business & Def. Services Adm.
Title of Project: Production of Water and Waste Water Treatment Equipment (1968)
Principal Investigators: K.L. Kollar and W.G. Youngwirth
Recipient Institution: U.S. Department of Commerce, Bus.&Defense Ser. Admin., Washington
D.C.
Summary of Project: Water Quality Management and Protection: A survey has been completed
of some 180 manufacturing establishments engaged in the production of water and wastewater
treatment equipment. The number and value of treatment equipment produced in 1968 and the
production capacity for 24 major product categories will be published in a report 9/1970.
Among the products the report will cover are chemical feed equipment, filtration equipment,
sludge digestion and disposal equipment and package treatment plants.
.Supporting Agency: Decatur City Government - Illinois
Title of Project: Thickening and Dewatering of Water Treatment Sludge
Principal Investigators: R.I. Dick and J.I. Barkman
Recipient Institution: Univ. of Illinois, School of Engineering, Urbana, Illinois
Summary of Project: Laboratory and full scale plant investigations are being conducted to
.develop operational parameters for a gravity thickener to yield optimum volume reduction
•and solids concentration. Further dewatering investigations have involved the use of
various polyelectrolytes to improve the filterability of the softening-clarification sludge
by an existing vacuum coilfilter.
Supporting Agency: Interior Department, Federal Water Quality Administration
Title of Project: Lime Sludge Recovery and Reuse
Principal Investigators: M.C. Mulbarger and R.B. Dean
Recipient Institution: U.S. Dept. of the Interior, Federal Water Quality, Admin, Cincinn-
ati, Ohio
Summary of Project: Lime in doses of 200 to 500 mg/1 as Ca(OH)2 removes phpsphates and
suspended matter from secondary effluents. The resultant sludge consists of calcium carbon-
ates and phosphates together with silicate minerals, magnesium hydroxide and organic matter.
Although the recovered lime may cost nearly as much as fresh lime, the problem of disposing
of large volumes of sludge is solved. Waters differing in hardness and phosphate content
have been treated through four cycles and the quantity and quality of the recovered lime
has been measured. In soft waters calcium phosphate builds up until it represents over
half of the weight of calcined lime without exerting any deleterious effect, provided
that fresh lime is added to make up the losses. In hard waters calcium carbonate is removed
from the water and must be continuously wasted along with low concentrations of calcium
phosphate.
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Supporting Agency: Interior Department, Federal Water Quality Admin.
Title of Project: The Thickening and Dewatering of Precipitates from the Lime/Limestone
Treatment of Mine Drainage
Principal Investigator: Edward Moss
.Recipient Institution: West Va. University, School of Mines, Morgantown, West Virginia
Summary of Project: The proposed work will consist of a detailed studyof the problem of
densification of ferric hydroxide — calcium sulphate sludges which result from the lime
or limestone treatment and aeration of acid waters from coal mines. The project will focus
on the interrelationship of mine water chemistry with the settleability of sludges and
possible methods used to chemically or mechanically concentrate and dewater these sludges.
Areas of study will include filtering, flocculation, decantation, centrifuglng, thickening,
and cycloning. A "State of the Art" review of potentially useful existing dewatering
methods as they apply to mine water treatment sludges will be completed early in the study.
The economics of alternative tr^i.-ment schemes will be examined with the objective of
reducing the overall costs of water treatment and sludge disposal. The project will begin
in February, 1972.
Supporting Agency: Interior Department, Federal Water Quality Admin. & Common, of Pa.
Title of Project: Neutralization and Precoat Filtration of Concentration Sludges from
Mine Water
Principal Investigator: Dr. D.R. Maneval
Recipient Institution: State Dept. of Mines & Min., Harrisburg, Pa.
Summary of Project: The project is directed at providing a cost-effectiveness evaluation
of various neutralization processes in the treatment of acid mine drainage. Sludge dis-
posal problems will be studied with emphasis on precoat filtration. Field test will be
accomplished on four abandoned mines in the Western Pennsylvania area. Johns-Manville
Company will perform the work. It is hoped that this method will provide significant
information on economic feasibility of reducing acid mine drainage by neutralization.
Supporting Agency: Interior Department, Federal Water Quality Admin.
Title of Project: Treatment of Acid Rinse Waters
Principal Investigator: J. Barker
Recipient Institution: Armco Steel Corporation Middletown, Ohio
Summary of Projecf. The project provides for construction, operation, tests, and reports
on facilities to treat 1500 gpm of acid rinse waters produced by the hydrochloric acid
pickling of strip-steel preparatory to cold-rolling. The treatment process will consist
'of limestone neutralization, aeration, coagulation, sedimentation, sludge recirculation,
vacuum filtration of the excess sludge, and effluent equalization. All or nearly all
of the acid and the compounds of iron will be removed by the treatment process. The
chloride content of the waste is not changed by this process and may be such that dilu-
tion with other available wastes will be required in order to meet the state's proposed
standards regarding total dissolved solids.
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Supporting Agency: Interior Department, Office of Saline
Title of Project: The Feasibility of Obtaining a Solid (Dry) Brine Effluent from De-
salting Plants at Inland Locations
Principal Investigators: W.F. Mcllhcnny, B.P. Shepherd, P.G. Legros, and J.C. Williams
Recipient Institution: Dow Chemical Company, Midland, Michigan
Summary of Project: In the first phase of this project a survey will be performed of
the chemical and process industries to determine applicable methods of reducing or remov-
ing solids from solutions. The constituents of brackish water will be determined and
the potential usefulness of the processes for treating of the brine effluents from desal-
ination plants will be determined. Secondly, tte economic feaseabilities and potential
size limitations of each alternation will be determined and the advantage, disadvantage,
and economic potentials of the alternatives will be compared. Processes which, at this
time, appear to merit for treating and desalting brines to produce dry solids include:
(1) Solvent extraction; (2) Fluid-bed drying; (3) Spray calcination.
Supporting Agency: Interior Department, Office of Saline Water
Title of Project: Determining the Feasibility of Obtaining Dry Brine Effluents from
Desalting Plants at Inland Locations
Principal Investigators: I. Yen, D. Garrett, E.A. Manker, M.J. Kallerud, and E. Chemtoe
Recipient Institution: Garrett Res. & Dev. Co. Inc., La Verne, California
Summary of Project: This project will prepare a conceptual design of a desalination plant
using solar ponds in conjunction with a multistage flash evaporator. The solar ponds
shall be used not only for evaporation but also as solar energy collectors to heat the
feed brine for further processing. The complete plant shall be designed for a total
potable water output of 2.5mgd. Plant scaling factors shall be provided for 1 to lOmgd
plants. The conceptual design shall include process flowsheet, heat and material bal-
ance, equipment layouts, materials of construction, design calculations and elevation
or sectional drawings required to fully describe the designed plant and/or principal
items of equipment capital and operating cost estimates shall be prepared for the
designed plant and related to the cost of fresh water output so that a cost of reduction
or removal of solids can be determined for a fresh water output.
Supporting Agency: Interior Department, Office of Saline Water
Title of Project: Feasibility of Obtaining a Solid (Dry) Brine Effluent from Desalting
Plants at Inland Locations
Principal Investigators: R.W. Fosterpegg, G.W. Blair, S.A. Laurich, N. Ganiaris, R.H.
Hedrick, and R.J. Glasser
Recipient Institution: Struthers Energy Systems Inc., Warren, Pennsylvania
Summary of Project: This project will investigate the recovery and use of solids from
the brine effluent from a 2.5 mgd desalting plant. Processes to be examined are: 1. The
use of a single and multiple effect crystallyzer/evaporators for removing or reducing the
solids from solution; 2. The operating parameters of a crystallizer to determine the
economic feasibility of designing for production of salts with a commercial value; 3. The
use of a direct contact spray type granulator and/or fluidized bed dryer for final effluent
drying. The above processes will be compared as to advantages, disadvantages, and economic
potential, and potential size limitations will be determined. For the most optimum of
these processes a conceptual design will be prepared for a plant treating the effluent of
a 2.5mgd desalination plant. The capital and operating cost estimates for this plant will
be determined so that the cost of reduction or removal of solids can be determined for a
unit of fresh water output.
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Supporting Agency: Interior Department, Office of Saline Water
Title of Project: Recovery of Chemicals as a Means of Brine Disposal
Principal Investigators: E. Rabin, C.J. Avery, and P. Hadzeriga
Recipient Institution: Environmental Qual. Eng. Inc., Oakland, California
Summary of Project: Candidate products, processes, and sites will be identified for the
recovery of chemicals from desalting plant effluents. Associated economic and process
design data will be assembled, and environmental problems will be examined. Feasability
criteria for the potential of the process will be established. Based on this information
and criteria, block flow diagrams will be developed for approximately eight products and
sixteen processes. A preliminary market analysis will be performed on each product under
consideration. The interrelation between chemical and desalting plants will be evaluated
' to include such factors as descaling, effluent brine concentration & composition, and
changes in residual waste disposal resulting from chemical recovery. Based on these
exploratory studies, the most promising products, processes and sites will be selected for
'a preliminary engineering and economic analysis. This will include determination of the
smallest plant size that will support chemical recovery. The results of this analysis
will be used to (1) identify the most promising integrated facility for desalting-chem-
ical recovery, and (2) determine research efforts necessary for advancement of chemical
recovery methods for brine disposal.
Supporting Agency: Interior Department, Office of Saline Water
Title of Project: Disposal of Brine Effluents by Conversion to By-Products
Principal Investigators: R.R. Grinstead and G.E. Fleig
Recipient Institution: Dow Chemical Company, Walnut Creek, California
Summary of Project: This project will examine the application of solvent extraction
methods to the separation and concentration of desalination brines to produce products
which can be disposed of in normal industrial channels. Such products will include sodium
chloride, sodium carbonate, magnesium and calcium carbonates, sodium and ammonium sulphates',
and chlorine and caustic soda (from electrolysis of sodium chloride brine). A dual extra-
ction system will be studied, and will be analogous to the Desal ion exchange process for
desalinating brackish water. The initial step would be based on the use of amine systems
to convert anionic constituents of the brine to bicarbonates, and the second step will
utilize acidic extractions to acidify the bicarbonates to carbon dioxide. Among the by-
products will be sodium carbonate, which can be used to remove divalent cations from the
brine feed or from the original brackish water, ahead of the desalination step. In the
latter case, the softened feed water would allow a greater recovery of water in the desal-
ination step. The rationale of using extraction methods in this application rests on the
abil ity of extraction processes to treat and produce stronger salt solutions than ion
exchange of methods, since problems of dilution due to mixing of aqueous phases are elim-
inated.
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Supporting Agency! Interior Department, Office of Saline Water
Title of Project: Determining the Feasibility of Alternative Approaches of Obtaining
a Solid Dry Brine Effluent from Detalination Plants at Inland locations
Principal Investigators: S. Lemezis, D.B. Boies, R.L. Coit, V.S. Ivins, and C.J. Bowden
Recipient Institution: Westinghouse Electric Corp., Philadelphia, Pennsylvania
Summary of Project: this project will prepare a conceptual design of a unique multistage
flash evaporator concentration system which can receive brine effluent waste from desalt-
ing plants of any process and reduce the waste volume to less than \ of 17.. The concen-
tration system design capacity shall be based on treating the brine effluent from a 2.5
mgd distillation plant. Plant scaling factors shall be provided for 1 to 10 mgd plants.
Capital and operating cost estimates for the 2.5 mgd plant shall be prepared so that the
cost of reduction or removal of solids can be determined for a fresh water output.
Screening runs on available equipment shall be performed to evaluate water characteristics
for design purposes.
Supporting Agency: Interior Department, Office of Saline Water
Title of Project: Study of Approaches of Obtaining Solid Brine Effluents from Desalina-
tion Plants
Principal Investigator: F.C. Stairiiford
Recipient Institution: W.L. Badger & Associates, Ann Arbor, Michigan
Summary of Project: In the first phase of this project, a survey will be performed of
the chemical and process industries to determine potential processes for removing or
reducing solids from solution when treating the brine effluent from desalination plants.
Secondly, the economic feasibility of each alternative will be determined and a cost of
reduction or removal of solids will be determined for a unit of fresh water and for the
plant sizes under consideration. The potential size limitations of each alternative will
be determined and the advantages, and disadvantages and economic potential of these
alternatives will be compared. A conceptual design will be prepared for a plant treating
the effluent of a 2.5.mgd desalination plant and capital and operating costs for this
plant will also be prepared. These costs will be used to determine a cost ot reduction
or removal of solids for a fresh water output.
Supporting Agency: Interior Department, Office of Saline Water
Title of Project: Evaluation of Soil Sealants from Solar Evaporation Ponds
Principal Investigator: L. Ellsperman
Recipient Institution: U.S. Dept. of the Interior, Bureau of Reclamation, Denver, Color-
ado
Sunmary of Project: The Bureau of Reclamation has been conducting studies on surface
facilities for the disposal of brine from inland desalting plants. Nine different linings
and a control, including two chemical sealants, have been evaluated at Dalpra Farms, Long-
mont, Colorado. These materials were installed as the base under 18-foot diameter metal
tanks. Seepage rates have been determined using brine effluent up to a 5 - foot depth.
At the present time the most economical and effective sealants for solar ponds are poly-
ethylene and polyvinyl chloride (PVC) films. However, film materials are subject to
mechanical damage which is difficult to repair. Chemical sealants are self-sealing. As
a result of the previous laboratory work two new chemical sealants were shown to have a
better potential for sealing ponds effectively and at lower cost than most of the materials
field tested to date. They are Dow Chemical Company's Sealant No. 1193 and Union Carbide
Company's product, DCA-70. The purpose of this project is to field evaluate these two new
chemical sealants.
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Supporting Agency: Interior Department, Office of Saline Water
Title of Project: Surface Facilities for Disposal of Desalting Plant Effluents
Principal Investigator: L.H. Ellsperman
Recipient Institution: U.S. Dept. of the Interior, Bur. of Reclamation, Denver, Colorado
Sunmary of Project: Objectives: To develop design criteria for surface facilities to
be used in the disposal of desalting plant effluents. Description of Work: a. Perform
"state of the art" bibliography, including literature and industry survey, b. Explore
and evaluate soil samples from probable sites, c. Conduct a laboratory evaluation of
the effectiveness of soil sealants and other lining materials with various brine efflu-
ents, d. Develop « monitoring system for continuous and routine measurements of seepage
losses, f. Field test soil sealants and other lining materials and develop optimum
methods of application, g. Prepare a manual on surface facilities for disposal of
desalting plant effluents, h. Conduct an economic study of salt disposal.
Supporting Agency: Interior Department, Office of Water Resources Res.
Title of Project: Conservation of Fresh-Water Resources by Deep-Well Disposal of Liquid
Wastes
Principal Investigators: Dr. D.M. Grubes, C.D. Haynes, and W.E. Tucker
Recipient Institution: Univ. of Alabama, Water Resource Program, University, Alabama
Summary of Project: This project will evaluate the geological and engineering parameters
• of subsurface rock formations which will permit disposal of liquid waste by deep-well
injection procedures. Criteria and techniques will be sought which will have both quanti-
tative and qualitative regional application in the development of underground disposal
facilities. This will in turn alleviate the problem of usage of surface waters as carriers
of waste effluent. Studies will be focused upon: 1. Derivation and analysis of informa-
tion such as rock core and cuttings lithology, analysis of reservoir fluids, results
of rock matrix and cementing material, electrical and other well-logging parameters, and
petrophysical data such as porosity and permeability; 2. Laboratory analysis from simi-
tated injection of wastes into actual reservoir core samples to determine capacity,
receptivity, continuity and compatibility, and pressure-time-distance response as a basis
for prediction or systems behavior; 3. Development of mathematical models applicable
to the identification and evaluation of potentially receptive disposal zones. Determina-
tion of restrictions to be placed upon types and volumes of liquid wastes which may be
.Injected into specific deep-well reservoirs.
'Supporting Agency: Interior Department, Office of Water Resources Res.
Title of Project: Ground Water Contamination Resulting from Waste Disposal
Principal Investigators: J.R. Anderson and J.N. Dornbush
Recipient Institution: South Dakota State University, School of Engineering, Brookings,
South Dakota
Summary of Project: Representative waste disposal methods In South Dakota including land
disposal of liquid and solid wastes will be investigated to determine: 1. A reconmended
procedure for selection of waste disposal sites in order to minimize ground water contam-
ination problems. 2. The effects of waste disposal practices including: a. The nature
and extent of ground water contamination, b. The.effect of ground water contamination
on proposed beneficial uses. c. The influence of such factors as climatic conditions,
soil types and waste characteristics on the degree and extent of travel of pollutants.
3. A means of combatting undesirable contamination of the ground water. It is also pro-
posed that the project will investigate the long term effects of solid waste landfill on
ground water quality in an area where adequate background data have been collected to
observe the initial influence.
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Supporting Agency: Interior Department, Office of Water Resources Res.
Title of Project: Use of Lime-Soda Ash Sludge for the Treatment of Municipal Wastewater
Principal Investigator: W.J. O'Brien
Recipient Institution: Univ. of Kansas, School of Engineering, Lawrence, Kansas
Summary of Project: The objectives of this reasearch are to analyze the excess sludge
produced by the lime-soda ash water softening process used in the municipal water treat-
ment plant at Lawrence, Kansas, and to determine the effectiveness of this material as
a precipitant for wastewater. The water softening sludge will be added to the primary
sedimentation basin on the municipal wastewater treatment plant to determine the level
of phosphate and suspended solids removal that can be obtained at a pH of 9.5 in the sedi-
mentation basin. Final disposal methods for the mixture of biodegradable organic matter
and chemical sludge produced at the wastewater treatment plant will also be investigated.
Both laboratory and plant scale tests will be conducted. An economic evaluation of the
process will also be prepared.
Supporting Agency: Interior Department, Office of Water Resources Res.
Title of Project: Economic Disposal of Waste Sludges from Water Treatment Plants
Principal Investigator: P.H. King
Recipient Institution: Virginia Polytechnic Institute, School of Engineering, Blacksburg,
Virginia
Summary of Project: The disposal of sludges resulting from conventional water treatment
processes such as coagulation, softening and filtration will be examined with a view
of developing alternatives to disposal by dilution in cases where water quality stream
standards would be violated or in situations where disoosal to lagoons would not be feas-
ible due to land costs. Particular attention will be given to the parameters of treatment
plant operation and to sludge conditioning techniques which result in rapid and tnorough
sludge dewatering on either open sand drying beds or through use of vacuum filters. The
use of newly developed synthetic organic polyelectrolytes as a conditioning aid will be
investigated. The economics of alternative methods of water treatment plant sludge dispo-
sal under varying conditions will be evaluated.
Supporting Agency: Interior Department, Office of Water Resources Res.
Title of Project: Effect of Environmental Factors on Design and Operation of Open-Air
Sludge Drying Beds
Principal Investigator: Dr. J.C. Jennett
Recipient Institution: Univ. of Missouri, School of Engineering, Rolla, Missouri
Summary of Project: In order to develop rational techniques for the design of open-air
sludge drying beds, it is necessary to understand the effect environment has on the
process. The main approach of this investigation is to study the fundamental aspects
of sludge drying and how environment is a factor. The specific objectives of this project
are to develop laboratory procedures which will allow the quantitative evaluation of the
effects of environment on sludge drying; to evaluate the experimental results gained from
the laboratory to determine how and to what degree environment and sludge bed design affect
the rate and extent of sludge drying; and to develop « rational approach to the design
and operation of these drying beds. Laboratory investigations will be performed using
model sludge drying beds in environmental chambers which allow the control of the physical
environment so that each variable may be held constant or changed as desired. Laboratory
and field data will be correlated to allow practical application of the results.
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Supporting Agency: Interior Department, Office of Water Resources Res.
Title of Project: Treatment of Water-Plant Sludges
Principal Investigator: Dr. J.F. Judkins
Recipient Insitutions: Auburn University, School of Engineering, Auburn, Alabama
Summary of Project: The objectives of the proposed research are to investigate the crys-
tal seeding process as a means of improving the filterability of water treatment plant
sludge. The process will be investigated for its annl lability to both coagulant sludges
and lime-softening sludges. Variables of iiterest will include crystal seed dosage, mixing
rate and the concentrations of impurities in the water. Studies will be conducted on
laboratory samples prepared by the* addition of typical concentrations of turbidity,
hardness and alkalinity to di;tilled water.
Supporting Agency: Illinois State Government
Title of Project: Water Treatment Plant Wastes
Principal Investigation: R.L. Evans
Recipient Institution: State Water Survey, Urbana, Illinois
Summary of Project: A study is under way to determine the effect, if any, that waste
generated by water treatment plants may have on potential or existing water simply
sources, as well as other legitimate users of water. An effort has been made on
a statewide basis to determine 1) existing methods of water treatment wastes disposal;
2) types and quantities of waste generated per unit quantity of water treated; and
3) chemical, physical, and biological characteristics of the wastes. That phase of the
project involving classification units and water softening is complete. Current efforts
are devoted to investigating municipal ion exchange units involving principally brine
wastes.
Supporting Agency: University of Illinois
Title of Project: Gravity Thickening Theory
Principal Investigators: R.I. Dick and B. Shin
Recipient Institution: University of Illinois, School of Engineering, Urbana, Illinois
Summary of Project: Kynch's theory is being used as a basis for study of the gravity
'. thickening behavior of suspensions. Extensions and modifications of the theory as sugg-
.ested by reported performance of gravity and continuous thickeners are being developed.
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Plant Visits
The Research Foundation staff visited two water utilities conducting pilot
and plant scale activities. The Hackensack Water Company of Oradell, New
Jersey, is using pilot plant units to determine the effect of recycling
and reusing filter washwater. The City of Atlanta, Georgia, is installing
two pressure filters to dewater the sludge from the Chattahoochee Water
Treatment Plant.
Hackensack Water Company
The Hackensack Water Company is conducting an in-house study on the "Recy-
cling and the Reuse of Filter Washwater." The water utility is funding
and staffing this project.
The one gallon per minute pilot plant includes flocculation, sedimentation,
and filtration units; it is supplied with water drawn from the influent
basin of the main treatment plant. This water contains the normal chem-
ical dosages of chlorine, alum and carbon; to it, in the flash mixer of the
pilot plant, filter backwash water is added. The backwash water represents
2 to 3 percent of the composite one gallon per minute flow processed.
The initial source of backwash wastewater was a composite sample of wash-
water from one of the full scale plant filters. In continuing pilot plant
operation, filter washwater from the pilot filters was recycled and reused.
Following rapid mixing and settling, the clarified effluent is fed to a
multi-media pilot filtration unit.
The experimental filters are composed of 42 inches of anthracite , with
gravel bottoms. The surface area is 0.233 sq. feet and the flow through
the filters is 4.5 gpm per sq. ft. The filters are washed every 30 hours
at 32 inches rise per minute for 8 minutes, corresponding to the use and
backwashing schedule of the actual full scale plant filters.
Samples of the pilot plant basin and filter effluents are collected for
analysis. Head loss readings are recorded both for control and experimen-
tal filters.
The effectiveness and economy of chemically coagulating a filter washwater
will be evaluated. It is proposed that this process will reclaim the
liquid portion of the washwater and eliminate the need for separate wash-
water sedimentation basins to settle potential solid pollutants.
Atlanta, Georgia
The City of Atlanta is installing Beloit-Passavant sludge dewatering equip-
ment to dewater the alum sludge generated at the Chattahoochee Water Treat-
ment Plant. The selection of this equipment followed extensive testing
in which air flotation, vacuum filtration, centrifugation, and filter press-
ing processes were evaluated. It is anticipated that Atlanta will be the
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first United States city to dewater alum sludge by filter pressing.on a
plant scale basis. The addition of seven new dual media filters will
increase the plant design capacity to 60 mgd.
The full scale waste dewatering plant will consist of two series 6400
Beloit-Passavant Pressure Filters. The presses are expected to produce
a filter cake with a solids concentration between 40 and 45 percent. The
alum sludge will be conditioned with lime before processing. The filter
cake can be disposed of as a landfill. The capacity of the two pressure
filters being installed is approximately 55,000 pounds of dry solids daily.
It is expected that the Chattahoochee Sludge Dewatering Plant will go into
service in late 1971.
Manufacturer Research
The Permutit Research and Development Center has reported initiating pilot
plant studies on the dewatering of alum, ferric hydroxide, and calcium
carbonate sludges. The Center is preparing a paper titled "Dewatering of
Water Plant Sludges." An abstract of this paper, submitted to the Research
Foundation, states:
"A method of gravity dewatering of typical water plant sludges is presented.
The sludges studied include aluminum hydroxide, iron hydroxide, magnesium
hydroxide, and calcium carbonate. Due to their greater complexity, water
plant sludges are more difficult to dewater than a pure aluminum hydroxide
or a pure ferric hydroxide sludge. Water plant sludges are fragile under
stress and of particle sizes unsuitable for rapid dewatering. The new
gravity dewatering treatment system judiciously utilizes; (1) polymers
which produce a floe having the proper particle size and integrity for
gravity dewatering, and (2) a moving bed gravity dewatering device that
maintains an extremely thin cake in its gravity dewatering compartment."
Water Quality Office, E.P.A.
There have been two studies identified through the Water Quality Office of
the Environmental Protection Agency.
The first study is titled "Treatment of Waste Alum Sludge." A grant of
$31,871 was awarded to the City of Albany, New York, Department of Water
and Water Supply. The project is expected to run from June, 1971 to
December, 1971.
The purpose of this study is "to conduct a detailed pilot plant alum
sludge filtration study at the Feura Bush Water Treatment Plant of the City
of Albany. The objectives are to optimize operating parameters, demon-
strate process reproducibility, and develop information necessary for full-
scale plant design.
The technical and economic feasibility of rotary vacuum precoat filtra-
tion of alum sludge will be evaluated. A comparison will be made of the
performance of various types and grades of filter aids, and other operat-
ing variables. Design and criteria for a full-scale facility will be
sought.
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The second study is jointly funded by the Water Quality Office of the
E.P.A.; The City of Montgomery, Alabama; and the AWWA Research Foundation.
The project is titled "Use and Recovery of Magnesium Carbonate for Color
& Turbidity Removal from Municipal Water."
The purpose of this study is to evaluate the effectiveness of magnesium
carbonate as a recycled coagulant for use in removing color and- turbidity
from raw water sources at municipal purification plants. Magnesium car-
bonate is presently reclaimed at the Dayton, Ohio, water softening plant
from a sludge containing calcium carbonate and magnesium hydroxide. The
calcium carbonate sludge is recalcined to recover lime for plant oper-
ation and excess lime is sold.
In the conversion of magnesium hydroxide to magnesium carbonate, sludge
from the softening facility is carbonated, using carbon dioxide produced
from the rotary kiln of the lime recovery furnace. The carbon dioxide
selectively converts the insoluble magnesium hydroxide to a soluble car-
bonate. A physical solid - liquid separation process allows the recovery
of a magnesium carbonate supernatent solution before the calcium carbon-
ate sludge is calcined. The use of magnesium carbonate as an alum coag-
ulant replacement represents a new technology in water treatment that will
alter the character of waste sludges.
Pilot and plant scale testing of this coagulant at the Montgomery, Alabama,
water treatment plant will determine operating and design variables for the
new process. The recycling of magnesium carbonate coagulant in purifica-
tion plants will alleviate the magnitude of wastes for ultimate disposal
at these facilities.
Correspondence - Domestic
Three studies on the treatment of settling basin sludge and filter wash-
water have been reported to the Research Foundation for incorporation into
this information resource. These studies deal with the centrifugation,
lagooning, and recycling of waste sludges.
The first study is titled "Treatment and Disposal of Sedimentation Tank
Sludge and Sand Filter Backwash Water, Van Bibber Treatment Plant, Edge-
wood Arsenal, Maryland."
The engineering firm of Van Reuth and Weidner, Inc. was contracted by the
Baltimore District, Corps of Engineers, Department of the Army, to study
and report on the treatment and disposal of sedimentation tank sludge and
sand filter backwash water from the Van Bibber Water Treatment Plant at
Edgewood Arsenal, Maryland. The study was undertaken for the purpose of
meeting more stringent state pollution abatement laws governing the dis-
charge of wastes from water treatment plants.
Several treatment processes were evaluated for concentrating the predom-
inantly aluminum hydroxide sludge at this purification plant with a design
capacity of 4.0 mgd. Laboratory tests were conducted on potential dewatering
methods including vacuum filtration, sand filtration, evaporation and
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decanting (lagooning), freezing, chemical treatment, and centrifugation.
Evaporative lagooning with decantation and centrifugation with chemical
treatment were found to warrant further investigation in this applica-
tion due to their practicality and efficiency.
Field demonstration tests on waste conditioned with synthetic organic
polymers were made using a Dorr-Oliver Merco Bowl Centrifuge. Tests
showed that at this plant, centrifugation was the most economical treat-
ment process for the handling of the sludge and filter backwash water.
The recommendations from the study have been adopted and now constitute"-
the basis for design and construction of new facilities which are scheduled
for early completion at the Van Bibber Plant. The construction costs
are estimated at $180,000 and annual operating and maintenance costs are
estimated at $29,000. This report is the result of investigations con-
ducted by the authors for the U.S. Army Engineer District, Baltimore, and
is released pursuant to current policy, as a matter of possible interest
to the engineering profession.
The second study reported is an engineering proposal made for the settling,
of filter washwater from a water treatment facility. The supernatant
from the settling process will be reclaimed.
Reagan & Me Caughan, Consultant Engineers from Corpus Christ!, Texas,
have proposed waste treatment facilities to control the pollution caused
by sedimentation tank sludge and filter backwash water at a Nueces County
Water Control & Improvement District No. 3 water treatment plant. This
utility provides l.Smgd of domestic water for the City of Robstown and the
surrounding area.
Lime, alum, and chlorine are used to treat the raw water at this plant.
The source water is pumped from the Nueces River into an earthen canal
and then flows into a series of lakes at the treatment plant site. The
wastewater from the coagulation and filter washing process is presently
discharged to a drainage ditch owned and operated by a Drainage District.
The Texas Water Quality Board has noted objections to this procedure and
has advised the District to find a .new disposal technique.
The consultants have proposed that the sludge and filter washwater be
treated in earth settling basins. The clarified effluent would then be
returned to the raw water lake. Two basins would be provided to allow
operation of one and cleaning of the other. The sludge from these basins
would be ultimately disposed of at a suitable site. The settled sludge
may have utility as a fertilizer for grain or cotton crops.
