United States
                   Environmental Protection
                   Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
                   Research and Deveiopment
EPA/600/S2-87/099  Jan. 1988
<>ERA          Project Summary
                   Technical  Resource  Document:
                   Treatment Technologies for
                   Corrosive-Containing  Wastes,
                   Volume  II

                   Lisa Wilk, Stephen Palmer, and Marc Breton
                     This Technical Resource Document
                    (TRD) for wastes containing corrosives
                    is one in a series of five documents
                    which evaluate waste management
                    alternatives to land disposal. In addition
                    to this TRD for corrosive wastes, the
                    other four TRDs in the series address
                    land disposal alternatives for the fol-
                    lowing  waste categories:  dioxins;
                    solvents; nonsolvent halogenated
                    organics; and metals/cyanides.  The
                    purpose of these documents is to
                    provide  a comprehensive source of
                    information that can be used by envir-
                    onmental regulatory agencies  and
                    others in evaluating available waste
                    management options, which include
                    waste minimization and recycling as
                    well as treatment. Emphasis has been
                    placed on the collection  and interpre-
                    tation of performance data for proven
                    technologies. However, all potentially
                    viable technologies are identified and
                    discussed. When  possible,  cost  and
                    available capacity data are provided to
                    assist the user of the TRDs in assessing
                    the  applicability of  technologies to
                    specific waste streams.
                     This Project Summary was devel-
                    oped by  EPA's Hazardous Waste Engi-
                    neering  Research Laboratory, Cincin-
                    nati, OH, to announce key findings of
                    the research project that is fully doc-
                    umented in a separate report of the
                    same title (see Project Report ordering
                    information at back).
                    Background
                     Corrosive acids and alkalis are widely
                    used by all segments of American
industry and result in the generation of
approximately 40 percent of all RCRA-
regulated hazardous wastes.1 Improper
management of these wastes can result
in altered pH of surface waters to the
detriment of aquatic organisms.  Land
disposal of these wastes can also lead
to the solubilization of toxic (e.g., heavy
metals) constituents of co-disposed
wastes, thereby enhancing the potential
for their transport into the environment.2
To combat the potential  negative effects
associated with current disposal practi-
ces, the 1984  RCRA Amendments
directed EPA to  ban corrosive wastes
from land disposal to the extent required
to  protect  human  health and  the
environment.
  The land disposal ban excludes acidic
corrosive wastes (pH less than or equal
to 2.0) from land disposal units(excluding
underground injection),  effective July 8,
1987.  Treatment standards for corro-
sives which are currently managed
through underground injection will be
promulgated on August  8, 1988. Finally,
alkaline corrosive wastes  (pH greater
than 12.5) will be banned from  disposal
effective May 8, 1990.  In addition,
treatment standards for hazardous con-
stituents which are commonly present in
corrosive wastes, such as heavy metals
and toxic organics, are also being pro-
mulgated under the 1984 RCRA Amend-
ments.  Thus, prior  to land disposal,
corrosive wastes will also have to meet
these standards as they are promulgated.
  In fiscal  year 1986, the U.S.  EPA
Hazardous Waste Engineering Research

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Laboratory (HWERL) began developing a
series of technical  resource documents
(TRDs) which evaluate waste manage-
ment alternatives to land disposal. These
documents are intended to serve a two-
fold purpose. First, they provide technical
support for current EPA efforts to identify
available alternative waste management
capacity  and  to evaluate the technical
feasibility of meeting proposed treatment
standards.  Secondly,  the  documents
provide a single, comprehensive source
of technical data to assist waste gener-
ators and regulatory agencies in evaluat-
ing  available   waste management
options.  To date,  in addition to the
Corrosives  Technical Resource Docu-
ment,  three  other  TRDs  have  been
completed covering the following waste
categories:  dioxins, solvents (halogen-
ated and non-halogenated), and  non-
solvent halogenated organics.


Scope
  This summary of the Corrosives Tech-
nical Resource Document provides envir-
onmental  regulatory agencies  and
hazardous waste  generators with  a
source of technical information describ-
ing corrosive  waste management alter-
natives.  These  options include waste
minimization (i.e., source reduction,
recycling, waste exchange), and treat-
ment and disposal of waste  streams.
Emphasis is placed on the collection and
interpretation of performance  data for
neutralization and recovery technologies
which have demonstrated both technical
and  economic  feasibility for handling
corrosives.
  Table 1 summarizes potentially appli-
cable  corrosive waste management
alternatives for various waste character-
istics and management objectives. With
the  exception  of  recycled  or  reused
wastes, all corrosive liquids and sludges
will require some form of neutralization
prior to ultimate disposal. Pretreatment
requirements are  generally limited to
phase separation, equalization, cyanide
destruction,  and chromium reduction.
Post-treatment  (i.e, post-neutralization)
requirements vary with contaminant
types and concentrations and selection
of neutralization reagent. Contaminants
of particular concern in residual streams
include heavy metals and toxic organics
which  exceed effluent limitations (e.g.,
NPDES, POTW) or land dipsosal treat-
ment standards.
  Determination of the overall applica-
bility and availability of these technolo-
gies for managing corrosives required an
understanding of the nature of current
waste management practices. Analysis
of these practices  served  to identify
available methods which have proven to
be both technologically and economically
capable of treating corrosive wastes. To
a significant extent, waste management
alternatives which  will  permit industry
to meet EPA disposal requirements (e.g.,
neutralization, metals precipitation,
organic  removal  techniques)  have
already been implemented. This occurred
in response  to increased regulatory
requirements  and  the  improved eco-
nomic viability of waste minimization and
treatment  options.  The latter resulted
from increased disposal costs and liabil-
ity, and advances in waste processing
technology.
  Determining the applicability of alter-
native technologies also required  an in-
depth  understanding of the  nature of
corrosive  wastes.  Data  requirements
included the  range  and variability in
corrosive waste physical, chemical,  and
flow (i.e., rate, periodicity) characteristics
which, in turn, required an understand-
ing of corrosive waste industrial origins.
Available data were summarized on  a
national basis to assist EPA  efforts in
evaluating  the existence  of  available
alternative treatment capacity to manage
wastes which will be excluded from land
disposal.  However,  these  data  were
found to be limited.  In particular,  waste
characteristics from industries  other
than the Chemical and Allied Products
Industries (SIC 28)  need to be compiled
on a national basis.
  Available data  on corrosive  waste
generation, characteristics and current
management  practices  are briefly sum-
marized below. This is followed by  a
discussion of potential  waste manage-
ment alternatives  which  have been
categorized as either neutralization (with
appropriate  pretreatment and  post-
treatment) or recycling  processes.
Emphasis  is placed on identifying  pro-
cess design and operating  parameters,
and waste characteristics which affect
overall process applicability. This discus-
sion concludes with  a summary of
technical and economic factors  which
should be considered in the selection of
an optimal waste management system.

Corrosive Waste Generation,
Characteristics, and
Management Practices

  The  most comprehensive source of
data regarding corrosive waste genera-
tion and management was a study1 based
on the  results of the EPA's  National
Survey of Hazardous Waste Generators
and  Treatment,  Storage  and  Disposal
Facilities(TSDFs) Regulated Under RCRA
in 1981.3 Highlights of the survey results
are as follows:1

• The total quantity of corrosive waste
  (D002 and K062; corrosives and spent
  pickle liquor from  steel finishing
  operations)  generated in the United
  Statesin 1981 was21.8to25.6billion
  gallons. This  represents approxi-
  mately 40  percent  of all  hazardous
  waste  generation.  However,   it
  includes mixtures of corrosive and
  non-corrosive wastes which signifi-
  cantly inflates the total estimate.
• The number of generators of D002
  corrosive wastes was  4,705  which
  represents over one-third of all RCRA
  waste generators. These wastes were
  handled  at  513 TSDFs in 1981. In
  addition, 64 TSDFs handled K062
  corrosive wastes.

