A TECHNICAL APPROACH TO AUDITING PLANTS

REDUCTION AND TREATMENT PERFORMANCE FOR CHEMICAL FACTORS INFLUENCING WASTE GENERATION,

Thomas F. Stanczyk Senior Vice President

Recra Environmental, Inc. 10 Hazelwood Drive, Suite No. 106

Amherst, New York 14150

INTRODUCTION

In an industrial society that relies on a multitude of complex, hazardous

chemicals, environmentalists, scientists, engineers .and lawyers are finding it

increasingly important to understand the chemistry of wastes and the potential

for environmental impairment. The creativity of many of our nation's scien- -I tists has led to the development of literally hundreds of thousands of

"unnatural" chemicals posing variable concerns relative to environmental fate.

It is estimated that about 50,000 chemicals will appear on the

Environmental Protection Agency's chemical inventory list of compounds which

have been prepared comnercially or have been identified as potentially useful

chemicals, The exact number of chemical substances is unknown, but Chemical

Abstracts Service's best estimate ranges from 6 to 8 million substances. In

the United States alone, there are over 5,000 chemical producers and petroleum

refiners that manufacture 50,000-70,000 chemicals. Approximately 1,000 new

chemicals are introduced into the market every year. The complexity of this

vast array of inorganic and organic matrices raises environmental issues with

-the quantifiable degrees of environmental concern associated with waste

generation. Waste elimination, prevention and optimum control management each

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require a scientific mentality that incorporates a multi-disciplinary approdch 1

to understanding the factors responsible for waste generation.

Recent and on-going regulatory attention to the issues and standards dic-

tating waste minimization, land disposal bans and BDAT performance criteria

magnifies the importance of chemistry and its role in the 'selection of tech-

nologies, process equipment, chemical controls and waste management practices.

Operable hazardous waste management units; i.e., incineration, secure land-

fills and treatment facilities, are being faced with stringent waste accep-

tance criteria encompassing variable degrees of chemical content verification

and hazard assessment. Design performance specifications must account for

concerns centering around pollutant mobility as defined by the potential for

transport in air and/or water environments. Proposed hazardous- waste iden-

tification criteria employing the analytical procedures involved with ii2

Toxic Characteristic Leach Protocol placed additional emphasis on

understanding modi lity concerns within variable waste matrices.

There is no question that in order to avoid serious environmental con-

cerns resulting from the management of contaminated waste residues as well as

chemical residues which could occur from future process formulations, it is

essential that industry develop a better understanding of chemical behavior

taking into account process mechanisms involving chemical transport, transfor-

mation and accumulation mechanisms before wastes are generated and treated.

Materi a1 balances need to describe where and at what concentrations chemical

contaminants are accumulating and effecting reduction strategies applicable to

recycling or source implementation, The combined factors can be readily iden-

tified using an audit approach that emphasizes chemical and physical b )e

properties and their impact on waste generation and strategic planning.

3

3 Considering

explore var

tion audit,

immobilizat

the potential complexity of waste chemistry, this paper wil

ous chemical factors which can be identified during a waste reduc

defining as appropriate, mechanisms enhancing pollutant removal

on and degradation at the origin of waste generation.

REGULATORY TRENDS DICTATING CHEMICAL CHARACTERIZATION

During the last decade, this country has seen the institution o f several

health, safety and environmental laws protecting human health and the environ-

ment from an increasingly number of known, quantifiable toxic substances,

Among the legislation are:

o The Toxic Substances Control Act (TSCA)

o The Resource Conservation and Recovery Act (RCRA)

o The Occupational Safety and Health Act (OSHA)

o The Hazardous Solid Waste Amendments (HSWA)

o The Federal Water Pollution Control Act (FWPCA)

o The Clean Air Act (CAA)

o The Safe Drinking Water Act (SDWA)

o The Food, Drug and Cosmetic Act (FDCA) .

o The Federal Insecticides, Fungicides and Rodenticides Act (FIFRA)

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With each legislation, a comnonality exists which addresses chemical

substances, potential routes of mobility, and hazard assessments measuring

health and potential environmental risks. On-going advances in design perfor-

mance standards have resulted in variable degrees of analytical sophistication

allowing for detection and confirmation of complex pollutants within various

a) waste matrices. Regulatory performance standards mitigating toxicological im-

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1 pacts have dictated sensitive analyses covering an array of inorganic and

organic pollutants typically characterized as priority pollutants.

