Industrial waste treatment handbook

This book has been developed with the intention of providing an updated primary reference for environmental managers working in industry, environmental engineering consultants, graduate students in environmental engineering, and government agency employees concerned with wastes from industries. It presents an explanation of the fundamental mechanisms by which pollutants become dissolved or suspended in water or air, then builds on this knowledge to explain how different treatment processes work, how they can be optimized, and how one would go about efficiently selecting candidate treatment processes. Examples from the recent work history of Woodard Curran, as well as other environmental engineering and science consultants, are presented to illustrate both the approach used in solving various environmental quality problems and the stepbystep design of facilities to implement the solutions. Where permission was granted, the industry involved in each of these examples is identified by name. Otherwise, no name was given to the industry, and the industry has been identified only as to type of industry and size. In all cases, the actual numbers and all pertinent information have been reproduced as they occurred, with the intent of providing accurate illustrations of how environmental quality problems have been solved by one of the leading consultants in the field of industrial wastes management. This book is intended to fulfill the need for an updated source of information on the characteristics of wastes from numerous types of industries, how the different types of wastes are most efficiently treated, the mechanisms involved in treatment, and the design process itself. In many cases, “tricks” that enable lower cost treatment are presented. These “tricks” have been developed through many years of experience and have not been generally available except by word of mouth. The chapter on laws and regulations is presented as a summary as of the date stated in the chapter itself andor the addendum that is issued periodically by the publisher. For information on the most recent addendum, please call the publisher or Woodard Curran’s office in Portland, Maine, at (207)

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Industrial Waste Treatment Handbook

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Industrial Waste Treatment Handbook

Frank Woodard, Ph.D., P.E.,

President

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A member of the Reed Elsevier group

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Library of Congress Cataloging-in-Publication Data

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A catalogue record for this book is available from the British Library.

The publisher offers special discounts on bulk orders of this book.

For information, please contact:

Manager of Special Sales

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my (almost) lifelong best friend, Jean McNeary Woodard, who deserves much of the credit for the existence of this book.

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1 Management of Industrial Wastes: Solids, Liquids, and Gases 1