• The total quantity of corrosive waste
  that was reportedly land disposed, and
  thus  affected by the proposed land
  disposal  ban,  was 3.6  to  4.2  billion
  gallons.

• Nearly 95 percent of land disposed
  corrosives were liquid acidic wastes.
• Disposal  by deep-well  injection
  accounted  for 87  percent  of land
  disposed corrosives  with  another  6
  percent disposed in surface impound-
  ments and 5 percent in landfills.

  Waste generation estimates  provided
by the National Survey compare favor-
ably with more recent, but less compre-
hensive, projections.4'5 However, data
indicate that  these estimates  include
large quantities of corrosive waste
mixtures;  i.e.,  corrosives mixed with
other wastes  or nonhazardous  mate-
rials.6 Thus, actual waste volume at the
point of production (i.e., excluding the
effects of mixing or treatment) may be
lower by 40 percent or more.1'6
  The primary  industrial applications for
acids and bases which result in gener-
ation of corrosive wastes are: (1) use as
chemical intermediates in the inorganic
and  organic  chemical manufacturing
industries; (2)  use as  a metal  cleaning
agent in metal production and fabrication
industries; and (3) use in boiler blow-
down and stack gas treatment, primarily
in electricity generating facilities. Other

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Table  1.     Waste Management AIternatives to Land Disposal

    Waste Management
         Objective
  Applicable Waste TypefsJ
                           Potential Waste Management
                                   Alternative
Waste minimization

Source reduction


Recycling
All
Concentrated inorganic
liquids (e.g.. plating,
etching solutions)
Raw material substitution   Process redesign
Product reformulation       Waste segregation
Crystallization
Ion exchange
Evaporation/distillation
Electrodialysis
Solvent extraction
Thermal decomposition
                           Dilute inorganic liquids
                           (e.g., plating rinses)

                           Concentrated organic
                           liquids (e.g., solvents
                           with acid/alkali)
                           Ion exchange
                           Electrodialysis
                           Reverse osmosis
                           Donnan dialysis/
                           coupled transport
                                    Neutralization followed by recovery such as distillation, evaporation,
                                                     steam stripping, or use as a fuel.
Waste exchange
Pretreatment
Concentrated liquids



Dilute inorganic liquids

Liquid with solids



Liquid—two-phase
                           Liquid or sludge with
                           cyanide
Recycling
Mutual neutralization

Screening
Distillation
Centrifugation

Decanting
Extraction

Cyanide destruction
through chlorination
Reuse in process with
lower raw material
specifications
Sedimentation
Flotation
Equalization

Flotation
Distillation
Mutual neutralization
Filtration
Settling


Centrifugation
Equalization
                           Liquid or sludge with
                           hexavalent chromium
                           Chromium reduction
                           Sludge
                           Bulky solids
                           Vacuum filtration
                           Other dewatering

                           Shredders
                           Filter press
                           Hammermills
                           Centrifugation
                           Crushers
Neutralization
Acidic waste

Alkaline waste

All
                                                      Limestone

                                                      Sulfuric acid

                                                      Mutual neutralization
                           Lime

                           Hydrochloric acid
                           Caustic soda

                           Carbonic acid (COi)
Post-treatment
Metal-containing liquid


Trace organic-containing
liquids
                                                      Precipitation and
                                                      clarification

                                                      Adsorption
                           Dilute organic-containing
                           liquid

                           Concentrated organic
                           liquid
                           Inorganic sludges and
                           solids
                           Biological treatment
                           Air stripping

                           Distillation
                           Extraction
                           Incineration

                           Solidification
                           Chemical oxidation
                           Incineration

                           Steam stripping
                           Supercritical fluids
                           Use as a fuel

                           Encapsulation
                           Ozonation
                           Evaporation
                           Wet air oxidation
                                                                                 Landfill
                           Organic sludges and
                           solids
                           Incineration
                                                      Wet air oxidation

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significant  corrosive  waste  sources
include refining processes in the petro-
leum industry and pulping liquor in the
paper industry. A summary of corrosive
waste  quantity  handled  by various
industrial classification codes (SIC)  is
provided in Table 2.1
  The  majority of corrosive wastes are
handled in onsite wastewater treatment
facilities  which  ultimately discharge
treated effluents to POTWs or to surface
waters under NPDES  permits.1'6  How-
ever, approximately 16.5 percent  of all
corrosives were reportedly land disposed
in 1981  in  methods which would be
affected by  the land  disposal  restric-
tions.1 A summary of these waste
management  practices is  provided  in
Table 3. As  shown, 87 percent of land
disposed corrosives   are managed
through deep well  injection.1 More
recent  data suggest  that  deep  well
injected  waste  volumes may  have
decreased significantly (24  perecent)
since  the National  Survey data  was
collected.8 However, other quantities
presented in Table 3  are  expected  to
adequately approximate current waste
management practices.
  Waste charcteristics  of land disposed
corrosives are less well defined. The vast
majority are acidic (82 percent), inorganic
(82 percent), and characterized as dilute
(94.3 percent, liquids only).1 Deep well
injection wastes have  a high tendency
to contain  toxic  organics,6 whereas
landfilled wastes are likely (38 percent)
to contain heavy metals at concentra-
tions which exceed proposed land dis-
posal restrictions.9 Detailed characteri-
zation data for the Chemical and Allied
Products Industries,  currently being
compiled by the EPA,6 will enable the
majority of deep well injected wastes to
be  characterized. Approximately 60
percent  of  landfilled  wastes  are
accounted for by spent pickle liquor from
the iron and steel industry (K062) which
has  also been adequately characterized.
However, data  are  limited for the
remainder of  land disposed corrosives.
These data  will  be required for EPA to
assess the availability of alternative
waste management  options when cor-
rosive wastes become prohibited  from
land disposal.

Neutralization

  Neutralization processes are the  most
commonly applied methods for managing
corrosive wastes. Adjustment of waste
pH  is  typically required prior to subse-
quent treatment  processes  to  limit
corrosion of processing equipment or to
enhance treatment; e.g., metals precip-
itation or biological degradation of toxic
organics.
  Alkaline reagents commonly used to
neutralize strongly  acidic waste streams
(greater than 5,000 mg/L of mineral acid
strength) include high calcium lime and
caustic soda.1 For the treatment of dilute
acidic waste streams (5,000 mg/L or
less), limestone treatment may  also be
economically feasible.10 Mineral acids
such as sulfuric or hydrochloric are the
primary reagents used for the neutral-
ization  of  corrosive alkaline waste
streams.11   However,  alkaline waste
streams which have flow  rates of  over
100,000 gpd or require greater than 200
tons of  reagent  per  year,  may  also be
economically treated  by  liquid carbon
dioxide.12
  Pretreatment  requirements  prior to
neutralization typically consist of gross
solids removal  (i.e., filtration),   flow
equalization, or treatment of individual
waste streams prior to combination  with
other process wastes. These treatments
of segregated wastes result in economic
benefits from reduced reagent costs and
smaller  equipment sizing.  Common
pretreatment processes include cyanide
destruction, chromium reduction, metals
precipitation from highly  chelated
wastes, and oil removal.
  Post-treatment of neutralized wastes
which do not contain metals or organics
typically  consists of liquid/solid separa-
tion (e.g., clarification)  to precipitate
insoluble salts, followed by sludge
dewatering (e.g., filter press) and dispo-
sal in a  secure  landfill. Post-treatment
of corrosives with metals or toxic organ-
ics  depends   primarily  on  their
concentration.13'14
  Neutralized waste streams containing
trace organics (less than 500 ppm) would
require  additional  post-treatment
through technologies such as carbon or
resin adsorption  or air stripping.13 Dilute
organic waste streams (500 to 10,000
ppm) are most often economically treated
via biological degradation  followed  by
filtration and polishing;  e.g.,  activated
carbon.14 Concentrated  organic waste
streams  usually  undergo phase separa-
tion (e.g., dissolved  air flotation) follow-
ing  neutralization.14 The  concentrated
organic phase can be recovered through
distillation,  steam stripping,  solvent
extraction, or thin film evaporation.13
 Table 2.    Corrosive  Waste Quantity Handled by Industrial Classification (million gallons/
           year)
SIC
Code
28
49
29
33
26
36
35
32
34
37
20