A third study has been reported by the superintendent of the water works
for the City of Cincinnati, Ohio.
"Plans are being formulated to recycle spent washwater, with raw incoming
water, through the primary sedimentation basins. The installations will
provide for two methods of initial experimentation:
46
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1. Recycling of spent washwater with sludge from secondary
treatment.
2. Recycling of spent washwater alone.
Experiments are now underway to concentrate secondary treatment plant sludge
in lagoons. In these, it is anticipated that some concentration will occur
due to perculation, evaporation and natural winter freezing.
The residual will be pumped in thin layers on farm land, harrowed in, fer-
tilized, and otherwise treated to form an acceptable base on which to grow
sod. The end result being a sod farm (to supply City Departments) with a
self-perpetuating top soil. Water is to be decanted from the lagoons using
a valved tower to regulate the effluent level being decanted. "
Correspondence - Foreign
Several foreign research organizations have been contacted to determine
the type and status of activity involving the treatment of water utility
wastes.
The Fylde Water Board provided three reports that were not referenced
in the Foundation's 1969 report on the disposal of wastes from water treat-
ment plants. These reports have been abstracted by the Research Foundation
and transmitted to the Water Resources Science Information Center. The
abstracts follow.
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Benn, D. and Bridge, L., "Sludge Disposal by Pressing," Paper of Fylde Water Board,
Blackpool, Lancashire, England.
Key Words: Design data, Filter pressing, Sludge conditioning, Operational experience
This study provides experimental, operational, design, and cost data from extensive filter
pressing testing of clarification sludge conditioned by a polyelectrolyte. A pilot press
was utilized to evaluate the dewatering of sludge from three water utilities. Filter
pressing of sludge from the Hodder water facility was successful. A full-size filter press
was installed. Filter washwater is dosed with a polyelectrolyte. The mixture undergoes
two stage settling. The final supernatant is discharged to a river and the sludge is
withdrawn from the settling basins and stored for pressing. Details of the press design
features and operation are provided. Operational experience is discussed including infor-
mation on sludge thickening, cyclic operation, power, economy, pipework and valves, auto-
matic control systems, filter cloths, and mechanical handling equipment. Capital, running
charge, debt charge, and comparative costs are tabulated. Conclusions based on operating
experience are made on the press cycle, degree of system automation, cloth materials, and
equipment sizing.
.Hilson, M.A., "Sludge Conditioning by Polyelectrolytes," Paper of Fylde Water Board,
Blackpool, Lancashire, England.
Key Words: Mathematical models, Sludge disposal, Sludge conditioning, Polyelectrolytes
This study defines the nature of polyelectrolytes and provides instances where these natural
or synthetic polymers made clarification sludges more amenable to dewatering. Polyelectrolyte
effectiveness can be influenced by seasonal water quality changes. At the Fishmoor plant,
sludge is withdrawn from the sedimentation basins and stored. The stored sludge is then trans-
ported to a mixing tank where a polyelectrolyte is added. The mixed sludge is gravity fed to
a thickener. At the Stocks plant, polyelectrolyte is added to the washwater. The washwater is
then settled. Laboratory jar tests to evaluate polymers for sludge thickening efficiency
concentrate on the rate of flocculation, floe size, settling rate, and water clarity. Sludge
dewatering by filter pressing is predictable by the Carman-Kozeny and D'Arcy equations. The
compressibility index and specific sludge resistance primarily affect the dewatering proper-
ties. A procedure is presented to evaluate these parameters in the laboratory. Flans are
explained to study the conditioning of lime softening sludges. Cost considerations are enumer-
ated.
Brown, A., and Leighton, J.,"Some Solutions to Sludge Treatment Problems at Fishmoor Treatment
Plant," Paper Presented at Fishmoor Treatment Plant, England (1966).
Key Words: Costs, Freeze-thaw tests, Filter pressing, Polyelectrolytes
This study presents design and cost data for the filter pressing, freezing, polyelectrolyte
conditioning, and lagooning of clarification sludge. The initial sludge dewatering facilities
planned for Fishmoor include slow stirring thickeners, sludge retention bunkers, and freezing
tanks. Sludge solids concentrations and quantities are listed. Operational difficulties are
discussed. The thickener did not function adequately. The thickener was modified and testing
was initiated with a Davy Paxman Vacuum Filter, Walmsleys Ltd. Rotoklene Strainer, filter press,
and polyelectrolyte sludge conditioning agents. Design, operational, and construction details
of a polyelectrolyte conditioning system are presented. Design parameters and operation
experience are discussed for the filter press. Lengthy contruction considerations are enumer-
ated for the freezing tank design. The freezing cycle time is related to sludge volume, re-
frigeration area, and freezing efficiency. Capital, operating and maintenance, power, and
chemical costs are presented for the major processes employed.
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The Manchester Corporation Waterworks of England reports "work on poly-
electrolytes as coagulant aids and for the pre-treatment of sludge press-
ing has continued since 1966, and the results will be published shortly
by the Society for Water Treatment & Examination."
The Copenhagen Water Department in Denmark has taken advantage of the
natural freezing, process to treat their clarification sludge. The Depart-
ment states "we are able to inform that the Copenhagen Water Supply has
run a lagoon plant for alum sludge during 7 years, using natural frost
as a means of reducing the volume of the aluminum hydroxide sludge. This
has till now, in our opinion, been a great success, but no special report
has been issued stating details. The sludge is reduced to negligible
quantities when frozen, and till now it has not been necessary to remove
the remainder."
The Water Resources Association of England has been contacted to determine
the type and status of work on water treatment plant waste control. The
Director of W.R.A. plans to establish an exchange of information between
the W.R.A. and the working committees of the Research Foundation. The
Research Foundation looks forward to the exchange of information with the
W.R.A. that will result in the development of new or modified treatment
methods that will benefit the water utility industries of both countries.
Literature Searches
Several reports on the treatment of wastes from water utilities have been
published since the report on the "Disposal of Wastes from Water Treatment
Plants." These articles, appearing in water utility trade publications,
have been abstracted in accordance with the specifications of the Water
Resources Science Information Center. The abstracts follow.
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Albertson, O.E., and Guidi, E., "Centrifugal:ion of Waste Sludges," WPCF JOURNAL. 41.
No. 4, pp 607-628 (1969).
Key Words: Centrifugation, Cost comparisons, Process variables, Case studies
A brief history of the application of centrifugation for the dewatering and thickening of
domestic and industrial wastes is presented. This paper describes the utility of basket,
disc, and solid-bowl conveyor centrifuges. A detailed study oE design and process variables.
including bowl design, bowl speed, pool volume, conveyor speeu, reed rate, teed consistency,
temperatures, and flocculants is given to show the versatility of solid-bowl centrifugation.
Reference is made to specific test facilities where case studies have shown this dewatering
technique can effectively handle raw primary and secondary sludges, digested primary and
secondary sludges, pulp and paper wastes, and water softening sludges. Cost comparisons
have been made evaluating sludge treatment by vacuum filtration, solid-bowl centrifugation,
and chemical flocculation. Centrifugation competes favorably with these processes when oper-
ating, maintenance, and capital costs are considered.
Middlebrooks, E.J., and Phillips, W.E., and Coogan, F.J., "Chemical Coagulation of Kraft Mill
Wastewater," Water & Sewage Works. 116, No. 3, pp IW 7 IW 9 (1969).
Key Words: Coagulation, Chemical oxygen demand, Organic polymers, Aluminum sulfate
This study shows that colloidal suspensions containing significant proportions of color,
suspended solids, and chemical oxygen demand material in paper mill wastewater can be re-
moved by chemical coagulation with organic polymers. Analytical grade aluminum sulfate
and 6 organic polyelectrolytes were tested on kraft mill wastewater. Previous work with
synthetic polymers and ferric sulfate is referenced. The coagulants were tested on grab
samples and composite samples from the raw waste stream. The jar test procedure and para-
meter analysis techniques are explained. The organic polymers were equally effective in
reducing chemical oxygen demand material, color and suspended solids. The aluminum sulfate
was effective but tripled the sludge volume produced by the organic polymers. The co-
agulation efficiency changed with variations in the solution pH. None of the coagulants
utilized could significantly reduce the biochemical oxygen demand of the waste.
Hamblin, C.W., "Recalcining Lime Sludge Produces Multiple Benefits," The American City, 84.
No. 11, pp 67-69 (1969).
Key -Words: Carbon dioxide, Water softening, Lime-recalcining, Washwater recovery
This study shows how lime recalcining and washwater recovery at a municipal water utility
can reclaim 9800 tons of 92 percent pure quicklime, 9950 tons of carbon dioxide and 170
million gallons of washwater annually. Extensive modifications to the existing facilities
'will permit handling of the 23,000 tons of dry solids produced annually while extending the
life of sludge storage units and controlling air pollution. Sedimentation of filter wash-
• water is accomplished in separate settling basins. The carbon dioxide produced from Che
recalcining facility will be used to stabilize the softened water. It is expected excess
quicklime can be recovered and sold to reduce plant operating costs. A flow diagram of the
60 ton per day vertically constructed fluid bed type recalcining system is presented. Fuel
requirements are 9 million Btus/ton of product output. Tables show chemical characteristics
of the lime sludge and the equipment required for construction.
50
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Fulton, G.P., "Disposal of Wastewater from Water Filtration Plants," AWWA JOURNAL, 61,
No.. 7, pp 322-326 (1969).
Key Words: Pollution abatement, Concentration, Sludge freezing, Alum recovery
Processes for the successful treatment and disposal of potential pollutants from settling
basin underflows and filter backwash water were examined to identify pollution abatement
techniques. Limited physical and chemical characteristics of wastewater were qualitatively
and quantitatively reviewed to evaluate sludge freezing, alum recovery, and vacuum filtration
operations. Consideration was given to the disposal of water plant wastes in local sewage
systems. Treatment goals of concentrating wastes and making these wastes suitable for dis-
posal are discussed. Treatment cost is reportedly minimized by simplifying operations for
personnel and limiting land area unit requirements. A settling rate of 250 gpd per sq. ft.
was found acceptable for settling alum sludge, in its semifluid state, by using mechanical
thickeners. The advantages and disadvantages of the treatment schemes are presented. Sludge
freezing and alum recovery processes are referenced to plant scale operations.
Keith, F.W., "Centrifuges Concentrate and Dewater Waste System Solids," Water & Sewage Works,
116, No. 3 , pp IW 10- IW 18 (1969).
Key Words: Centrifugation, Dewatering, Scroll centrifuge, Electrochemical machining
The utility of centrifugation as a concentrating mechanism to treat municipal sewage sludge
and paper, petroleum, and electrochemical machining waste water is discussed. The study
reveals that centrifugation processes can clarify waste streams in a primary treatment capac-
ity or provide supplemental treatment by dewatering concentrate streams from flotation and
thickening processes. Design features and waste stream parameters are presented for scroll
and disc type centrifuges. The scroll centrifuge is most effective when there is a high solids
loading and a high concentration cake is desired. The disc centrifuge can handle finer sized
particles economically and is suitable for dewatering activated sludge. The applicability of
centrifugation to concentrate waste activated sludge, to prepare primary and secondary sludge
for incineration, and to treat electrochemical machining wastes is referenced.
Scott, J.C., "Ann Arbor's Recalcining Process and Problems," AWWA JOURNAL, 61, No. 6,
pp 285-288 (1969).
Key Words: Reclamation, Lime recalcining facility, Costs
Although a comprehensive report on Ann Arbor's water needs showed that the lagooning of lime
sludge is an adequate disposal technique, the development of a lime recalcining facility was
•undertaken. The cost of the 24 ton per day lime reclamation facility is estimated at $1,200,000,
including handling and treatment of the sludge from the clarifier to the finished lime storage
tanks. This paper outlines the basic format of the process methodology from the lime sludge
withdrawal to a lime product. The problems associated with this installation are those arising
from personnel requirements, type of operation, characteristics of sludge collected, winter
equipment maintenance, and other equipment needs. The cost estimate is shown to be highly
'variable and a study of the proposed site and surroundings among other factors must be carefully
evaluated. The problems are related to construction, maintenance, and operating costs.
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AWWA Committee, "Diatomite Filtration Sludge Disposal," AWWA JOURNAL. 62. No. 8, pp 507-509
(1970).
Key Words: Solid wastes, Liquid wastes, Diatomite filtration, Slurry disposal
.The purpose of this study ±s to provide information on the problem of sludge disposal from
diatomite filtration operations with specific consideration given to potable water treatment.
A table is presented comparing the characteristics of plant process wastes from diatomite
filtration and conventional filtration plants. Several slurry disposal methods are discussed.
Although a diatomite filtration slurry is stated to be a good soil conditioner for agricultural
lands, the discolored waste material is esthetically objectionable. The'advantages and dis-
advantages of disposing slurries to sewerage facilities are enumerated with consideration given
to the abrasive and settling nature of the waste. Settling lagoons, vacuum drum filtration,
and pressure bag filtration are suggested as solids separation techniques. Disposal of liquid
wastes can be accomplished by discharge to sanitary sewers and recovery. Solid wastes will
provide good landfill. A number of secondary waste uses are listed.
Faber, H.A., "Research on Water Treatment Plant Waste Disposal," Water & Sewage Works. 117,
No. 11, pp 379-383 (1970).
Key Words: Freezing, Dewatering, Centrifugation, Lime recovery, Economical disposal
This survey highlights active research, demonstration, and in-plant studies of sludge and
filter washwater disposal. The problem of economical waste disposal techniques for puri-
fication and softening plant sludges is being investigated in various areas. The disposal
of aluminum and ferric hydroxide sludges and the recalcination of lime sludge are enumer-
ated for several dewatering processes. The survey cites references to freezing, centri-
fugation, precoat vacuum filtration, thickening, filter pressing, and lagooning procedures.
Water reuse and phosphate removal systems are also listed. Projects examining sludge
conditioning through chemical addition, and operations substituting polyelectrolytes as
primary coagulants to treat filter washwater or raw water are discussed. A systematic
program for the organization, coordination, and dissemination of research and demonstration
projects is stressed. A central information resource program would promote pollution
control technology beneficial to the water utility industry.
Bugg, H.M., and King, P.H., and Randall, C.W., "Polyelectrolyte Conditioning of Alum Sludges,"
AWWA JOURNAL. 62, No. 12, pp 792-795 (1970).
Key Words: Zeta potential, Polymer conditioning, Specific resistance
Data show that alum sludge is more amenable to dewatering by gravity drainage or vacuum
filtration with polymer conditioning. Water plant wastes are potential pollutants contain-
ing metallic ions and organic material that deplete the oxygen resources of a watercourse
while inhibiting natural biological activity. The polymers investigated were 2 cationic,
2 nonionic, and 3 anionic polyelectrolytes manufactured by Nalco. Jar tests showed that
sludge-polmer mixing beyond 2 minutes caused a break up in the agglomerated floe. The
cationic polymers were effective over a low pH band and the other polyelectrolytes were effi-
cient in the pH 6.0 to 10.0 range. Anionic polymers performed best at the 2 percent sludge
concentration and unadjusted pH of 6.6. Data are presented for the parameters of specific
resistance and zeta potential for conditioned and unconditioned sludge. Bench-scale sand-bed
drainage studies qn a 4.2 percent alum sludge showed that conditioned material with 100 mg
per liter of anionic polymer dewatered in one-fifth the time of unconditioned material.
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Francis, P., and Knight, H.W., "The New Langford Treatment Works of the Southend Waterworks
Company," Water and Hater Engineering. 74. No. 894, pp 319-327 (1970).
Key Words: Construction, Hydraulic design, Lime-soda ash softening, Recycling
This article describes the- site, layout, foundation, administration and plant specifi-
cations tor a 12 million gallon per day lime soda softening facility. In addition to the
softening process, construction and hydraulic design considerations are outlined for the
prechlorination, hydrogen ion concentration adjustment, gravity filtration, chlorination,
and dechlorination processes. The lime soda sludge is concentrated to 7000 gallons per
hr. and pumped at a rate of 3% feet per second through k inch PVC piping to a gravel pit.
The sludge settles and the supernatant effluent from the pit is recycled to the plant
intake line. Details are provided on the treated water pumping station and the archi-
tectural features of the utility. The main contractors and contract costs are listed.
A history of the operating record of the Southend Waterworks Company is presented. A
diagram of the water treatment processes and the site layout is included.
Degremont, S.A., "The Orly Waterworks of the City of Paris," Water and Water Engineering, 74,
No. 890, pp 135-146 (1970).
Key Words: Water purification, Sludge treatment, Orly waterworks, Alum recovery
This article describes the treatment technology utilized at a water purification plant
employing a coagulant recovery process. This highly automated treatment facility handles a
nominal flow capacity of 66 million gallons per day of Seine River water. Details of the
pretreatment, clarification, filtration, sterilization, reagent storage and feeding, pump-
ing, alum recovery, and monitoring, electrical, and control equipment facilities are provided.
Filtration is accomplished under a 3.9 foot head of water. This head is required to prevent
the degassing of the process water in the filters during low and hot weather flows. The
sludge from the clarification units is concentrated at 8 grams per liter and then acidified
with sulfuric acid to pH 3 to 3.2. The acidified sludge is fed to settling basins where the
aluminum sulphate solution is recovered. The remaining sludge is neutralized with calcium
carbonate in separate tanks. Physical and chemical characteristics of the water at different
stages of the treatment process are presented. A flow diagram of the plant is also provided.
Welch, A.W., "Reclamation-of Filter Backwash Water," Water & Sewage Works, 117. No. 7,
pp 189-190 (1970).
Key Words: Settling basins, Lagoons, Washwater recovery, Polyelectrolytes
This study stresses Che importance of the disposal of sludge from settling basins and the
disposal of filter washwater in water treatment plant pollution abatement. A polyelectrolyte,
Zeta Floe WA, is stated to produce a dense floe when added to filter washwater during the
backwash cycle. The coagulating chemical is fed dry to the waste water stream and is capable
of producing an 80 to 85 percent washwater recovery when the waste is settled in lagoons or a
recovery basin. Data for a typical backwash of 6 to 8 minutes with 60,000 gallons of water
showed that 8 to 10 pounds of polyelectrolyte were required at a cost of $.11 per pound. The
sludge produced can be dewatered, recycled to the primary settling tanks, or utilized as a
sewage sludge conditioner.
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Fulton, G.P., "Alum Recovery for Filtration Plant Waste Treatment," Water & Wastes Engineer-
ing, 7, No. 6, pp 73-C1 (1970).
Key Words: pH, Filtration, Alum recovery, Aluminum hydroxide sludge, Acidulation
A description is supplied of process considerations to be evaluated for alum recovery from
an aluminum hydroxide sludge. The suspended solids content and other impurities contribut-
ing to the nature of the waste are examined with reference made to specific operating condi-
tions and raw water quality. The advantages of a preliminary thickener before the acidulation
step are explained. A settling basin overflow rate of 250 gpd per sq. ft. and a hydrogen ion
concentration representing a pH of 2.0 is considered to enhance sludge settling in final solids
separation. A 10-minute minimum detention time is suggested for the acidulation step. An
alum solution between 1 and 2 percent should be obtained for an efficient operation. Filtration
plants in the 200 to 500 mgd range with raw water suspended solids at 20 mg per liter indicate
recovery costs to be $3 to $5 per million gallons of water produced. The utility of alum
recovery is cited.
Me Colgan, R., "Water Treatment Plant Wastes Disposal," Report of Orange County Sewer District,
(1970).'
Key Words: Injection wells, Water treatment plant wastes
The project goal was to determine effective treatment or disposal of activated carbon and
aluminum hydroxide sludges and the neutralization of the waste supernatant before discharge
to a lake. Sludge disposal techniques included injection wells and pipeline disposal to
roadbase pits. Sludge treatment methods included gamma ray sludge destruction, dewatering,
and filtration. Sludge injection caused clogging of the aquifer and elimination of the ground-
water as a potential supply. Pipeline disposal created a dewatering problem in the roadbase
pits. A .0.1 mg/1 Nalco 671 polymer addition generated less sludge than radiation treatment
and was as effective. Vacuum filtration, sand bed drying, centrifugation, and filter press-
ing concentrated sludge solids up to 20 percent. Basic research is recommended for sludge
lagoons. Lagoon design considerations are a 2^ foot maximum depth, a 10 foot clearance for
dump trucks, and a. buffer zone between lagoons and residential communities.
Me Colgan, R., "Waste Alum and Activated Carbon Sludge Solids Reduction Methods," Report
of Orange County Sewer District. (1970).
Key Words: Waste storage, Landfills, Water treatment plant wastes, Lagoons
The study described a technique to limit alum and activated carbon sludge carryover from a
w^te storage lagoon of a water treatment plant. Initially, buckets were dragged through the
settling lagoon to remove the sludge. This technique re-suspended settled material and pro-
duced a carryover In the effluent. A new lagoon, 2% to 3 feet deep, with a 2 to 1 slope was
constructed. Pumping enabled a sludge transfer from the original primary lagoon to the new
thickening lagooning. Sludge thickening was accomplished at the influent end of the lagoon,
and the supernatant was recycled to the primary lagoon. The solids content of the thickened
sludge was 6 to 10 percent. After additional drying, the sludge was used as a landfill.
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Farrell, J.B., and Smith, J.E., and. Dean, R.B., and Grossman, E., and Granc, O.L.,
"Natural Freezing for Dewatering of Aluminum Hydroxide Sludges," AWWA JOURNAL. 62,
No. 12, pp 737-791 (1970).
Key Words: Snow cover, Freeze-thaw test, Lagoons, Natural freezing, Layered freezing,
Filtrability
Data presented provide a basis for the design of lagoons for the dewatering of aluminum
hydroxide sludge by natural freezing. Temperature considerations and convective heat losses
are considered in the freezing experiments. The freezing rate of aluminum hydroxide sludge
parallels the freezing rate of water. Field testing at Ely, Minnesota showed that a snow
cover could reduce the freezing efficiency of the sludge, but careful management could
minimize this problem by freezing the sludge in thin layers and removing snow from frozen
layers. With complete freezing, the dewaterability and solids content of the sludge can be
significantly increased. Freezing in a mild climate as Cincinnati, Ohio, would be success-
ful in 1 inch layers. Layered freezing in partial freeze-thaw tests was not as effective as
a complete steady freezing. The ratio of phosphorus to aluminum in the sulfate form is shown
to barely affect the filtrability and solids content of aluminum hydroxide sludges.
Thomas, C.M., "The Use of Filter Presses for the Dewatering of Sludges," WPCF JOURNAL,43,
No. 1, pp 93-101 (1971).
Key Words: Dewatering, Filter presses, Chemical conditioning
The utility of a. filter press to successfully dewater various wastewater treatment sludges is
presented. The advantages of a filter press operation are cited for a specific range of
application over alternative methods as centrifugation, thickeners, vacuum filters, and pres-
sure filters. The, enumerated benefits include efficient filtration even with feed character-
istic variations, minimized maintenance, improved filtrate quality, facility in cake handling,
and competitive capital costs. Design consideration should be based on theory and pilot test-
ing. Additional requirements for filter pressing may include sludge storage tanks and mixers,
chemical conditioning plants, feed pumps, filter cloths, interconnecting pipework and pressure
vessels, and filtrate collection trays. Conditioning, filtration cycle, feed and cake charac-
terization, and cake thickness data are presented for water plant sludge.
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SECTION VII
SURVEY OF REGULATORY AGENCIES
Introduction
One purpose of the information resource project is to determine current
problems and practices of regulatory agencies with respect to water treat-
ment plant waste disposal requirements, and to identify measures contem-
plated to meet more stringent pollution abatement laws. A survey form
was designed with the assistance of the Project Advisory Committee, to
obtain new information on pollution control regulations. This survey was
sent to regulatory agencies in March, 1971.
Historical Background
The AWWA Research Foundation published a survey, in its 1969 report on
"Disposal of Wastes from Water Treatment Plants," on the regulatory aspects
of the sludge disposal problem. The survey included ten questions relat-
ing to statistical, research, and regulatory information of sludge treat-
ment requirements. The responding regulatory agencies submitted additional
information on the problems and practices of water utilities within their
area of control.
The 1968 survey showed that a majority of state and interstate regulatory
agencies considered the discharge of wastes from water treatment plants to
surface waters a violation of pollution control laws or regulations. Many
of these agencies have laws or regulations applicable to the control or
treatment of these wastes before discharge to surface waters. Several of
the state, interstate, and territorial agencies could identify water treat-
ment facilities controlling these wastes.
In 1953, Dean reported on a survey made of the state sanitary engineers.
The survey questioned the engineers with respect to the discharge of sedi-
mentation basin sludge and filter washwater into watercourses. The respon-
ses showed "that, in nearlv every state, the health department or a commis-
sion or board has the authority to prevent the pollution of streams or
lakes. Apparently these regulatory bodies are concerned with the disposal
of sewage and industrial wastes and have usually not restricted the purifi-
cation plants."
Summary of 1971 Survey
The 1971 survey by the AWWA Research Foundation indicates that the trend
towards more stringent pollution abatement laws, as predicted by Dean and
as illustrated in the 1968 survey, is becoming increasingly important. In
the majority of cases, it will no longer be possible to design or operate
a new water utility or modify an existing utility without providing ade>- ••
quate waste treatment facilities. In areas with growing population densities,
the amount of wastes produced at water utilities will increase. Effective
means to eliminate or alleviate the amount of pollution caused by these
wastes will be required to meet state and federal legislation.
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Survey of Regulatory Agencies
The AWWA Research Foundation survey form was sent to the fifty states;
District of Columbia; Guam; Puerto Rico; Virgin Islands; and eight inter-
state agencies. The survey was also sent to the ten Canadian Provincial
pollution control authorities.
The response to the survey was excellent. Replies were received from the
fifty states, District of Columbia, Puerto Rico, Guam, eight interstate
agencies, and eight Canadian provinces. Some agencies did not have suffi-
cient experience with these problems to complete all the questions within
the survey. These agencies did provide several useful comments, present-
ing new material for dissemination.
The survey form (see Appendix) included eight questions requiring single
or multiple choice responses. The survey was concerned with wastes from
coagulation, softening, iron-manganese removal, diatomaceous earth, ion-
exchange regeneration, filter backwash, desalination, and microstraining
water treatment processes.
There were five statistical, two research, and one regulatory questions.
The respondents were requested to complete the survey and to supplement
it with any further information which would be helpful in our study.
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Summary of Survey Responses^
Question 1
Based on "your Agency's experience, please indicate, in order
of magnitude, your concern regarding wastes from the follow-
ing water treatment processes (use numerals 1 to 8 with 1
as a major and 8 as a minor concern):
Coagulation Filter Backwash
Softening Desalination
• Iron-Manganese Ion Exchange
Removal Regeneration
Diatomaceous Earth Microstraining
Coagulation Processes
The wastes from coagulation processes were identified as of major concern
by the regulatory agencies responding. Russelman (1968) reported the number
of water utilities producing sludges from coagulation processes in the
United States to be about 3,600. Coagulation wastes are variable in compo-
sition. The magnitude and nature of the waste are dependent upon the
coagulants and other chemicals utilized in the treatment process, the effi-
ciency of the treatment, variations in the physical and chemical constitu-
ents in the raw water supplies, seasonal variations in influent water
quality, and the use of the drainage basin as effected by increased recrea-
tional, agricultural, industrial development, etc.
There are several waste treatment process alternatives available to control
or concentrate the volume of waste material to be disposed. Processes to
concentrate the solid materials in these sludge volumes include: cemtrifu-
gation, lagooning, natural and artificial freezing, filter pressing, thick-
ening, dewatering on sludge drying beds, vacuum filtration, and rotary
precoat vacuum filtration. The recovery of aluminum sulfate from coagula-
tion sludges, as a plant scale operation, has been accomplished in Tokyo
and Paris. The reduction of the final solids in these wastes is increas-
ingly important. The use of solid material for landfill is a disposal
alternative to by-product recovery.
Softening Processes
The treatment and disposal of sludges from water softening installations
was second in priority among the regulatory agencies. Chemically coagu-
lated softening wastes contain calcium carbonate, magnesium hydroxide,
and various inorganic and organic constituents depending upon the raw
water supply source. Water supplies softening by means of synthetic zeo-
lites or organic exchange resins, must regenerate the ion exchange units.
Regeneration with a brine solution (sodium chloride) releases divalent
59
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metallic ions originally removed in the softening process, chloride ions,
and excess sodium chloride. Both the chemically coagulated waste and ion
exchange brine stream must be disposed of.
The Cities of Dayton, Ohio, and St. Paul, Minnesota, are examples of facili-
ities chmically softening their supplies. Each treatment plant recalcines
the calcium carbonate sludge. The calcium carbonate is reduced to quick-
lime and carbon dioxide. The carbon dioxide can be used for recarbonation
of water in the treatment process following the lime softening step. Re-
claiming lime and carbon dioxide from these wastes lessens the final solids
disposal problems and reduces the operation cost of the facility.
A primary consideration in the recovery of lime from softening sludges for
reuse is the build-up of impurities in the treated water. Magnesium, iron,
and inert materials may be recirculated with the recycled lime.
The separation of magnesium compounds from softening sludge has been demon-
strated at the City of Dayton, Ohio. Sludge withdrawn from the settling
basins at this facility is carbonated. The carbon dioxide selectively
converts the insoluble magnesium hydroxide to a soluble magnesium carbon-
ate form. A physical process is then required to separate the soluble
magnesium carbonate from the insoluble calcium carbonate.
Pilot facilities are being constructed at the City of Montgomery, Alabama,
water treatment plant to demonstrate the utility of MgCOs as a recycled
coagulant to remove color and turbidity from raw water.
The recovery of lime and production of magnesium carbonate for reuse as a
purification coagulant minimizes solid wastes disposal problems. The
recovery and recycling of chemicals for softening and purification plant
treatment significantly reduce waste volumes.
Additional Process Wastes
The remaining area of concern in decreasing importance were: filter back-
wash water, iron - manganese removal wastes^ ion exchange regeneration>•
brines, desalination brines, diatomaceous earth filtration waste, and
microstraining waste.
Filter backwash water can be recycled and the liquid portion of the waste
recovered. Backwash water requirements are generally 1 to 5 percent of
the daily plant flow. The backwash water represents a supply that .has
undergone treatment in the purification or softening plant. The recovery
of backwash water through recirculation may be economically justifiable.
The sedimentation of filter backwash water in lagoons or settling basins
provides another means of controlling the solid wastes. The supernatant
from this sedimentation process can be discharged to a watercourse or
recycled to the plant influent line, depending upon the water quality.