Waste reduction audits quantifying feedstock usage and material flow’ must

take into account individual constituents and their potential f o r being found

in wastes as priority pollutants. Typical classifications warranting review

i ncl ude:

o Metals and Inorganics; i.e., arsenic, cadmium, cyanide, mercury, chromium

and lead

o Pesticides, PCB, and Related Compounds; i.e., aldrin, DDT, heptachlor,

lindane, TCDD and polychlorinated biphenyls

o Halogenated Aliphatic Hydrocarbons; i.e., dichloromethane, bromomethane. I

tetrachloromethane, trichlorofluoromethane

o Halogenated Ethers; i.e., bis(chloromethyl)ether, 2-chloroethylvinyl-

ether, 4-bromo-phenylphenylether

o Monocyclic Aromatics; i.e. benzene, chlorobenzene, ethylbenzene, phenol,

pentachlorophenol, 1,2,4-trichlorobenzene

o Phthalate Esters; i .e., dimethyl, di-n-butyl , diethylbutylbenzyl; and

Polycyclic Aromatics; i.e., naphthalene, chrysene, benzo(a)pyrene,

anthracene

o Nitrosamines; i.e., diphenylhydrazine, benzidine, acrylonitrile,

dimethylnitrosamine

Correlating the presence/absence of these constituents with feedstock usage

and process by-product generation becomes even more important when it is

necessary to account for Appendix I X , Hazardous Substance List (CERCLA,,

Appendix I 1 1 (California List) and several state mandated land disposal bans

accounting for total organic content. Table 1 provides a cross-reference of

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some o f the pertinent constituents dictating proper management, remediation

and/or control. '3

T A R E 1

APPEHDIX I X . SUPERFUHD, AND P R I O R I T Y POCCUTAHT COMPOUNDS

acenaphthene acenaphthyl ene aldrin anthracene aroclor 1016-1260 benzene benz(a1anthracene benzo(b)fluoranthene benzo(k)fluoranthene benzo(ghi Iperylene benzo( a)pyrene alpha-BHC beta-BHC gamna-BHC bis(2-ch1oroethoxy)mthane bis(2-chloroethy1)ether bis(2-chloroi sopropyl lether bromodichlormethane bromomethane 4-bromophenyl phenyl ether butyl benzyl phthalate carbon tetrachloride chlordane p-chloroani 1 i'ne chlorobenzene .- p-chloro-m-cresol c hl orodi bromome t h ane chl orof om chloromethane 2-chloronaphthalene 2-chlorophenol chrysene 4.4' DDD 4,4l ODE 4,4l DOT dibenzo(a,h)anthracene di-n-butyl phthalate m-dichlorobenzene o-dichlorobenzene p-di ch 1 orobenzeoe 3,3'-dichlorobenzidine 1,l-dichloroethane 1,P-dichl oroethane 1,l-dichloroethylene trans-1,2-dichloroethylene dichloromethane 2,4-dichlorophenol 1,2-dichloropropene dieldrin diethylphthalate 2,4-methylphenol 4,6-dinitro-o-cresol

4-dinitro h no1 $14, di ni tro! oeuene

2,6-dinitrotoluene di-n-octyl phthalate di-n-propylni t r o s m i n e endosulfan I (alpha) endosulfan I 1 (beta) endrin fluoranthene fluorene heptachlor heptachlor epoxide hexachlorobenzene hexachlorobutadiene hexachlorocyclopentadiene hexachloroethene hexachlorophene indeno(l,2,3-cd)pyrene naphthalene nitrobenzene 2-nitrophenol 4-nitrophenol fl-nitrosdiphenylamine pentachlorophenol phenanthrene phenol pyrene 1,1,2,2-tetrachloroethane toluene toxaphene tri bromomethane 1,2,4-trichlorobenzene l,l,l-trichloroethane 1,2-trichloroethane trichloroet ylene 2,4,6-trich orophenol vinyl chlor d e

antimny arsenic beryllium cadmium chromi un copper lead mercury nickel .sei enium silver tha 1 1 i um zinc

W I SCELL AHEOUZ

cyani de

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Total Organic Content

Some of the specific concerns dictating wzste acceptance criteria f o ,

land management units are:

Physical State: Free liquid test determinations are dictating the

need for volume reduction (liquid-solid), phase

separtion and chemical stabilization effective i n

pollutant imnobilization.