Industry Description
Chemicals and allied products
Electric, gas and sanitary services
Petroleum refining
Primary metals
Paper and allied products
Electric and electronic
machinery, equipment and
supplies
Machinery, except electrical
Stone, clay, glass, concrete
Fabricated metals
Transportation equipment
Food and kindred products
Other industries
Total:
Waste
High
18,337
2,305
1,150
1,143
1.126
581
417
190
183
136
27
50
25,645
Quantity Handled"

Low Percent
15.590
1,960
978
972
957
495
354
162
156
115
23
42
21.803
71 5
9.0
45
4.5
4.4
23
1.6
0.7
0.7
05
0.1
0.2
1000
 'Includes O002 andK062 only.

 Source: National Survey, Reference 1.

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Table 3. Management Practice Summary for Corrosive Wastes National Estimates (million gallons)
High Quantity Estimate' Low Quantity Estimate"

Handled0
Disposed0
Injection well
Landfill
Land treatment
Surface impoundment
Other
Treated0
Tanks
Surface impoundment
Incineration
Other
Stored0
Tanks
Containers
Surface impoundment
Waste piles
Other
Recycled"
Onsite:
Generator
TSDF
Offsite:
Generator
TSDF
Corrosive
Waste
D002
24.596
3,970
3,635
85
18
206
26
15.912
7,040
5,614
6
3.252
10.094
1.542
9
6,530
6
2.007
373
330
42
288
43
14
29
Spent
Pickle
Liquor
K062
1.048
236
28
131
56
20
218
139
39
40
265
211
47
7
354
34
6
28
320
170
150
Total
25,644
4,206
3,663
217
18
262
46
16.031
7,180
5.653
6
3,292
10.360
1,754
9
6,577
13
2.007
727
364
48
316
363
184
179
Corrosive
Waste
D002
20,912
3.375
3,090
73
15
175
22
13,528
5,986
4,773
5
2,764
8.582
1,311
8
5,552
5
1,706
327
280
35
245
36
11
25
Spent
Pickle
Liquor
K062
891
200
24
112
48
17
185
118
33
34
226
180
40
6
301
30
6
24
272
143
129
Total
21,803
3,576
3,114
185
15
223
39
13,714
6.104
4.806
5
2.799
8.809
1.491
8
5.592
11
1.706
618
310
41
269
308
154
154
°1.235 x base data.
"1.05 x base data.
cSource of base data: Reference 1.
"Source of base data: Reference 7.

  The  aqueous  phase will  be treated
through wastewater treatment methods
as previously  discussed. Sludges con-
taining significant concentrations of toxic
organics (e.g.,  greater than 20 percent)
must be incinerated or otherwise treated
through processes which will destroy or
detoxify organic compounds; e.g., pyrol-
ysis, and wet air  oxidation.13 Solidifica-
tion/encapsulation  technologies  have
not  been adequately  developed  for
wastes with high organic content such
that  land disposal treatment standards
can be achieved.13
  Metals  containing  aqueous  wastes
generally undergo precipitation followed
by sludge consolidation. Solidification or
encapsulation of the sludge product will
be required prior to disposal in  a secure
landfill if the leachate exceeds EPtoxicity
standards  for  heavy metals. Unlike
fixation of organics, this technology is
demonstrated and widely available.13
  A  key consideration  in  the use  of
neutralization technologies is  selection
of the most appropriate reagent.  Table
4 summarizes the most commonly used
reagents, applicable waste types,  resid-
uals generated, and system costs. Neu-
tralization reagents and  acid/alkali
waste combination are discussed in more
detail below.

Mutual Neutralization
  Acid/alkali mixing (mutual neutraliza-
tion)  is  often  the  most economical
method  of neutralization  available,
particularly m cases where  compatible
wastes are present  in the same plant.1
The primary advantage of waste combi-
nation is reduced operating costs  since
neutralizing reagent requirements are
minimized. The main disadvantage is that
mixing two waste streams, each with its
own variability in composition and flow,
may require more  conservative system
design; i.e.,  larger  equalization  and
neutralization tanks and back-up neutral-
ization  reagent  systems.  Additionally,
care must be exercised when combining
waste streams or accepting wastes from
another firm  to  prevent any hazardous
products or releases during the neutral-
ization reaction.

Limestone  Neutralization
  Limestone  treatment  is  a well-
developed and established technology for
the neutralization of dilute acidic waste
streams. However,  limestone (CaCO3) is
limited in  its  ability to achieve neutral-
ization  endpoints  over pH  6.0 or to
neutralize wastes  with  acid  conentra-

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Table 4. Summary of Neutralization Technologies
Applicable Waste Stage of
Process Streams Development
Acid/ alkali mutual
neutralization








Limestone










Lime










Caustic soda








Suit uric acid







Hydrochloric acid







All acid/ alkali
compatible waste
streams except
cyanide.






Dilute acid waste
streams of less
than 5.000 mg/L
mineral acid
strength and
containing low
concentrations of
acid salts.



All acid wastes.










All acid wastes.








All alkaline wastes
except cyanide.






All acid wastes.







Well developed.









Well developed.










Well developed.










Well developed.








Well developed.







Well developed.
but rarely applied
due to high
reagent cost.




Performance
Generally slower
than comparable
technologies due
to dilute
concentrations of
reagents. May
evolve hazardous
constituents if
incompatible
wastes are mixed.
Requires stone
sizes of 0.074 mm
or less. Requires
45 minutes or
more of retention
time. Can only
neutralize acidic
wastes to pH 6.0.
Must be aerated to
remove evolved
CO*
Requires 15 to 30
minutes of
retention time.
Must be slurried
to a concentration
of 10 to 35%
solids prior to use.
Can under- (below
pH 7) or over-
(above pH 7)
neutralize.
Requires 3 to 15
minutes of
retention time. In
liquid form, easy
to handle and
apply. Can under-
or over- neutralize
including pH 13 or
'higher.
Requires 15 to 30
minutes of
retention time. In
liquid form, but
presents burn
hazard. Highly
reactive and
widely available.
Requires 5 to 20
minutes of
retention time.
Liquid form
presents burn and
fume hazard.
More reactive
than sulfuric.
Residuals
Generated
Variable.
dependent on
quantity of
insolubles and
products
contained in each
waste stream.



Will generate
voluminous sludge
product when
reacted with
sulfate-containing
wastes. Stones
over 200 mesh
will sulfonate. be
rendered inactive.
and add to sludge
product.
Will generate
voluminous sludge
similar to
limestone.







Reaction products
are generally
soluble, however.
sludges do not
dewater as readily
or as easily as
lime or limestone.