The recycling of filter washwater should be studied before being put into
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plant scale operation. The process might not be acceptable if bacteria
are so highly concentrated in the washvater as to degrade the finished
quality. This problem should be studied at each water treatment plant.
Research is being supported by the Office of Saline Water to study the
recovery of chemicals and the evaporation of brine streams from desal-
ination wastes. Several of the techniques developed might be adaptable
for the treatment of ion-exchange brine streams.
The development of new or modified treatment technology demands respon-
sible actions. The ability to maintain an integrated system of potable
water production and waste control is important to comply with pollution
abatement legislation. The control of pollution from water treatment plant
wastes requires laboratory and pilot evaluation of processes, economic
analyses of treatment alternatives, and planning to consider the possible
uses of the source water. Versatility in design is necessary in the
production of water and control of waste to counter seasonal and future
water quality changes.
Comments
The State of Hawaii reported that it "obtains the majority of drinking
water from groundwater supplies which require no treatment."
The State of Kansas reports that "wastes from softening, ion exchange
regeneration, desalination, diatomaceous earth filtration, and microstra-
ining are considered to be water pollutants. Iron - manganese removal,
coagulation, and filter backwash wastes are not considered pollutants."
Question 2
In determining treatment requirements for wastes from
water treatment processes, does your Agency consider the
following:
Yes No Yes No
TDS COD
Settl. Solids BOD
Susp. Solids Chloride
pH Color
Coliforms Heavy Metals
Table 2, titled "Utilization of Waste Treatment Parameters", indicates
the availability of specific data to characterize water utility wastes.
Each of these parameters has effects on downstream users, if the waste is
61
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discharged to a watercourse. The monitoring of waste parameters from
water treatment plants defines the magnitude of the discharge on the
quality of the receiving stream or river.
The discharge of wastes containing a high total dissolved solids concen-
tration (TDS) may significantly change the quality of the water in the
receiving stream. Depending upon the nature of the dissolved materials,
intake and piping systems can be affected. In a large watercourse, the
TDS concentration may be slightly altered. In a small stream, the TDS
concentration may be significantly increased: it may affect aquatic life,
and place the burden of lowering these solids to acceptable USPHS stand-
ards on a downstream user.
Settleable solids in waste streams require quiescent conditions for set-
tling. They can settle in slow-moving watercourses, forming sludge blan-
kets. Organic sludge undergoes anaerobic decomposition, producing nuisance
by-products. Inorganic sludge inhibits the natural biological activity
in a watercourse.
Suspended solids can be conspicuous and are aesthetically objectionable.
Organic suspended solids may be aerobically and/or anaerobically decom-
posed and thus deplete the oxygen content of streams. The assimilative
capacity of a watercourse is affected by the magnitude of biodegradable
material it receives.
The pH of a raw water has an important effect in coagulation, disinfection,
water softening, and corrosion control. A rapid and extensive pH change
in a stream is detrimental to much aquatic life.
Coliform organisms, such as Escherichia Goli, are used as indicators of
the presence of pathogenic bacteria. If the dilution capacity of the
receiving stream is low, the discharge of water treatment plant wastes
containing large numbers of pathogenic bacteria will impair the quality
of the stream as a subsequent source of water supply. The coliform
content of wastes, therefore, is a useful parameter for measuring the
quality of the waste discharged.
The biochemical and chemical oxygen demands provide an indfcation of the
oxygen requirements for stabilization of a waste. The utilization of
oxygen by BOD and COD materials depletes the dissolved oxygen supply in
a watercourse. Rapid oxygen depletions for significant time spans can
seriously affect the more delicate biological activities.
Chlorides of 250 mg per liter produce objectionable taste problems in a
water supply. The discharge of softening exchange brines changes the
chloride concentration of the receiving stream.
Highly colored water is aesthetically unacceptable to most consumers.
Color removal may be required as a treatment process to keep consumers
from alternative sources, such as springs or wells which may be of unsafe
quality.
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TABLE 2
UTILIZATION OF WASTE TREATMENT PARAMETERS
Respondent
Parameter
TDS
Settleable Solids
Suspended Solids
PH
Coliforms
COD
BOD
Chloride
Color
Heavy Metals
State
YES
31
41
40
31
28
18
18
30
29
28
NO
12
2
3
12
15
25
25
13
14
15
Agencies
Interstate
YES
2
4
4
4
4
2
2
4
4
4
NO
2
0
0
0
0
2
2
0
0
0
Territorial
YES
1
2
2
2
1
1
1
1
1
1
NO
1
0
0
0
1
1
1
1
1
1
The degree of heavy metal concentrations has not been considered a prob-
lem by water utilities until recently. This is principally due to the
fact that analytical methods were not capable of measuring very low con-
centrations of trace metals. Standards for the toxicity levels of certain
heavy metals have recently been established, and concentrations in wastes
should be established.
The ten parameters listed affect downstream users by impairing water qual-
ity and reducing the assimilative capacity of watercourses. The extent
of water quality degradation depends upon the relation of the waste flow
to the river flow. The degree of treatment required for water utility
wastes will be determined through the use of water quality or waste efflu-
ent standards.
.-Comments
The State of New Jersey indicates that "the degree of concern for all of
these parameters depends on the particular receiving stream."
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The State of South Dakota "expects to consider both color and heavy metals
in the future" in determining waste treatment requirements from water
utilities.
Question 3
Please indicate which of the following methods of sludge
disposal would not be consistent with your Agency's regu-
lation.
Discharge to Sanitary Sewers Incineration
Barging to Sea Landfill
Pipeline Transport Agricultural Use
Please submit a copy of your Agency's regulations governing
water treatment plant sludge.
Table 3, titled "Acceptability of Sludge Disposal Methods," illustrates
the sludge disposal techniques that can be utilized by water treatment
plants.
Comments;
The State of Alabama reports that "as of now, problems of waste from
water treatment plants are relatively few in Alabama, represented by a
few large plants. In view of this, we have adopted neither requirements
nor regulations pertaining to these wastes, but may find it necessary to
do so in the future."
The State of Colorado "doubts whether a municipality would allow a dis-
charge to sanitary sewers. No specific regulations exist for water treat-
ment plants. The requirement is to meet Water Quality Standards."
The State of California reports "pipeline transport depends upon the dis-
charge point."
The District of Columbia reports "solids from one municipal water treat-
ment plant do enter our sewer system at the present time. The discharge
of waste to the sewerage system is presently under study.
The State of Maine reports " standards are not specific. Regulation de-
pends upon general approval of the Department."
The State of Montana reports "no regulation at present. However, plants
located on smaller streams have been requested to use sludge disposal
facilities."
The Delaware River Basin Commission reports "no new facility may discharge
sludge back to the river. Old facilities are being required to correct
this method when they need to make adjustments or expansions."
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TABLE 3
ACCEPTABILITY OF SLUDGE DISPOSAL METHODS
Respondent Agencies
Disposal by:
Discharge to
Sanitary Sewers
Barging to
Sea
Acceptable
Method
30 State
3 Interstate
1 Territorial
21 State
4 Interstate
1 Territorial
Pipeline Transport 31 State
4 Interstate
2 Territorial
Unacceptable
Method
12 State
1 Interstate
1 Territorial
18 State
1 Territorial
4 State
Incineration
Landfill
Agricultural
Use
40 State
4 Interstate
2 Territorial
41 State
4 Interstate
2 Territorial
42 State
4 Interstate
1 Territorial
2 State
2 State
1 State
1 Territorial
The State of Oregon reports "any or all of the methods of sludge disposal
may be satisfactory for a particular situation."
The State of Texas reports "municipal water treatment plant sludges are
considered to be in the category of municipal solid wastes and are assign-
ed to the Texas State Department of Health for regulatory control. Those
generated by industry are regulated by the Texas Water Quality Board by
specific waste control orders or regulations."
ORSANCO reports "all methods of sludge disposal would be consistent with
appropriate controls."
The New England Interstate Water Pollution Control Commission reports
"regulations should be developed by states and administered by them."
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The States of Florida, Maryland, Massachusetts, Mississippi, and South
Carolina report that they have no specific regulations governing water
treatment plant sludge.
Some of the respondents have submitted regulations dealing in part with
water treatment plant waste sludges. Other survey participants have refer-
enced the control of these wastes to their water quality standards. Sever-
al of these responses follow.
The State of Arizona transmitted a publication from the State Department
of Health titled "Rules and Regulations for Public Water Supply Systems."
The State of Arkansas transmitted a publication from the Arkansas Pollu-
tion Control Commission titled "Air Code and Water Quality Criteria for
Interstate Streams for State of Arkansas."
The State of Idaho places water treatment plant wastes under regulations
contained within the water quality standards. Copies of the "Idaho Drink-
ing Water Standards" and the Idaho Water Quality Standards" were trans-
mitted.
The State of Maryland transmitted a publication titled "Water Resources
Regulation 4.8, General Water Quality Criteria and Specific Water Quality
Standards."
The State of Minnesota transmitted "WPC 14, 15, and 23." These control
laws are titled "Rules, Regulations, Classifications and Water Standards."
The State of Missouri transmitted a publication of the Missouri Water
Pollution Board titled "Design Criteria to Treat Wastewater Discharges
from Water Treatment Plants."
The State of Nevada reports "there are no regulations. There are Water
Pollution Control Regulations adopted by the State Board of Health."
The Delaware River Basin Commission transmitted a publication titled "Admin-
istrative Manual - Part III, Basin Regulations - Water Quality."
The State of New Jersey transmitted a publication titled "Rules and Regu-
lations for Approval of Public Water Supply Systems and Water Treatment
Plants." Section 3.5 of this publication deals with wastewater treatment
disposal. Section 12.4 applies to filter backwash water. These sections
follow.
Section 3.5 Wastewater Treatment and Disposal
i
a. Wastewater,. such as sludge from coagulation and sedimenta-
tion tanks and filter backwash water, shall ordinarily be
treated before being discharged into any of the waters of
this State. The degfee of treatment will be contingent upon
the character of the wastewater and its effect upon the
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receiving waters. Disposal of sanitary sewage shall be in
accordance with existing statutes and regulations promul-
gated thereunder.
b. Unless otherwise approved, minimum treatment shall be plain
sedimentation in lagoons. A minimum of two (2) lagoons shall
be provided with a minimum total combined capacity equivalent
to twenty-four (24) hours wastewater flow. They shall be de-
signed with suitable baffles to minimize short - circuiting,
and shall be provided with slow-release outlet devices.
c. Wastewaters containing high concentrations of dissolved solids
shall be controlled as to discharge rate and the point of
discharge, so as to meet the requirements of the Department
for the specific situation.
Section 12.4 Backwash Water
d. Unless otherwise permitted, untreated filter backwash shall
not be discharged to any of the waters of this State, (see
subsection 3.5)
The State of North Carolina reports "we have no special requirements for
wastes from water treatment processes. The streams in North Carolina are
classified according to the best usage being made of the water in accord-
ance with the Rules, Regulations, Classifications and Water Quality Stand-
ards Applicable to the Surface Waters of North Carolina."
The State of Ohio, Division of Engineering & Water Pollution Control Board,
State Department of Health, transmitted information on the "Discharge of
Wastes from Water Treatment Plants." Minimum quality requirements have
been established for all waters of tine state. Waste discharges from water
treatment plants must conform to the requirements of the Ohio Water Pollu-
tion Board. These regulations fallow.
"Minimum conditions applicable to all places at all times
are as follows:
*
1. Free from substances attributable to municipal, industrial
or other discharges; that will settle to form putrescent or
otherwise objectionable sludge deposits;
2. Free from floating debris, oil, scum, and other floating
materials attributable to municipal, industrial or other
.discharges in amounts sufficient to be unsightly or dele-
terious ;
3. Free from materials attributable to municipal, industrial,
or other discharges producing color, odor or other condi-
tions in such degree as to create a nuisance; and
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4. Free from substances attributable to municipal, industrial
or other discharges in concentrations or combinations which
are toxic or harmful to human, animal, plant or aquatic life.
The following wastes from water treatment plants can no longer
be discharged directly without treatment or other satisfactory
control to the waters of the state.
1. Sludge from settling tanks.
2. Waste wash water.
3. "Red" or "black" waste water frpm iron or manganese
removal plants.
4. Waste brine from ion exchange plants.
5. Domestic sewage wastes.
6. Other wastes.
The Ohio Department of Health has established the following program to
achieve the results required by the Water Pollution Control Board:
1. All water treatment plants discharging wastes to the "waters
of the state" will be placed under the permit system of the
Water Pollution Control Board.
2. Water treatment plants not having acceptable facilities for
handling of wastes will be required to install such facilities
as a condition for future permits.
3. Provisions for handling of waste shall be included in the
original construction for all new water treatment plants
and shall be included in any construction for enlargement
or substantial modifications of existing water treatment
plants. These provisions must be included in all plans pre-
sented for approval after July 1, 1967.
4. Waste water from backwashing of filters at lime-soda soften-
ing plants and plain filtration plants cannot be discharged
directly to the "waters of the state" unless there will be
no problem in the receiving water. Designing engineers may
present evidence to the Department if they believe that
treatment of waste filter backwash water is not necessary.
It should be noted that adoption of criteria or standards by the Water
Pollution Control Board in the future may require further upgrading of
water quality criteria."
The State of Tennessee reports "this agency has no printed regulations."
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The Commonwealth of Virginia reports "Virginia does not have regulations
that pertain exclusively to water treatment plants. We consider the waste
waters generated from water treatment plants as industrial wastes, thus,
our regulations concerning industrial establishments would apply. The
Commonwealth has "State Water Control Law" and "Water Quality Standards".
The Commonwealth of Virginia is requiring all new water treatment plants
being constructed to provide acceptable waste water treatment facilities.
Virginia has not required the existing water treatment plants to install
sludge treatment facilities, however, this is in our future program."
The State of West Virginia transmitted Section 17 of the amended publica-
tion titled "Administrative Regulations (1970)."
Section 17. Water Purification Waste Water Control Measure
17.01 Waste Disposal - Provision must be made for proper
disposal of wastes from water treatment plants. Such wastes
include but are not limited to those eminating from sanitary
facilities, laboratories, clarification facilities, softening
facilities, and filter backwash. Discharges shall be governed
by Chapter 20, Article 5A, Code of West Virginia and the follow-
ing regulations:
(a) The following means of waste and sludge disposal may
be considered:
1. Lagoon design must provide the following:
.(a) Location free from flooding.
(b) Dikes, deflecting gutters or other means of divert
ing Surface water when necessary.
(c) A minimum depth of 4 to 5 feet.
(d) Multiple cell.
(e) Adjustable decanting devices.
(f) Convenient cleaning.
2. Sludge beds for lime softening sludge or other sludges must
provide the following:
(a) Location free from flooding.
(b) Multiple beds, each designed for at least one year's
storage.
(c) Size of sludge beds will be governed by the concen-
tration of solids disposed of with an ultimate depth
of 12 inches dry basis.
(d) Distribution channels may be required for spreading
sludge over entire area.
(e) Easy access roads and loading ramps with proper under
drains must be provided.
(f) Tank Truck - Trucking wet sludge to agricultural lands
or disposal areas requires proper handling, vehicles
and equipment to-permit hauling and spreading without
creation of nuisances. It is necessary to provide
sludge holding facilities for use during times that
trucks cannot operate.
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Community Wastewater Treatment Facility - Discharges to sewer
systems and their treatment facilities depend on type of treat-
ment, rate of discharge, plant design capacity, character of
waste, and Local conditions.
Other Methods-These include holding tanks, vacuum filters,
centrifuging and recalcining. Detailed studies must be made
to justify their use.
Sanitary Waste - The sanitary waste from water treatment
plants, pumping stations, etc., must receive treatment.
Waste from these facilities must be discharged either direct-
ly to a sanitary sewer system with approved treatment or to
an individual waste disposal facility providing suitable
treatment. The effluent must be acceptable for discharge to
the surface of ground waters.
The states of Colorado, Connecticut, Iowa, and South Dakota
have submitted water quality standards to govern these wastes.
Question 4
Please indicate which of the following methods of liquid
disposal would not be consistent with your Agency's reg-
ulations :
Recycle Sanitary Sewers
Stream Transport Underground Injection
Table 4, "Acceptability of Liquid Waste Disposal Methods," shows the liquid
waste disposal techniques that can be utilized by water treatment facilities,
Comments
The State of Alabama reports "underground injection is dependent on the
individual case."
The State of Hawaii would not accept "stream transport if there is a viola-
tion of the State's Water Quality Standards."
The State of Idaho "would prefer pretreatment of waste prior to the dis-
charge to sanitary sewers." r
The State of Kansas states disposal method consistency "depends on the
specific liquid and the volume. All methods would be possible."
The State of Montana reports "stream transport and sanitary sewers would
not be consistent in some cases."
The Delaware River Basin Commission suggests "stream transport would be
consistent after adequate treatment."
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TABLE 4
ACCEPTABILITY OF LIQUID WASTE DISPOSAL METHODS
Disposal by:
Recycle
Stream Transport
Sanitary Sewers
Underground Injection
Acceptable
Method
42 State
4 Interstate
2 Territorial
21 State
3 Interstate
1 Territorial
36 State
4 Interstate
2 Territorial
25 State
1 Interstate
1 Territorial
Unacceptable
Method '
2 State
23 State
1 Interstate
1 Territorial
8 State
19 State
3 Interstate
1 Territorial
Question 5
Please indicate whether your Agency requires water utilities
to perform the following:
YES NO
a. Maintain records of waste production
b. Submit reports of waste production
c. Monitor waste receiving streams
Table 5, titled "Waste Production and Monitoring", shows the agencies that
require maintenance and submittal of waste production reports, and monitor-
ing of waste receiving streams.
Comments
The State of Colorado reports "regulations to this effect are being consid-
ered."
The State of California reports "the maintenance of waste production records
is dependent upon the size and location of the water utility. Requirements
are established on a case by case basis."
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TABLE 5
WASTE PRODUCTION AND MONITORING
Maintain records
of waste production
Submit reports of
waste production
Monitor waste
receiving streams
YES
10 State
1 Territorial
11 State
1 Territorial
5 State
1 Interstate
2 Territorial
NO
33 State
3 Interstate
1 Territorial
33 State
3 Interstate
1 Territorial
39 State
3 State
The District of Columbia reports "solids are not discharged to the receiv-
ing stream when the water is clear. Material is discharged when the stream
is heavy with sediment."
The State of Idaho "does not presently maintain records of waste production.
The State monitors streams."
The State of Kansas reports "the maintenance of waste production records
and the submittal of waste production reports will probably be required
by 1975."
The Delaware River Basin Commission reports "these functions are required
by the Basin states."
ORSANCO reports "contents of plant operating records are determined by the
pollution control agencies of the signatory states of the ORSANCO inter-
state compact."
Question 6
Please indicate,in your judgment which of the following
should be the malor contributor in supporting research for
treating wastes from water treatment plants (Question 1):
State Government
Federal Government
Water Utilities
Equipment Mfr.
Educational Inst.
Consulting Engineers
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Table 6, titled "Major Contributors to Support Research," shows the insti-
tutions the agencies feel should provide the funds for water treatment
plant waste research. Some agencies placed equal weight on two or more
potential contributors.
Question 7
Please indicate, in your judgement, which of the follow-
ing should conduct most of the research effort for treat-
ing wastes from water treatment plants(Question 1):
State Government Equipment Mfr.
Federal Government Educational Inst.
Water Utilities Consulting Engineers
Table 7, titled "Major Conductors of Research Effort", shows the organiza-
tions each agency feels should conduct the research on treating water
utility wastes. Some agencies placed equal weight on two or more organiza-
tions .
Question 8
Please indicate, if the wastes from a water treatment plant
could be reduced to the same form as the wastes in the origi-
nal source water, would your Agency accept the discharge of
these wastes to a.watercourse?
YES NO
If not, what standards would you require?
Table 8, titled "Acceptability of Discharging Reduced Wastes to a Water-
course", shows the number of agencies that would allow a waste of the same
form as the source water to be discharged to a watercourse. The comments
indicate "yes" replies were qualified.
Comments
The State of California reports "specific numerical criteria are estab-
lished for each discharge. Discharges of sludge are generally prohib-
ited."
The District of Columbia reports "the policy is that once wastes are removed,
they are not to be returned to the receiving stream without treatment
to an acceptable level. However, at the present time the policy is not
followed and the problems of proper disposal of wastes fxm our municipal
water treatment plants are under study. The District of Columbia Police
Regulations, Sections 12, 18, & 19 should be noted."
73
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TABLE 6
MAJOR CONTRIBUTORS TO SUPPORT RESEARCH
Responding Agencies
State Government 3 State
Federal Government 35 State
3 Interstate
2 Territorial
Water Utilities 18 State
2 Interstate
1 Territorial
Equipment Manufacturers 9 State
1 Interstate
1 Territorial
Educational Institutions 6 State
The State of Hawaii responds "yes, if it is of the same quality as when
it was taken out."
The State of Indiana reports "if wastes are concentrated, they should not
be recommited to receiving waters. Any addition of plant waste would re-
sult in an increase of some sort in the receiving stream."
The State of Iowa reports "possibly yes if on a continuous discharge basis."
The State of Kansas reports "yes, but this position may have to be changed
as a result of the Corps of Engineers implementation of the 1899 Refuse
Act."
The State of Kentucky reports "yes, but this depends on the condition and
water quality of the receiving stream."
The State of Massachusetts requires that "pollutants must be reduced by
at least 80 percent and effluent must meet river classification require-
ments ."
The State of Minnesota reports "no, use regulations WPC 14, 15, and 23."
The State of Missouri reports "no, under present regulations by the Fed-
eral Environmental Protection Agency it will soon become necessary to
treat or dispose of all material once it has been removed in some manner,
other than discharge back to the source."
74
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TABLE 7
MAJOR CONDUCTORS OF RESEARCH EFFORT
Responding Agencies
State Government 4 State
Federal Government 25 State
2 Interstate
2 Territorial
Water Utilities 11 State
1 Interstate
1 Territorial
Equipment Manufacturers 20 State
2 Interstate
Educational Institutions 19 State
2 Interstate
Consulting Engineers 2 State
The State of Montana responds "no, not unless from the aesthetic stand-
point they were the same. On high quality waters there should be at least
the removal of suspended and settleable solids."
The State of Nebraska reports "this question cannot be answered at this
time because our Water Quality Standards indicate that there be no dis-
charges of settleable or floating materials. Therefore, we are attempt-
ing to prohibit any wastes into Nebraska waters. Another responsibility
of our Water Quality Standards is that of enhancing water quality. There-
fore, if water is taken from a stream and the pollutants such as silt,
and sand are removed, enhancement is realized. From the standpoint of
practical application, Federal and State Water Quality Standards will have
to be given careful study to determine whether or not the pollutants that
were taken out of the water could not be returned. This, of course, does
not permit the discharge of lime, aluminum sulfate, iron, manganese, cal-
cium, magnesium and other undesirable minerals from a water treating plant.
At the present time, these are all being discharged^into sanitary sewers
where they are removed with the sludge.
Omaha is now facing the problem of disposing of the silt, sand and other
settleable solids from the Missouri River water supply in their treating
plants. They f,ace a huge landfill program if prohibited from returning to
the River which they are now doing."
75
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The State of New Hampshire reports "requirements of stream classification
must be met."
The Delaware River Basin Commission reports "wastes would be accepted for
discharge if they meet requirements."
The State of New Mexico reports "yes, at present. Most domestic water in
New Mexico are from wells with no treatment involved except chlorination
and some fluoridation. Farmington and Raton are the two larger supplies
having water treatment including flocculation and filtration. The back-
wash from treatment plants could find its way into streams; however,
due to the dry and arid nature of the state, this backwash material has
not been considered a problem-perhaps it should. During periods of rain,
streams are very muddy and turbid."
The State of Ohio reports "no, the enhancement of stream quality " would
be required.
The State of Oklahoma reports "this depends on the particular sub-basin
in the State. Some cases would be "yes and some cases no1.'
The State of Oregon reports "the problem is presently minimal in our State."
The State of Pennsylvania requires "at least 85 percent reduction of BOD,
reduction of practically all suspended solids, and disinfection will be
required."
The State of Tennessee reports "yes, if they could be returned at essen-
tially the same conditions.
Standards require:
i
1. No more than 1.0 mg per liter settleable solids.
2. No distinctly visible floating solids.
3. BOD5 limitations would be stipulated in accordance with receiving
stream.
4, Chloride limits might be set where applicable.
This agency has no set, uniform standards relating to waste materials from
•water treatment plants."
The State of Texas reports "no, we require reasonable control of solids,
sludge and other concentrated materials (salts,etc.) which result from the
various water treatment operations."
The State of Wisconsin "does not have effluent standards at the present
time, however, turbidity and solids would have to be be below an accept-
able level."
76
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TABLE 8
ACCEPTABILITY OF DISCHARGING REDUCED WASTES
TO A WATERCOURSE
Acceptable Unacceptable
Method Method
21 State 17 State
3 Interstate
1 Territorial
Additional Regulatory Agency Survey Information
The State of Connecticut provided a list of water filtration plants which
have washwater and/or sludge to dispose of, and the method of waste disposal
utilized.
The Government of Guam reports that it "obtains the majority of its water
requirements from groundwater, except in the case of the Fena River water.
Raw water from Fena Resevoir is combined with the spring supply and passes
through a Venturi meter. Alum and lime are then added to the raw water
in a mixing tank prior to its flow into a 1.25 million gallon circular
clarifier. Activated carbon is also added at this point on the rare occa-
sions . that taste and odor control is needed. Chlorine gas is added to the
clarified water prior to filtration. The plant has six anthrafilt filters.
Sodirm silica flouride solution and chlorine gas are added after filtration
and before storage in a one-million gallon clearwell. It is possible to
add chemicals before the Venturi meter and by-pass the Venturi meter
mixing tank and clarifier.
Normally all filters are used and are backwashed at two-seven day inter-
vals. Filter backwash and clarifier sludge are dumped into a nearby
creek, causing pollution problems. There have been complaints of this,
but the appropriate corrective action has not been decided. It would
be possible to pond and evaporate the water, but downstream users want the
water vithout the waste.
The State of Washington reports that "backwash water from water treatment
plants has not in the past been the subject of an active control program
in this state. It is safe to say that water treatment backwash water will
be subject to some federal and perhaps state control soon, This amounts
to one or two dozen water treatment plants discharging alum floe wastes
with one or two small sodium zeolite softening units. Several of the fil-
ter plants are in the 10 to 30 mgd range, but the majority would be 1 mgd
or less. Several have already been provided with sludge lagoons and in
most cases the solution probably will be lagooning or discharge to muni-
cipal sewers."
A copy of a letter from the E.P.A. to the State of Washington, Environmental
Programs, Division of Health was included. This letter "indicates clearly
77
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that the agency (E.P.A.) intends to become interested in this source of
waste water. It also seems rather clear that such control will be at
least coordinated, if not directly regulated, by the Environmental Protec-
tion Agency with the possible assistance of the Corps of Engineers."
The E.P.A. letter states in part "that waste discharge from water treat-
ment plants will be subject to the permit provisions of Section 13 of the
River and Harbor Act of 1899. This means it will be necessary for each
purveyor operating a treatment plant to make application to the Corps of
Engineers for such a permit if wastes are discharged to a navigable water-
way (this includes practically all surface waters)."
Canadian Survey Responses
The collection of information on the control of pollution caused by wastes
from water treatment plants was extended to obtain information from the
ten Canadian Provincial regulatory agencies. Eight of these provinces
have responded to the survey.
Question 1 - Canadian Replies
The Department of Health in Edmonton, Alberta, Canada, listed the wastes
from the following water treatment processes as items of major concern
in decreasing importance: softening, coagulation, filter backwash, iron-
manganese removal, ion-exchange regeneration, diatomaceous earth, micro-
straining, and desalination,wastes.
The Department of Health in Regina, Saskatchewan, Canada, provided the
following list in decreasing importance: coagulation, filter backwash,
iron-manganese removal, softening, diatomaceous earth, ion-exchange regen-
eration, desalination, and microstraining.
The New Brunswick Water Authority of Fredericton, New Brunswick, Canada,
reports wastes from coagulation and filter backwashing operations of
only minor concern.
The Prince Edward Island Water Authority of Charlottetown, P.E.I.,
Canada, states "groundwater is used exclusively on P.E.I. We do not have
any experience with the wastes from the water treatment processes noted."
r Question 2 - Canadian Replies
The Edmonton, Alberta, agency considers TDS, settleable solids, and sus-
pended solids in determining treatment requirements for wastes from water
treatment plants.
The Regina, Saskatchewan, agency considers settleable solids, suspended
solids, coliforms, COD, and BOD for treatment requirements.
The Fredericton, New Brunswick, agency does not consider any of the ten
parameters.
78
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The Charlottetown, P.E.I, agency considers the following parameters in
determining the treatment requirements for wastes from industries utili-
zing water treatment processes : suspended solids, pH, coliforms, COD, BOD,
color, and heavy metals.
Question 3 - Canadian Replies
The Edmonton, Alberta and Regina, Saskatchewan agencies consider the dis-
posal of sludge by barging to sea inconsistent with their regulations.
The Fredericton, New Brunswick agency indicates the treatment of sludge
by discharge to sanitary sewers, barging to sea, pipeline transport,
incineration, landfill, and agricultural use of these wastes are all
consistent disposal methods.
The discharging of sludge to sanitary sewers and the barging of sludge
to sea are not consistent methods with the Charlottetown, P.E.I, agency.
There are no specific regulations governing water treatment plant sludge
reported by any of the Canadian Provincial agencies responding.
• Question 4 - Canadian Replies
Edmonton, Alberta indicates that the underground injection of liquid
wastes would not be consistent with their Agency's regulations.
Fredericton, New Brunswick would not accept the recycling and under-
ground injection of liquid wastes.
Charlottetown, P.E.I, does not consider recycling and stream transport of
liquid wastes as consistent disposal techniques.
Question 5 - Canadian Replies
The four regulatory agencies providing responses to this survey question
do not require water utilities to maintain and submit records of waste
production or monitor waste receiving streams.
Question 6 - Canadian Replies
The Edmonton, Alberta, Regina, Saskatchewan, and Charlottetown, P.E.I.
agencies indicate that the Federal Government should be the major contrib-
utor in supporting research for treating wastes from water treatment
plants.
Fredericton,New Brunswick agency indicates that State Government, Fed-
eral Government, and water utilities should make equal contributions
in supporting research for treating wastes from water treatment plants.