Sol ubi 1 i ty: In addition to EP Toxicity and TCLP, several states

have pl aced sol ubi 1 i ty 1 imitations of several c o m n

contaminants including metals, metal salts, inorganic

non-metallics, reactives and oxidizers, Values

exceeding accepted concentrations are requiring

pollutant removal and/or imnobilization. \

Flash Point/ In addition to restrictions on total organic content, Vapor Pressure

several states have restrictions on flash point and

volatility, forcing generators to treat wastes in a

manner that will suppress flash point or remove

constituents of concern.

Tot a1 Vol at i 1 e Federal and state land disposal acceptance criteria Organic Content

have limited the total content of volatile organics

which can be present in a waste being considered f o r

1 and disposal .

Restrictions are in place which dictate total allow-

able quantities of organic constituents which can be

present in a waste categorized as toxic.

1 There are several other limitations and restrictions addressing mode of

handling, special cover, reactivity, compatibility, and leachability. In

terms of leachability, the proposed TCLP procedure for characterizing hazar-

dous waste on the basis of toxicity could significantly increase waste volumes

impacting large volumes of solid waste that may, by the nature of the process

unit's current mode of hand1 ing, contain hazardous substances deemed mobile

under the proposed tests. Table 2 sumnarizes some of the mobility charac-

teristics of organic constituents identified by the TCLP organic fraction.

Table 2 . nobility characteristics o f organic compounds.

Bo1 1 ing Solubility Volatility Point in Water at at Ambient "C Ambient Temp. Temp. (mnHg)

Chlorobenzene 132 472 ppm Cresols 192 24,000-31,000 ppm 1,2-Dichlorobenzene 180 145 ppm Ethyl acetate 77 100 ppm Methyl Ethyl Ketone 80 353,000 ppm Methyl Isobutyl Ketone 116 . 200,000 ppm To1 uene 111 535 ppm

Trichloroethylene 87 1,000 ppm Xylene 137-144 183 ppm Methylene Chloride 40 16,700 ppm

l,l,l-Trichloroethane 75 4,400 PPm

9 (Extrap. 0.012( 25" 1.5 (25") 73 (20" ) 77.5 (20") 15.7 (20") 28.7 (25") 96 (20" )

6 (25') 362 (20")

A review of the proposed extract limitations, referenca Table 3, raises con-

cerns that many of the wastes comnonly generated in indgstry will fail the

test, thus resulting in their redefinition as a hazardc.:s waste.

i

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m

X 1 8 m Do05 D319 Do20

9006 w 2 1 w2 2 0023 W 2 4 0025 Do07 0026 0027 0028 0016 m 2 9 0030 003 1 0032 0033 0012 0034

0035 m 3 t m3i -

C O h m S

Lcryloni t ri 1 e Arsenic Bariua Benzene Bis(2-chloroethyll

ether Cadmi- Carbon disulfide Carbon tetrachlorid Chlordane Chlorobcnzme Chloroforn C h r m i u a o-Cresol .-Cresol p-Cresol 2,4-D 1,2-Dichlorobcnzme l,4-Dichloroknzme lI2-Dichloroethane 1,l-Dichloroethylm 2,4-Dinitrotolume Endrin Heptachlor (and its

Hexichloroknzme Hurchlorobutidimc Hexachloroethane

hydroxi de)

?kLi;~Y,! L E V E L (aq/1)