1.1 Management of Industrial Wastewater 1

1.2 O&M Costs 10

1.3 Management of Solid Wastes from Industries 18

1.4 Management of Discharges to the Air 20

1.5 Bibliography 28

2 Fundamentals 29

2.1 Introduction 29

2.2 Characteristics of Industrial Wastewater 29

2.3 The Polar Properties of Water 30

2.4 Electrical and Thermodynamic Stability 33

2.5 Chemical Structure and Polarity of Water 36

2.6 Hydrogen Bonding 37

2.7 Polar Solvents versus Nonpolar Solvents True Solutions 38

2.8 Emulsification 40

2.9 Colloidal Suspensions 43

2.10 Mixtures Made Stable by Chelating Agents 44

2.11 Summary 44

2.12 Examples 45

2.13 Bibliography 48

3 Laws and Regulations 49

3.1 Introduction 49

3.2 History of Permitting and Reporting 49

3.3 Requirements 49

3.4 Water Pollution Control Laws 50

3.5 Groundwater Pollution Control Laws 52

3.6 Air Pollution Control Laws 55

3.7 Bibliography 60

4 Wastes from Industries 61

4.1 Chemical Descaling 61

4.2 Degreasing 62

4.3 Rinsing 64

4.4 Electroplating of Tin 65

4.5 The Copper Forming Industry 74

4.6 Prepared Frozen Foods 77

4.7 Wastes From De-inking 86

4.8 Die Casting: Aluminum, Zinc, and Magnesium 93

4.9 Anodizing and Alodizing 99

4.10 Production and Processing of Coke 103

4.11 The Wine-Making Industry 107

4.12 The Synthetic Rubber Industry 110

4.13 The Soft Drink Bottling Industry 119

4.14 Production and Processing of Beef, Pork, and Other Sources of Red Meat 124

4.15 Rendering of By-Products from the Processing of Meat, Poultry, and Fish 130

4.16 The Manufacture of Lead Acid Batteries 138

5 Industrial Stormwater Management 149

5.1 General 149

5.2 Federal Stormwater Regulations 149

5.3 Prevention of Groundwater Contamination 151

5.4 Stormwater Segregation, Collection, Retention, and Treatment 152

5.5 Design Storm 152

5.6 System Failure Protection 153

5.7 Stormwater Retention 153

5.8 Stormwater Treatment 153

5.9 Stormwater as a Source of Process Water Makeup 154

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6 Wastes Characterization: The Wastes Characterization Study, Wastes

Audit, and the Environmental Audit 166

6.1 Wastes Characterization Study 166

6.2 Wastes Audit 169

6.3 Environmental Audit 172

6.4 Characteristics of Industrial Wastewater 179

6.5 Characteristics of Discharges to the Air 192

6.6 Sample Analysis 198

6.7 Ambient Air Sampling 198

6.8 Characteristics of Solid Waste Streams from Industries 201

7 Pollution Prevention 208

Findings and Policy 208

7.1 General Approach 209

7.2 Source Reduction 212

7.3 The Waste Audit 215

7.4 Benefits of Pollution Prevention 216

8 Methods for Treating Wastewaters from Industry 219

8.1 General 219

8.2 Principle and Nonprinciple Treatment Mechanisms 220

8.3 Waste Equalization 223

8.4 pH Control 227

8.5 Chemical Methods of Wastewater Treatment 230

8.6 Biological Methods of Wastewater Treatment 255

8.7 Development of Design Equations for Biological Treatment of Industrial Wastes 256

8.8 Physical Methods of Wastewater Treatment 322

9 Treatment and Disposal of Solid Wastes from Industry 397

9.1 Characterization of Solid Wastes 398

9.2 The Solid Waste Landfill 400

9.3 Solid Waste Incineration 409

9.4 The Process of Composting Industrial Wastes 421

9.5 Solidification and Stabilization of Industrial Solid Wastes 427

10 Methods for Treating Air Discharges from Industry 437

10.1 Reduction at the Source 437

10.2 Containment 437

10.3 Treatment 438

Index 461

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Preface

This book has been developed with the

inten-tion of providing an updated primary reference

for environmental managers working in

indus-try, environmental engineering consultants,

graduate students in environmental

engineer-ing, and government agency employees

concerned with wastes from industries It

pre-sents an explanation of the fundamental

mechanisms by which pollutants become

dis-solved or suspended in water or air, then builds

on this knowledge to explain how different

treatment processes work, how they can be

optimized, and how one would go about

effi-ciently selecting candidate treatment processes

Examples from the recent work history of

Woodard & Curran, as well as other

environ-mental engineering and science consultants,

are presented to illustrate both the approach

used in solving various environmental quality

problems and the step-by-step design of

facili-ties to implement the solutions Where

permis-sion was granted, the industry involved in each

of these examples is identified by name

Other-wise, no name was given to the industry, and

the industry has been identified only as to type

of industry and size In all cases, the actualnumbers and all pertinent information havebeen reproduced as they occurred, with theintent of providing accurate illustrations ofhow environmental quality problems have beensolved by one of the leading consultants in thefield of industrial wastes management This book is intended to fulfill the need for

an updated source of information on the acteristics of wastes from numerous types ofindustries, how the different types of wastes aremost efficiently treated, the mechanismsinvolved in treatment, and the design processitself In many cases, “tricks” that enable lowercost treatment are presented These “tricks”have been developed through many years ofexperience and have not been generally avail-able except by word of mouth

char-The chapter on laws and regulations is sented as a summary as of the date stated in thechapter itself and/or the addendum that isissued periodically by the publisher For infor-mation on the most recent addendum, pleasecall the publisher or Woodard & Curran’soffice in Portland, Maine, at (207) 774-2112