Question 7 - Canadian Replies
Edmonton Alberta and Fredericton, New Brunswick, respond that the Federal
79
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Government should conduct most of the waste treatment research effort.
Regina, Saskatchewan, places the major responsibility on educational
institutions.
Charlottetown, P.E.I., reports that State and Federal Government should
share the conduct of major research efforts. The State Government could
utilize consultants but local government must be involved in terms of
reference, etc.
Question 8 - Canadian Replies
The four agencies responding to the survey question indicate that if the
wastes from a water treatment plant could be reduced to the same form as
the wastes in the original source water, they would accept the discharge
of these wastes to a watercourse.
Fredericton, New Brunswick reports "we have only four filter plants in
New Brunswick. These are very small. None of these plants discharge to a
small watercourse." .
The Department of Health Services and Hospital Insurance in Victoria,
British Columbia, Canada, reports "this province has no more than four
water treatment plants. There is very little restriction placed on the
waste disposal from water treatment plants, and there is doubt xAiether any
of them have a permit from the Pollution Control Branch for their discharge
of waste products. The plants we have are for very small communities and
they are insignificant."
The Water Resources Commission in Halifax, Nova Scotia, reports that "this
Province possesses, within its boundries, very few water treatment plants
of a type sophisticated enough to have sludge problems. To date, what
few problems occur of this nature are readily resolved by disposal to
receiving waters such as the open sea. We anticipate that this sort of
problem will develop in time and, in view of the magnitude of our present
problems with other forms of pollution, we have not yet started to consid-
er the matter of sludge disposal from water treatment plants."
The Quebec Water Board in STE FOY, Quebec, Canada, reports that "in the
province of Quebec, the treatment of such waste (water treatment plant
waste) is not required. We are looking forward to adopt regulations to
take care of that pollution source."
The Department of Mines, Agriculture and Resources, Clean Air, Water, and
Soil Authority of the Government of Newfoundland and Labrador states "we
do not c6nsider we have a pollution problem at present with water treatment
plant wastes. In fact, there are only four water treatment plants in
the province, and the wastes from them holds an insignificant problem when
compared with untreated sewage discharge."
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SECTION VIM
WATER UTILITY SURVEY
Introduction
A water utility survey was prepared with the assistance of the Project
Advisory Committee, The purpose of the survey was to inventory quan-
titative data and qualitative data on the character of wastes from water
treatment plants. Survey questions were prepared convering the basic
data of new and finished water, chemical additions, waste handling and
treatment operations, waste production, and character of purification
and softening sludges. The survey (see appendix) required the respond-
ents to make several physical and chemical tests on waste products.
It was originally planned to specify the physical and chemical test pro-
cedures for the waste sampling and analysis. A special committee was
organized to prepare standardized sampling, analysis, and categorization
techniques for waste from water treatment plants. Work has been initi-
ated towards this goal. It was necessary, however, to distribute the
survey before the test procedures could be completed.
The survey was sent to 171 water treatment plants. At least one survey
was sent to each state in the continental United States. The purpose
of the information resource program and the importance of the survey
was explained. The Research Foundation received ninety-four replies
to this survey from the U.S. water utilities.
The collection of information was extended to ten Canadian water treat-
ment plants and to seven desalting facilities identified through the
Office of Saline Water.
The survey replies demonstrate that wastes from water treatment plants
are highly variable in character. Data tabulations were made to show
the range of values reported from the cross-section of water treatment
plants surveyed.
Summary of Survey Replies
A summary of survey replies and special comments made by the respond-
ents follows.
Basic Data on Water Treatment Plant Wastes
The physical and chemical nature of waste sludges produced at water
treatment plants depends upon the quality of raw water, the processes
utilized, and the effectiveness of the unit operations. Some basic
parameters that define the magnitude of the waste treatment or disposal
problem include: density of the dry solids; settling characteristics
of the coagulated wastes; floe formation time and size; sludge concentra-
tion at time of withdrawal from basins; physical and chemical constituents
81
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in the sludge; filter washwater volumes and concentrations; and dewater-
ing ability.
The quantitative and qualitative character of the waste resulting from
water treatment depends primarily upon the quality of the raw water
sources. Raw water sources can be influenced by seasonal variations,
obviously affecting both the amount and type of potential pollutants
that must be removed in producing a potable water.
Raw water quality may be significantly altered due to changes in the
utilization of a watershed area. Multi-purpose reservoirs and the dis-
charge of domestic and industrial pollutants to watercourses in highly
populated areas will present new problems that will affect the type and
degree of treatment required.
The selection of unit processes and chemicals and the operation of treat-
ment facilities are contributing factors to the character of the waste.
Integrated process designs are required to produce a finished water of
high quality and minimize the waste products from purification and soft-
ening facilities. Plant design must incorporate much needed flexibil-
ity to cope with seasonal quality variations in the source water, the
changing nature of the watersheds, and the development of new technol-
ogy, such as the use of organic or inorganic coagulants to replace or
aid existing coagulants. The utilization of polymers as primary coagu-
lants, coagulant aids, and sludge conditioning agents will change the
physical and chemical composition of wastes.
A chief goal, outlined by the Project Advisory Committee, should be
the minimization of sludge volumes. Methods of desludging contact or
sedimentation basins require careful study. Desludging may be continuous,
cyclic, or intermittent. The methods of discharging wastes from basins
is important in evaluating the type of equipment to be used for sludge
thickening or separation operations.
The Research Foundation is not presently aware of any particular sludge
thickening or separation method that is universally applicable. The
treatment process finally selected to handle purification and softening
sludges should be the result of careful laboratory and pilot plant scale
evaluations of the most economical alternatives. Process selection
should be directed towards producing waste components suitable for reuse
and ultimate disposal without impairing water quality of downstream users.
The operating practice group members of the Project Advisory Committee
suggested several parameters that could be readily available at the
majority of water utilities to be contacted by the Foundation. These
parameters include: raw water turbidity; raw water suspended solids;
raw water hardness; treated water hardness; raw water total dissolved
solids; and treated water total dissolved solids. The amount and type
of chemical additions producing sludge was also included. These data
help define the degree of solids produced and removed within the plant.
The total solids entering the plant plus the chemical additions resulting
82
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in precipitates minus the total solids leaving the plant equal the solids
removed.
The monitoring of basic data parameters is necessary to the designing
engineer, manufacturers of equipment and supplies, and the water utili-
ties. Before treatment processes at specific utilities can be modified
or new treatment schemes developed, an inventory of constituents expect-
ed in the purification and softening process must be available.
Response to Water Utility Survey
Ninety-four treatment facilities responded to this survey. These plants
process water from twenty-eight impounded, fifty eight river, seven
groundwater, and one groundwater and surface supply sources.
Turbidity
The majority of water treatment plants utilizing surface and the combined
supplies recorded turbidity of the raw water. Three of the plants treat-
ing groundwater did not measure this parameter. Turbidity generally is
caused by the suspension of fine or coarse particles in a solution.
Significant amounts of suspended materials are removed during the flow
of surface water into ground supplies due to natural filtration in sur-
rounding soil formations.
Suspended Solids
The raw water suspended solids were recorded at twenty impounded, thirty
river, and three groundwater supply sources. The suspended solids deter-
mination shows the material that will be removed during sedimentation
and/or filtration.
Hardness
The raw water hardness was measured at each facility except one treat-
ing a river source. The treated water hardness was recorded at each
facility except one processing a groundwater source. The extent of hard-
ness removal in a softening facility provides data for a designing en'glr•
neer to determine if recovery of the lime is economical. The importance
of recording hardness is necessitated by the effect of its potential
scaling properties in water distribution systems.
Total Dissolved Solids
Both the raw and treated water total dissolved solids were monitored at
most facilities. The partial demineralization of dissolved solids through
chemical precipitation or ion-exchange presents data on solids production.
Total Drv Solids
The total dry solids produced in a treatment facility must be reused or
disposed of. The total dry solids produced was defined in the survey as
83
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the total solids of the influent source water, the chemicals added for
treatment of this water, minus the total solids of the treated water.
The added chemicals are those resulting in a precipitate. These chem-
icals should include alum or ferric salts, polyelectrolytes, activated
carbon, lime and/or soda ash. These should not include chlorine salts
of ammonia or lime used only for pH connection.
Graphical Correlation
A graphical correlation of the total dry solids production and the raw
and treated water quality character was attempted. Data were tabulat-
ed for the total dry solids production and the six basic data param-
eter. Data were arranged by the nature of the treatment process, and plotted
on cartesian coordinates. Treatment classifications were: purifica-
tion plants with impounded supplies; purification plants with river
supplies; and softening facilities.
Graphical scatter was significant in each correlation attempted. Varia-
tions exist in the raw and treated water quality of water in different
geological locations. Each utility has a different combination of basic
data constituents. The treatment plant tailors each source water to
acceptable drinking levels as recommended by the United States Public
Health Service. In several instances, two purification plants treating
impounded supplies remove nearly equal dry solids amounts, but combina-
tion of raw and finished water parameters may be markedly different.
Dry Solids Production.
Data collected for treatment facilities sharing a common discharge area
with similar influent water quality and utilizing similar treatment may
illustrate correlations. The record of dry solids production should
be evaluated at a specific utility for a yearly period. The dry solids
production can be correlated with basic data parameters and system-relat-
ed variables such as temperature, treatment efficiency, runoff, etc.
The yearly fluctuation of waste production is an important considera-
tion for the design and operating requirements of integrated water-waste
treatment systems.
Data Categorization
The general categorization of data from impounded, rivei; groundwater,
and combined supply sources displays a trend of water quality. To be
complete, the survey would require each treatment facility in the United
States to provide data. Table 9 classifies the data received from the
cross-section of survev participants the Research Foundation has contacted.
Water Treatment Plant Waste Handling and Treatment
Sludge Thickening
Waste volumes can be minimized by concentrating or thickening the sludge
withdrawals from sedimentation basins and solids from filter washwater.
84
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Volumetric sludge reduction alleviates the problem of final disposal
and provides a starting point for the recovery of by-products. Water
utilities of all sizes can thicken or concentrate their waste solids.
Table 10 shows the treatment facilities of different capacities employed
for thickening sludge withdrawals from sedimentation and/or contact
bas ins.
Filter Backwash Recovery
The recycling and recovery of the liquid portion of filter backwash
water was suggested as a primary research need during the Project
Advisory Committee meeting. The recovery of this water can be economi-
cally advantageous. Table 11 illustrates the number of treatment facili-
ties that settle or recirculate filter backwash water to thicken the
solids concentration and eliminate the discharge of suspended solid pollu-
tants to other sources.
The Dalles, Oregon, Water Treatment Plant reports "we do not presently
additionally concentrate or thicken sludge (slurry) withdrawals prior
to disposal. We will soon be adding polymer to our sludge (basin sludge
and filter washwater) as it goes to its new lagoon. This will enhance
the settling rate of the sludge."
The East Bay Municipal Utility District reports "there is direct filtra-
tion and no sedimentation at their Lafayette, Orinda, and Walnut Creek
plants. Sludge disposal is being evaluated at the Sobrante, San Pablo,
and Upper San Leandro Filter Plants. Polyelectrolytes are being inves-
tigated. Some changes will be made."
The Chester Water Authority of Lancaster County, Pennsylvania, reports
"sludge is held in lagoons. Later the sludge is removed and spread on
the ground to dry before final disposal."
The Fridley Softening Plant in Minneapolis, Minnesota, reports "sludge
beds concentrate sludge withdrawals prior to disposal. A sludge dewater-
ing plant for concentration of softening plant sludge, filter backwash
water and coagulation basin sludge will be in operation by November,
1972. Solids will be trucked to a dump."
The City of Atlanta, Georgia Water Department reports "they are building
two pressure filtration plants now to concentrate sludge withdrawals
prior to disposal ."
Characteristics of Solids
The character of the suspended solids in the wastes from sedimentation
or contact basins and filter backwashing operations at the point of
final disposal defines the waste treatment required to dispose or recover
the solids. A highly concentrated waste is more readily adopted for use
as a landfill or for by-product recovery. The great majority of purifi-
cation and softening facilities surveyed reported that the wastes from
basin -desludging and filter backwashing were in fluid form at the point
of final disposal.
85
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TABLE 9
CATEGORIZATION OF SURVEY DATA PARAMETERS
Raw Water
Turbidity
Raw Water
Sus. Solids (mg/1)
Raw Water
Hardness*
Treated Water
Hardness*
Raw Water
TDS (mg/1)
Treated Water
TDS (mg/1)
* - mg/1 as CaC03
Mean
Range
Samples
Mean
Range
Samples
Mean
Range
Samples
Mean
Range
Samples
Mean
Range
Samples
Mean
Range
Samples
Sources
Surface-
Impounded
12
0.2-63
27
33
0-250
20
93
5-249
28
93
21-251
28
175
27-1032
27
166
40-1033
28
Surface-
River
72
3-625
58
90
1-658
30
119
10-297
58
101
15-297
58
237
35-737
37
196
21-680
45
Ground-
water
1
0-4
3
1
0-2
3
324
199-625
7
175
50-475
6
377
230-600
5
225
100-405
5
The suspended solids concentrations in sludge withdrawals from sedimen-
tation or contact basins was reported from as little as 0.05 percent
to 100 percent dry solids by weight. The former figure represents a
waste that undergoes no thickening other than sludge compaction within
the basins. The latter figure represents utilization of by-products
from the waste sludge, recalcination of lime softening sludge.
The suspended solids concentrations of filter washwater were reported
from 0.03 percent to 6 percent dry solids by weight and from 1 to 1420
mg per liter. The comparison of waste concentrations from filter wash-
ing operations is dependent on the establishment of standardized sampling,
analysis, and categorization techniques to examine water treatment plant
wastes. The variation in solids concentrations is significantly differ-
ent, depending on the time and method of washwater sampling. A uniform
86
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TABLE 10
CONCENTRATION OF BASIN SLUDGE
Average Flow
Range (mgd)
0-5
0-5
>5-10
>5-10
>10-20
>10-20
>20-30
> 20-30
> 30-50
>30-50
>30-50
>50-80
>50-80
>50-80
>50-80
>50-80
>50-80
Supply
Source
River
Groundwater
Impounded
River
Impounded
River
Impounded
River
Impounded
River
River
Impounded
Impounded
River
River
River
Groundwater
Number of
Facilities
2
1
2
1
1
1
2
1
2
1
1
4
1
1
1
1
1
Method
Settling
Settling
Settling
Settling
Settling
Settling
Settling
Settling
Settling
Settling
Settling,
thickeners
Settling
Centrifuga-
tion
Settling
Mechanical
thickeners
Drying beds
Centrifu-
gation
>120-200
River
Settling
87
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TABLE 11
CONCENTRATION OF FILTER WASHHATER
Average Flow
Ranee (med)
>5-10
>5-10
>10-20
>20-30
>20-30
>20-30
>30-50
>30-50
>30-50
>30-50
>50-80
>50-80
>50-80
>50-80
>50-80
>50-80
>80-120
Supply
Source
Impounded
Groundwater
Impounded
Impounded
River
River
Impounded
Impounded
River
River
Impounded
Impounded
Impounded
Impounded
River
Groundwater
River
Number of
Facilities
1
1
1
1
1
1
1
1
1
1
1
2
2
1
1
1
1
Method
Settling
Settling
Settling
Settling
Recycle to
f locculators
Lagoon
drying
Settling
Lagoon
Settling
Clarifiers
Settling,
Recovery
Recycling
Lagoon
Settling
Recycling
Recycled
Pressure
filters
sampling technique did not accompany the survey. Comparisons will be'
possible only when standard methods are developed and utilized.
88
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Similarly, sludge concentrations in sedimentation or contact basins,
depend, in part, on the type of system and the manner of desludging.
The degree of sludge compaction varies with the nature of the raw water
impurities to be removed and the coagulants utilized. Continuous, cyclic,
and intermittent desludging operations must be evaluated in terms of opti-
mizing waste concentration and minimizing waste volumes.
Comments
The City of Atlanta, Georgia, expects that the two Beloit-Passavant pressure
filtration units will concentrate the dry solids content of the sedi-
mentation basin sludge to forty-five percent and the filter washwater
waste to forty percent.
The City of Des Moines, Iowa, Water Treatment Department settles filter
washwater in a stilling pond. This settling is effective in increasing
the dry solids concentration to ten percent.
The City of Dayton, Ohio, Water Department thickens, centrifuges and
recalcines their lime sludge. The Department reports "all solids are
reclaimed or recycled. Ninety-five percent of the solids are recalcined.
The only solids necessary to lagoon are a small percent from the lime
plant."
The Gary - Hobart Water Corporation concentrates sludge from their set-
tling basins to six percent dry solids by settling.
The City of St.Paul, Minnesota, Water Department operates a lime recla-
mation facility at this softening plant. The lime recovery treatment con-
sists of centrifugation and recalcining of sludge from the settling basins.
Pellets of calcium oxide are reclaimed for reuse.
The City of Columbus, Ohio, Water. Department recycles the filter back-
wash water to the sedimentation basins of the main plant. The solids
from the filter washing are removed with the sludge withdrawals from
the sedimentation basins. The wastes from the basins are settled and
concentrated to forty-five percent dry solids.
The Chester Water Authority of Lancaster County, Pennsylvania, settles
filter washwater wastes in lagoons. The wastes are periodically removed
from the lagoons and placed on sludge drying beds. The dry solids con-
tent has been increased to fifteen percent by this method.
Table 12,titled "Disposal Techniques for Basin and Filter Washwater
Solids, and Liquid Wastes", shows the techniques utilized for final dis-
posal of these waste volumes at the utilities surveyed.
Several alternative techniques were reported in use to dispose of solid
and liquid water treatment plant wastes. Table 13, titled "Techniques
Employed for Final Disposal of Solid and Liquid Waste", illustrates the
methods used.
89
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TABLE 12
DISPOSAL TECHNIQUES FOR
BASIN AND
FILTER WASHWATER
SOLIDS, AND LIQUID WASTES
Responding Water Utilities
Disposal by
Watercourse
Lake
Dry Creek
Ocean
Lagoons
Sewer
Landfill
Agriculture
Recalcining
Other
Basin Solids
31
7
4
1
15
8
9
1
1
4
Filter Washwater
Solids
36
7
4
1
11
7
6
1
0
8
Liquid
Wastes
54
9
5
1
5
9
8
Comments
The Chester Water Authority of Lancaster County, Pennsylvania, reports
"sludge is given to an organic compost plant. They add it into their
process in the manufacture of organic fertilizers."
Vaste Production and Waste Characteristics
There are few alternatives for disposal of dried or concentrated waste
solids. The solids must be disposed of in a manner consistent with the
regulations of the authorized control body governing wastes from water
utilities. By-products from the purification and softening processes
can be recovered for reuse and/or resale. Inert materials that cannot
be utilized remain for disposal . by-product recovery has been practiced
when it is economical.
The magnitude of final disposal problems for solids wastes is partly
dependent on the dry density of the solids. Thirteen treatment facilities
90
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Basin Solids
Plants
1
TABLE 13
TECHNIQUES EMPLOYED FOR
FINAL DISPOSAL OF SOLID AND LIQUID WASTES
Method
Settles solids in recovery pond and uses solids
as a landfill
Discharges solids to sanitary storm sewer which
discharges to a reservoir
Contract to have waste solids hauled away
Filter Washwater
Plants
1
1
4
1
Method
Settles solids in recovery pond and uses solids
as landfill
Discharges solids to sanitary storm sewer which
discharges to a reservoir
Contract to have waste solids hauled away
Recycles filter washwater to main plant intake
Discharges to a swamp
Liquid Wastes
Plants
6
1
1
Method
Recirculate liquids for recovery
Evaporation and percolation of liquid
Basin liquid wastes is lagooned following centri-
fugation. Filter washwater is recycled.
reported dry solids densities of sludges from seventy-two to 141 pounds
per c u ft. These values include sludges from purification and soften-
ing plants. A standard density determination method did not accompany
the survey.
91
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The density value partially describes the volume required for a waste
that has been completely dried. More important indicators of the waste
volume to be treated or disposed are the"' water volumes needed for basin
desludging and filter backwashing.
The water used for filter washing has been treated to a high level of
quality. The recovery of this water seems to be an almost obvious
solution that may significantly reduce plant operating costs and elimi-
ate the pollution caused by discharging this waste.
The survey participants reported ranges of 0 to 21.8 percent of the treat-
ed water was required fa: basin desludging. In some cases, the treated
water was recovered. Most utilities presently dispose of this solid and
liquid waste from the basin desludging operation.
Filter washwater requirements ranged from 0.2 to 9 percent of the treat-
ed water used. Some plants reclaim this water.
The separation of solids from filter washwater and the recovery of the
liquid portion of this waste demands consideration. The use of liquid-
solids separation devices to reclaim filter washwater should be investi-
gated. The suitability of .separation technology such as microstraining
should be examined if recycling or sedimentation of filter washwater is
not feasible at a particular location.
The analysis of sludge samples from basins and filter washing operations
depends upon the sampling method. Well defined waste sampling methods
are currently being developed. A broad range of values for basin sludge
and filter washwater sludge concentrations was found in this survey.
Table 14, titled "Basin Sludge Concentration Data", shows the range
of values reported.
Table 15 titled "Filter Washwater Sludge Concentration Data", demonstra-
tes the variation in solids concentrations of filter washwater. By the
nature of the filter washing procedure, a single measurement made on a
single sample at a single time may be misleading. Several concentra-
tions measured during the1 complete backwash cycle provide a temporal-
concentration relationship. A plot of solids concentrations (mg/1)
versus the time of backwash defines the solids release pattern of a
particular filter. The more frequent the sampling of a waste during a
backwash cycle, the more continuous are data points for the solids
release curve. The area under the curve represent a time-concentration
product (mg/1 . min). With a constant backwash rate (gpm), the time-
concentration product can be converted to total solids. Each filtration
plant will have different relationships, dependent upon solids release
patterns, rate of backwash, and total backwash water.
Table 16 titled "Chemical Analysis of Basin Sludge", provides a range
of data accumulated from the purification and softening facilities
responding to this survey. It is interesting to note that the largest
response to any parameter was thirty-two participants (8102). Of the
ninety-four utilities included in this survey, the majority were unable
92
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Concentration
Data
% of Dry Solids by Range
Weight at Withdrawal Samples
Time
% of Original Volume in Range
24 hr. settling and Samples
liquid decantation
% of Dry Solids by Range
Weight in 24 hr. Samples
settling and liquid
decantation
Suspended solids in Range
supernatant in 24 hr. Samples
settling and liquid
decantation (mg/1)
a - Pittsburgh, Pennsylvania
b - Columbus, Ohio
TABLE 14
BASIN SLUDGE CONCENTRATION DATA
Supply Sources
Impounded
0.15-6
12
0.9-75
10
0.1-19
9
7.8-111,000
9
River
0.12-69
18
0-89.6
17
1.5-62
16
a
Groundwater
4-4.4
2
17
1
16
1
1.5-2000 17
17 1
to supply much data on waste production and waste character. The regu-
latory information shows a trend toward the strict enforcement of exist-
ing legislation and the elimination of waste discharges from water
treatment plants. Sampling, analysis, and categorization methods from
water treatment plant wastes are being developed. The establishment
of suitable sludge treatment processes at any water utility will require
an analysis of waste production and character. These types of data
will be necessary for laboratory, piloC, and plant scale design.
Table 17, titled "Chemical Analysis of Filter Washwater", illustrates
variations in chemical analysis of purification and softening plant filter
washwaters. The orderly classification of waste characterization data
is an important step in treatment method evaluation.
Tables 18 and 19 illustrate the character of chemical and biochemical
oxygen demand data of wastes from water purification and softening facili-
ties. Table 38 contains data assembled from those purification plants
responding to the survey. Table 19 is accumulated data on the water
softening installations participating. The number of samples in these
tables are quite small. The ability to measure and control these waste
parameters will have added significance with the enforcement of state
93
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TABLE 15
FILTER WASHWATER SLUDGE CONCENTRATION DATA
Concentration
Data Impounded River
Average Dry Solids Range 0.35-3000 0.18-6888
Concentration in Samples 14 20
Washwater (mg/1)
Average Dry Solids Range 68-97,000 2.5-106,200
Concentration after Samples 8 17
24 hr. settling and
liquid decantation (mg/1)
Suspended Solids in Range 2-35 2.5-330
Supernatant after Samples 7 17
24 hr. settling (mg/1)
and federal water quality or effluent standard requirements. Water utility
wastes represent one type of industrial waste input into streams. The
chemical and biochemical oxygen requirements of these wastes utilize
a ssimilative capacities of watercourses. The magnitude of this problem
is proportional to several variables. These variables include: other waste
inputs along the watercourse, reaeration coefficients in the streams,
seasonal variation, decay rates of BOD material in streams, flow condi-
tions, and others. The dissolved oxygen sag curve has been utilized to
predict the effect of waste inputs in river basin systems. The oxygen
deficits at each point in a stream can be predicted by using the principle
of superposition for each waste source. Water utility wastes, added to
other wastes, impair stream quality. The reduction or elimination of these
wastes will ultimately be proportional to the degree of regulatory enforce-
ment and the classification of the watercourse.
Additional Survey Information
The City of Laramie, Wyoming reports "all sludge from the sedimentation
basins and filter washwater goes into a lagoon. When the lagoon fills
up, it will be dewatered and the sludge will be spread on city owned prop-
erty."
The City of Tucson, Arizona, "obtains its entire supply from deep wells,
and the product water is distributed directly without treatment. Chlorine
is added only to the water stored above the surface. The study of sludge
disposal technology will become increasingly important to Tucson as this
city looks forward to importing surface water as a supplemental source
to be supplied through the Central Arizona Project, perhaps by 1980."
94
-------
Volatile Matter
Fe203
/o
A1203
/o
CaC03
%
Mg(OH)2
Remainder
TABLE 16
CHEMICAL ANALYSIS OF BASIN SLUDGE
Plant Type
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Purification
1-50
20
0.4-64
20
0.2-57.4*
18
0-82
19
1-86.6b
13
0-24.3
12
0-77.9C
12
a- as Fe(OH)3 Providence, R.I.
b-San Diego Alvarado Plant
c-Cincinnati Water Works
Softening
2.88-82,75
0.2-47
12
0.29-9.5
11
0-1.2
9
8.76-98
12
0.35-14.9
12
0.46-10.7
8
d-Bismarck, North Dakota
e-Bismarck, North Dakota
The Water Supply Board of Providence, Rhode Island, reports "ferric sulfate
is added as a coagulant to their water. Chemically treated water flows
through a tangential mixer. Floe commences to form at the mixer, and the
coagulated water enters the north basin. The flow in the basin is baffled
to prevent short circuiting. The settled water then flows in the south
settling basin. The combined capacity of the two series operated basins
is 160.21mg. Average retention time for the two basins is over two and
one-half days. Settled water from the surface of the south basin is
treated with chlorine, filtered, and then fluoridated. The north basin
is cleaned every two years, requiring about one week to drain, flush and
refill. The' south basin requires about ten days every four years for the
same cleaning. The amount of flushing water is not monitored.
The time interval between discharges of basin sludge to the lagoon is
quite long. The filter washwater is not stored in a tank or holding pond.
The washwater with its solids flows from the washwater drain to the lagoons
95
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Volatile Matter
Si02
TABLE 17
CHEMICAL ANALYSIS OF FILTER WASHWATER
A1203
CaCOs
Mg(OH)2
Remainder
a - Rochester, N.Y.
b - Detroit, Michigan
c - San Diego, California
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Range
Samples
Plant Type
Purification
0.5-40
15
0.65-69
15
0.08-18.4
11
Ob-45
13
1-55. 8C
12
0.3-22.1
10
2-70. 3d
10
Softening
4.5-99.066
3
0.1-18.8
7
0.06-20.1
7
0-34.1
6
0.31-98
7
0.1-6
6
0.53-54.41
6
d - Pittsburgh, Pennsylvania
e - Bismarck, North Dakota
f - Bismarck, North Dakota
as the washing is in process. The solids in the washwater of course are
different for each interval of time during backwash."
Canadian Survey Responses
Surveys were sent to ten Canadian water treatment facilities. Five re-
sponses were received by the Research Foundation.
The water purification plant in Hamilton, Ontario, treats water from the
western end of Lake Ontario. This utility reports that "solids in slurrry
withdrawals f TO m sedimentation basins are concentrated by settling prior
to disposal. The final disposal of water treatment plant sludge solids
is to a creek emptying into Hamilton Bay, which is itself a large settling
basin."
96
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TABLE 16
CHEMICAL AND BIOCHEMICAL OXYGEN DEMAND CHARACTER
OF PURIFICATION PLANT WASTES
Sludge Withdwawn BOD5 COD
From
Range 0-350 6-23,000
Basins
Samples 16 15
Range 0-25 4.5-200
Filter Washwater
Samples 15 15
Liquid Waste @
Final Disposal
From
Range 2.8-350 16-7000
Basins
Samples 11 10
Range 1.6-72.8 21.1-2617
Filter Washwater
Samples 9 9
The Municipality of Metropolitan Toronto reports that "at the present
time wastes from the four water treatment plants in Metropolitan T oronto
are returned to the source, Lake Ontario. The Municipality is currently
investigating this matter with a view to completely remove solids in the
future before returning settling basin and backwash wastes to the lake."
The Department of Energy, Mines, and Resources of Canada reports to the
Foundation that "the Government of Canada has built a fairly large Pilot
Plant at Burlington, Ontario, to accomodate both basic and applied re-
search on water pollution. It is expected to be in operation in about
six months (early 1972; . One of its main functions will be research and
development into new and improved methods for the reclamation, reuse,
and ultimate disposal ofi sludges, wastes from treatment processes, brines,
etc. The Department plans to establish rapport with the Research Foun-
dation, as a clearing-house to collect and distribute information and
exchange data."
97
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TABLE 19
CHEMICAL AND BIOCHEMICAL OXYGEN DEMAND CHAJRACT.ER
OF SOFTENING PLANT WASTES
Sludge Withdrawn BOD5 COD
From
Range 7.2-145 14.2-5000
Basins
Samples 5 6
Range 0.7-14 5.6-300
Filter Washwater
Samples 4 3
Liquid Waste @
Final Disposal
From
Range 3-145 6.5-5000
Basins
Samples 7 3
Range 0.7-14 0.4-300
Filter Washwater
Samples 4 2
The Region of Niagara, Niagara Falls, Ontario, Water Treatment Plant
and the Petersborough, Ontario, Public Utilities Commission discharge
the water treatment plant sludge solids to watercourses.