5 . 0 5 . 0

0.07 0.05

1.0 14.4 0.07 0.03 1.4 0.07 5.0 10.0 10.0 10.0 1.4 4.3

10.8 0.40 1.0 0.13 0.033 0.001

0.13 0.72 4.3

100

m - Do38 Do08 Do13 Do1 4 0039 Dol0 0041 M W Z m 3 0044 W l O 0011 !xn5 0016

0047 DM8

0049 5315 wso Oosl W 5 2 a n 3 a m 0017 a n 5 -

1 robutanol L e a d Lindane Mthoxychlor Methylene Chloride Nthylethyltetone nitrobenzene Pmtachl orophenol Phenol Pyridine Selenim Silver 1.1,1,2-Tetrachloro-

ethane lIl,2,2-Tetrachloro-

ethane Tetrachloroethylene 2,3,4,6-Tetrachloro-

phenol Toluene Toxaphene l,l,l-Trichloroethane 1,1,2-Trlchloroethane Trichloroethylene 2,4,5-Trichlorophenol 2,4,CTrichlorophenol 2,4,5-TP (Silvex) Yinyl Chloride

TbULAiO2v

(mq/l)

5.0 0.05 1.4 8.6 7.2 0.13 3.6

14.4 5.0 1.0 5.0

10.0

1.3

0.1 1.5

14.h

30

LEVEL

36

0.07

1.2 0.07 5.8 0.30 0.14 0.05

In retrospect, a waste reduction audit can uti 1 i ze a "Cause-Effect"

approach to existing waste management practices. By defining pollutants o f

concern,

pollutant loadings and environmental impact, taking into account restrictions

on current disposal practices. This approach will generally result in a

reassessment of existing waste management practices with emphasis being placed

individual waste types can be prioritized on the basis o f volum5, 1

on source reductionjtreatment alternatives effective in removing pollutants.

It is important to keep in mind that this approach has application, as well,

to wastewaters, oils,'solvents, air emissions, and other waste types not typi-

cally managed by land disposal units. Waste generation profiles will allow

for objective assessments of source reduction, recycling and treatment. Sone

of the basic questions which need to be addressed in the audit are:

o Is the waste amenable to treatment and land disposal in its existing

form? If not, can the waste be modified in a manner acceptable t o the

process as well as the final mode of disposal?

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o Will the treatment process create a waste by-product(s) more hazardous

and/or toxic than the waste originally generated? 3 o Can the waste and/or constituent(s) be segregated in a manner that would

eliminate and/or reduce hazard potential and/or toxicity?

o Can the chemical and/or process resulting in the hazardous by-product be

substituted or modified in a manner eliminating the problem?

FEEDSTOCK PROCUREMENT AND USAGE

An audit o f individual plant processes should account for feedstock pro-

curement, storage, distribution and usage policies and procedures. Some of

industry’s problems with excess waste generation culminate from: excess volu-

mes of inventory, off-spec reagents, poor controls over purchasing and distri-

bution, no accountability of ancillary process chemical usage, and a basic

1 lack o f hazard awareness.

One o f the objectives o f this audit approach is to establish a tracking

system that, in addition to accounting for inventory, distribution, and usage,

will allow the generator to correlate the presence of hazardous substances

with feedstock. The lack of hazard awareness is generally one of the major

contributors to waste generation. In most cases, the problems are not process

by-products but anci 1 1 ary chemicals; i .e., maintenance chemicals and/or pol lu-

tant abatement reagents which, in themselves, contribute to the hazard charac-

teristics of a spent residue (liquid or solid) by interaction (gaseous, liquid

or sol id) .

Material Safety Data Sheets, chemical technical assays and in-house

laboratory quality control samples all generate chemical data indicative o f

hazard potential. In addition to recognizing special precautions for $3

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubr i s i 1 l , l , l -Tr ich loroe thane CERCLA RQ 1 l b .

RCRA Hazardous Waste U226, FO32

i i

) handling, storage and disposal, it is necessary to assess this data for I t s

impact on waste generation. This source of data in a Waste Minimization Study

is often overlooked. For example, listed on Table 4 zre the properties and

hazard identification potential of some c o m n chemicals used by maintenance

and/or process generators. The presence of highly mobile constituents that

are predominantly covered on all regulatory lists; i.e., California, priority

pollutants, Hazardous Substance List (HSL), can contribute to hazardous waste

generation, especi a1 ly since trade-name chemicals are rarely assessed for

impact on waste volume. Recognizing potential impact will allow for the deve-

lopment o f strategies effective in product substitution and/or segregation.