Will generate
large quantities of
gypsum sludge
when reacted with
calcium-based
alkaline wastes.


Reaction products
are generally
soluble.





Cost
Least expensive of
all neutralization
technologies.







Most cost-
effective in
treating
concentrated
wastes. May be
cost-effective in
treating dilute
acidic wastes.



More expensive
than crushed
limestone (200
mesh).







Most expensive of
all widely used
alkaline reagents
(five times the cost
of lime).




Least expensive of
all widely used
acidic reagents.





Approximately
twice as expensive
as sulfuric on a
neutralization
equivalent basis.




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Table 4.
Continued
Process
Carbonic acids.
liquid carbon
dioxide









Applicable Waste Stage of
Streams Development
All alkaline wastes Emerging
except cyanide. technology.










Performance
Retention time 1
to 1 Viminu1.es. In
liquid form, must
be vaporized prior
to use. Can only
neutralize alkaline
wastes to pH 8.3
end point.




Residuals
Generated
Will form calcium
carbonate
precipitate when
reacted with
calcium-based
alkaline wastes.






Cost
Approximately 3 to
4 times as
expensive as
sulfuric.
Therefore, limited
to applications
using more than
200 tons of
reagents per year
or with flow rate
greater than
1 00.000 gpd.
tions  greater than 5,000 mg/L10 The
primary advantage of limestone neutral-
ization is that limestone is a low cost and
widely available reagent. It can be used
in an  upflow expanded bed mode or as
a pretreatment in combination with lime.
In the latter case, the pH is raised to
approximately  3.0 to  6.0  with  lime
addition completing the process of
neutralization.15  However, in the pres-
ence  of concentrated  acidic  wastes,
limestone particles will  become  coated
with precipitate, rendering them inactive
and adding to already voluminous sludge
product.
Lime Neutralization
  Lime slurry treatment of acidic waste
streams is analogous to that of limestone
in that both are calcium-based  rea-
gents.18 Lime (CaO) is typically hydrated
(slaked) and slurried with water to  a 10
to 35 percent solids concentration  prior
to use.17 Slurried lime (Ca(OH)2) reacts
more rapidly than limestone,  typically
requiring only 15 to 30 minutes retention
time  versus 45  minutes or more for
limestone. The ability of lime slurry to
treat  a wide variety  of  manufacturing
waste streams has been well demon-
strated in bench, pilot,  and full-scale
systems. Lime slurry treatment  is more
versatile than limestone since  it can
effectively  neutralize both  dilute and
concentrated acidic waste streams to pH
endpoints ranging  from  6.0 to 12.4.
However, when  reacted  with  sulfate-
containing  wastes (e.g., sulfuric acid),
lime (and limestone) will form a volumi-
nous  calcium sulfate (gypsum)  sludge
product.

Sodium Hydroxide
Neutralization
  After lime, sodium  hydroxide  (NaOH)
is the second most widely used alkaline
                              reagent  for the neutralization of both
                              dilute and  concentrated  acidic  waste
                              streams. Its chief advantage over lime
                              slurry neutralization is that as a liquid
                              reagent, it is easier to store and handle,
                              will rapidly dissociate into solution, and
                              has minimal hold-up time.18 As a result,
                              retention times are typically 5  to 20
                              minutes19 with a corresponding reduc-
                              tion in feed system and tankage require-
                              ments. In addition,  sodium hydroxide is
                              highly caustic (can  neutralize to a 14.0
                              pH  endpoint), and  as a sodium-based
                              reagent, it generates reaction products
                              which are usually soluble.
                                The main disadvantage of sodium
                              hydroxide are burn dangers from splash-
                              ing and a 500 percent increase in reagent
                              costs on a neutralization equivalent basis
                              as compared to lime. Thus,  in high
                              volume  applications where reagent
                              expenditures constitute  the  bulk  of
                              operating expenses, lime is generally the
                              reagent of choice. In low volume appli-
                              cations where low  space requirements,
                              soluble end-products, and rapid reaction
                              rates are important factors  in reagent
                              selection,  caustic  soda  becomes
                              superior.
                              Mineral A cid Neutralization
                                Mineral  acid  treatment  is the  most
                              widely used and demonstrated technol-
                              ogy for the neutralization  of corrosive
                              alkaline  waste  streams. Both sulfuric
                              (H2SCu) and hydrochloric(HCI) acids have
                              very high dissociation constants, so that
                              quantities required for neutralization are
                              relatively low in comparison to other
                              acids 1  Consequently,  reactor volumes
                              and  handling/storage  facilities are
                              smaller.  Sulfuric acid, being the most
                              widely available and lowest  in cost on
                              a  neutralization equivalent basis, is the
                              most prevalent  acidic reagent.12 It  is
                              typically used in combination with an
alkali reagent to control pH fluctuations
in both  the acidic and alkaline ranges.
Hydrochloric acid is generally used  in
situations requiring  rapid reaction rates
and soluble reaction products.
  The primary disadvantage  in the use
of mineral acid reagents is the generation
of potentially hazardous sludge (sulfuric
acid), and acid mist, or toxic/hazardous
fumes  (hydrochloric acid). The  highly
corrosive nature of  mineral acids pres-
ents a burn hazard  to personnel, and
increases the  likelihood  of  a possible
catastrophic release during bulk trans-
port or storage.

Carbonic Acid Neutralization
  Carbonic acid (H2C03> treatment, using
liquid carbon dioxide as  a neutralizing
agent, is a relatively new and emerging
technology. Currently, applications are
limited to waste streams with flow rates
greater  than  100,000 gpd or facilities
using more than 200 tons of reagent per
year.12 Since  liquid  carbon dioxide  is
vaporized  prior to  use and  applied as
extremely fine (15  microns  or less)
bubbles, capital requirements are min-
imal (e.g., sparger system) and reaction
times are typically only 1 to 11/2 minutes.
However, liquid CC>2 can only neutralize
to a pH 8.3 endpoint.12 In addition, it costs
two to three times as much  as sulfuric
acid and will form an insoluble calcium
carbonate precipitate when reacted with
calcium-based alkaline waste streams.

Recovery/Reuse Technologies
  As an alternative to  conventional
neutralization treatment,  recovery/
reuse technologies  may  be employed.
Certain recovery technologies have been
established as  being cost-effective for
specific applications. Additional research
has shown the technical and potential
economical feasibility of a  number  of

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other emerging technologies. With the
implementation of the land disposal ban
and the resulting increases in costs for
sludge disposal, it  is  anticipated  that
recovery/reuse will be cost-effective for
an  increasing  number of corrosive
wastes.
  Crystallization and  evaporation/distil-
lation  involve  the  use  of temperature
changes  to effect a separation  of con-
taminants  and  recovery  of  corrosive
solutions. Ion  exchange methods are
based on the use of an anionic or cationic
selective resin to remove ionic contam-
inants (i.e.,  metal ions) from corrosive
wastes. Electrodialysis, reverse osmosis,
donnan dialysis, and coupled transport
processes involve the use of a membrane
to separate contaminants from corrosive
solutions.  The driving force of the
membrane  separation is  an electric
current  for electrodialysis,  hydraulic
pressure (generated by a  pump)  for
reverse osmosis, and a concentration
gradient  (between spent corrosive solu-
tion  and a  metal stripping solution) for
donnan dialysis and  coupled  transport.
Solvent extraction uses the differential
distribution of constituents between the
aqueous phase waste and an  organic
solvent to separate constituents from  a
mixed solution of metal salts and acid
wastes. Thermal decomposition involves
decomposing  metal  salts, present  in
spent  acid  wastes,  in a roaster and
collecting vaporized acid in a condenser.
  In general,  recovery/reuse  process
selection will be limited to  wastes
possessing specific chemical,  physical,
and  flow characteristics. A summary of
the  overall performance,  applicable
waste streams, residuals generation, and
status ot development for the corrosive
recovery/reuse technologies is provided
in Table  5. A  brief description of  these
processes and their  current status is
presented below.