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Acknowledgments

This work was produced over a period of more

than five years; during that time, a very large

number of individuals, corporations, and various

business organizations contributed significant

material I have tried to cite each contributor,

and I apologize mightily if I have missed one or

more Thus, I extend heartfelt gratitude and

acknowledgement to:

Adam H Steinman; Aeration Technologies,

Inc.; R Gary Gilbert; Albert M Presgraves;

Andy Miller; Claire P Betze; Connie Bogard;

Connie Gipson; Dennis Merrill; Dr Steven

E Woodard; Geoffrey D Pellechia; George

Abide; George W Bloom; Henri J Vincent; Dr

Hugh J Campbell; J Alastair Lough; Janet

Robinson; Dr James E Etzel; James

D Ekedahl; Karen L Townsend; KatahdinAnalytical Services; Keith A Weisenberger;Kurt R Marston; Michael Harlos; Michael

J Curato; Patricia A Proux-Lough; PaulBishop; Randy E Tome; Eric P King; Ray-mond G Pepin; Robert W Severance; Steven

N Whipple; Steven Smock; Susan G Stevens;Terry Rinehart; and Thora Knakkergaard, all ofwhom contributed text or verbal informationfrom which I freely drew, either word-for-word

or by way of paraphrase I extend specialthanks to Adam Steinman, Esq., who providedtext and verbal information regarding laws,regulations and environmental audits

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1 Management of Industrial

Wastes: Solids, Liquids, and Gases

The approach used to develop systems to treat

and dispose of industrial wastes is distinctly

different from the approach used for municipal

wastes There is a lot of similarity in the

char-acteristics of wastes from one municipality, or

one region, to another Because of this, the best

approach to designing a treatment system for

municipal wastes is to analyze the performance

characteristics of many existing municipal

sys-tems and deduce an optimal set of design

parameters for the system under consideration

Emphasis is placed on the analysis of other

sys-tems, rather than on the waste stream under

consideration In the case of industrial waste,

however, few industrial plants have a high

degree of similarity between products

pro-duced and wastes generated Therefore,

emphasis is placed on analysis of the wastes

under consideration, rather than on what is

tak-ing place at other industrial locations This is

not to say that there is little value in analyzing

the performance of treatment systems at other,

more or less similar, industrial locations Quite

the opposite is true It is simply a matter of

emphasis

Wastes from industries are customarily

clas-sified as liquid wastes, solid wastes, or air

pol-lutants, and often the three are managed by

different people or departments The three

sep-arate categories are regulated by sepsep-arate and

distinct bodies of laws and regulations, and

his-torically, public and governmental emphasis

has moved from one category to another from

one time period to another The fact is,

how-ever, that the three categories of wastes are

closely interrelated, both as they impact on the

environment and as they are generated and

managed by individual industrial facilities

Solid wastes disposed of in the ground can

influence the quality of groundwater and

surface waters by way of leachate entering thegroundwater and traveling with it through theground, then entering a surface water bodywith groundwater recharge Volatile organics inthat recharge water can contaminate the air Airpollutants can fall out to become surface water

or groundwater pollutants, and water pollutantscan infiltrate into the ground or volatilize intothe air

Waste treatment processes can also transfersubstances from one of the three waste catego-ries to one or both of the others Air pollutantscan be removed from an air discharge by means

of a water solution scrubber The waste ber solution must then be managed to enable it

scrub-to be discarded within compliance with cable water regulations Airborne particulatescan be removed from an air discharge using abag house, thus creating a solid waste to bemanaged On still a third level, waste treatment

appli-or disposal systems themselves can directlyimpact on the quality of air, water, or ground.Activated sludge aeration tanks are very effec-tive in causing volatilization of substancesfrom wastewater Failed landfills can be potentpolluters of both groundwater and surfacewater

The total spectrum of industrial wastes, then,must be managed as substances resulting from

a system of interrelated activities Materialsbalances must be tracked, and overall costeffectiveness must be kept in focus