\

Table 4. Chemical Feedstock Charac te r i s t ics .

I FEEDSTOCK HAZARDOUS SUBSTAHCE REGUTMY IMPACT

K e m k 100-W . Haphtha (Spray Lubricant)

RCRA Hazardous Waste DO01

RCRA Hazardous Waste I R-ver U W , FW2

-) modified through feedstock substitution and/or process modifications or

whether specific by-products contain any substances which would be deemed

. highly mobile and/or amenable to transformation by treatment or source

Task 3 nobility Profile

Air: pathways, releases, quantities Water: characteristics, dispersion Soil: factors influencing loadings

1

control.

Figure 1.

.

A typical approach to u s i n g material balances is

FIGURE 1

TECHNICAL APPROACH TO REVIEWIMG M E R I A L BALAMCES I N WASTE REDUCTION AUDITS

Task 1 Chemical Loadings

Input:

Du tpu t :

Physical Properties Chemical Content Volatile Organics, Hetals, Soluble Hetals, Toxic Organics and Inorganics

Physical Properties Reactivity, Stabi 1 i ty Phase Loadings, Free Liquid Potential, Solubility, Volatility, F 1 amnabj 1 i ty , Redox Potential

Chemical Properties Screening Protocol indicative of product quality,

Hazardous Substances, Priority Pollutants, Appendix 111, Specific Restricted Parameters identified by available. current &des of disposal

I

Task 2 Hateri a1 s Bal ance

Input: Synthesis, Controls Use, Storage, Ancillary Chemical Usage and Storage

Output: Production Records By-product Releases and Locations

Variations in Releases Impacts o f Continuous , Intermittent, Batch Operations

Reaction By-products Ancillary Chemical Waste Generation

depicted in

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ASSESSING D A T A FOR OBJECTIVE REDUCTION STRATEGIES

The IICause-Effect" kvaluation of each source will generally result in the

prioritization of specific waste streams and constituents o f prime concern,

This section identifies'specific concerns and strategies for several generic

1

1

waste types and/or consiituents amenable to minimization by source control,

elimination, recycling and treatment. It is important to keep in mind that I

all waste matrices will: generally vary in terms o f chemical content, hazard

potential and waste pro:perties dictating mobility. As such, the following

guidelines should be retiewed in the context o f typical guidelines for waste

minimization strategic p'lan development.

i

i 1 !

Metals I

There are several ;mechanisms for isolating metal pollutants from their

inorganic as well -as orcjanic waste matrix. Precipitation, coprecipitation or

cocrystallization are d o n g the comnon approaches to isolating metal pollu-

tants in aquatic media.

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Typical reaction mechanisms are depicted in Table 5.

I TABLE 5

PRECIPITATION RUCTIONS

Cd+' + 20HL + Cd(OE), + , K @ 25°C

Cr+3 + 306- + Cr(06)3 + , K = 7 x @ 25'C

Co+' + 206- + CO(OH)~ + K = 2 x @ 25'C

C U + ~ + 208' + Cu(OH), + K = 2 . 2 x lo-'' @ 25'C

Ksp = 1.6 x lo-' @ 25'C

Ra+' + + BaS04 + K = 1 x 10-l' @ 25'C = 1.5 x @ 25'C Pb" + C03-3 + PbC03

Pb+' + 208- + Pb(06), + K = 4 x @ 25'C

+ co3-2 + h C O 3 + K - 8.8 x @ 25'C

Hn" + 206- + H n ( O H ) 2 + , K = 1.6 x @ 25'C

+ , K = 6.8 x lo-' @ 25'C -2 Hg+' + SO4 + HgS04

h.1" + 206- + NI(06)2 + K - 2 x @ 25'C

Zn+' + 206- + Zn(OH), + Ksp = 7 x @ 25'C

= 2.8 x SP SP SP SP + Eia+' + Cog -2 + BaC03

SP

+ ' K*p

SP SP SP

SP

SP

i

3 Beryllium and antimony can be quantitatively coprecipitated with a

variety of hydroxides depending on the pH used. Sulfides, sulfur, calcium

silicate, several phosphates, sulfates and several carbonates are all docu-

mented for their specific application to coprecipitation of metals, including

but not limited to, mercury, arsenic and selenium.