' Desalting Facilities
Although many of the survey questions did not directly apply to desalt-
ing operations, several surveys were sent to desalting facilities. A
general description of the operation at two facilities was received by
the Research Foundation.
The Office of Saline Water operates a test facility at Webster, South
"•akota, treating an average flow of 150,000 gpd of well water. This
installation reports lime softening is utilized at this test(facility to
remove iron, manganese, and bicarbonate hardness prior to treatment by
electrodialysis. Raw water total dissolved solids are reduced from 1500
mg per liter to 700 mg per liter iti the treated water. The reduction in
hardness is from 800 mg per liter as CaC03 in the raw water to 150mg per
liter as CaCOo in the treated water.
98
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Solids in sludge withdrawals from basins are concentrated to twenty per-
cent prior to disposal. The water treatment plant basin solids are used
as landfill. Filter washwater is discharged to a lake. The average
total dissolved content of these waste waters is 1800mg per liter. This
brine waste is discharged to a lake.
The Town of Buckeye, Arizona, reported on its electrodialysis plant. The
raw water comes from deep wells with 1400 to 1800 ppm of total dissolved
solids. The treated water from the electrodialysis plant contains 500
ppm or less of total dissolved solids. The total hardness of the raw
water is from 8 to 12 grains per U.S. gallon. The treated water hard-
ness is less than 3 grains per U.S. gallon. Impurities in the raw water
are principally calcium carbonate, sodium, bicarbonate, chloride, and
sulfate ions.
Following treatment in the electrodialysis plant, the major impurities
with the exception of fluoride, are brought down within public health
standards. The raw water has 4ppm of fluoride and the treated water
contains 2ppm.
The waste stream from the water plant is concentrated to approximately
7500 ppm total dissolved solids before it is dumped to waste. The
waste stream is mixed with the effluent from the sewage treatemmt plant
with a resulting combination of approximately 2700 to 2800 ppm total
dissolved solids. The farmers are satisfied with the effect of this
combined effluent on their products.
Conclusions
The development of reliable research and development data is necessary
in organizing an orderly approach to the control of pollution caused
by water treatment plant wastes. Meaningful correlations and compari-
sons of waste parameters will benefit water treatment plants investigat-
ing or operating laboratory, pilot, or plant scale waste handling pro-
cesses. The design of waste treatment facilities is dependent both on
the physical and chemical waste character. A record of reliable data,
accumulated through standardized sampling and analysis methods, will
reflect seasonal changes and other important variations in waste con-
tent.
Two goals of the Research Foundation, confirmed by the analysis of
this survey are:
1. To continue with the development of uniform sampling, analysis,
and categorization techniques for water treatment plant wastes.
Subject these methods, as developed under the coordination
of the Foundation, for review and revision. Submit final meth-
ods to an appropriate Sub-Committee for review and incorpora-
tion in the next edition of Standard Methods For the Examinar
tion of Water and Wastewater.
99
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To disseminate the standard testing procedures to the water
utility industry and encourage the use of the procedures in
the evaluation of water treatment plant wastes. These pro-
cedures must be utilized to provide a basis for comparison
of waste problems.
100
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SECTION IX
NEW TECHNOLOGICAL DEVELOPMENTS
Introduction
A principal goal of the AWWA Research Foundation is to coordinate and
assist in the development of research and demonstration projects. It
is essential that the information generated through this program provide
the water utility industry with a basis for effective and economical
waste disposal practices. As a clearinghouse, the Foundation serves to
transfer technology and to exchange communication among scientific, tech-
nical, and administrative personnel in the identification of specific
problems.
In the coordination of information, the Foundation is responsible for
supplementing data presently available with plans for future research
and demonstration requirements. New, and prehaps more imaginative,
approaches to the control of water treatment plant wastes should be
investigated.
Two needs were identified by the Project Advisory Committee for further
development. These needs are:
1. The development of uniform sampling, analysis, and categoriza-
tion techniques for water treatment plant wastes; and
2. The use of polymers in treatment processes to perform as primary
coagulants, coagulant aids, and sludge conditioning agents.
A third approach to identify new developments was initiated by the Foun-
dation: the availability of sludge dewatering devices from manufacturers
of equipment required coordination. The suitability of different equip-
ment to handle purification and softening wastes, and filter washwater
should be presented. The Foundation has initiated work to accumulate
this type of information.
The progress of each of these endeavors follows.
Standardization Sub-Committee
A Sub-Committee of the Project Advisory Committee was fornred to develop
documents for^tthe uniform sampling, analysis, and categorization of water
treatment process wastes. The Committee consisted of Messrs. Ralph Evans,
H.O. Hartung, R.N. Kinman, and K.E. Shull. The Research Foundation func-
tions as coordinator of the information developed.
The Research Foundation plans to:
101
-------
1. Continue to coordinate activities in the development of the
documents for standardized sampling, analysis, and categoriza-
tion techniques for water treatment plant wastes.
2. Publish the finished documents and request reviews and comments
from individuals on the Foundation's mailing list.
3. Transmit the final proposed procedures to the appropriate Stand-
ard Methods Sub-Committee to consider incorporating these methods
in forthcoming editions of Standard Methods for the Examination
of Water and Wastewater.
At the time of publication of this report, members of the Sub-Committee
have submitted: (1) five tests which give basic information and which
may be expanded into step by step standard methods; and (2) a labora-
tory procedure that has been successfully used by the Illinois State
Water Survey in analyzing boiler scale or other scale occuring on the
interior of water conveying conduits. These tests and analysis proce-
dures will be building blocks in the construction of the final documents.
Five Basic Tests - Preliminary Contribution
1. Volume Per Cent Solids:
a. 60 minutes settling
b. 30 days settling
The volume per cent solids can be determined by reading the settled
sludge volume after Settling 100ml of slurry in a 100ml graduated cylinder.
2. Weight Per Cent Solids:
The determination of grams of dry solids in 100 ml of sludge can
be made on an aliquot portion, dried for 24 hours @ 105 C.
a. Solids Ratio = Volume PerCent Solids (60 minute settling)
Weight Per Cent Solids (Dried 24 hrs. @ 105°C)
b. Pounds of dry solids per cubic foot of slurry =
0.623 x (grams of solids / 100 ml)*
where o.623 = 28,320 ml . I . Ib
ft3 100ml 454gms
c. Slurry volume per 100 pounds of dry solids =
16 cf
(gms of solids / 100ml)*
102
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3. Specific Gravity of Slurry:
The specific gravity can be determined by weighing an exact vol-
ume of slurry in a laboratory specific gravity bottle.
Specific gravity = Weight of given volume of slurry
Weight of equal volume of water
4. Density:
The density can be determined on the weight per cubic foot of
undisturbed, thickened, non-flowing sludge from the sludge
lagoon. The method can be based on soils laboratory procedures
using standard spoon sampling and cores.
5. Density of Solids (dried 12hrs @ 105°C - pounds per cubic foot):
The method is to add a known weight of dried solids to a specific
gravity bottle completely filled with water. Weigh the displaced
water.
Pounds = 62.4 x weight of solids
Cubic foot weight of displaced water
* Weight - Per Cent Solids in
The investigation of procedures to examine waste solids is still in a
preliminary phase. These suggestions are methods used by the Illinois
State Water Survey.
Scale Analysis
General Rules Applying to All Scale Analyses
1. All calculations will be made on the basis of the oxide of the
element so that hypothetical combinations will be easier to
calculate.
For example:
CaO + C02 -» CaC03
CaO + S03 -» CaSO^
2. All filtrations will be made using 15 cm, No. OK, ashless
filter paper unless specific directions to the contrary are
given.
3. Samples ignited in the electric muffle, whether ignited to 1000°C
or 1100°C will be allowed tg cool to 300 - 500°C in the muffle,
then transferred to the 180 C oven for at least 1 hour, then
placed in a desiccator to cool for 20 minutes before weighing.
103
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Procedures for Analysis of Sludge
1. Preparation of Sample
a. Grind representative sample in agate mortar until a fine,
powdery consistency is obtained.
b. Dry the sample at 105° for at least two hours or prefer-
ably over night so that all calculations,-, can be made on a
dry basis.
2. Organic and Volatile Matter (Loss on Ignition)
Weigh accurately about 0.5 gm of the prepared sample into an ignited
porcelain crucible. Ignite to 1000 C. Cool and weigh.
Loss of Weight x 100%
Weight of the Sample = % Loss on Ignition
3. Silica (Si02)
Weigh accurately about 1 gram 'of the dried sample into a platinum
crucible. Add to the sample three or four scoops ( #1A Scoop) of
C.P. anhydrous sodium carbonate. Thoroughly mix the materials.
(quantitatively) in the crucible. Cover the material in the crucible
with two or three scoops of C.P. anhydrous potassium carbonate.
Ignite to 1000°C.
After cooling, place the platinum crucible in a 400 ml beaker. Add
100 ml of doubly distilled water and 20 ml of concentrated HCL, Heat
gently on the hot plate until no further evolution of C02 is noticed.
Do not boil. Care must be taken to avoid spattering during the evolu-
tion of C02. Wash out the platinum crucible and remove it from the
solution. Evaporate the solution to dryness on the steam bath and 1-
bake in the 105°C oven for at least four hours. This procedure is
necessary to completely dehydrate the silica so that it will filter
quickly and easily.
Cool, moisten the residue with concentrated HCL, then, after a short
period of contact, dilute with doubly distilled water to a 10% acid
solution. Boil for a few minutes, then filter off the silica. Wash
the precipitate on the filter paper thoroughly, first with a hot
solution of 1% HCL and then with hot doubly distilled water until
the chloride ion is absent in the filtrate. Make filtrate up to
250 ml volume and save for later use. Ignite the residue in a plat-
inum crucible to 1000 C. Cool and weigh. Carefully moisten the '
material in the platinum crucible with 1 to 2 ml of doubly distilled
water, add 4 or 5 drops of 1:2 ^SO^ and then, carefully add 5 ml
of HF. Place the crucible on the hot plate under the hood and evap-
orate to fumes of 803, then increase heat and fume off the SO^.
Ignite the platinum crucible to 1000°C. Cool and weigh.
104
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(original weight of precip. - remaining weight of precip.) x 100 = IS102
weight of sample
note; If the amount of silica in the scale is large, it may be
necessary to dehydrate the filtrate a second time to recover all
of the silica.
4. R203
To a 100ml aliquot of the filtrate from the silica, add a few drops
of concentrated HN03 and boil for a few minutes to oxidize all the
iron to the ferric state. Remove from the hot plate, neutralize
with concentrated NH^ OH using methyl red indicator. Boil for a few
minutes, add organic filter pulp and filter (save filtrate). Wash
the precipitate with a hot 1% solution of NH^NC^. Ignite to 1000°C.
Cool and weigh.
weight of precipitate x 2.5 x 100 = % R203
weight of sample
5a. Iron (Fe CU - Jones Reductor Method)
To a 100ml aliquot of the filtrate from the silica, add 10-20
drops of H^SO, , and evaporate to the fumes of SOo. The solid
mass at the bottom of the beaker should be straw colored
fFe2(SO/)3]. Dissolve the mass in 100-150 ml of doubly distilled
water, (the mass will dissolve more rapidly if the solution is
kept hot by leaving it on the steam bath) . This may take a few
minutes to several hours. Cool the solution.
Clean the Jones Reductor by passing 3% l^SO^ through 3-4 times,
then rinse the reductor with doubly distilled water. (A good test
is to add a drop of K^O^ to the rinse solution. If the reduc-
tor is clean, this will produce a pink color). Rinse again
with 3% l^SO^.. Pour sample through clean Jones Reductor using
gentle suction to regulate the flow to under 75ml per minute. Do
not allow the level of liquid in the reductor to fall below the
zinc column at anytime. The zinc reduces the ferric sulphate
to ferrous sulfate. Wash through 3 times with 37o H2SO, , then 3
times with doubly distilled water. Draw each portion through
before adding the next. Wash the tip of the reductor off and
titrate immediately with 0.1000N KM 0^ to pale pink end point.
The KtLOi oxidized the iron to the terric state.
ml kMnO/, x O.INx 0.05585 x 2.5 x 1.4297 x 100 = % Fe203
weight of the sample
5b. If the sample is not high in iron, the iron may be determined
by one of the i col crime trie methods shown in Standard Methods.
6. Phosphate (P205 by Molybdate)
Take a 10 ml aliquot of the filtrate of the silica, dilute to
50 ml in a Nessler's tube. Place the solution in a 125 ml
105
-------
Erlenmeyer flask. Add 1 ml of standard (NH4)6M0702A
followed by 1 ml of standard 1 amino 2 napthol 4 sulfuric acid
solution. Let stand for exactly 10 minutes, transfer to a colori-
metric tube and read color transmission on photometer using filter
no. 660. Results are read on PO molybdate curve as ppm. PO,
on the basis of a 50 ml sample and calculated as 7o P 0 :
PPM x 5x .7474 x 100 = 7, P205 2 5
mgms of sample x 4
Note: If acid concentration is high, color development will be de-
creased, therefore it is wise to run a 5 ml aliquot also. If the
acid concentration is high, the 5 ml aliquot will give a greater
color development indicating the necessity of diluting out the sample
to reduce the high acid concentration.
7. Aluminum Oxide (Al~0o)
7»R20 - 7cFe203 = 7oAl203*
* Assuming that there is no titanium, manganese or phosphate in the
sample.
8. Calcium Oxide (CaO)
Evaporate the filtrate from the R203 separation to approximately
200 ml. Using HCL, make the solution slightly acid to the methyl
red.
Add 10 ml of a 107o solution of (NIL-) 2 Co04 dropwise with constant
stirring. Neutralize with concentrated NlfyOH. Digest on the steam
bath for two hours. Filter while hot using a sintered glass cruci-
ble. Wash with doubly distilled water. Save filtrate for the MgO
determination.
Dissolve the calcium oxylate precipitate by adding hot 6N H2SO, to
the crucible 3 times, then washing with doubly distilled water.
Heat to 60 to 80°C and titrate immediately with 0.1N KMnO^ to a
faint pink color.
ml KMn04 x 0.0028 x 2.5 x 100 = 7o CaO
weight of sample
9. Magnesium Oxide (MgO)
Use the filtrate from the calcium oxide determination. Add the
following: 20 ml of saturated microcosmic salt solution, a few
drops of thymol blue indicator and then concentrated NH,OH to the
appearance of a dark bluish-green color. Let stand overnight.
Filter the precipitate using an ignited and weighted Gooch crucible.
Wash with mg washwater. Ignite at 1000 C, cool, and weigh as
wt of ppt x 0.3621 x 2.5 x 100 = 7oMgO
weight of sample
106
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10. Calcium and magnesium may be determined also by EDTA titration.
The filtrate from the R20 extraction is made up to a 500 ml
volume, and the hardness and calcium content determined.
mg/1 hardness (as CaCOs) - mg/1 Ca (as CaC03) = mg/1 Mg (as €3003)
mg/ICa (asCaC03) x 0.07 = % CaO
weight of sample
mg/lMg (as CaCOQ x 0.05 = % MgO
weight of sample
11. Carbon Dioxide (C02)
Refer to pages 355 thru 359 in "Elementary Quantitative Analysis"
by Willard and Furman.
12. a. If the analyst has reason to suspect the presence of other
elements in the scale, these should be determined by appropri-
ate methods.
b. When a scale analysis is completed the sum of the percentages
of each of the constituents should total approximately 100%.
Summary of Development of Standard Test Documents
The work of the Standardization Sub-Committee is continuing. More infor-
mation is required for recommended sampling procedures for wastes from
sedimentation basins and filter washwater. Additional comments and sug -
gestions are required on the tests and procedures that have been submitted,
in order to obtain the analytical data needed for the characterization of
sludges. Answers are also required on the need for supplemental tests
and whether the methodology already described is sufficiently detailed.
The Research Foundation will evaluate additional comments on these pro-
posed documents and remaining areas of research. Correspondence will be
coordinated with individuals expert in the treatment or water and the
analysis of sludge from water purification and softening facilities.
Introduction to Polymer Evaluation Program
The amount and type of sludge produced at a treatment plant is partially
dependent upon the processes utilized and the efficiency of operation.
Another approach to the sludge disposal problem is through the use of
new coagulants. This view was stated in the report titled "Disposal of
Wastes from Water Treatment Plants", and later at the meeting of the
Project Advisory Committee.
The use of polyelectrolytes as coagulants in place of alum could repre-
sent a new tecnological change that would significantly alter the waste
character. The effectiveness of polyelectrolytes as coagulant aids
107
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might reduce the quantity of alum utilized in treatment processes.
Finally, polyelectrolytes have been shown to effectively act as
sludge conditioning agents, making waste sludges more amenable to
dewatering.
The Research Foundation has initiated the organization of material
which can be utilized in the evaluation of polymers. The extent of
progress in this undertaking follows.
Polymer Evaluation Program
The Research Foundation made a literature search of the Journal American
Water Works Association to determine if a standard jar testing procedure
had been utilized to evaluate polymers as primary coagulants, coagulant
aids, and sludge conditioning agents at different water utilities. Four
articles were found that suggested possible parameters to be considered
in a jar testing program.
A search for additional publications produced an AWWA manual titled
"Simplified Procedures for Water Examination - M-12." This manual con-
tains a basic jar testing format and recommendations useful in struc-
turing a polymer evaluation program.
In addition to the literature sources, the Research Foundation utilized
the expertise of two water utility operating practice personnel and one
university research investigator in preparing the preliminary test doc-
uments. The suitability of the basic test documents has been agreed
upon by the experts and the Foundation as a good starting point. It is
planned to utilize wider experience to conduct an evaluation program
which will lead to revision and modifications to these documents.
Seven basic documents have been coordinated to allow the testing of the
polymers. These documents are: jar test data sheet; basic data test pro-
cedure,; procedure to evaluate sludge conditioning ageints; sludge condi-
tioner data sheet; filter aid evaluation by means of a filter test leaf;
standard column test procedure; and a simplified jar test procedure.
Jar Test Data Sheet
The data required for the polymer evaluation has been limited mainly to
physical tests. These tests provide meaningful information and mini-
mize lengthy chemical analyses.
In attempting to correlate the data to the raw water quality, a raw
water analysis data sheet will be submitted for the day the polymer was
tested.
A settling speed test was included. The settling speed test should
provide some indication of how much a polymer primary coagulant or aid will
increase the settling rate and compress the sludge when compared to
the coagulant presently used. Most of the rapidly settling curves will
be exponential in form. Settling data will be recorded and plotted.
108
-------
The data can be plotted on semi-logarithmic coordinates to give an
indication of an exponential settling factor k from the equation:
S = Cle ~kt
where S = settling height
GI= initial height of interface
k = time 1
t = time
The data sheet for the investigation of polymers as primary coagulants
and coagulant aids is illustrated in reduced form. Figure 1, the front
of the sheet, contains information on chemical additions to each jar
and basic data recorded. This side also contains instructions for the
settling speed test. Figure 2, reverse side of the sheet, shows the
record of data and plot of the interface level versus the time on carte-
sian coordinates.
Basic Data Test Procedure
The specification of data procedures will provide a basis for compari-
son. The parameters on the data sheet are to be determined in the follow-
ing manner:
Water Temperature (°C);
Temperature measurements should be made in accordance with the specifi-
cations outlined in Standard Methods. The temperature of each jar sample
should be taken immediately before rapid mixing.
Supernatant Turbidity (JTU);
Turbidity measurements should be made in accordance with Standard Methods
or by approved instruments that are used in daily laboratory evaluations.
Indicate the method of measuring the turbidity.
22
The pH measurement should be made in accordance with Standard Methods.
The measurement can be made with a commercial pH meter approved for use
in daily laboratory evaluations. Indicate the method (pH meter) used
to obtain the measurement.
Floe Formation Time:
Reference is made to an article titled "Techniques of Coagulation Test-
ing - Part 1" appearing in the September, 1970, issue of the Journal
American Water Works Association. The test for floe formation time is
taken from this article. The test follows.
"This is a very simple test in which the time between the coagulant
addition and the first appearance of visible floe is recorded. Often,
109
-------
Reporting Utility
Location
Raw Water pH
FIGURE 1
PRIMARY COAGULANTS AND COAGULANT AIDS
Date
Source of Supply
Official Reporting
Raw Water Turb.
CHEMICALS ADDED (mg/1):
Jars l 2 3 4 5.6
Alum
Carbon ,
Lime
Soda Ash
Ferric Sulfate
Aid (Name)
BASIC DATA;
Water Temperature ( C)
Supernatant Turb. (JTU)
Supernatant pH , _____
Floe Formation Time(min) _____ ' i___
Visual Floe Size
Supernatant Hard.(CaCO_)
SETTLING SPEED:
1. Observe the results of the testing for jars 1 to 6.
2. Select the best or two best coagulant dosages on the basis of the data.
3. Set up beakers with the same dosages of the best coagulant(s) and the
control jar and repeat the jar test procedure.
4. Following slow mixing, measure the height of the solid-liquid interface
in centimeters. Record this height at the times indicated on the data
sheet provided.
5. Plot the height of the interface versus the time recorded on the graph
provided.
(See reverse side of this page for data sheet and graph)
110
-------
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a Tyndall light beam is used to help detect the small initial floe.
Even with this aid, the nearly colorless floe particles formed in many
instances are difficult to see when first formed and as a result,
visual observations are quite qualitative. Also, there is no assurance
that the first floe to form will possess the most durable properties in
the later stages of the process."
Visual Floe Size;
This test is derived from the same article as the floe formation test.
"This test merely consists of an observer qualitatively recording or
comparing the floes as they are formed. Different observers may reach
different conclusions about the same suspension. In addition, this
technique overlooks the importance of floe strength and density. An
attempt to partially quantify the visual evaluations of the floe size
has been made by the establishment of the Wilcomb's Floe Index. This
approach consists of relating visual characteristics of floe formation
and settling to an index number from 0 to 10. High index numbers
represent relatively large floe particles with good settling properties."
A modification of this test appears in the "Simplified Jar Test Proce-
dure." This test uses the size of the control jar floe as unity and
then requires an estimation of the floe size in the remaining jars in
relation to this unity floe. For example, a floe size appearing twice
as large as that in a control jar has a visual floe size of 2.
Supernatant Hardne s s:
Hardness can run on the same sample used for supernatant turbidity.
The hardness test should be performed in accordance with Standard
Methods.
S imp1 i fled Jar Test Pr oc e dure:
A standard jar test procedure is contained within AWWA manual M-12
titled "Simplified Procedures for Water Examination." A standard test-
ing plan is required to provide a basis for the comparison of polymers
as primary coagulants and for coagulation aids in a centrally directed
program. The purpose of this phase of the Research Foundation informa-
tion resource program is to determine the suitability of polymers in
either reducing the total amount of sludge or concentrating the waste
volume of sludge generated at water treatment plants.
The following procedure will be used to initiate testing. This procedure
combines the use of information established by AWWA in its publication.,
and the modifications and suggestions as determined by water utility ,
experts and the Foundation.
Purpose of Jar Tests
Manual M-12 states "the jar tests are designed to show the nature and
112
-------
extent of the chemical treatment which will prove effective in the
full scale plant. Many of the chemicals added to a water supply can
be evaluated on a laboratory scale by means of jar tests. Among the
most important of these chemicals are coagulants, coagulant aids,
alkaline compounds, softening chemicals, and activated carbon for taste
and odor removal. The test also permits the appraisal of the relative
merits of the aluminum and iron coagulants, or in conjunction with such
coagulant aids as activated silica, polyelectrolytes, clays, stone
dust, activated carbon, settled sludge, lime, and soda ash."
Warning
The manual also notes several considerations that may affect the outcome
of jar testing. It states "even the smallest detail may have an impor-
tant influence on the result of a jar test. Therefore, all samples in
a series of tests should be handled as nearly alike as possible. The
purpose of the test will determine such experimental conditions such as
flocculation and settling intervals. Since temperature plays an impor-
tant role in coagulation, the raw water samples should be collected and
measured only after all other preparations have been made, in order to
reduce the effect that room temperature might have on the sample."
Apparatus
The following equipment will be utilized to evaluate the polymers:
1. A variable speed (0 to 0 to 100 revolutions per minute)
stirring machine with three to six paddles (each paddle size
1" to 3").
2. A floe illumination device to be located under the base of the
laboratory stirrer. This illuminator will be used to determine
both the floe formation time and the visual floe size included
on the data sheet.
3. Six standard beakers of 1500 - ml capacity (approximately
4.5 inches diameter by 6.4 inches high). These pyrex beakers
will be required as reaction vessels.
4. A plastic pail or similar sample collection container with a
capacity in excess of 2 gallons will be required. The sample
should be homogeneous for each complete jar test run.
5. One 1,000 ml graduated cylinder.
6. Measuring pipets of 1, 5, and 10 ml, graduated in 0.1 ml steps,
for dosing samples rapidly with the necessary coagulants, sus-
pensions, and solutions. These pipets should be thoroughly
rinsed with distilled water after using to prevent the caking
of solutions.
113
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7. A 100 ml pipet for withdrawing the coagulated softened water
supernatant sample for turbidity and hardness determinations.
8. Instrumentation for the monitoring of water temperature, turbi-
dity, floe formation time, and hardness (for softening plants) is
required.
9. Special apparatus for softening test:
a. Filter Funnel
b. Filter paper of medium retentiveness. Either Whatman No. 40
or Schleicher & Shuil No. 589 is satisfactory.
Dosing Solutions and Suspensions
The importance of simulating plant conditions as closely as possible
cannot be overemphasized. The manual states "dosing solutions or sus-
pensions should be prepared from the stock materials actually used in
plant treatment. Distilled water used for the preparation of lime sus-
pensions should be boiled for 15 minutes t& expel the carbon dioxide
and then cooled to room temperature before the lime is added. "
Details are presented in AWWA Manual M-12 on the preparation of coagu-
lant dosing solutions and suspensions; preparation of an activated silica
dosing solution* and preparation of an activated carbon dosing solution.
In testing polymeric coagulants or coagulant aids supplied by coopera-
ting polymer manufacturers, solutions of these products will be prepared
in accordance with manufacturer specifications.
The frequency of preparing dosing solutions and suspensions is explained.
These instructions will be used to insure uniform testing.
Reagents
The reagents needed in determining turbidity and hardness can be found
in Standard Methods.
Test Procedure for Coagulant Aid Treatment
The addition of alkaline agents, clay suspensions, or activated silica
are covered under number 14 in this format. When the water contains
natural color, alum should be added before other agents or coagulant
aids.
Items 1 to 6 and 14 have been taken from Manual M-12. The remaining
items have been developed through the coordination of the. Foundation.
j
1. Rinse six 1,500 ml beakers with tap water and let the beakers
drain for a few minutes in an upside - down position. Beakers
that have had several days of use should be scrubbed inside
114
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and out with a brush and a household dishwashing detergent,
finishing with a thorough rinse of tap water.
2. Clean the stirring machine paddles with a damp cloth.
3. Collect a sample of raw water and complete Steps 4 through 8
within 20 minutes. Throw away the sample and collect a fresh
sample if the work must be interrupted during this critical
stage. Otherwise, the settling of high turbidity and an in-
crease in the sample temperature from the heat of the laboratory
may cause erroneous results.
4. Stand the beakers right side up and pour more than 1 liter of
raw water into each one.
5. Taking one beaker at a time, pour some of the raw water back
and forth between the beaker and a 1-liter graduated cylinder.
Finally, fill the graduated cylinder to the 1-liter mark, and
discard the excess raw water in the beaker. Return the meas-
ured 1-liter sample.to the beaker.
6. Place all the beakers containing the measured 1-liter samples .
on the stirring machine.
7. Lower the stirring paddles into the beakers, start the stirring
machine and operate it at 100 r.p.m.
8. With a measuring pipet, add the same dosages of the coagulant-
solution that is used in your treatment facility to the six
test beakers, at nearly the same time as possible. Record the
time required to produce a visible floe on the data sheet.
9. Apply the polymeric coagulant aid at dosages of 0.05, 0.1,
0.15, 0.2 ppm, etc. to the five above beakers at 100 rpm for
three minutes. The sixth beaker should be a control jar to
which no coagulant aid is to be added. With a proper series,
the beakers should show good to excellent coagulation results
depending on the control jar. It may be necessary to repeat
the jar test to ascertain the proper series of doses for the
desired results.
10. Reduce the stirring speed over the next 30 seconds to 40 rpm,
and continue stirring at this speed for a 15 minute period.
11. Stop the stirring machine and allow the samples to settle for
5 minutes. Observe the floe sizes in each jar. Use the control
jar floe size as unity. Then visually compare the size of the
remaining floe particles in jars 1 to 5 under visual floe size,
an example, if the floe in jar 5 appears twice as large as the
floe in control jar 6, record 2 for jar 5 under visual floe size
on the data sheet.
115
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12. Using a 100 ml pipet, withdraw a sample for turbidity measure-
ment one inch below the surface of each beaker.
13. a. Determine the turbidity of the coagulated sample in accord-
ance with Standard Methods or approved turbidimeters. Record
this on the data sheet.
b. Using the sample from the turbidity measurement, determine
the supernatant pH and record the pH on the data sheet.
14. a. Add alkaline agents if the plant normally adds these agents.
b. Addition of clay suspensions. Where clay is used to improve
the coagulation of low turbidity water, add a well-shaken
clay, kaolin or stone dust dosing suspension (prepared in
accordance with dosing solution and suspensions specifica-
tions) just before the coagulant. Then follow procedures
1 to 13.
c. Addition of activated silica. Where activated silica is
employed as a coagulant aid, use the activated silica sol
in amounts to give a dosage range of 1 to 7 mg/1. On the
average, activated silica dosages of 2 to 5 mg/1 yield
satisfactory results. Determine by experiment whether the
activated silica sol should be added before or after the
coagulant for best results. Then follow the procedure in
items 1 to 13.
Test Procedure for Lime-Soda Ash Softening Treatment
1. Determine the Hardness according to Standard Methods.
2. Follow steps 1 through 6 under Procedure for Coagulant Aid Treat-
ment.
3. Prepare each jar with the lime or lime-soda ash dosages re-
quired to soften the water in the actual plant.
4. Lower the stirring paddles into the beakers, start the stirring
machine and operate it for one minute at a speed of 80 revolu-
tions per minute.
5. Select a range of coagulant aid dosages so that the first beaker
will represent undertreatmant and the fifth beaker will repre-
sent overtreatment. The sixth beaker should be a control jar
to which no coagulant aid is to be added.