Evaporation/Distillation
  Evaporation/distillation techniques
can be used to recover a variety of plating
and other process chemicals. They are
most commonly used in metal finishing
and electroplating industries to recovery
plating solutions, chromic acid and other
concentrated acids, and metal cyanides
by  evaporating water  from  the  dilute
rinse  solution and  concentrating  the
corrosive  solution  for return to  the
concentrated bath.1'20'21 Water recovered
from  the  distillation  (condensation)
process  is of  high  purity and can  be
reused in process waters.
  Evaporation  systems used to recover
corrosive  plating  rinses  are  cost-
competitive with conventional neutrali-
zation and disposal technologies. Greater
cost savings are realized  with larger
operations. However, the use of evapo-
ration/distillation systems  to recovery
concentrated streams directly from the
spent bath solution is limited. Pilot-scale
evaporation/distillation systems for
recovery  of  nitric/hydrofluoric acid
pickling liquors have  been  tested  at
facilities in Europe.22'23  However, cost-
effective systems for direct recovery  of
spent solutions via evaporation/distilla-
tion have not  been developed  at the
commercial-scale for application in the
United States.

Crystallization
  Crystallization is a recovery technique
whereby metal contaminants in a spent
corrosive  solution are crystallized and
removed by settling or centrifugation. It
is  a  demonstrated  and commercially
available technology for the recovery of
acid pickling liquors and caustic etching
solutions.24'25'2*27
  The use of crystallization techniques
for the recovery of sulfuric  acid pickling
liquors and caustic  aluminum etching
solutions is limited by economics. This
is due to the small quantities of these
solutions used by individual  manufactur-
ers, the costs for plant modifications, and
the varying demand  for  the crystal
product.1'28 Nitric-hydrofluoric acid pic-
kling liquors are used in larger quantities
by  individual manufacturers in the steel
industry than sulfuric acid pickling
liquors. Therefore,  crystallization tech-
niques would have wider application for
this waste type. Despite these limita-
tions, these processes are currently
being used in the metal finishing industry
in specialized applications.

Ion Exchange
   Ion exchange has been used to recover
acids, bases, and process  wastes from
the metal finishing, electroplating, and
fertilizer  manufacturing industries  by
removing metal contaminants and rec-
ycling  the treated  solution.1'29  Ion
exchange techniques involve the use of
an anionic or cationic selective resin to
remove ionic contaminants (i.e., metals)
from  solution.  Three types  of  ion
exchange configurations can be used:
cocurrent, countercurrent (reverse flow)
fixed bed, and countercurrent (reverse
flow) continuous.
  Cocurrent ion exchange systems are
generally not employed for direct treat-
ment of corrosive wastes.  Cocurrent
systems  using  weak  exchangers  have
inefficient  exchange  capacities  in the
corrosive  pH  ranges. Thus, they are
generally used  as polishing  systems
following  other treatment operations.
Corrosive   systems  using   strong
exchangers  are  not cost  effective
because  of the  high  costs for column
regeneration.  However,  reciprocating
flow ion exchange (RFIE) systems  have
been shown  to be  effective in  the
treatment  of corrosive wastes.  These
may be  more cost-effective for the
treatment  of corrosives  than conven-
tional neutralization,  particularly  when
enactment of land disposal  restrictions
increase costs  associated  with  land
disposal of residuals.
  Chemical recovery systems using fixed
bed  RFIE have  been  used  to recover
chromic  acid and metal salts, and to
deionize mixed-metal  rinse solutions for
recovering process water and concen-
trating the metals for  subsequent treat-
ment. °'31 Commercial units are available
from several vendors.
  Acid purification  systems  using con-
tinuous RFIE have been used to remove
aluminum salts from sulfuric acid anod-
izing solutions, to remove metals from
nitric acid  rack-stripping  solutions, and
to remove metals from  sulfuric  and
hydrochloric  acid pickling solutions.30
Acid purification systems are most cost-
effective for removing high  concentra-
tions of contaminants relative to  other
ion exchange systems.

Electrodialysis
   Electrodialysis  (ED) uses  an electric
field and a semipermeable ion-selective
membrane to concentrate or separate
ionic species in a water solution.32'33 Its
primary application in the treatment of
corrosive wastes is recovery of corrosive
plating solutions, pickling solutions, and
etchants by removing  contaminant metal
ions. Three types of configurations may
be used  in  the design  of  ED  units:
concentrating-diluting, ion-substituting,
and electrolytic.
   Currently, electrodialysis has a limited
area of application in the recovery/reuse
of  corrosive  wastes. Concentrating-
diluting and ion transfer ED units have
been  successful  in  the  recovery of
chromic acids from dilute solutions.34'35
Electrolytic ED units have demonstrated
the  ability to recover concentrated acid
solutions by removing metal  ion contam-
                                    8

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Table 5. Summary of Recovery/ Reuse Technologies for Corrosive Wastes
Applicable Waste Stage of
Process Streams Development Performance
Evaporation/
distillation




Crystallization













Ion exchange



















Electrodialysis

















Metal plating
rinses; acid
pickling liquors



HiSOt pickling
liquors; HNOa/HF
pickling liquors;
caustic aluminum
etch solutions.









Plating rinses;
acid pickling
baths; aluminum
etching solutions;
HiSOt anodizing
solutions; rack-
stripping solutions
(HF/HNOsl.












Recovery of
chromic/ sulf uric
acid etching
solutions.

Recovery of
plating rinses
(particularly
chromic acid rinse
water).


Recovery ofHNOs/
HF pickling
liquors.



Well-established
for treating plating
rinses.



20 to 25 systems
currently in
operation (fewer
applications for
caustic recovery).









Several RFIE units
in operation for
treatment of
corrosives.







Units for direct
treatment of acid
bath only available
fromECO-TEC,
Ltd.




Units currently
being sold, but
limited area of
application.
5 in operation.
Several in
operation.





Marketed, none in
operation to date.




Plating solution
recovered for
reuse in plating
bath. Rinse water
can be reused.

97-98% recovery
f or HsSOt (80-85%
metal removal)


99% HN03 and
50% HF recovered.



80% recovery of
NaOH


Cocurrent systems
not technically
feasible for direct
treatment of
corrosives, can be
used in
conjunction with
neutralization
technologies to
lower overall
costs
RFIE units show
good results.
Conventional RFIE
performs best with
dilute solutions
APU performs best
with high metal
concentration (30
to 100g/L)
85% recovery of
etching solution.
45% copper
removal.
30% zinc removal
Works best when
copper
concentrations are
in the 2 to 4 oz/
gal usage.


3 M HF/HN03
recorded.




Residuals
Generated
Impurities will be
concentrated.
therefore.
crystallization/
filtration system
may be required
Ferrous sulf ate
heptahydeate
crystals lean be
traded or sold).

Metal fluoride
crystals (can
recover additional
HF by thermal
decomposition)
Aluminum
hydroxide crystals
(can be traded or
sold).
Cocurrent process
generates spent
regenerant, which
is also corrosive







Recovered metals
which can be
reused, treated.
disposed, or
marketed




Metals which can
be treated.
disposed, or
regenerated for
reuse
Chromic acid can
be returned to
plating bath, rinse
water can be
reused.