Management of Industrial Wastewater

With respect to industrial wastewater, Figure1-1 illustrates the approach for developing awell-operating, cost-effective treatment system.The first step is to gain familiarity withthe manufacturing processes themselves This

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2 Industrial Waste Treatment Handbook

Figure 1-1 Approach for developing an industrial

waste-water treatment system.

usually starts with a tour of the facility, andthen progresses through a review of the litera-ture and interviews with knowledgeablepeople The objective is to gain an understand-ing of how wastewater is produced, for tworeasons The first is to enable an informed andtherefore effective wastes reduction, or minimi-zation (pollution prevention) program; thesecond is to enable proper choice of candidatetreatment technologies

Analysis of Manufacturing Processes

One of the first steps in the analysis of facturing processes is to develop a blockdiagram that shows how each manufacturingprocess contributes wastewater to the treatmentfacility, as is illustrated in Figure 1-2 In Figure1-2, a block represents each step in the manu-facturing process The supply of water to eachpoint of use is represented on the left side ofthe block diagram Wastewater that flows awayfrom each point of wastewater generation isshown on the right side

manu-Figure 1-2 is representative of the processesinvolved in producing finished woven fabricfrom an intermediate product of the textileindustry The “raw material” for this process isfirst subjected to a process called “desizing,”during which the substances used to size thewoven greige goods, or raw fabric, areremoved The process uses sulfuric acid; there-fore, the liquid waste from this process would

be expected to have a low pH as well as containwhatever substances were used as sizing Forinstance, if starch were the substance used tosize the fabric, the liquid waste from the desiz-ing process would be expected to exhibit a highbiochemical oxygen demand (BOD)

As the knowledge became available, fromthe industry’s records, if possible, or from mea-surements taken as part of a wastewater charac-terization study, the flow rates, total quantitiesfor a typical processing day, upper and lowerlimits, and characteristics such as BOD, chemi-cal oxygen demand (COD), total suspendedsolids (TSS), total dissolved solids (TDS),and specific chemicals would be indicated onthe block diagram Each individual process

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Management of Industrial Wastes: Solids, Liquids, and Gases 3undergone during the industrial process would

be developed and shown on the block diagram,

as illustrated in Figure 1-2

Wastes Minimization and Wastes

Characterization Study

After becoming sufficiently familiar with the

manufacturing processes as they relate to

wastewater generation, the design team shouldinstitute a wastes minimization program(actually part of a pollution prevention pro-gram) as described in Chapter 7 Then, after thewastes reduction program has become fullyimplemented, a wastewater characterizationstudy should be carried out, as described inChapter 6

Figure 1-2 Typical woven fabric finishing process flow diagram (From the EPA Development Document for the Textile Mills Industry.)

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The ultimate purpose of the wastewater

characterization study is to provide the

design team with accurate and complete

information on which to base the design of

the treatment system Both quantitative and

qualitative data are needed to properly size

the facility and to select the most appropriate

treatment technologies

Often, enough new information about

mate-rials usage, water use efficiency, and wastes

generation is learned during the wastewater

characterization study to warrant a second level

of wastes minimization effort This second part

of the wastes minimization program should be

fully implemented, and its effectiveness should

be verified by more sampling and analyses,

which amounts to an extension of the

wastewa-ter characwastewa-terization study

A cautionary note is appropriate here

con-cerning maintenance of the wastes

minimiza-tion program If, after implementaminimiza-tion of the

wastes minimization program, operation of the

manufacturing facilities and/or housekeeping

practices loses attention and becomes lax so

that wastewater increases in volume, strength,

or both, the treatment facility will be

underde-signed and will be overloaded at the start It is

extremely important that realistic goals be set

and maintained for the wastes minimization

program, and that the design team, as well as

the industry’s management team, are fully

aware of the consequences of overloading the

treatment system

Treatment Objectives

After the volume, strength, and substance

char-acteristics of the wastewater have been

established, the treatment objectives must be

determined These objectives depend on where

the wastewater is to be sent after treatment If

the treated wastewater is discharged to another

treatment facility, such as a regional facility or

a municipal treatment system, pretreatment

requirements must be complied with As a

minimum, the Federal Pretreatment

Guide-lines issued by the Environmental Protection

Agency (EPA) and published in the Federal

Register must be complied with Some

municipal or regional treatment facilities havepretreatment standards that are more stringentthan those required by the EPA