There are several mechanisms whereby organics can be applied as metal

coprecipitates providing the proper state of the metal is well understood.

As+3, Se+4, Cr+6, Pb+*, Fe**, and Fe+3 can be concentrated by coprecipitation

using diethyldithiocarbamate, Thionalide has been used as a coprecipitate for

arsenic and antimony at ppb levels in highly elevated salt environments.

Other reagents having documented success and potential applicability to source

reduction include coprecipitations with quanidates, thioxinates, - EDTA, alpha-

mercaptobenzothi azo1 e, cupf erron and phenylf luorone. )

Another strategy having application to metal isolation and potential

recycling is electrodeposition.

Other methods, each having specific application to the isolation and con-

I centration of metals, include: evaporation; freezing; sorption which includes

b 'i absorption, adsorption, ion-exchange, membrane and combinations thereof; 5

solvent extraction; and reverse osmosis. Despite the many advantages of pre-

concentration techniques, it is important to consider physical and chemical

B variables having the potential for reducing performance efficiency. Some

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examples of the stated metal removal strategies are sumnarized as follows:

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o evaporation of wastewaters t o recover metals of specific reuse value;

i .e., mercury.

o evaporation with reduction to remove metal halides and oxyhalides of

selenium and tellurium.

o activated carbon, oxidized with nitric acid, has been used to extract

divalent nickel, cadmium, cobalt, zinc, manganese, and mercury, from

wastewaters includins brine sol uti ons.

o zeolite extraction of copper, nickel, zinc and cobalt.

o starch xanthate as an insoluble material was used to extract metals

without pH dependency.

o several natural materials; i.e. peat moss, protein containing species

(wool, hair, feathers), peanut skins, walnut meal and various woods

including cellulosic materials, have extracted metals from aqueous medi-

o shredded tires, including carbon black, were documented as additives to

remove mercury from aqueous solutions.

1

o chelating polymer resins are employed to remove trace metals.

o cation exchange resins have been used to separate many transition metals

such as Fe(III1, Cu(II), Zn(II), Ni(II), Ag(I), Mn(II), etc.

o chelate-type complexes have been documented with oximes, hydroxyquino-

lines, nitrosophenols, naphtols, dithiocarbamates, xanthates and high

molecular weight amines.

An example of a solvent extraction system having application to mercury

in brine solutions i s illustrated in Figure'2.

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Figure 2 . Solvent Extraction System

-7 r l r [ y k Hg2+ in Extract With Aqueous Waste To Disposal

Brine Solution Organic Solvent Brine Solution or Back to e.g. HaCl, 3M 0.1M R4HC1-DEB Free o f Hg2t Electrolytic

H 10-11 Cell

Organic Solvent Loaded With Hg2t Ions

thy ene i m i n e -1

4 Stripping c1 Regenerated Sol vent

Hg Values

Organics

There are a number of physical-chemical mechanisms applicable to isola-

tion, removal, recycling, as well as, transformation of organic constituents,

This section will attempt to summarize some of the generally documented con- 1

cepts influencing mobility and treatment performance. The conceptual basis of

these mobility concepts can be extrapolated in the context o f source eva-

luation and reduction o f waste pollutants in aquatic, air and sludge matrices.