2 M KOH Soln
which can be
recycled back to
the pretreatment
step for this ED
application.
Cost
Can be cost-
effective for
recovering
corrosive plating
solutions from
rinse waters
Cost-effective if
treating large
quantities of
waste










RFIE and APU are
cost-effective.


















Cost-effective for
specific
applications
(chromic/ sulf ate
acid etchantsl
Low capital
investment; cost-
effective for
specific
application
(chromic acid
rinses)
Cost-effective for
large quantity
generator.




-------
Table 5. (Continued)
Applicable Waste
Process Streams
Reverse osmosis Plating rinses.










Donnan dialysis/ Plating rinses;
coupled transport potentially
applicable to acid
baths.












Solvent extraction HN03 /HF pickling
liquors.






Thermal Acid wastes.
decomposition






Stage of
Development
Corrosive waste
membranes
marketed by four
companies. RD
module systems
applicable to
corrosives
available from two
companies.


Donnan analysis
only lab-scale
tested.

Coupled transport
lab and field
tested. Coupled
transport system
is currently being
marketed.






Commercial-scale
systems installed
for development
purposes in
Europe and Japan.
No commercial-
scale installations
in U.S.
Well-establshed
for recovering
spent pickle
liquors generated
by steel industry.
Pilot-scale stage
for organic
wastes.
Performance
90% conversion
achieved with
cyanide plating
rinses.







Data not available
for Donnan
analysis (further
testing required).
Coupled transport
has demonstrated
99% recovery of
chromate from
plating rinses.
Other plating
rinses should be
applicable, but not
fully tested.



95% recovery of
HNO3;70%
recovery of HF.





99% regeneration
efficiency for
pickling liquors.





Residuals
Generated
Recovered plating
solution returned
to plating bath
(after being
concentrated by
an evaporator).
Rinsewater
reused.



Data not available
for Donnan
analysis.

For chromate
plating rinse
applications.
sodium chromate
is generated; can
be used elsewhere
in plant or
subjected to ion
exchange to
recover chromic
acid for recycle to
plating solution.
Metal sludge (95%
iron can be
recovered by
thermal
decomposition).



98-99% purity iron
oxide which can
be reused, traded.
or marketed.




Cost
Cost-effective for
limited
applications.
Development of a
more chemically
resistant
membrane would
make it very cost-
effective for a
wider area of
application.
No cost data
available for
Donnan analysis.

Average capital
cost for plating
shop is $20,000.
Can be cost-
effective for
specific
applications.





Not available.







Expensive capital
investment. Only
cost-effective for
large quantity
waste acid
generators.


inants; e.g., removing copper ions from
spent chromic acid/sulfuric acid brass
etchants and bright dipping solutions.36
Another  recently developed  application
uses electrodialysis in conjunction with
neutralization  to   recover   spent
hydrofluoric-nitric   acid    pickling
liquors.37'38
  Current research in the application of
electrodialysis to the treatment of  cor-
rosive wastes is directed  at  using the
electrolytic ED configuration. The  U.S.
Bureau of Mines is currently investigat-
ing techniques for the removal of  iron
from  nitric-hydrofluoric acid pickling
liquors.39'40  In addition, Ionics, Inc.  is
currently developing improved ED mem-
branes for use with corrosive wastes.
However, their  research is  currently
limited to bench-scale studies  and
preliminary results  have not yet  been
released.41
Reverse Osmosis
  RO involves passing the wastewater
through a semipermeable membrane at
a  pressure  greater  than  the osmotic
pressure caused by the dissolved mate-
rials in the solvent.42 Thus, the osmotic
flow, defined as the flow from a concen-
trated solution  to  a  dilute solution, is
reversed due to the increase in pressure
applied to the system. The technology
has been applied in the metal finishing
industry to  recover  plating  chemicals
from rinsewater, permitting reuse of both
plating chemicals arid rinsewaters.29'43
  Reverse osmosis systems are currently
available for recovering corrosive waste-
water  streams;  e.g.,  plating  rinses.
However, cost-effective use of RO sys-
tems for corrosive waste  applications is
generally limited due to reduced mem-
brane lifetime and high costs for mem-
brane cleaning and replacement.  How-
ever, future  development  of membranes
which  are able  to withstand corrosive
                                   10

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and oxidizing solutions is expected.32
  If membrane  lifetimes are increased,
reverse osmosis would be a very cost-
effective alternative  to  conventional
treatment technologies. Excluding mem-
brane cleaning  and replacement costs,
the only significant operating cost is the
electricity required for operation of the
pump.  However,  current systems  are
limited in  the degree of attainable
concentration in the recovered corrosive
solution. Thus,  many  applications may
also require the use of an evaporator in
conjunction with the RO unit. This
combined system is generally more cost-
effective than  evaporation alone for
dilute solutions.

Donnan Dialysis and Coupled
Transport
  Donnan dialysis and  coupled transport
are similar processes in that both employ
a concentration gradient to drive ions
from a spent solution across a membrane
into a metal stripping solution. The major
difference between  these processes is
the type of membrane and  transport
mechanism employed. The coupled
transport membrane is highly selective
and, therefore, has more specific process
applications, whereas  the donnan dial-
ysis membrane  is applicable to a wider
variety of solution  constituents. How-
ever,  greater purity can be  achieved
using the coupled transport membrane.
  Donnan dialysis has not been tested
on a pilot-scale. Much of the research
that has been  performed  to  date  has
concentrated on  membrane  develop-
ment.44 However, preliminary research
performed by the Southwest  Research
Institute has encouraged them to develop
a pilot-scale unit.45 Pilot-scale testing is
needed to determine if sufficient solution
concentrations can be achieved with the
process.
  Bend Research Corporation has per-
formed most of the development work for
coupled transport technology and has a
patent  pending  on  the  process.46
Although the process is applicable to the
treatment of  several  metal-containing
solutions, the most developed application
is for the treatment of hexavalent chro-
mium in plating rinses. The process was
recently licensed to Concept Membrane,
Inc. for marketing and sales  purposes.
However, commercial  units are  not
currently available for purchase.46
  Both  membrane  technologies show
good potential as  cost-effective alterna-
tives to conventional neutralization  and
disposal practices. In  addition, donnan
dialysis and coupled transport offer
potential  economic advantages  over
other membrane  technologies,  due to
lower energy requirements. The large
hydraulic pressures required for reverse
osmosis and the  large electric  current
flow required by electrodialysis  are not
required for these technologies.44'46


Solvent Extract/on
  Solvent  extraction  is a separation
technique utilizing the differential distri-
bution of  constituents  between  the
aqueous phase and an organic solvent
phase to separate constituents from a
mixed solution. It is widely used as an
analytical  chemistry technique  and  for
the recovery of metals in  the  field of
hydrometallurgy. Recently, research has
also shown applications  for  solvent
extraction in the recovery of spent nitric-
hydrofluoric acid pickling liquors gener-
ated by the steel  industry. Commercial-
scale systems have been tested in both
Sweden and Japan but none have yet
been employed  in the United States.47'48
  Of the  four  solvent extraction pro-
cesses developed for acid waste recov-
ery, the Kawasaki (or Solex) process has
shown  the most promising  results.
Commercial-scale testing of the Kawa-
saki  process has demonstrated 95 per-
cent recovery  of nitric acid  and  70
percent  recovery of hydrofluoric acid.48
In addition, 95 percent of the iron in the
waste solution  was recovered  for
reuse.48 Kawasaki intends to eventually
market the process.48 However, although
the technology  has been demonstrated
to be technically feasible, limited eco-
nomic data are available to assess its
economic viability.