6. Reduce the stirring speed over the next 30 seconds to 30 revo-
lutions per minute, and continue stirring at the speed for 15
minutes.
7. Stop the stirring machine and allow the sample to settle for 5
minutes.
116
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8. Observe the floe sizes in each jar. Use the control jar floe
size as unity. Then visually compare the size of the remain-
ing floe particles in jars 1 to 5 to the control jar. As an
example, if the floe in jar 5 appears twice as large as the
floe in control jar 6, record 2 for jar 5 under visual floe size
on the data sheet.
9. Using a 100 ml pipet, withdraw adequate samples for turbidity,
pH and hardness measurements one inch below the surface of each
beaker.
10. a. Determine the turbidity of the softened sample in accord-
ance with Standard Methods or approved turbidmeters. Record
this on the data sheet.
b. Measure the hardness of the supernatant sample and record
on the data sheet.
c. Determine the supernatant pH and record the pH on the data
sheet.
Test Procedure Involving Activated Carbon Treatment
Use the carbon dosage required in the treatment plant. Add this reagent
to each jar and follow the same coagulation and softening techniques de-
scribed herein.
Test Procedure for Primary Coagulant (Polymer) Treatment
1. Follow steps 1 through 6 under Procedure for Coagulant Aid Treat-
ment.
2. Apply dosages of 0.4, 0.8, 1.2, 1.6 ppra, etc. to five 1 liter
water samples with mixer set at 100 rpm for 1-3 minutes for
initial floe formation. The sixth jar should be a control and
contain the primary coagulant, in the appropriate dosage, used
in the full scale plant. Record the flpc formation time on
the data sheet.
3. Reduce the mixer speed to 40 rpm for the remainder of the 15
minute period.
4. Discontinue stirring, remove beakers and start timing immedi-
ately for 5 minute settling time.
5. -Siphon a sample for turbidity and pH measurements one inch
below the surface of each beaker at the end of the 5 minute
settling period. Record this data.
6/ Compare the results to that of the present primary coagulant
(jar 6).
117
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Sludge Conditioning
The utility of polymers to enhance the dewatering characteristics of
purification and softening plant sludges is an important consideration.
Polymers may demonstrate applicability as sludge conditioning agents by
reducing total waste volumes prior to•additional treatment or ultimate
disposal.
A method to evaluate polymers as sludge conditioning agents, titled "Pro-
cedure to Evaluate Sludge Conditioning Agents"; and a "Sludge Conditioner
Data Sheet", were developed through the efforts of the water utility ex-
perts and the coordination of the Research Foundation. Figure 3 illus-
trates the data to be collected in this evaluation. A procedure titled
"Filter Aid Evaluation by Means of Filter Test Leaf", published by the
Nalco Chemical Company will also be used in the program.
Procedure to Evaluate Sludge Conditioning Agents
1. Place 1000 ml of well agitated sludge in each of six 1500 ml beakers
or suitable jar test equipment.
2. While stirring at 25 revolutions per minute, add polymer to five
beakers. Each of these five beakers should have a different polymer
dosage. One beaker will have no addition of polymer and will function
as a control.
3. Stir the beakers at 25 revolutions per minute for two minutes, then
stop the stirrer and remove the paddles.
4. Measure the height of the interface between sludge and supernatant
liquid in centimeters at 5 minute intervals and record up to 30
minutes.
5. Determine the turbidity and pH of the supernatant.
6. Insert filter leaf equipment (35 mesh Teflon cloth) %" above the
bottom of the beaker and, using a vacuum of 20 inches of mercury,
filter for 2 minutes.
7. Remove solids from filter leaf carefully and record weight.
8. Dry above solids for one hour at 105 C and record weight.
9. If necessary, repeat the above procedure using smaller incremental
dosages of polymer over the most favorable range.
Calculations
Wet Solids (7) - Dry Solids (8) x 100 = "L moisture
Wet Solids (7)
118
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FIGURE 3
SLUDGE CONDITIONER DATA SHEET
Reporting Utility ___^ Date
Type Sludge Sample Source
Polymer Tested Analyst
Jars 1234
CHEMICALS ADDED (mg/1):
1.
2.
3.
BASIC DATA:
Water Temperature ( C)_
Interface (cm)
5 min.
10 min. _
15 min.
20 min. _
25 min. _
30 min. _
Wet Solids (gr) _
Dry Solids (gr) _
% Moisture _
Supernatant Turb(JTU) _
Supernatant pH _
SLUDGE ANALYSIS AND REMARKS:
119
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Filter Aid Evaluation by Means of Filter Test Leaf
The Nalco publication states "a laboratory filter test leaf can be used
to determine the filtration aid chemical or chemicals necessary, approx-
imate dosages, order of addition in the case of more than one chemical,
the amount of agitation necessary in conditioning the sludge and the
filtration cycle (time), to obtain optimum sludge dewatering."
The apparatus required and the test procedure is detailed. Illustra-
tions and a sample calculation are provided.
Standard Filter Column Test Procedure
The filter column test may be utilized to further substantiate the floe
settling rate as determined by turbidity measurements in the jar test.
The filter column test also aids in determining floe strength and filter-
ability. A dense, rapidly-settling floe should resist pull-through at
filtration rates of 6 gallons per minute per square foot, and headlosses
of 6 feet and higher. Low turbidities in the filter effluent at high
rates and headlosses indicate a strong floe. Comparatively long filter
cycles and low turbidities indicate a highly filterable floe. This test
is useful for the evaluation of filter aids.
Evaluation of Filter Aids
Evaluation of a polymer to determine its suitability for use as a filter
aid requires two separate procedures. The first procedure involves the
"Simplified Jar Test Procedure" to determine the effectiveness of the
polymer in producing a good floe (as a primary coagulant) or the devel-
opment of a rapidly settling floe (as a coagulant aid). The effective-
ness of the polymer is determined by examining the basic data of the
jar test.
If the jar tests show a polymer to be effective in producing a good floe
and/or promoting a rapidly settling floe at economical dosages, then the
polymer should be evaluated as a filter aid. This evaluation is. accom-
plished through the "Standard Filter Column Test Procedure."
Procedure
Efficient performance of cationic, anionic, or nonionic polymers as
filter aids requires a considerably lower dosage than when polymers are
used as primary coagulants or coagulant aids. Dosage requirements as
filter aids range from 10 to 100 parts per billion (ppb).
1. The design of the filter column and specifications are shown in
Figure 4. The filter media may be of the type shown, or the sand
and coal may be replaced by 20 inches of #20 sand.
2. Polymers to be tested should be prepared at a solution concentration
such that the volume applied is approximately ten percent of the total
120
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FIGURE 4
EQUIPMENT FOR STANDARD FILTER COLUMN TEST
filter
influent
filter aid
application point
2.25 I.D. plexiglas
tube approximately
60 inches in height
with rubber stopper
top 6e bottom
media support;
perforated plate
-or U.S. 20 mesh
screen
backwash
effluent
filter
effluent
20 inches anthracite
coal (1.0 to 1.1 mm
effective size)
8 inches # 20 sand,
(0.45 to 0.55mm
effective size)
2 inches # 6x14
gravel
backwash
influent
valve
symbol
121
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volume being filtered. This insures good mixing of filter aid with
the water being filtered. Dilute solutions of polymers are not stable;
therefore, the polymer feed solution must be prepared fresh daily.
3. Filter column tests should be performed at filtration rates of 6 to
10 gallons per minute per square foot.
Example:
A filter rate of 6 gallons per minute per square foot equals 627 ml
per minute in a 2.25 inch inside diameter column. The volume of filter
aid required is 60 ml per minute. To feed 30 ppb, a filter aid solution
concentration of 0.31 mg per liter is needed.
4. The filter column should be backwashed for a period of 3 to 5 minutes
at approximately 2500 ml per minute prior to each test.
5.. A filter column test may be considered complete when turbidity values
determined each 15 minutes show that maximum filter efficiency has
been attained; that is, when the turbidity of the filtered water
remains at a minimum level. This level of turbidity is the measure
of the performance of the filter aid.
The results of the filter column test will be recorded on the "Filter
Column Data Sheet." Figure 5 illustrates the data to be recorded in
this evaluation.
A Cooperative Program
The cooperation of water utilities and suppliers of polymer products
is essential for the development of polymer evaluation methodology.
Several chemical suppliers were informed of the Foundation's centrally
directed program to organize, coordinate, and disseminate information
on new or modified water treatment technology. Each supplier was
informed of the Foundation's plans to publicize the applicability of
polymers, approved by the United States Public Health Service, that
have utility in the water utility industry.
Three types of polymers are of importance:
1. Primary coagulants, capable of replacing alum or ferric salts
and reducing total waste volume;
2. Coagulation aids, capable of partially reducing alum dosages,
reducing waste volumes and improving treatment efficiency; and
3. Sludge conditioning agents, capable of enhancing sludge Set-
tling characteristics and sludge dewatering ability.
A list titled "Approved Chemicals Available for Treatment and Disposal"
was sent to each supplier for review.
122
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to
FIGURE 5
FILTER COLUMN DATA SHEET
Sample No.
Sample Source
Sample Collection Date Sampler
Testing Laboratory
Testing Date Analyst
Filter
Filter Aid Rate
Test *Name Dosage gpm
No. & Type (ppra) sq ft
1.
2.
Sample Quality Data
PH
Temperature (WC)
Turbidity (JTU)
TDS (ppm)
TEST DATA
FILTER EFFLUENT
Filter Turbidities (JTU)
Influent Time after start of Minimum Turbidity
Turbidity filter run (min) Time after
(JTU) 5 10 20 30 (JTU) start (min)
.
3.
4.
5.
6.
Remarks :
* After name, designate type in parenthesis; (=) for cationir: (-) for anionic; (0) for nonionic.
-------
Approved Chemicals Available for Treatment and Disposal
The purpose of this phase of the Foundation's study is to evaluate USPHS
approved chemicals for effectiveness as primary coagulants, coagulant
aids, and sludge conditioning agents. The cooperation of chemical sup-
pliers was requested in providing the following information and concern-
ing each available product.
Technical Data:
A. Product Description F. How to Use Product
B. Advantages G. Methods of Feeding
C. Physical and H. Packing and
Chemical Properties Shipping Information
D. Applications I. Laboratory Test
Procedure
E. How It Works J. Range of Dosages
Samples':
The following request was directed to chemical suppliers:
The Research Foundation would like to be advised of the availability of
free samples. These samples would be tested at water treatment plants
of the Foundation's choice in accordance with your suggested applications."
"The plants we choose will represent a broad geographic area and have a
variety of raw water and waste characteristics. The testing personnel
will be experienced. The laboratory equipment required will be avail-
able.
Publicity;
"The utility of each chemical will be reported to the Research Founda-
tion. The staff will then prepare a paper about the tested polymers.
The approved paper will be published by the Research Foundation."
Acknowledgement;
"A. Please acknowledge our letter to let us know if your organi-
zation is interested in such a program."
"B. If your organization wishes to participate, please explain the
extent of cooperation your organization can provide."
Summary - Polymer Evaluation Program
124
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This program is designed to accomplish several purposes. Through the
use of the standard procedures to evaluate polymers as primary coagu-
lants and coagulation aids, the Research Foundation and participating
water utilities can systematically:
1. Define the type of data that illustrates the effectiveness of
primary coagulants and/or coagulation aid products. The method-
ology will provide a means of selecting various polymer prod-
ucts that warrant further investigation.
2. Produce a data sheet that has applicability in evaluating poly-
mers at both purification and softening plants.
3. Publicize the experience of a standard testing program, noting
the revisions in the procedures, and promote the findings for
the benefit of the water utility industry.
Through the use of the three documents to evaluate polymers as condi-
tioning agents for water treatment sludges, the Research Foundation and
participating water utilities can:
1. Determine the ability of polymers to concentrate water treat-
ment plant wastes and make the wastes more easily dewater-
able.
2. Determine the order of magnitude of final waste volumes that
can be expected due to the increase in dewatering ability of
the concentrated wastes.
3. Relate this conditioning to the use of polymers as a treatment
before landfill disposal or as a step in a by-product recovery
operation.
4. Publicize this waste conditioning procedure for treating sludges,
Through the use of the documents to evaluate polymers as filter aids, the
Research Foundation and participating water utilities can:
1. Define the data and procedures that are useful in illustrating
the effectiveness of filter aids.
2. Publicize the experience of the standard filter test procedure
for the benefit of the water utility industry.
It is realized that this polymer testing program is restricted by several
factors due to the degree of standardization specified. The importance
of several parameters will be evaluated in the program: the value and
significance of floe formation time, and a subjective visual floe size
test, the ability to read a representative interface in the settling
speed test, and standard speeds and times of mixing. The testing pro-
gram may require further modification before specific products can be
adapted for full scale use .
125
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Response from Chemical Suppliers
Each chemical supplier acknowledging interest in participating in this
program received copies of the testing procedures. The suppliers were
notified that a copy of the raw water characteristics of perhaps ten
participating water utilities would be forwarded to them. The Foundation
has enlisted four water utilities to date. The treatment plants are
not named. The special instructions of each supplier relating to each
product will be incorporated into the test procedure for that product.
Examples are: recommended dosage range; method of application (dry,
liquid solution); applicability of product (primary coagulant, coagulant
aid, sludge conditioning agent); frequency of mixing dosing solutions;
and other appropriate suggestions.<
The evaluation of this polymer testing program by water utilities is
still to be initiated. The Research Foundation anticipates that the
experience and constructive comments received will be utilized to modify
and improve the basic test documents. Such a testing program has never
before been conducted, and the program planned should be of mutual bene-
fit to the water utility industry and manufacturers of chemical supplies.
Manufacturers of Equipment
Many new or modified sludge treatment processes will require the use of
equipment that is principally designed for or adapted to water utility
wastes. Several water and waste water trade publications include yearly
product guides to define the availability of equipment from various
manufacturers.
The Research Foundation recognized that the identification of sludge
processing equipment and its relation to water treatment plant wastes
will be a useful reference. The accumulation and publication of infor-
mation on this equipment can provide a guide for water utilities to use
in individual plant studies or design.
Three trade publications were used to provide a list of manufacturers
supplying equipment that will have potential application in processing
water treatment plant wastes. These publications were:
1. Industrial Water Engineering Buyer's Guide - 1971
2. Water and Sewage Works, Reference No. 1970
3. 1970 - 1971 AWWA Yearbook
The types of equipment that the Research Foundation identified includes:
centrifugation, deep-well disposal, dewatering, pressure and vacuum
filtration, incineration, sludge concentrating, and sludge processing
equipment.
Over one hundred equipment manufacturers have been contacted. The manu-
facturers received background information on the nature of the informa-
126
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tion resource program. The Research Foundation plans the publication
of a guide to such equipment, describing its applicability for han-
dling water treatment plant wastes.
A form titled "Equipment Available for Treatment and Disposal" was pre-
pared for review by the manufacturers.
Equipment Available for Treatment and Disposal
Specifications for Reporting:
Please provide the fallowing information for each product your organi-
zation has available for water treatment plant waste dewatering, recov-
ery, and disposal operations. This must be limited to two 8%xll pages.
1. Graphic Illustration - Provide either a photo or drawing of waste
treatment equipment, indicating the physical dimensions of the treat-
ment unit (or units). If a specific process has been developed
which comprises a series of units, also provide a separate flow dia-
gram illustrating the sequence of operations beginning with waste
influent, and ending with waste concentrate and .supernatant disposal.
2. Operational Capabilities - Provide a general description of the basic
operation of the waste treatment device indicating the following
items:
A. Specific applications of the unit. For example, what type
of material can this device handle successfully? Is it
more suited to alum, lime, or iron - manganese sludges?
What concentrations of waste can the system handle? Exlain
how this unit is applicable and under what conditions it
will optimally operate.
B. Indicate tie type of results one may expect if this device
is utilized. For instance, "this unit can take 4% alum
sludge and produce a cake of 35% solids and a filtrate with
20 ppm suspended solids". Similarily, indicate estimated
results on other water plant wastes as determined by pilot
or plant scale operation of the treatment device.
C. Hydraulic Capacity - Provide information on the range of
hydraulic capacities that the unit can handle. Indicate
whether the device is more suitable for 'low range or high
range flows. List special hydraulic considerations, as
flushing sprays for cleaning the unit. As an example, "the
ABC unit produced a 10% waste concentrate that was 15% of
the waste influent flow."
D. Note specific locations where the unit has been, is being,
or will be used to treat water treatment plant wastes.
127
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3. Manufacturer Contact - The equipment publicity is expected to pro-
duce further inquiries among the readers of our Newsletter. To
facilitate the handling of these inquiries the following items will
be published.
A. Exact name of specific equipment.
B. Manufacturers name, address, and individual to be contacted.
The Research Foundation anticipates that those equipment manufacturers
that have not undertaken research and development of sludge handling
equipment for water utility wastes will realize the need for new .pro-
cesses and equipment.
Manufacturers of lagoon covers and linings were identified using the same
trade publications. These products may be useful in the lining of evap-
oration ponds for the treatment concentrated brine solutions from ion-
exchange softening facilities and desalination plants.
Responses to this survey have been received, and the accumulation and
inventory process of applicable sludge handling equipment is a continu-
ing operation. Interested manufacturers transmit material on products
they market in accordance with the report specifications previously
outlined.
The need for effective and economical sludge treatment equipment cannot
be overemphasized. The importance of developing equipment to handle the
water utility industry's wastes is becoming increasingly important, as a
result of new and more demanding pollution control legislation. As
an additional clearing-house function, the Research Foundation can publi-
cize and promote the application of appropriate equipment.
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SECTION X
REFERENCE ABSTRACTS
One function of the AWWA Research Foundation, as a central information
resource, is to abstract and index all available literature on the treat-
ment and disposal of wastes from water treatment plants. The abstracts
are prepared in accordance with the specifications of the Water Resources
Science Information Center (WRSIC). WRSIC reviews, edits, and stores
abstracts into a computerized system for future retrieval.
The Research Foundation selected and reviewed technical articles from
a variety of sources. These sources include: articles identified through
literature searches; articles transmitted to the staff from engineering,
research, and operating practice advisory group members; papers deliv-
ered at national and local AWWA section meetings; and articles listed in
the bibliography of the report titled "Disposal of Wastes from Water
Treatment Plants."
A series of reference abstracts is presented on the following pages. These
abstracts are capsule summaries of technical articles on water plant waste
treatment. Several of these abstracts will be of historic value. All
provide references to the development of pollution control technology.
129
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Kelly, Earl M., "Discussion of Reclamation and Re-use of Lime in Water Softening," AWWA
JOURNAL. 31. No.4 pp 671-675 (1939).
KeyWords: Sludge treatment, Lime recovery, Lime-soda ash softening
Manufacturers producing caustic soda by the lime-soda ash process employed calcining to
reclaim calcium oxide from the waste sludge. Ihe Stauffer Chemical Company reclaims 20
tons/day of calcium oxide using clarification, vacuum filtration, calcination, classifi-
cation, and slaking processes in a simply staffed operation. The raw water chemical
nature and treatment utilized restrict the re-use. Magnesium and inert material must be
eliminated to optimize the amount of calcium oxide in the calcined product. The pilot
study illustrates the success of the Lykkens-Estabrook process and uncovered operational
problems to be corrected.. The use of ferrous sulphate as" a coagulant increased filter rates
from 68 to 194 pounds /ft /day. The filter cake contained fine calcium carbonate and
magnesium hydroxide crystals and was too coarse for good flocculation or filtration.
Filtration rates increase with heating and thickening of the sludge according to labora-
tory studies. The coagulant can be eliminated. Sludge carbonation increases filterability.
Suggestions are made for future study on calcination and slaking.
Hoover, C.P., "Discussion of Reclamation and Re-use of Lime in Water Softening, "AWWA
JOURNAL. 31. No.4 pp 675-679 (1939).
Key Words: Sludge disposal, Lime-recovery, Lime-soda ash softening
Lime recovery reduces the cost of lime and sludge handling and generates carbon dioxide
for recarhonation in the softening facility. The process has not been adopted for five
reasons. Large plants located near waterways discharge their wastes into waterways.
Plants, softening river supplies of rapidly changing physical-chemical characteristics,
_would require intermittent calcining operation and mud-lime .-separation. The problem of
magnesium build-up has only recently been solved. Multiple-hearth furnaces are now avail-
able for calcining. Small communities are not interested in new procedures. 'Planned recla-
mation activities at the Columbus, Ohio plant in 1914 were curtailed due to various construc-
tion and lime cost changes and water quality changes. Laboratory studies show that magne-
sium hydroxide aids settling. Lime can be utilized as a coagulant for vacuum filtration.
At Oklahoma City, provisions are made to return lime sludge to the lime slaker for use in
slaking the quicklime. The mixture is fed to the mixing basins. Sludge disposal methods
include discharge to streams, lagooning, and reclamation by burning.
Gordon, C.W., "Calcining Sludge from a Water Softening Plant," AWWA JOURNAL. 36 No.11,
pp 1176-1177 (1944).
Key Words: Water softening, Flash drying, Calcination
Details are provided on a flash drying system that prepares calcium carbonate sludge for
marketing or calcining at two water softening installations. The advantages oC this two
stage counterflow gas drier are low gas discharge temperature and the minimization of
particulate emissions in the stack gas. Before drying, the carbonate sludge is ccntrifuRcd
to a 60% solids consistency and conditioned with the previously dried material. Operating
parameters and product characteristics are described for the process. The dried calcium
carbonate contains 0.5% moisture and can be bagged for marketing or calcined. The calcin-
ation system employed at the Marshalltown Water Works is evaluated in relation to the limit-
ations of the water plant operating requirements. These limitations include intermittent
operation, ability to produce calcium carbonate, freedom from dust nuisance, maximum thermal
efficiency, minimum building space, and adaptability to plant capacity variations.
130
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Hoover, Charles P., "Recovery of Spent Lime at the Columbus Water Softening and Purification
Works," AWWA JOURMAL. 3. No. 4, pp 889-896 (1916).
Key Words: Sludge treatment, Lime recovery, Lime-soda ash softening
The release of calcium carbonate sludge to the Scioto River during low flow in the summer
months created sludge deposits and legal problems between Columbus and riparian property
. owners. Maximum sludge production occurs in the summer with maximum river hardness, ampli-
' fying the problem. No objection to discharging sludge to the river exists in the fall and
winter months when the stream is muddy. The proposed recovery system includes sludge thick-
ening, suction filtering of the continuous type, and rotary kiln burning. Construction
details of the furnace are provided. Operating and cost data are presented for the calcium
oxide product. The sludge treatment facilities will process lime-soda ash softening sludge
and limestone from a nearby quarry alternately for six month durations. A description of
the suction filter is given. The settleability of the sludge, build-up of impurities,
replenishment of lime, disposal of extra lime and planned additions to the existing plant
are discussed.
Sperry, W.A., "The Liine-Sof tening of Water and the Use of the Sludges as an Aid Thereto,"
AWWA JOURNAL, 6, No. 2, pp 215-229 (1919).
Key Words: Water softening, Sludge recirculation
The lime-softening process contains several variables that must be considered in producing
a stable water. Among these parameters are the residual hardness, colloidal magnesium
structure, reaction temperature, reaction time, lime requirements, and coagulant addition.
These parameters must be balanced to eliminate filter sand incrustation, lime damage to water
meters, coating of service mains, gates, and valves, and scaling of hot water, gas, and
furnace heaters. A water softening method that compensated for insufficient settling
basins and could eliminate distribution system problems without increasing the use of an
alum coagulant was considered for Grand Rapids. Sludge recirculation was tested to remove
colloids, save alum, and stabilize the water. Laboratory results on contact time, recir-
culated sludge volume, coagulant addition, and yearly effectiveness are presented. This study
enumerates advantages and disadvantages of plant-scale sludge recirculation testing. Further
testing was suggested after these preliminary investigations.
Aultman, W.W., "Reclamation and Re-use of Lime in Water Softening," AWWA JOURNAL. 31,
No. 4, pp 640-671 (1939).
Key Words: Sludge treatment, Lime recalcining, Available lime
This report illustrates the economic benefits of reclaiming calcium oxide at a lime-soda
ash softening installation in Boulder City, Nevada. The process water is Colorado River
water, high in magnesium content. The Lykken-Estabrook process was investigated because
tthis method eliminates increased magnesium content in the reclaimed lime. A predominantly
'calcium carbonate sludge is pumped to a vacuum filter for dewatering. The filter cake is
.fed to a multiple-hearth furnace for calcining. Operation and construction details are
provided for the furnace and vacuum filter and for the chemical feeding and slaking,
iflocculation and clarification equipment. The percent of recovery, defined as the available
lime to total calcium (CaO), averaged above 90 percent. Data are presented for a gravi-
metric analysis of a composite calcined lime product. Fuel and power consumption require-
ments are prepared for the experimental furnace. The test program is summarized. The
direct reuse of the reclaimed lime is not suitable with this water.
131
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Pederson, H.V. , "Calcining Sludge from a Softening Plant," AHWA JOURNAL. 36. No. 11,
pp 1170-1175 (1944).
Key Words: Water softening, Calcining, Stationary flash type calcining furnace
This study describes the trial and error construction of ta stationary flash type calcining
furnace and the utility of the recovered calcium oxide at a water softening installation.
Calcining experimentation was initiated due to a poor market demand for dried calcium car-
bonate. Problems associated with sludge characteristics and furnace design are discussed.
A system that handles 700 pounds (dry carbonate) per hour at a 2000° F initial combustion
temperature was developed after eight furnace modifications. Carbonate sludge, withdrawn
from the clarifiers, is pumped to a storage tank. The sludge is gravity fed to « Bird
^centrifuge for dewatering. The concentrated sludge is flash dried and lifted to a cyclone
from which it is screw fed to the combustion chamber. Five tons of calcined lime were
produced and a plant scale study initiated. Sludge cake impurities were less than 15%
based on thirty days operation with calcined lime. Operating data and benefits for reclaimed
lime are discussed.
Nelson, F.G., "Recalcination of Water Softening Sludge," AHWA JOURNAL. 36. Noill,
pp 1178-1184 (1944).
Key Words: Calcium carbonate, Calcining
This study shows that the recovery of lime from a partially dewatered calcium carbonate
sludge can be economical if the magnesium content of the recycled product is controlled.
A correlation between the settling rate and the concentration of a calcium carbonate sludge .
is suggested. Four factors affecting the settling rates of calcium hydrates are presented.
Operating data on the dewatering of a calcium carbonate sludge at the Findlay, Ohio plant
by a Bird contimous centrifuge are listed in graphical and tabular form. The parameters
investigated include solid feed rates, cake moisture, cake recovery, temperature, and
power considerations. The centrifugation process can produce a 500 pound per hour (dry
solids) cake of 61% solids. The recovery was 757. of the feed solids. The magnesium
.content was reduced in the recovered cake. Higher solids capacities and recoveries are
possible with carbonated sludges. Data on centrifuged softening sludges are presented
.for the Marshalltown, Iowa and Wright Aeronautical Corporation softening facilities.
Sheen, R.T., and Lammers, H.B., "Recovery of Calcium Carbonate or Lime from Water Soft-
ening Sludges," AWWA JOURNAL. 36. No.11, pp 1145-1169 (1944).
Key Words: Calcium carbonate, Water Softening, Sludge disposal, Lime recovery
This study describes the development of two industrial water supply systems including
sludge treatment processes and economics. Detailed process descriptions are presented for
the selective calcium softening installation of the Wright Aeronautical Corporation. Data
are tabulated for the design parameters used for the softening basin, chemical feeders,
filters, recarbonation system, and chemical unloading and storage facilities. Cost compar-
isons show the advantages of calcium carbonate production to lime recovery. A flow diagran
illustrates the calcium carbonate drying sequence. The sequence consists of thickening,
centrifugation, and flash drying. A Bird centrifuge with a capacity of 4000 to 6000
pounds (dry solids) per hour is used. The product quality including market price, color
comparisons, particle size, and purity is discussed. A process description and flow
diagram are provided for the selective calcium softening installation of the Columbia
Steel Corporation. Economic considerations of lime reclamation at this facility are tabu-
lated. The advantages and disadvantages of the wedge furnace and rotary kiln calcination
units are discussed.
132
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AWWA Committee Report, "Disposal of Water Purification anf Softening Plant Wastes, "
'AHWA JOURNAL.39. No.12. pp 1211-1223 (1947).
Keywords: Lagoons, Evaporation, Brine Disposal, Lime-soda ash softening, sodium zeolite
softeners
The purpose of this report Is to review the methods and practices utilized to handle
wastes from lime and lime-soda ash softening plants, sodium zeolite softening install-
ations and filter washwater operations. The report contains data on the chemical char-
acter of softening, filter washwater, and brine stream wastes. The softening sludge
disposal methods considered include lagoon storage, discharge to water courses, drying
and dewatering, and lime reclamation. Information is provided on proposed lime recal-
cining facilities and equipment and the advantages and problems associated with this oper-
ation. The pollutional effects of wastes discharges to watercourses and sanitary sewers
are presented. The controlled dllnMon of brine discharges to a watercourse is considered
more practical than disposal by uncontrolled dilution, evaporation ponds, and brine disposal
wells. Several disposal schemes are suggested for filter washwater. Special consideration
is given to the sedimentation of wastes at the Washington Surburban Sanitation District
Willis School Plant.
AWWA Committee Report, "Disposal of Softening Plant Wastes, AWWA JOURNAL. 41. No. 9,
pp 819-836 (1949).
Key Words: Brine disposal, Waste dilution, Lagoons, Lime reclamation
The pollutional effects of discharging lime and lime-soda sludge and sodium zeolite soft-
ening brine wastes to watercourses Is discussed. Data on the physical and chemical char-
acteristics of softening sludge and a brine waste sample has been presented. The results
of a sludge disposal survey distributed to 21 states representing 371 lime or lime-soda
softening plants are summarized. In addition to sludge disposal to lagoons and discharge
to watercourses, the utility of municipal softening sludge to provide chemical coagulation
In the primary treatment process at the Daytona Beach, Florida sewage treatment plant is •
referenced. Cost comparison data are presented for the Miami lime reclamation plant.
Brine disposal techniques discussed Include controlled and uncontrolled dilution in natural
watercourses, evaporation ponds, and brine disposal wells. A summary of state health
department responses to a survey querying zeolite brine discharges procedures Is presented.
An outline Is prepared on how to plan for brine disposal.