Predicting distribution o f a waste pollutant and/or hazardous chemical consti-

tuent is the prime objective of this assessment. Some of the basic mechanisms

requiring evaluation incl ude:

o Solubility; tendency o f a chemical to move from a waste matrix (i,e.,

solid, sludge) into solution (aqueous, organic).

o Equilibrium Vapor Pressure; quantified potential of a pollutant to move

from a liquid or solid, i.e,, chemical solubility in air.

o Partition Coefficient; particularly important in multi-phase (liquid/

liquid or liquid/solid) waste generation. 9

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o pK; behavior of pollutants under variable pH.

o Adsorption; isolation of select chemicals from solution onto a solid,

Key properties influencing adsorption include: mineral fraction, organic

fraction, Van Der Waal's forces, hydrophobic bonding, hydrogen bonding,

ligand exchange, dipole-dipole interactions, chemisorption pfoperties of

the adsorbate, and kinetics.

o Diffusion; movement of air, water pollutants through variable water

matrices.

o Leachability; particularly using EP Toxic and TCLP protocol, with atten-

tion to waste matrix.

o Evaporation; particular attention to solvent and inorganic matrices.

In order to be able to define possible reduction strategies and The

) extent of pollutant mobility and environmental impact, it is necessary to L

able to define the manner in which the chemical will be distributed during the

processing phase, as well as after waste generation and management. Some

strategies which can be developed for source evaluation, reduction and treat-

ment are summarized as follows:

o Several chlorinated hydrocarbons can be transformed using the concepts of

chemical reduction.

o Esters of carboxylic acids, organophosphates, carbamates, halogenated

compounds can be subjected to hydrolysis under variable pH conditions

resulting in transformation of chemical content and reduction of toxi-

city.

o Stripping/evaporation of volatile and semi-volatile constituents, Table

6 sumarizes the theoretical ease of stripping volatiles from wastewa?

and the anticipated performance levels.

1

S t e m s t r i p p i n g performance and theoretical ease o f stripping. T A E L i 6,

1 Constituent Average Level Achieved (mg/l)

1,1,2-trichloro-1,2,2-trifluoroethane* Trichlorofluoromethane* Tetrachloroethylene* Carbon t et rac hl ori de* 1,l-Oichloroethylene Chloroethane Trichloroethylene* Ethyl benzene* 1,1,2-Tr i ch 1 oroe thane* Toluene* Benzene 1,2,-trans-Oichloroethylene 1.1.1-Trichloroethane* Chlorobenzene* Chlorof o m Methylene chloride* 1,1,2-Trichloroethane 1,2-Oichloroethane Tetrahydrofuran Methyl isobutyl ketone*

<0.010 <0.010 <o. 010 <0.010 <0.010 <o. 010 0.019 0.200

<o ,010 0.036 0.027

<o. 101 0.457 <0.010 <o. 010 <0.010 <o. 010 0.051

<o .OlO <o. 010

I

Other strategies having individual effects on pollutant loadings

degradation, oxidation, extraction, and chemical stabilization.

are thermal

Glith each

strategy, the understanding of chemical factors i s important in optimizing

treatment performance and the potential for source reduction. 1

SUMMARY

Initiating a waste minimization program can prove to be a very difficult

and unsuccessful task if the chemistry of feedstocks and waste by-products are

not well understood.

Since plant questionnaires and audits are generally accepted as initial

work efforts in a waste minimization program, this paper attempted to identify

many of the chemical factors which needed to be considered in the evaluation

of source reduction, recycling and treatment strategies.

Considering the complexity o f many of the chemicals used today in

industry, it is imperative that the initial aspects of a plant survey take

into account chemical properties inherent to feedstock, as well as waste.

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Using a "Cause-Effect" rating matrix, a systematic approach can be under take1

that would allow for the development of reduction strategies for specific ! !!

sources as well as chemical pollutants. i 11

Overall, this approach will allow industry to quantify reduction in waste 8 ,

volumes, as well as hazard, inclusive of toxicity. Problems relative to ; existing waste disposal and treatment performance can be eliminated and

viable, practical solutions, can be recognized without major capital

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investment.

REFERENCES

Soxena, Jitendra, Fisher, Farley; " A Hazard Assessment of Chemicals Current Development"; 1983.

Office o f Water Planning and Standards, U.S.E.P.A.; "Water Related Environmental Fate of 129 briority Pollutants." 1 Tinsley, Ian 3. ; "Chemical' Concepts in Pollutant Behavior"; 1979.

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