Thermal Decomposition
  Thermal decomposition is an effective
but capital intensive regeneration pro-
cess which has been used to recover both
free and bound acids from wastes. The
process  involves  precipitating and
decomposing metal salts in a roaster, and
collecting  the vaporized acid in a con-
densor. Several  steel manufacturers use
the thermal decomposition process for
the recovery of hydrochloric acid from
spent pickling liquors. Although there are
currently  no other commercial-scale
applications, research has demonstrated
the technical feasibility of using thermal
decomposition  to  regenerate waste
sulfuric acid effluents from spent pickling
liquors and  organic chemical industry
corrosive wastes.
  The thermal  decomposition  process
has the  advantage of  being  able  to
recover bound, as well as free acid from
waste, which distinguishes it from the
previously mentioned recovery technol-
ogies.  More  than  99  percent  of  the
hydrochloric acid equivalents in waste
pickle liquor can be regenerated, and an
estimated 93 to 96 percent  of sulfuric
acid equivalents  can potentially  be
regenerated   by   thermal  decom-
position.28'49
  However,  capital costs  for thermal
decomposition  will be  prohibitive  for
small  volume generators. Although the
total quantity of waste sulfuric acid
generated by the steel industry is greater
than the  amount of hydrochloric acid
generated, the latter is generated by a
small  number of large quantity genera-
tors. Combined with the higher purchase
price of hydrochloric acid, HCI regener-
ation systems may be more economically
viable than  sulfuric acid regeneration
systems in the steel industry. However,
large quantities of waste sulfuric acid are
generated by individual organic chemical
manufacturing  plants  and,  therefore,
acid regeneration  may have a  wider
application for this  industry. With
increasing  costs  for disposal, and
increasing development of the technol-
ogy for  other  waste  types, thermal
regeneration  systems  are likely to find
wider application  in  corrosive waste
treatment.

Selection of Optimal Waste
Management Alternative
  Waste management options have been
summarized previously in Table 1. These
include source reduction, recycling, use
of a neutralization treatment system or
some  combination of these waste han-
dling practices. Selection of the optimal
management alternative will ultimately
be a function of regulatory compliance,
economics, and availability of onsite and
offsite  processing systems and equip-
ment.  Economic considerations include
processing (including pretreatment and
post-treatment) and disposal costs, value
of recovered products, and potential
adverse effects on product  quality or
process equipment  resulting from waste
minimization  or  reuse of  recovered
products.  Additional consideration  in
system selection must be given to factors
such  as  safety, public and employee
acceptance,  liability,  and  degree  of
                                                                               11

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uncertainty in cost estimates and ability
to meet treatment objectives.

References
  1.  Camp, Dresser & McKee, Inc.,
     Boston, MA.  Technical  Assess-
     ment of Treatment Alternatives for
     Wastes Containing Corrosives.
     Prepared for USEPA under Con-
     tract No. 68-01-6403. September
     1984.

  2.  USEPA. Identification and Listing
     of Hazardous Waste Under RCRA,
     Subtitle C, Section 3001—Corro-
     sivity  Characteristics  (40 CFR
     261.22). U.S.  Environmental Pro-
     tection Agency, Washington, D.C.
     PB81-184319.  May 1980.

  3.  Deitz, S. et al., Westat, Inc. National
     Survey of Hazardous Waste Gener-
     ators and Treatment, Storage, and
     Disposal  Facilities  Regulated
     Under  RCRA  in  1981.  Rockville,
     MD. U.S. EPA/OSW. April 1984.

  4.  U.S. Congressional Budget Office.
     Hazardous Waste Management—
     Recent Changes and Policy Alter-
     natives.  CBO  Congress of the
     United States. May 1985.

  5.  Noll, K. E. et al. Recovery, Recycle
     and Reuse of  Industrial Wastes.
     Lewis Publishers, Inc., Chelsea, Ml.
     1985.

  6.  Science Applications International
     Corporation. Industry Studies Data
     Base. August 1985.

  7.  DPRA, Inc. Written Communication
     to  M.  Arienti, GCA Technology
     Division, Inc., regarding analysis of
     Recycling Data from the National
     Survey Data Base. Data Request
     No. M850415W. June 10, 1985.

  8.  ICF, Inc. Survey of Selected Firms
     in  the Commercial Hazardous
     Waste Management  Industry:
     1984  Update.  Prepared for  U.S.
     EPA  Office  of Policy  Analysis.
     September 1985.
  9.  Radimsky, J. et al. Recycling and/
     or Treatment Capacity for Hazard-
     ous Wastes Containing Dissolved
     Metals and Strong Acids. California
     Department of Health Services.
     October 1983.
10.   Gehm, H. W. Neutralization of Acid
     Wastewaters   with    Upflow
     Expanded Limestone Bed. Sewage
     Works Journal 16:104-120. 1944.

11.   Capaccio,  R.  S., and R. Sarnelli.
     Neutralization and  Precipitation.
     Plating and  Surface Finishing.
     September 1986.

12.   Ponzevik,  D.  Liquid Air  Products.
     Telephone conversation  with Ste-
     phen Palmer,  GCA Technology
     Division, Inc. September  6, 1 986.

13.   Breton, M. et al., GCA Technology
     Division, Inc. Technical  Resource
     Document: Treatment  Technolo-
     gies   for  Solvent-Containing
     Wastes.  Prepared  for USEPA
     HWERL under Contract No. 68-03-
     3243. August 1986.

14.   Warner, P. H. et al. Treatment
     Technologies for Corrosive Hazard-
     ous Wastes. Journal of the  Air
     Pollution Control Federation. April
     1986.

15.  Arthur D.  Little, Inc.  Physical,
     Chemical, and  Biological Treat-
     ment Techniques  for  Industrial
     Wastes.   U.S.   EPA   SW-148.
     November 1976.

16.  Kirk-Othmer  Encyclopedia  of
     Chemical Technology. Volume 14,
     3rd Edition.  John Wiley & Sons,
     New York, NY. 1981.

17.  Cushnie,  G. C. Removal of Metals
     from Wastewater.  Neutralization
     and  Precipitation.  Pollution Tech-
     nology Review No. 107, Noyes Data
     Corporation.

18.  Kirk-Othmer  Encyclopedia  of
     Chemical Technology.  Volume 1,
     3rd Edition.  John Wiley & Sons,
     New York, NY. 1981.

19.  Mabbett,  Cappacio & Associates.
     Industrial Wastewater Pretreat-
     ment Study: Preliminary Engineer-
     ing Design Report. January 1982.

20.  Stephenson, J. B., J. C. Hogan, and
     R. S. Kaplan. Recycling  and Metal
     Recovery Technology for Stainless
     Steel Pickling Liquors.  Environ-
     mental Progress, (3)1:50-53. Feb-
     ruary 1984.
21.   Chacey, K., L. Mellichamp, and W.
     Williamson. Chrome Electroplating
     Waste BAT. Pollution Engineering.
     April 1983.

22   Solderman, J.  New Method for
     Recovery of Spent Pickling Acids.
     In: Third International Congress on
     Industrial   Wastewaters   and
     Wastes, Stockholm, Sweden. Feb-
     ruary 6-8, 1980.

23.   Delu,  H.,  L. Xiuchung,  and W.
     Chingwen. The Regeneration of
     Nitric and Hydrofluoric Acids from
     Waste Pickling  Liquor. In:  Sympo-
     sium on Iron and Steel Pollution
     Abatement Technology  for  1980
     held in Philadelphia, Pennsylvania.
     November 18-20, 1980.