Lawrance, C.H., "Lime Sludge Recirculation Experiments at Vandenberg Air Force Base,"
AWWA JOURNAL. 55. No. 2, pp 177-192 (1953).
Key Words: Water softening, Sludge recirculation, Lime-soda ash softening
This paper describes the testing of sludge recirculation as a treatment modification to
eliminate the carryover of lime-soda ash floe, deposition of solids in clarlfler effluent
channels, and Incrustation of filters at a water softening facility. Jar tests were con-
ducted on sludge samples from the flocculators, clarlfiers, and drying beds. The suspended
solids concentrations were varied from 1 to 6%. These tests Illustrated that sludge recir-
culation reduced the hardness, phenolphthalein alkalinity, and Langelier saturation index
significantly when compared to raw water receiving only softening chemicals. The optimum
suspended solids concentrations were from 5 to 6%. Fresh flocculator or cjarifier sludge
had more utility than dry sludge. The plant scale testing confirms the benefits of the
jar tests. The optimum sludge source, optimum suspended solids concentrations, and sludge
hydraulic characteristics were determined in the sludge recirculation'experiments. Data
are presented on the sludge carryover, softening efficiency, sludge volume index, and
sludge composition in plant testing. A full-size recirculation system was put into plant
operation.
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AHWA Committee Report, "Purificatio'ii Plant Waste Disposal." AWWA JOURNAL. 45. No.11,
pp 1225-1237 (1953).
Keywords: Sludge disposal, Regulations, Filter plant, Coagulation basin
The purpose of this study is to provide a general review of the current methods employed
to treat and dispose the wastes generated at water filtration and coagulation facilities.
The physical- and chemical character of the waste to be expected in grit chambers, plain
settling or sedimentation besins, coagulation and sedimentation basins, and filter wash-
water are defined. A questionnaire concerning current sludge disposal procedures' and
state regulations regarding waste dispce al to water courses was sent to the chief sanitary
engineer of each state and territory. The survey was systematically analyzed with respect
to the arrangement of the purification plants, the sludge removal and disposal techniques,
and filter washing disposal procedures. The utility of sludge as a fertilizer and the
handling of sludge for landfill is discussed. Consideration is given to the biological
effect or waste discharges to watercourses and the criteria established by the states to
regulate these discharges. ,
Waring, F.H., "Methods of Lime Softening Sludge Disposal" AHWA JOURNAL. 47. No. 2, pp 82-
€4 (1955).
Key Words: Sludge disposal, Coil spring vacuum filter, Recalcining
The techniques employed to dispose of lime sludge from Ohio's 130 municipal lime-softening
facilities include discharge to streams, dewatering in lagoons or sludge drying beds,
discharge to abandoned quarries or city sewers, and vacuum filtration. Lagoons and drying
beds are generally aesthetically undesirable and require periodic costly cleaning. Each
of these dewatering methods are contingent upon available and isolated land sites. Detri-
mental effects of stream discharge included increasing the river pH, creating visible
white turbidity, and depositing sludge blankets that may inhibit natural stream bilogical
activity. The Ohio Water Pollution Control Board has classified lime sludge a pollutant.
Recalcining is practiced in Miami, Florida, and Marshalltown, Iowa. A spring coil vacuum
filter was installed in Gallion, Ohio, that produces a lime sludge cake of 8 pounds/ft^/hr
(dry solids) with a 6 to 7 inch mercury vacuum. Sludge thickening is recommended prior
to filtration. The filtrate is economically recycled. The cake of 70% moisture can be
further dried and used as a sanitary landfill. Vacuum filtration has utility for both
sewage and industrial applications.
Krause, F., "Value of Sludge Calcining," AWHA JOURNAL. 49. No. 3, pp 327-330 (1957).
Key Words: Cost analysis, Calcining, Operating difficulties
Successful sludge calcining depends upon tie sludge quality. Settling and clarification
prior to softening may remove inert materials as silica and clay to increase sludge
purity. A change in pH or solids separation by centrifugation can reduce magnesium
contents. Pure calcium carbonate produced good lime. The carbonate slurries may harden
in storage. Details of lime reclamation at Lansing, Michigan are provided. The process
sequence includes sludge carbonation, thickening, centrifugation, conditioning, drying,
burning and storage. Carbon dioxide is supplied from the calcining process. The drying
gases are scrubbed. A cyclone distributes dried solids to storage and to mixing facilities
to condition the sludge for drying. The calcium carbonate is calcined on a fluidized air
stream in a rotary kiln furnace. Lime production versus cost is graphically presented.
Operating difficulties discussed include proper equipment sizing, minimization of fuel
requirement while maintaining proper furnace temperatures, and the need for continuous
operation.
134
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.Eidsness, F.A. and Black, A.P., "Carbonation of Water Softening Plant Sludge," AWWA JOURNAL.
49, No. 10, pp 1343-1351 (.1957).
Key Words: Magnesium hydroxide, Carbonation, Settleability
The Hoover, Lykken-Estabrook, and centrifugation processes are available techniques to
reduce the magnesium content of softening sludges. Sludge volume is dependent upon the
physical characteristics of the suspended solids and the treatment process. The sludge
settleability decreases and volume increases as the magnesium content increases. Sludge
Carbonation before centrifugation reduces the magnesium content by converting the hydroxide
of magnesium to a soluble bicarbonate. Laboratory and pilot plant testing centered on
determining carbon dioxide requirements for the hydroxide to bicarbonate conversion,
the effect of detention time, the possible dissolution of calcium carbonate, and the improve-
ment of sludge settleability and concentration due to Carbonation. Magnesium removal curves
are plotted for various carbonation levels and detention times utilizing sludge from the
Dayton, Ohio, and Gainesville, Florida softening facilities. Carbon dioxide selectively
converted 967. of the magnesium hydroxide to magnesium bicarbonate in 15 minutes. Magnesium
hydroxide in raw and carbonated sludges influences sludge settleability and volume.
Nelson, F.G., "Discussion of Carbonation of Water Softening Plant Sludge," AWWA JOURNAL.
49, No.TO, Ppl351-1354 (1957).
KeyWords: Magnesium, Carbonation, Settleability
This discussion describes the testing equipment and procedures utilized to evaluate the
carbonation of softening sludges at Dayton, Ohio, and Lansing, Michigan. Carbonation
is a simple and economical procedure to significantly reduce the magnesium concentration
^nd improve solids settleability of softening sludge before dewatering and recalcination.
iData are presented characterizing settling and magnesium removal efficiency at both facili-
ties. Magnesium hydroxide was converted to the bicarbonate form at Dayton and to th»
normal carbonate form at Lansing. Preliminary investigations show that solid-bowl centri-
fugation may remove magnesium from the sludge cake at Lansing. Laboratory and pilot plant
tests are recommended before designing carbonation and thickening equipment for magnesium
removal and sludge thickening at other installations.
Doe, P.W., "The Treatment and Disposal of Washwater Sludge," Paper of Fylde Water Board.
•(1958).
Key Words: Sludge disposal, System parameters
This study describes an approach to dewater sludge to a solids concentration suitable for
handling and disposal. Water clarification sludges vary in composition as well as quantity
and concentration. Treatment systems must be flexible. Test results are given for freezing,
filter pressing, porous ceramics filtration, and electroosmosis processing of clarification
sludge. Experimentation shows preliminary thickening of sedimentation basin sludge to 67.
solids should be considered. A thickening tank with a slow stirrer was designed. System
parameters investigated include stirring speed, raw sludge concentration, sludge nature,
tank shape, mesh used, paddle shape, temperature, and scaling effect. Preliminary test
conclusions are enumerated. Washwater sludge can be thickened economically by slow stirring
to 57. solids in a relatively short time. Further testing of filter pressing, heat treat-
ment under pressure, and freezing was suggested to handle the prc-thickened sludge.
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Crow, W.B., and Wertz, C.F., "Techniques and Economics of Calcining Softening Sludges,"
AWWA JOURNAL. 52, No. 3, pp 322-332 (1960).
Key Words: Cost comparisons, Water softening, Recalcination
The purpose of this study is to provide a review of recalcination technology and identify
economic factors to be considered. These factors include reclamation plant capacity, lime
transportation costs, sludge disposal expense, carbon dioxide cost, and fuel and power costs.
^Details of the rotary kiln, pellet-seeding, and flash calciner processes are presented and
'referenced to six water softening installations. A comprehensive description of the 80 ton
capacity quicklime Miami lime reclamation plant is presented. Before rotary kiln recalcination,
their lime sludge is thickened to 30% solids and dewatered by centrifugation to 66.8% solids.
Carbon dioxide generated in the kiln is reused and the stack gases are scrubbed to minimize
air pollution. Production, lime utilization and profit return on investment cost comparisons
are tabulated for the first seven operating years. Plans to construct a lime reclamation
facility at the Alexander Orr, Jr. Water Treatment Plant are disclosed.
Doe, P.W. and Benn, D., and Bays, L.R., "The Disposal of Washwater Sludge by Freezing,"
Institution of Water Engineers JOURNAL, 19, No. 4, pp 251-175 (1965).
Key Words: Sludge disposal, Freezing, Washwater sludge
This study describes design, layout, and operating data for a sludge treatment sequence.
Clarification sludge was thickened by slow stirring and retention basin storage before
freezing and thawing. Design principles include low capital costs, minimum building space,
and future automatic operation of this facility. Plant testing concentrated on improving
sludge thickness, freezing efficiency, and thawed sludge supernatant. Operational considera-
tions include settling tank efficiency, sludge build-up, stirring speed variation, sludge
extraction, retention tank design, and freezing process cycles. Testing of the freezing
equipment generated design improvements that were incorporated into a new plant. Ignition
of the thawed sludge followed by alum recovery at the Stocks plant concentrated the iron and
showed other disadvantages. Frozen sludge lagoon effluent was mixed with sedimentation tank
effluent to meet stream standards. Capital depreciation (plant, building), operation,
maintenance, and power consumption costs are given. Recommendations are made for future
treatment work.
Aultman, W.W., "Introduction to Waste Disposal - Water Treatment Plants," AWWA JOURNAL, 58,
No. 9, pp 1102-1103 (1966).
Key Words: Waste disposal, Pollution control
More wastes are generated in the production of water for an ever growing population. The
value of land for waste disposal facilities is steadily rising. Watercourses are needed
for supply and not for waste transport. Increasing wastes volumes often impair water quality
in river, lakes, and groundwater. The Federal government has enacted the Water Quality Act
of 1965 to control discharges. An AWWA Committee was organized to study and report on the
Disposal of Wastes from Water Purification and Softening Plants. This Committee's reports
are enumerated. The Committee notes an increasing awareness of the public for pollution
abatement and improved water quality. Their work concludes that lands are limited for
ponding and lagooning wastes due to concentrated population centers. Local waste disposal
research is suggested to provide treatment that will comply with state and federal pollution
control legislation.
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Howson.L.R., "Problem of Pollution," AWWA JOURNAL. 58. No. 9, pp 1104-1106 (1966).
Key Words: Waste disposal, Natural resources utilization
Each water treatment facility has waste disposal problems unique to itself. The magnitude
of filter washwater and sludge disposal problems depends on the character and volume of the
wastes and the assimilative capacity of the waste receiving watercourses. Water pollution
is factual and depends on the effects discharges have on the stream and the degree of water
quality degradation. Two examples illustrate the perspective in determining pollution.
Sludge disposal to rivers may be insignificant during high river flow periods. Wash water
can be properly diffused at outfalls, returned to the raw water at the mixing basins, and
settled, with the liquid supernatant returned to the stream. The topic of waste discharges
must be approached realistically. The utilization of natural resources for waste disposal
must be considered when downstream users are not significantly affected.
Poston, H.W., "Federal Pollution Control," AWWA JOURNAL, 58, No. 9, pp 1108-1112 (1966).
Key Words: Water quality, Water pollution control program
The American Water Works Association issued a policy statement supporting a national program
to preserve high-quality water supplies and reasonably restore the quality of polluted water
supply sources. The Federal program provides aid to communities for waste treatment construc-
tion, enforces state and interstate pollution regulations, provides research on water quality
problems, utilizes a river basin approach, promotes water quality standards, and provides
technical assistance. Pollution control legislation was introduced in Congress to establish
funds for sewage treatment plant construction, demonstration of new or modified water purifi-
cation methods, demonstration of joint municipal-industrial waste treatment, and utilization
of a river basin approach to pollution abatement. Water utility discharges are water pollution
sources. These wastes impair water quality. The AWWA policy statement sets a trend for the
water utility industry to control waste discharges.
'Lyon, W.A., and Lazarchik, D.A., "Influence of State Quality Standards," AWWA JOURNAL. 58.
No. 9, pp 1106-1108 (1966).
A pollution concerned society has been instrumental in urging stronger state and federal
pollution control legislation. The state health agency regulates pollution legislation to
protect streams in Pennsylvania. Water utility wastes are considered as industrial wastes.
Waste sources include filter washwater and settling basin sludges. Thes« wastes contain .
suspended solids and chemically coagulated floes. Water quality discharge parameters include
a 200 p p m suspended solids limit, carbon removal from washwater, chloride and sulfate~
.•concentrations of 250 p p m limit, soluble iron and manganese concentration of 7 p p m , and
undissolved iron and manganese concentration conforming to the suspended solids limit. The
concentrations are based on low flow conditions, 10% of the flow-duration curves. The Clean
'Streams Law resolves to restore streams to clean and unpolluted conditions. Streams uses
are enumerated. Waste transport is not a primary use. The law has been enforced since 1959
'at new and modified water treatment plants.
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'Remus, G.J., "Detroit's Waste Water Problems," AWWA JOURNAL. 58. No. 9, pp 1112-1116 (1966).
Key Words: Reclrculated water, Waste wash water
The City of Detroit, Michigan, utilizes four wash water disposal techniques at its treatment
facilities. These methods are direct discharge to the river, discharge to a sanitary sewer,
recirculation and reuse of washwater, and clarification before discharge to a storm drain.
Settling basin sludges and sanitary wastes are discharged to sanitary sewers. Data are
presented on the flow characteristics and silt loading of the Detroit River and the quanti-
tative and qualitative waste characteristics of the four treatment facilities. The waste
washwater discharged to the river disperses within 25 feet, leaving no sludge deposits.
Downstream water quality is unimpaired as the waste is chemically unharmful and bacteriologi-
cally superior to the raw water due to chlorination. This report states that economics govern
the disposal method when these wastes have no detrimental effect on public health and down-
stream users. Limited cost, design, and bacteriological data are presented. The disadvantages
of recycling are discussed.
•ORSANCO Report, "Control of Wastewater Discharges from Water Purification Plants on the Ohio
•River," Staff Report. (1968).
!Key Words: Water purification plants,Pollution abatement, Basin sludge, FLiter washwater
This report describes waste discharge practices of water purification plants on the Ohio
River. Highlights of ORSANCO member states waste control policies are provided. The effects
of discharging sediment from raw water basins, sludge from settling basins, filter backwash
water, and ion-exchange regeneration wastes from coagulation and softening plants to the
Ohio River are described. The detrimental effects of these wastes include the formation of
sludge deposits that inhibit aquatic life cycles,an increase in the river mineral content,
and esthetic objections caused by color or suspended material. The report shows that ORSANCO
states will require the construction of waste control facilities at both new purification
plants and enlarged or improved existing treatment plants. A questionnaire concerning water-
plant waste control policies was distributed to the ORSANCO members. A summary of this
survey is included.
Bishop, S.L., and Fulton, G.P., "Lagooning and Freezing for Disposal of Water Plant Sludge,"
Public Works, 99. No. 6, pp 94-96 (1963).
Key Words: Lagoons, Freezing, Waste sludge storage, Water filtration plants.
The treatment of gelatinous hydroxide sludge and filter washwater from water filtration
plants is a. recognizable problem in pollution abatement. Alum recovery, vacuum filtration,
and discharge of these wastes to sewerage systems are among some available treatment schemes.
The advantages and disadvantages of these processes are discussed. Lagoons are shown to
effectively settle and thicken sludges from the coagulation phase of the clarification process.
Design parameters and sludge characteristics are given for the Shoremont Water Treatment Plant.
In addition to providing waste sludge storage, the utility of lagoons for freezing the sludge as
a treatment is discussed. The freezing process releases the water of hydration from hydroxide
sludges and concentrates the sludge significantly upon thawing. This process is economical
in climates where natural freezing could be used. At the Shoremont plant, the sludge con-
centration increased from 3.5 to 17.5% and the volume decreased considerably after freezing. '
Design considerations and operating procedures for lagoon-freezing operations are presented.
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Benn, D.,and Doc, P.W., "The Disposal of Sludge by the Freezing and Thawing Process," Paper
of_Fylde Water Board, (1969). ~*~
Key Words: Freezing, Thawing, Aluminum hydroxide sludge
This study defines the physical and chemical constituents of clarification sludge and an
effective sludge treatment process. Clarification sludge is a thick jelly-like colloidal
liquid containing organic, inorganic, and coagulant chemical material. The sludge is variable
in color, thixotropic, and the organic material can be anaerobically digested. Sludge
treatment processes include coagulant recovery, thickening, vacuum filtration, centrifugation,
filter pressing, freezing, lagooning, and disposal into sewers or rivers. The steady slow
freezing of sludge to 15°F creates pure ice crystals. These crystals are necessary for
effective liquid-solid separation during thawing. A complete description of the freeze-thaw
cycle, using ammonia as a refrigerant, is given. Latent heat is recovered and the thawed
mixture flows by gravity. Important design considerations are listed. The process is clean,
efficient, automatable, and produces an end product that can be handled. Cost considerations
include high capital, operating and maintenance costs, plant depreciation costs, and power
costs. Costs are listed for four freezing installations.
Sanders, P.V., "How We Solved Our Lime Sludge Disposal Problem," Public Works, 100. No. 2,
pp 88-89 (1969).
Key Words: Softening plant, Solids disposal method
The City of Sioux Falls required additional sludge drying bed capacity to handle 29 tons
(dry weight) per day of calcium carbonate sludge. Since the expansion of existing facilities
near to the softening plant was impossible, plans were made to pump the sludge 4550 ft to an
elevation of 50 ft and provide gravity flow 1900 ft at a 5% grade. The waste generated dur-
:ing the construction of the lagoons, providing 20 year storage, is being disposed of in a
'nearby drainage ditch. Farmers and fertilizer companies are removing this material as needed.
^The sludge is pumped by a 4-inch Model D L Weraco pump in a 6-inch pressure line to low eleva-
tion areas at present. The line to the new facilities will be kept free by periodic flushing
with a clean water service. The Water Department is working on new disposal applications
for the sludge including uses as soil stabilizers, crop and pasture fertilizers, and soil
sweeteners.
Sutherland, Earl R., "Treatment Plant Waste Disposal in Virginia," AWWA JOURNAL. ',6-1, No. 4,
pp 186-189 (1969).
Key Words: Sedimentation basin, Filters, Water treatment plant wastes, Filter washwater
As part of a stream standards implementation program for the control of pollution caused
by sewage, industrial, or other wastes, the Virginia State Water Control Board will provide
specific provisions for the control of water treatment plant wastes. Four general water
quality stream standards are provided. The study states that water plant waste character-
istic vary considerably with raw water quality, treatment processes, cyclic filter backwashing
and sedimentation basin cleaning. Bacteriological problems were not significant, but waste
solids concentrations and turbidity were extremely high. The advantages of waste lagooning,
washwater recirculation, and sand bed drying ire presented. Design parameters and operating
and capital costs are referenced to wastewater characteristics and plant capacity. Waste
treatment by vacuum filtration, centrifugation, alum recovery, recalcining, and discharge to
sewage treatment plants is considered. The board's policy is expressed and the applicability
of this policy is discussed for new and existing water plant facilities.
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Krasauskas, J.W., "Review of Sludge Disposal Practices," AWWA JOURNAL. 61. No. 5,
pp 225-230 (1969).
Key Words: Sludge disposal, Water treatment plant wastes,Filter washwater
This review indicates that additional legislation will implement the Water Quality Act
of 1965 and control the discharge of water treatment plant wastes to natural watercourses.
The Washington Aqueduct Division conducted a survey of United States water treatment plants
that showed that filter washwater and basin sludge were discharged to surface waters in the
majority of plants. A list of research centers and treatment facilities studying treatment
processes is provided. The study shows that the sludge composition of water plant wastes
are highly dependent upon the source water and the chemicals utilized for treatment. Refer-
ence is made to several sludge -disposal methods. These methods include discharge to streams,
storm sewers and sanitary sewers, settling in lagoons, sludge freezing, centrifugation,
vacuum filtration, filter pressing, wedge wire filtration, sand drying beds, and barging.
Some design parameters, equipment operating characteristics and cost data are given for actual
installations.
Doe, P.W., "The Disposal of Sludge from Water Treatment Plants," Paper of Fylde Water Board.
Key Words: Sludge disposal, Dewatering, Sludge reduction methodology, Prevention principles
This study relates the sludge disposal problem to economic and operational considerations
while enumerating sludge reduction methods to alleviate the potential pollution from these
wastes. The English Rivers Acts provide monetary penalties for discharging washwater,
settling basin and lime sludge, and ion exchange regenerant to watercourses. Sludge preven-
tion principles are enumerated. The choice of the process and raw water source can lessen
sludge quantity or concentration. The advantages and disadvantages of lamella sedimentation
basins, flotation tanks, slow stirring thickeners, and polyelectrolyte sludge conditioning are
discussed. Lime and alumina recovery are referenced to specific plant locations. Design, oper-
ating, maintenance, and design considerations are mentioned for vacuum filtration, filter
pressing, freezing and thawing, lagooning, disposal into sewers or rivers, and centrifugation
processes. No universal treatment solution exists. Systems should be flexible and research
information coordinated. '
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SECTION XI
INFORMATION RESOURCE DEVELOPMENTS
The state-of-the-art report on the "Disposal of Wastes from Water Treat-
ment Plants, prepared by the Research Foundation in 1969, defined two
areas in need of research. The first area was the generation of infor-
mation that would be generally applicable to the water utility industry.
This included the development of data on waste quantity and quality, and
the suitability of waste treatment technology to effectively handle vari-
ous types of wastes.
The second important area was the need to develop new or modified treat-
ment technology to solve specific problems. Among the primary consider-
ations, was the establishment of a uniform methodology to properly eval-
uate the dewaterability of sludges, using different treatment processes.
Information Clearing-House
The Report also recommended the establishment of a central information
resource to coordinate information on continuing, research and demonstra-
tion projects. The information clearing-house could oreanize, coordi-
nate and disseminate research and development information to provide the
direction for an industry-wide pollution control effort.
The AWWA Research Foundation has undertaken action to become a national
clearing-house of information on the control of pollution caused by
water treatment plant wastes for the benefit of the water utility indus-
try. The first year of operation has been devoted to the simultaneous
development of the structure of a clearing-house system as well as to
the organization and coordination of information relating to sludge
treatment and idsposal methodology.
It is intended that the publication of current information on pilot and
plant scale research will accelerate the development and application of
waste treatment technology for the entire water utility industry. The
Foundation has attempted to identify projects completed, in-progress,
or projected that will provide valuable reference material for individ-
ual researchers. ,
The cooperation of researchers, dealing with waste treatment problems
of water utilities, is necessary for the overall development of a compre-
hensive inventory program. The failures and successes of the treat-
ment technology require critical reporting to allow the systematic inves-
tigation of new or modified treatment alternatives. In this way, money
and time will be channeled into constantly identified gap areas of re-
search needs.
Related Projects
The Research Foundation has become involved in two related projects that
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may significantly alter the waste character of treatment plants. The
first project is a study awarded to the Research Foundation by the Office
of Saline Water, U.S. Department of the Interior. The program, titled
"A Study of Using Desalting Techniques for the Improvement of the Qual-
ity of Water Supplies", will identify and evaluate applications of new
processes which may be used by municipal water utilities to improve
water quality. The wastes from desalting processes principally consist
of concentrated brine solutions and pretreatment sludges from coagula-
tion processes.
Desalination processes have potential applicability in making available
new potable water supplies, especially in areas that must rely on brack-
ish supply sources. Methods for the successful disposal of concentrated
brine solutions will be necessary before municipalities can readily employ
desalting technology. The information resource nrogram will coordi-
nate efforts between the two programs in relation to studies on the dis-
posal of desalting facility wastes.
The second project is jointly funded by the Water Quality Office of the
E.P.A.; City of Montgomery, Alabama; and the AWWA Research Foundation.
The demonstration project is titled "MgCO^ Coagulation in Treatment of
Potable Water." This study involves a completely new integrated process
of water treatment and will evaluate the efficiency and effectiveness of
magnesium carbonate as a recycled coagulant to replace alum for the remov -
al of turbidity and color. Data will be accumulated and incorporated
into the information resource program.
Surveys Conducted
Two surveys were initiated through the Research Foundation. The first
survey was sent to the state, interstate, and territorial authorized
regulatory agencies. The purpose of this survey was to determine new
information on the treatment requirements, disposal techniques, and
responsibility of supporting and conducting research. The survey illus-
trated that the disposal of water treatment plant waste's to watercourses
would be unacceptable in the majority of fetates unless these waste
discharges could conform to the water quality or effluent standards set
forth by each agency.
The second survey was sent to water treatment facilities in the United
States and Canada. The purpose of this survey was to identify and
inventory basic data (qualitative and quantitative)on waste handling
and production. In conducting this survey, the need for the development
of standard testing documents for sampling and analyzing water treatment
wastes was demonstrated.
The Research Foundation, assisted by the Project Advisory Committee, was
able to develop two new approaches for the systematic classification and
reduction of wastes. A Project Sub-Committee is currently developing
information on sampling, analysis, and categorization techniques for
water plant purification and softening wastes. A separate Sub-Committee
has developed documents to evaluate the applicability of polymers as
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primary coagulants, coagulation aids, and sludge conditioning agents.
The testing of polymers at participating water utilities will be initi-
ated and the results publicized.
Abstracts of Research Reports
The Research Foundation has collected and organized articles dealing with
the treatment or disposal of water treatment plant wastes. These articles
have been prepared in accordance with the Water Resources Science Infor-
mation Center (WRSIC) specifications. These abstracted articles provide
reliable reference material for the initiation of individual research
for waste treatment process selection.
Project Advisory Committee
The collection and structuring of an information resource is, at best,
a slow process. The development of reliable research and development
data is an operation that requires concentrated efforts among researchers.
A Project Advisory Committee, sensitive to the needs of the water utility
industry, has utility in providing guidance and consultation to the Re-
search Foundation which cannot be ^overemphasized.
Information on Foreign Research
The initiation of the resource program has been acknowledged by both
national and international organizations. Correspondence has been extend-
ed to Canada and select foreign research institutions in Europe. Much
can be gained from organizations such as the British Water Research
Association (WRA). The WRA recognized the need to treat water utility
wastes several years ago. A great deal of practical research effort has
been conducted in England. Several plant size treatment facilities are
operative there. Corresondence with domestic and foreign research organ-
izations will be continued and expanded to identify additional development
in pilot and plant scale processes. The WRA will cooperate with the
Research Foundation in coordinating research information.
Expanded Information Program
The Foundation plans the continuation and expansion of the clearing-house
functions in the coming year. Special reports on research information
as identified through: Science Infomation Exchange; Water Quality
Office, E.P.A.; and the Office of Saline Water, U.S.D.I., will be pub-
lished. Information is being compiled presently from water and waste-
water equipment manufacturers to identify equipment for dewatering or
reclaiming water treatment wastes.
The Research Foundation looks forward to the cooperation of those associ-
ated with the water utility industry to submit information on their
research activities. The development, publication, and transfer of sig-
nificant new information will promote its application for the control
of pollution by the water utility industry.
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SECTION XII
ACKNOWLEDGMENTS
Prefect Steering Committee
The assistance of the Project Advisory Committee is gratefully acknowl -
edged. Committee members provided expert guidance to the Research
Foundation throughout the conduct of the study. This Committee includes
Research Group
Riley N. Kinman James C. Lamb, III
Associate Professor of Professor of Sanitary Engineering
Sanitary Engineering Dept. of Env. Sciences and Eng.
College of Engineering University of North Carolina
University of Cincinnati P.O. Box 630
Cincinnati, Ohio 45221 Chapel Hill, N. Carolina
Engineering Gf oup
Peter W. Doe G.P. Fulton
Havens & Emerson Consulting Engineer
Consulting Engineers Metcalf & Eddy
507 Boulevard 60 E. 42 St.
East Paterson, New Jersey 07407 New York, New York 10017
Operating Practice Group
Robert J. Becker Herbert Hartung
Superintendent of Purification Exec. Vice Pres. & Mgr. of Prod.
Indianapolis Water Co. St. Louis County Water Co.
1220 Waterway Boulevard 8390 Delmar Boulevard
Indianapolis 7, Ind. St. Louis, Missouri
Kenneth E. Shull Lee Streicher
Vice-President, Research Water Purification Engineer
Philadelphia Suburban Metropolitan Water District of
Water Company Southern California
762 Lancaster Avenue 700 N. Moreno
Bryn Mawr, Pa. La Verne, Ca. 91750
Regulatory Group
Ralph Evans, Head Robert Boes
Water Quality Section Chemical Engineer
Illinois State ORSANCO
Water Survey 414 Walnut Street
Urbana, III. Cincinnati, Ohio 45202
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Projact Support
The support of this project by the Water Quality Office, Environmental
Protection Agency, and the assistance provided by Mr. William J. Lacy
and Mr. George R. Webster, the Grant Project Officer, is gratefully
acknowledged.
Thirty water utilities contributed matching funds for the conduct of
this project. The contributing water utilities are:
California - East Bay Municipal Utility District, Oakland
Connecticut - Greenwich Water Company, Greenwich
Georgia - Department of Water Works, Atlanta
Illinois - Department of Water and Sewers, Chicago
Illinois - Kankakee Water Company, Kankakee
Illinois - Lake County Public Water District, Waukegan
Illinois - Northern Illinois Water Corporation, 'Champaign
Indiana - Indianapolis Water Company, Indianapolis
Iowa - Des Moines Water Works, Des Moines
Maryland - Washington Suburban Sanitary Commission, Hyattsville
Michigan - Metropolitan Water Department, Detroit
Missouri - City of Kansas City, Kansas City
Missouri - City of St. Louis, St. Louis
Missouri- St. Louis County Water Company, St. Louis
Missouri - Missouri Water Company, University City
Nebraska - Metropolitan Utilities District, Omaha
New Jersey - Garden State Water Company, Hamilton Square
New York - Monroe County Water Authority, Rochester
New York " Wanaka Water Company, Hamburg
Ohio - Ashtabula Water Works Company, Ashtabula
Ohio - City of Cincinnati Water Works, Cincinnati
Oklahoma - Oklahoma City Water Department, Oklahoma City
Pennsylvania - Philadelphia Suburban Water Company, Bryn Mawr
Pennsylvania - Chester Water Authority, Chester
Pennsylvania - City of Philadelphia Water Department, Philadelphia
Pennsylvania - ' /re Water Company, Sayre
Pennsylvania - fa., ."ango Valley Water Company, Sharon
Texas - Water Utilities Department, Dallas
West Virginia - luntington Water Corporation, Huntington
Wisconsin - Milwaukee Water Works, Milwaukee
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.Research Foundation Staff
The AWWA Research Foundation staff for conducting the project "Infor-
mation Resource on Water Pollution Control in the Water Utility Indus-
try", and for preparing this report was:
Harry A. Faber, Research Director
Anthony D. Nardozzi, Project Research Director
Kitty C. Klotap, Administrative Assistant
Mary L. Long, Secretary
147
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SECTION XIII
REFERENCES
1. Albertson, O.K., and Guidi, E.E., "Centrifugation of Waste Sludges,"
WPCF JOURNAL. 41. no. 4, pp 607-628 (1969).
2. Andersen, J.R., and Dornbush, J.N., "Ground Water Contamination
Resulting from Waste Disposal," Notice of Research Project. Science
Information Exchange (1971).
3. Aultman, W.W., "Introduction to Waste Disposal-Water Treatment Plants "
AWWA JOURNAL. 58, No. 9, pp 1102-1103 (1966).
4. Aultman, W.W., "Reclamation and Reuse of Lime in Water Softening,"
AWWA JOURNAL. 31. No. 4, pp 640-671 (1939).
5. AWWA Committee Report, "Diatomite Filtration Sludge Disposal,"
AWWA JOURNAL. 62. No.8, pp 507-509 (1970).
6. AWWA Committee Report, "Disposal of Softening Plant Wastes," AWWA
JOURNAL. 41. No. 9, pp 819-836 (1949).
7. AWWA Committee Report, "Disposal of Water Purification and Softening
Plant Wastes" AWWA JOURNAL, 39. No. 12, pp 1211-1223 (1947).
8. AWWA Committee Report, "Purification Plant Waste Disposal," AWWA
JOURNAL. 45. No. 11, pp 1225-1237 (1953).
9. AWWA Research Foundation, "Disposal of Wastes from Water Treatment
Plants," FWPCA Report. Project No. WP 1535-01-69 (1969).
10. AWWA Standard Methods Committee, "Simplified Procedures for Water
Examination." AWWA Manual M-12. (1969).
11. Barker,J., "Treatment of Acid Rinse Water," Notice of Research Project.
Science Information Exchange (1971).
12. Barnhill, K.G., "Sludge Disposal Alternatives," Paper Presented at
31st Annual Meeting of the International Water Conference of the
Engineer's Society of Western Pennsylvania (1970).
13. Benn, D. and Bridge, L., "Sludge Disposal by Pressing," Fylde Water
Board. Blackpool, Lancashire, England, (No Date).
14. Benn, D. and Doe, P.W., "Disposal of Sludge by the Freezing and
Thawing Process," Fylde Water Board, Blackpool, Lancashire, England
(1969).
15. Bishop, S.L., and Fulton, G.P., "Lagooning and Freezing For Disposal
of Water Plant Sludge," Public Works. 99. No. 6, pp 94-96 (1968).
149
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16. Black, A.P.; Shuey, B.S., and Fleming, P.J., "Recovery of Calcium
and Magnesium Values from Lime-Soda Softening Sludges," Paper Pre-
sented at Annual AWWA Conference, June 1971, Denver, Colorado. Paper
scheduled for publication in AWWA JOURNAL. 63, No. 10 (1971).
17. Brown, A. and Leighton, J., "Some Solutions to Sludge Treatment Prob-
lems at Fishmoor Treatment Plant," Fylde Water Board. Blackpool,
Lancashire, England (1966).
18. Bugg, B.; King, P.H., and Clifford, W., "Polyelectrolyte Conditioning
of Alum Sludges," AWWA JOURNAL. 62. No. 12, pp 792-795 (1970).
19. Christensen, W., Copenhagen Water Department, Personal Correspondence
(1971).
20. Crow, W.B., "Techniques and Economics of Calcining Softening Sludges,"
AWWA JOURNAL,52, No. 3, pp 322-326 (I960).
21. Davis, S.} "Alternatives for Phosphate Removal," Water and Sewage
Works, 117, No. 10, pp 336-338 (1970).
22. Degremont S.A., "The Orly Waterworks of the City of Paris", Water
and Water Engineering, 74. No.890, pp 135 - 146 (1970).
23. Dick, R.I., and Barkman, J.I., "Gravity Thickening and Mechanical
Dewatering of Alum - Lime Sludge, Decatur, Illinois," Notice of
Research Project. Science Information Exchange (1971).
24. Dick, R.I., and Shin, B., "Gravity Thickening Theory," Notice of
Research Project, Science Information Exchange (1971).
25. Doe, P.W., "The Disposal of Sludge from Water Treatment Plants,"
Fylde Water Board. Blackpool, Lancashire, England (No Date).
26. Doe, P.W., "The Treatment and Disposal of Washwater Sludge," Fylde
Water Board, Blackpool, Lancashire, England (1958).
27. Doe, P.W.; Benn, D.; and Bays, L.R., "The Disposal of Washwater
Sludge by Freezing," Institution of Water Engineers Journal, 19, No.4,
pp 251-275 (1965).
28. Eidsness, F.A., and Black, A.P., "Carbonation of Water Softendaig
Plant Sludge," AWWA JOURNAL, 49,No.10, pp 1343-1351 (1957).
29. Ellsperman, L.M., "Evaluation of Soil Sealants for Solar Evapora.-.
tion Ponds," Notice of Research Project, Science Information Exchange
(1971).
30. Ellsperman, L.M.," Surface Facilities for Disposal of Desalting Plant
Effluents," Notice of Research Project, Science Information Exchange
(1971).
150
-------
31. Environmental Protection Agency (Water Quality Office)/'Treatment of
Waste Alum Sludge," Project Number 12120 FRM, Information Sheet of
Research, Development or Demonstration Project (1970).
32. Evans, R.L., "Water Treatment Plant Wastes," Notice of Research
Project, Science Information Exchange (1971).
33. Faber, H.A., "Research on Water Treatment Plant Waste Disposal,"
Water and Sewage Works, 117. No.11, pp 379-383 (1970).
34. Farrell, J.B.; Smith, J.E.; Dean, P.B.; Grossman, E., and Grant,0.L.,
"Natural Freezing for Dewatering of Aluminum Hydroxide Sludges,"
AWWA JOURNAL, 62, No. 12, pp 787-791 (1970).
35. Forster, H. , "Test Results on Basin Sediment from the Chattahoochee
Water Treatment Plant, City of Atlanta, Georgia," Beloit-Passavant
and City of Atlanta, Personal Correspondence (1971).
36. Fosterpegg, R.W.; Blair, G.W.; Laurich, S.A.; Ganiaris, N.; Hedrick,
R.H., and Glasser, R.J., 'Feasibility of Obtaining a Solid (Dry) Brine
Effluent from Desalting Plants at Inland Locations," Notice of
Research Project. Science Information Exchange (1971).
37. Francis, P., and Knight, H.W., "The New Langford Treatment Works of
the Southend Waterworks Company," Water and Water Engineering, 74,
No. 894, pp 319-327 (1970).
38. Fulton, G.P , "Alum Recovery for Filtration Plant Waste Treatment",
Water and Wastes Engineering, 7, No. 6, pp 78-81 (1970).
39. Fulton, G.P., "Disposal of Wastewater from Water Filtration Plants,"
AWWA JOURNAL. 61, No. 7, pp 322-326 (1969).
40. Garrett, D.; Yen, I.; Manken, E.A. ; Kallerud, M.J., and Chemtoe, E.,
"Determining the Feasibility of Obtaining Dry Brine Effluents from
Desalting Plants at Inland Locations," Notice of Research Project.
Science Information Exchange (1971).
41. Gordon, C.W., "Calcining Sludge from a Water Softening Plant," AWWA
JOURNAL, 36, No. 11, pp 1176-1177 (1944).
42. Grinstead, R.R., and Fleig, C.E., "Disposal of Brine Effluent by
Conversion to By-Products," Notice of Research Project, Science
Information Exchange (1971).
43. Grubes, D.M. ; Haynes, C.D, and Tucker, W.E., "Conservation of Fresh-
Water Resources by Deep-Well Disposal of Liquid Wastes," Notice of
Research Project, Science Information Exchange (1971).
44. Hamblin, C.W., "Recalcining Lime Sludge Produces Multiple Benefits,"
The American Citv. 84, No.11, pp 67-69 (1969).
151
-------
45. Harrison, R.L., Manchester Waterworks Corporation, Personal Cocre -
spondence (1971).
46. Hilson, M.A., "Sludge Conditioning by Polyelectrolytes," Fylde Water
Board, Blackpool, Lancashire, England.
47. Hoover, C.P., "Recovery of Spent Lime at the Columbus Water Softening
and Purification Works, AWWA JOURNAL. 3. No. 12, pp 889-896 (1916),.
48. Hoover, C.P., 'Discussion on Reclamation and Re-use of Lime in Water
Softening," AWWA JOURNAL.31. No. 4, pp 675-679 (1955).
49. Howson, L.R., "Problem of Pollution," AWWA JOURNAL. 58. No. 9,
pp 1104-1106 (1966).
50. Illinois AWWA Section Water Resources Quality Control Committee,
"Water Treatment Plant Wastes," Paper at Annual Illinois AWWA Confer-
ence (1970).
51. Illinois State Water Survey, "Scale Analysis," Laboratory Procedure,
Personal Correspondence (1971).
52. Jennett, J.C., "Effects of Environmental Factors on Design and Oper-
ation of Open-Air Sludge Drying Beds," Notice of Research Project.
Science Information Exchange (1971).
53. Judkins, J.F. , "Treatment of Water Plant Sludges 5" Notice of Research
Project. Science Information Exchange (1971).
54. Keith, F.W., "Centrifuges Concentrate and Dewater Waste System Solids,"
Water and Sewage Works. 116. No. 3, pp IW10-IW18 (1969).
55. Kelly, E.M., "Discussion of Reclamation and Re-use of Lime in Water
Softening," AWWA JOURNAL. 31. No. 4, pp 671-675 (1939).
56. King, P.H."Economic Disposal of Waste Sludges from Water Treatment
Plants," Notice of Research Project. Science Information Exchange
(1971).
57. Krasauskas, J.W., "Review of Sludge Disposal Practices," AWWA JOURNAL.
61, No. 5, pp 225-230 (1969).
58. Krause, F., "Value of Sludge Calcining," AWWA JOURNAL. 49. No. 3,
pp 327-330 (1957).
59. Lawrance, C.H., "Lime-Soda Recirculation Experiments at Vandenberg
Air Force Base," AWWA JOURNAL. 55. No. 2, pp 177-192 (1953)./ ,
60. Lemezis, S.; Boies, D.B.; Coit, T.L.; Ivins, V.S., and Bowden, C.J.,
"Determining the Feasibility of Alternative Approaches: of Obtaining
a Solid Dry Brine Effluent from Desalination Plants at Inland Loca-
tions," Notice of Research Project. Science Information Exchange (1971),
152
-------
61. Lyon, W.A. , and Lazarchik, D.A., "Influence of State Quality Stand-
ards," AWWA JOURNAL. 58. No. 9, pp 1106-1108 (1966).
62. Maneval, D.R., 'Neutralization and Precoat Filtration of Concentrated
Sludges from Mine Water," Notice of Research Project, Science Infor-
mation Exchange (1971).
63. Me Caughan, F.A. , "Proposed Waste Water Treatment Facilities for
Nueces County Water Control and Improvement District No. 3, "Prelim^
inarv Engineering Report. Personal Correspondence (1970).
64. Me Colgan, R., "Waste Alum and Activated Carbon Sludge Solids
Reduction Methods," Orange County Sewer District, Orlando, Florida,
Personal Correspondence, (1970).
65. Me Colgan, R., "Water Treatment Plant Wastes Disposal," Orange County
Sewer District, Orlando, Florida, Personal Correspondence, (1970).
66. Mcllhenny, W.F.; Sheperd, B.P.; Legros, P.G., and Williams, J.C. ,
"The Feasibility of Obtaining a Solid (Dry) Brine Effluent from
Desalting Plants at Inland Locations," Notice of Research Project.
Science Information Exchange (1971).
67. McKinney, R., Microbiology for Sanitary Engineers, McGraw-Hill Book
Company, Inc., New York (1962).
68. Middlebrooks, E.J.; Phillips, W.E., and Coogan, F.J., "Chemical Coagila-
tion of Kraft Mill Wastewater," Waterand Sewage Works, 116, No. 3,
pp IW7-IW9 (1969).
69. Moss, E.A., "The Thickening and Dewatering of Precipitates from..the
Lime/Limestone Treatment of Mine Drainage," Notice of Research Project,
Science Information Exchange (1971).
70. Mulbarger , M.C. , and Dean, R.B., "Lime Sludge Recovery and Reuse,"
Notice of Research Project, Science Information Exchange (1971).
71. Nalco Chemical Company, "Filter Aid Evaluation by Means of Filter
Test Leaf," Technical Publication (1968).
72. Nelson, F.G., "Discussion on Carbonation of Water Softening Plant
Sludge," AWWA JOURNAL, 49. No. 10, pp 1351-1354 (1957).
73. Nelson, F.G.,"Recalculation of Water Softening Sludge," AWWA JOURNAL.
36, No.10, pp 1178-1184 (1944).
74. Neubauer, W.K., "Waste Alum Sludge Treatment," AWWA JOURNAL, 60..
No. 7, pp 819-826 (1968).
75. O'Brien, W.J., "Use of Lime-Soda Sludges for the Treatment of Munic -
ipal Wastewater," Notice of Research Project, Science Information
Exchange (1971).
153
-------
76. ORSANCO Staff/'Control of Wastewater Discharges from Water Purifi-
cation Plants on the Ohio River," Technical Report (1968).
77. Pedersen, H.V., "Calcining Sludge from a Softening Plant," AWWA
JOURNAL. 36. No. 10, pp 1170-1175 (1944).
78. Plautz, W.H., and Van Kirk, F.N., "Disposition of Sediment and Waste
Backwash Water at the Central and South Water Filtration Plants,
City of Chicago, Illinois," Report of Consoer & Townsend Consulting
Engineers, Chicago, Illinois, Personal Correspondence (1971).
79. Poston, H.W., "Federal Pollution Control," AWWA JOURNAL. 58. No. 9,
pp 1108-1112 (1966).
80. Rabin, E., and Hadzeriga, P., "Recovery of Chemicals as a Means of
Brine Disposal ," Notice of Research Project, Science Information '
Exchange (1971).
81. Remus, G.J., "Detroit's Waste Water Problems," AWWA JOURNAL. 58.
No. 9, pp 1112-1116 (1966).
82. Russelmann, H.B., "Characteristics of Water Treatment Plant Wastes,"
Proceedings of 10th Sanitary Engineering Conference, Univ. of Illi-
nois, Urbana. (1968)
83. Sanders, P.V., "How We Solved Our Lime Sludge Disposal Problem,"
Public Works, 100, No. 2, pp 88-89 (1969).
84. Sawyer, C.N., and McCarty, P.L., Chemistry for Sanitary Engineers,
McGraw-Hill Book Company Inc., New York (1967).
85. Scott, J.C., "Ann Arbor's Recalcining Process and Problems," AWWA
JOURNAL, 61. No. 6, pp 285-288 (1969).
86. Schwartz, B., "Recycling and Reuse of Filter Washwater," Hackensack
Water Company, Oradell, New Jersey, Personal Correspondence (1971).
87. Schwoyer, W.L. and Luttinger, L.B., "Dewatering of Water Plant Sludge,"
Permutit Technical Abstract (1971).
88. Sheen, R.T., and Lammers, H.B., "Recovery of Calcium Carbonate or
Lime from Water Softening Sludges," AWWA JOURNAL, 36, No.11, ppl!45-
1169 (1944).
89. Smithsonian Institute, "Science Information Exchange, A National
Registry of Research in Progress," Pamphlet (1970).
90. Sperry, W.A., "The Lime-Softening of Water and the Use of the Sludges
as an Aid Thereto," AWWA JOURNAL, 6. No. 6, pp 215-229 (1919).
154
-------
91. Standiford, F.C., "Study of Approaches of Obtaining Solid Brine
Effluent from Desalination Plants," Notice of Research Project.
Science Information Exchange (1971).
92. Sutherland, E.R., "Treatment Plant Waste Disposal in Virginia," AWWA
JOURNAL. 61. No. 4, pp 186-189 (1969).
93. TeKippe, R.J., and Ham, R.K., "Coagulation Testing: A Comparison
of Techniques - Part I, AWWA JOURNAL. 63. No. 9, pp 594-602 (1970).
94. Thomas, C.M. , "The Use of Filter Presses for the Dewatering of
Sludges," WPCF JOURNAL. 43. No. 1, pp 93-101 (1971).
95. Van Reuth, A.G., "Treatment and Disposal of Sedimentation Tank Sludge
and Sand Filter Backwash Water, Van Bibber Water Treatment Plant,
Edgewood Arsenal, Maryland," Report Prepared under U.S Corps of
Engineers Contract No. DACA 31-69-0-0072.
96. Waring, F.A., "Methods of Lime Softening Sludge Disposal," AWWA
JOURNAL. 47, No. 2, pp 82-84 (1955).
97. Welch, A.W., "Reclamation of Filter Backwash Water," Water and Sewage
Works. 117, No. 6, pp 189-190 (1970).
98. WertE, C.F., "Miami Lime Reclamation Plant," AWWA JOURNAL, 52.
NO. 3, pp 326-332 (1960).
99. Youngwirth, W.G. , and Kollar, K.I., "Production of Water and Waste-
water Treatment Equipment (1968)," Notice of Research Project,
Science Information Exchange (1971).
155
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SECTION XIV
APPENDICES
Page No.
Research & Development Information Storage &
Retrieval System 158
Basic Data Survey for
Water Utility Industry 162
Regulatory Agency Survey 166
157
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RESEARCH & DEVELOPMENT
INFORMATION STORAGE AND RETRIEVAL SYSTEM
Each article to be Included in the retrieval system abstracts will be used to inform water util-
ities and others of studies pertaining to sludge treatment and disposal. The information will
be stored on a McBee punch card as shown below. The back of the card will be used to store the
abstracts.
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Researcher, Title of Research or Study
Citation- Journal or Publication
Reference Number Date of System Entry
Key Words
Abstract
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As each article is reviewed, the reviewer will classify the information on the R&D Information
Storage & Retrieval System Punch Guide. The reports also will be indexed on 3x5 file cards,
both by Author-Title and Title-Author alphabetically.
All information received will be listed chronologically to provide a ready reference to new
information on the treatment and disposal of sludges from water treatment plants.
158
-------
RESEARCH & DEVELOPMENT INFORMATION STORAGE AND RETRIEVAL SYSTEM
Basic Classifications:
1. Research (R-#)
2. Demonstration (D-#)
3. Pilot Plant Scale (PPS-#)
4. Plant Scale (PS-//)
Status:
9. Conceptually proposed or being developed
10. In-Progress
11. Completed
Developer:
Supply Type:
Waste Sources:
13. Utility (Public)
14. Utility (Investor-Owned)
15. University or Educational Institution
16. Manufacturers of Equipment and Supplies
17. Association or Foundation
18. Consultant Engineer
19. Government, County
20. Government, State
21. Government, Federal
22. Government, Foreign
23. Government, Interstate Agencies
24. Surface - River Water
25. Surface - Impounded Water
26. Groundwater
27. Surface & Groundwater
28. Estuarine
29. Ocean
30. Sedimentation Basin
31. Washwater
32. Desalting Pretreatment Sludges, Brackish
33. Desalting Pretreatment Sludges, Sea
34. Ion Exchange Regenerant Streams
35. Reverse Osmosis Brine Streams
Ll. Electrodialysis Brine Streams
L2. Evaporator Brine Streams
159
-------
RESEARCH & DEVELOPMENT INFORMATION STORAGE AND RETRIEVAL SYSTEM
Waste Types;
L9. Alum
L10. Lime Softening
Lll. Lime-Soda Softening
L12. Iron-Manganese
L13. Iron Salt Coagulation
L14. Polymers
Sedimentation:
Filtration &
Exchange;
L17. Intermittent Cleaning
L18. Continous Cleaning
L19. Solids Contact
B5. Slow Sand
B6. Rapid Sand
B7. Dual Media
B8. Multi-Media
B9. Anthracite
BIO. Pressure Sand
fill. Microstraining
B12. Ion Exchange
Waste Treatment:
B16. Sedimentation
B17. Lime Recovery
B18. Alum Recovery
B19. Lagooning
B20. Vacuum Filtration
B21. Drying Beds
B22. Centrifugation
B23. Freezing
B24. Filter Pressing
B25. Recycling
B26. Chemical Coagulation
Solids Disposal;
B33. Discharge to Sanitary Sewers
B34. Barging to Sea
B35. Pipeline Transport
160
-------
RESEARCH AND DEVELOPMENT INFORMATION STORAGE AND RETRIEVAL SYSTEM
Rl. Incineration
R2. Underground Injection
R3. Landfill
RA, Lagooning
R5. Other
R9. Recycling to Plant Intake
Liquid Disposal: RIO. Discharge to Waterways after treatment
to meet effluent standards.
Rll. Underground Injection
R12. Discharge to Sanitary Sewers
161
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Project 2
"Information Resource for Water Pollution
Control in the Water Utility Industry"
Water Utility Survey
Water Utility Source of Supply
Location Official Reporting
(Name and Title)
Date
I. Basic Data (Water Treatment Plant) ; Yearly
Average Minimum Maximum
Raw Water Turbidity (JTU)
Raw Water Suspended Solids (mg/1)
Raw Water Hardness (mg/1 as CaCOo)
Treated Water Hardness (mg/1 as CaCO-j)
Raw Water TDS (mg/1)
Treated Water TDS (mg/1)
Water Treated (mgd)
Chemicals Used
(Ibs/mg treated water)
Alum
Carbon
Lime
Chlorine
Other (name)
NaCl
Special Comments:
162
-------
WATER UTILITY SURVEY
(Please Circle Reply)
•II. Water Treatment Plant Waste Handling and Treatment
1. Are solids in sludge (slurry) withdrawals from Sedimentation Basins
or Contact Basins additionally concentrated or thickened prior to
disposal? Yes N£
By what Method? Settling mechanical thickeners in tanks
freezing centrifugation vacuum filtration
Other (Describe)
2. Are solids in filter washwater concentrated or thickened prior to
disposal? Yes Np_
By what Method? (Describe)
3. In what form are the suspended solids from water treatment plants
basins at point of final disposal? Fluid Solid Semi-Fluid
What is the Per Cent Dry Solids by Weight?
4. In what form are the suspended solids from filter washwater at
point of final disposal? Fluid Solid Semi-Fluid
What is the Average concentration of solids at point of final
disposal - either mg/liter or % dry solids by weight?
5. What is the final disposal of water treatment plant sludge solids?
Watercourse Lake Dry Creek Ocean Lagoons Sewer
Landfill Agriculture Ground Treatment Recalcining Alum Recovery
Other (Describe)
a. Which method applies to solids from basins?
b. Which method applies to solids from Filter Wash Water?
6. What is the final disposal of the liquid portion of water treatment
plant wastes? (See above alternatives) i
7. What is the final disposal of brines and other high TDS waste
waters? '
What is the average TDS content of these waste waters, mg/1.
163
-------
WATER UTILITY SURVEY
III.Waste Production and Waste Characteristics
1. Total Plant - Dry Solids Produced Ibs/M.G. water treated.
(T.S. influent water + ^Chemicals Added - T.S. treated water)
2. Density-of dry solids produced Ibs./cu. Ft.
3. Volume water used for basin desludging, % of treated water.
4. Water used for basin desludging which is not reclaimed, %
of treated water.
'5. Volume water used for filter washing, % of treated water.
6. Filter wash water which is not reclaimed ^ °f treated water.
7. Basin Sludge Concentration Data (typical samples)
a. Average dry solids concentration at time of withdrawal from
basins, % Dry Solids by Weight.
b. Volume of sludge after 24 hr. settling and decantation of
supernatant, % of original volume.
c. Average dry solids concentration after 24 hr. settling and
decantation of supernatant % Dry Solids by Weight.
d. Suspended solids in supernatant after 24 hr. settling,
mg/1.
8. Filter Washwater Sludge Concentration Data (typical samples)
a. Average dry solids concentration in filter washwater,
mg/1.
b. Average dry-solids concentration after 24 hr. settling and
decantation of supernatant, mg/1.
c. Suspended solids in supernatant after 24 hr. settling,
mg/1.
*Chemicals added - chemicals that will result in a precipitate.
Should include alum or Ferric salts, polyelec-
trolytes, activated carbon and lime and/or
soda-ash. Should not include chlorine, salts
of ammonia or lime used solely for pH correction.
164
-------
WATER UTILITY SURVEY
III: Waste Production and Waste Characteristics (cont.)
9. Chemicals Analysis of Water Treatment Plant Wastes
From Basins
a. Waste solids after drying at 105°C
Volatile Matter
Si02
Fe2°3
A12°3
CaC03
Mg(OH)2
Remainder
100%
v.
Filter Wash Water
100%
b. Sludge as withdrawn from water treatment plant:
From Basins Filter Wash Water
mg/1 mg/1
mg/1 mg/1
C.O.D.
B.O.D.5
c. Liquid waste at time of final disposal:
C.O.D.
B.O.D.,
Ffo'ffl Ba'sins
mg/1
mg/1
Filter Wash Water
ing/I
mg/1
165
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Project 2
"Information Resource for Water
Pollution Control in the Water Utility Industry"
Survey of Regulatory Agencies
Statistical Information
1. Based upon your Agency's experience, please indicate, in order of
magnitude, your concern regarding wastes from the following water
treatment processes (use numerals 1 to 8 with 1 as a major and 8 as
a minor concern):
Coagulation Ion Exchange Regeneration
Softening Filter Backwash
Iron-Manganese Removal Desalination
Diatomaceous Earth Micros training
2. In determining treatment requirements for wastes from water treatment
processes (question 1), does your Agency consider the following?
Yes No Yes No
TDS COD
Settleable Solids BOD
Suspended Solids Chloride
pH Color
Coliforms Heavy Metals
3. Please indicate which of the following methods of sludge disposal would
not be consistent with your Agency's regulations:
Discharge to sanitary sewers Incineration
Barging to sea Landfill
Pipeline transport Agricultural Use
Please submit a copy of your Agency's regulations governing water
treatment plant sludge.
166
-------
Survey of Regulatory Agencies
Statistical Information (cont.)
4. Please indicate which of the following methods of liquid disposal
would not be consistent with your Agency's regulations:
Recycle Sanitary sewers
Stream Transport Underground Injection
5. Please indicate whether your Agency requires water utilities to
perform the following:
Yes No
a. Maintain records of waste production
b. Submit reports of waste production
c. Monitor waste receiving streams .
.If yes, reference which and enclose copies of records or
reports.
Research
6. Please indicate, in your judgment, which of the following should be
the major contributor in supporting research for treating wastes from
water treatment plants (Question 1):
State government Equipment Manufacturers
Federal government Educational institutions
• Water utilities Consulting engineers
7. Please indicate, in your judgment, which of the following should
conduct most of the research effort for treating wastes from water
treatment plants (Question 1):
State government Equipment Manufacturers
Federal government Educational institutions
Water utilities _ Consulting engineers
167
-------
Survey of Regulatory Agencies
Regulatory
Please indicate, if the wastes from a water treatment plant could be,
reduced to the same form as the wastes in the original source water,
would your agency accept the discharge of these wastes to a water-
course?
Yes No
If not, what standards would you require?
* * *
Agency Completing Survey
Name
Title
Agency
Address
•«* GOVERNMENT PR.NT.NG OFP.CE: 1972.,M_M3/ ,„„
168
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SELECTED WATER
RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
1. Report No. \ 2.
INFORMATION RESOURCE:. WATER POLLUTION CONTROL IN
_ THE WATER UTILITY INDUSTRY.
7. Author(s)
Faber, H.A., and Nardozzi, A.D,
9. Organization
American Water Works Association Research Foundation,
New York, New York
3. Accession No.
w
5. Report Date
6.
S. Performing Orgaxdzatiott
Report If o.
10. Project No.
12120 EUR
12. Sponsoring Organization
IS. Supplementary Notes
11. Contract/Grant No.
13. Type of Report aad
Period Covered
16. Abstract
This report describes the accomplishments of a program conducted to organize,
coordinate, and disseminate information on new or modified sludge treatment
technology for water treatment plant wastes. The reliable control of these
potential pollutants is of increasing importance with the enactment and
enforcement of more stringent pollution control legislation. The report
contains information on research, engineering, plant operation, and regu-
latory aspects of the problem. A Project Advisory Committee provided recommen-
dations for development of information resources, and assisted the Research
Foundation in structuring an information clearinghouse. The report describes
current research activities and new approaches for characterizing and reducing
water treatment plant waste volumes. A program was initiated to evaluate the
applicability of polymers as primary coagulants, coagulant aids, and sludge
conditioning agents. A Sub-Committee was established to prepare uniform
sampling, analysis and categorization techniques for water utility sludges.
Each program is in progress. Surveys were distributed to water utilities
and regulatory agencies to provide information on sludge treatment methods and
requirements. The AWWA Research Foundation plans the continuation and expan-
sion of this centralized information resource program. (Nardozzi - AWWA
Research •Foundation')
17a. Descriptors
*Sludge Disposal, *Sludge Treatment, Water Treatment
17b. Identifiers
information Clearing-house, information Resource, Surveys, Regulatory
Information, Water utility sludge, Information Dissemination
17c. COWRR Field & Group
18. Availability
05D
'». Security Class.
(Report)
20. Security Class.
(Page)
Abstractor
21. No. of
Pages
22. Price
Institution
Send To:
WATER RESOURCES SCIENTIFIC INFORMATION CENTER
U.S. DEPARTMENT OF THE INTERIOR
WASHINGTON. D. C. 20240
WRS1C 102CREV. JUNE 1971)
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