24.   Peterson, J. C.,  Crown Technology,
     Inc., Indianapolis, Indiana.  Tele-
     phone conversation with  L.  Wilk,
     GCA Technology Division, Inc. Re:
     Sulfuric Acid  Recovery  System.
     July 10, 1986.

25.   Luhrs, R. Acid  Recovery Systems,
     Inc., Lenexa,  Kansas.  Telephone
     conversation with  L. Wilk,  GCA
     Technology Division, Inc. Re: Sul-
     furic Acid Recovery System. Sep-
     tember 4, 1986.
 26.  Smith, I., G. M. Cameron,  and H
     C. Peterson.  Chemetics Interna
     tional Co., Toronto, Ontario, Can
     ada. Acid Recovery  Cuts  Wast<
     Output.  Chemical Engineering
     February 3, 1986.
 27  Krepler, A. Total Regeneration o
     the Waste Pickle Liquor for Stain
     less Steel. Ruthner Industrieanla
     gen  Aktiengesellschaft Technica
     Report  No.  3,  Vienna, Austria
     1980.

 28.  Versar,  Inc.  National Profile
     Reportfor Recycling/A Prehminar
     Assessment. Draft Report Prepare*
     for the U.S. EPA, Waste Treatmen
     Branch, under  EPA Contract  Nc
     68-01 -7053, Work Assignment Nc
     17. JulyS, 1985.

 29.  U.S. EPA, Office of Research  an
     Development,  Washington,  DC
     Treatability  Manual,   Volume  II
     Technologies for Control/Remove
     of Pollutants.  EPA/600/8-80
     042c. July 1980.
                                  12

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30.  Fontana, C. Eco-Tech, Ltd., Picker-
     ing, Ontario,  Canada. Telephone
     conversation with L. Wilk. August
     21, 1986.

31.  U.S. EPA Industrial Environmental
     Research  Laboratory,  Cincinnati,
     Ohio.  Summary  Report:  Control
     and Treatment Technology for the
     Metal  Finishing  Industry—Ion
     Exchange. EPA/625/8-81/007.
     June 1981.
32.  Higgins, T. E. CH2MHill. Industrial
     Proceses to Reduce Generation of
     Hazardous Waste  at DOD Facili-
     ties—Phase 2 Report, Evaluation of
     18 Case Studies. Prepared for the
     DOD Environmental  Leadership
     Project  and the U.S. Army Corp of
     Engineers. July 1985.

33.  Radimsky,  J., D. I. Daniels, M. R.
     Eriksson, and R. Piacentini. Califor-
     nia Department of Health Services.
     Recycling  and/or  Treatment
     Capacity  for Hazardous Wastes
     Containing Dissolved Metals  and
     Strong Acids. October 1983.
34.  Eisenmann, J. L. Membrane Pro-
     cesses for Metal  Recovery  from
     Electroplating  Rinse Water. In:
     Proceedings of the 2nd Conference
     on Advanced Pollution Control for
     the Metal  Finishing  Industry, co-
     sponsored  by the American  Elec-
     troplaters  Society and  the  U.S.
     EPA;  held  in  Kissemee, Florida,
     February 5-7,  1979.  EPA/600/8-
     79/014. May 1979.

35.  Pouli, D. Innova Technology, Inc.
     Clearwater,  Florida. Telephone
     conversation with L. Wilk,  GCA
     Technology Division, Inc. August
     26, 1986.
38.  Basta, N. Use Electrodialytic Mem-
     branes for Waste Recovery. Chem-
     ical Engineering. March 3, 1986.

39.  Horter, G. L. U.S. Bureau of Mines,
     Rolla, Missouri. Telephone conver-
     sation with L. Wilk, GCA Technol-
     ogy Division, Inc. August 29,1986.

40.  Horter, G. L., J. B. Stephenson, and
     W. M. Dressel.   Permselective
     Membrane Research for Stainless
     Steel Pickle Liquors. In: Proceed-
     ings of the International Sympo-
     sium on Recycle  and  Secondary
     Recovery of Metals; sponsored by
     the metallurgical Society of AIME,
     Warrendale, Pennsylvania; held in
     FortLauderdale, Florida. December
     1-4,1985.
41.  Jain, S. M. Ionics, Inc. Telephone
     conversation  with  J.  Spielman,
     GCA Technology Division, Inc.
     August 12, 1986.

42.  U.S. EPA. Sources and Treatment
     of Wastewater in the Nonferrous
     Metals  Industry.  Prepared  by
     Radian Corporation for the U.S.
     EPA,  Industrial Environmental
     Research Laboratory, Cincinnati,
     Ohio, under EPA Contract No. 68-
     02-2068.  EPA/600/2-80/074.
     April 1980.

43.  U.S. EPA, Office of Research and
     Development,  Cincinnati,  Ohio.
     Handbook for  Remedial Action at
     Waste Disposal Sites. EPA/625/6-
     85/006. October 1985.

44.  Hamil, H. F. Southwest Research
     Institute, San  Antonio, Texas.
     Project Summary: Fabrication and
     Pilot-Scale Testing of a Prototype
     Donnan Dialyzer for the Removal
     of Toxic Metals from Electroplating
     Rinse Waters. EPA/600/S2-85/
     080. August 1985.
47.  Rydberg, J., H. Reinhardt,  B.
     Lunden, and P. Haglund. Recovery
     of  Metals from Stainless Steel
     Pickling Bath. In: Proceedings of
     the 2nd Annual International Sym-
     posium on HydroMetallurgy, Chi-
     cago, Illinois.  February 25-March
     1, 1973.
 48.  Watanabe, T.,  M.  Hoshimo, K.
     Uchimo, and Y. Nakazato. A New
     Acid and Iron Recovery Process in
     Stainless Steel Annealing  and
     Pickling Line. Kawasaki Steel Tech-
     nical  Report  No.  14,  pp. 72-82.
     March 1986.

 49.  Wadhawan, S. C. Perox, Inc., Pitts-
     burgh, Pennsylvania. Letter to J.
     Spielman, GCA  Technology  Div-
     ision, Inc. August 7, 1986.
36.  Gary, S. Scientific Control,  Inc.,
     Chicago,   Illinois.  Telephone
     conversation  with  L. Wilk, GCA
     Technology Division,  Inc. August
     29, 1986.

37.  Rodgers, B. Aquatech  Systems,
     Bethel,  New Jersey. Telephone
     conversation with J. Spielman,
     GCA  Technology Division, Inc.,
     August 11, 1986.
45.  Hamil, H. F. Southwest Research
     Institute,  San  Antonio, Texas.
     Telephone conversation with L.
     Wilk, GCA Technology  Division,
     inc. September 24, 1986.

46.  Friesen,  D. Bend Research Corpo-
     ration, Bend,  Oregon.  Telephone
     conversation with  L. Wilk,  GCA
     Technology Division,  Inc.  Sep-
     tember 25, 1986.
                                                                             13

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Lisa Wilk. Stephen Palmer, and Marc Breton are with Alliance Technologies
  Corporation, Bedford, MA 01730.
Harry M. Freeman is the EPA Project Officer (see below).
The  complete report,  entitled "Technical Resource Document:  Treatment
  Technologies for Corrosive-Containing Wastes,  Volume II," (Order No. PB
  88-131 289/AS; Cost: $38.95) will be available only from:
        National Technical Information Service
        5285 Port Royal Road
        Springfield,  VA 22161
        Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
        Hazardous Waste Engineering Research Laboratory
        U.S. Environmental Protection Agency
        Cincinnati, OH 45268

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