If the treated effluent is discharged to anopen body of water, then a National Pollut-ant Discharge Elimination System (NPDES)permit, plus a permit issued by the appropri-ate state agency, must be complied with Inall cases, Categorical Standards issued by theFederal EPA apply, and it is necessary towork closely with one or more governmentagencies while developing the treatmentobjectives

Selection of Candidate Technologies

Once the wastewater characteristics and thetreatment objectives are known, candidate tech-nologies for treatment can be selected.Rationale for selection is discussed in detail inChapter 8 The selection should be based onone or more of the following:

• Successful application to a similar water

waste-• Knowledge of chemistry, biochemistry, andmicrobiology

• Knowledge of what technologies are able, as well as knowledge of theirrespective capabilities and limitationsThen, bench scale investigations should beconducted to determine technical as well asfinancial feasibility

avail-Bench Scale Investigations

Bench scale investigations quickly and ciently determine the technical feasibility and

effi-a rough effi-approximeffi-ation of the fineffi-ancieffi-al feeffi-asi-bility of a given technology Bench scalestudies range from rough experiments inwhich substances are mixed in a beaker andresults are observed almost immediately, torather sophisticated continuous flow studies inwhich a refrigerated reservoir contains repre-sentative industrial wastewater, which ispumped through a series of miniature treat-ment devices that are models of the full-sizeequipment Typical bench scale equipment

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feasi-Management of Industrial Wastes: Solids, Liquids, and Gases 5includes the six-place stirrer shown in

Figure 1-3(a), small columns for ion exchange

resins, activated carbon, or sand, shown in

Figure 1-3(b), “block aerators,” shown in

Figures 1-3(c) and (d), for performing

micro-biological treatability studies, and any number

of custom-designed devices for testing the

technical feasibility of given treatment

technologies

Because of scale-up problems, it is seldom

advisable to proceed directly from the results

of bench scale investigations to design of the

full-scale wastewater treatment system Only in

cases for which extensive experience exists

with both the type of wastewater being treated

and the technology and types of equipment to

be used can this approach be justified

Other-wise, pilot scale investigations should be

conducted for each technology that appears to

be a legitimate candidate for reliable, effective treatment

cost-In the absence of pilot scale investigations,the design team is obliged to be conservative inestimating design criteria for the treatment sys-tem The likely result is that the cost for thefacility will be greater than the total cost for thepilot scale investigations plus the treatmentfacility that would have been designed usingthe information that would have been devel-oped from the pilot scale investigations Saidanother way, the objective of pilot scale investi-gations is to develop the data necessary todetermine the minimum size and least costlysystem of equipment to enable the design of atreatment system that will reliably meet itsintended purpose

Figure 1-3(a) Photograph of a six-place stirrer (Courtesy of ©Phipps & Bird, Inc., 2000.)

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Figure 1-3(b) Illustration of a column set-up to evaluate treatment methods that use granular media (From Wachinski and

Etzel, Environmental Ion Exchange: Principles and Design, 1997 Reprinted by permission of CRC/Lewis Publishers.)

Figure 1-3(c) Diagrammatic sketch of a block aerator set-up for performing treatability studies in the laboratory.

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Management of Industrial Wastes: Solids, Liquids, and Gases 7

Pilot Scale Investigations

A pilot scale investigation is a study of the

per-formance of a given treatment technology

using the actual wastewater to be treated,

usu-ally on site, and using a representative model

of the equipment that would be used in the

full-scale treatment system The term

“repre-sentative model” refers to the capability of the

pilot treatment system to closely duplicate theperformance of the full-scale system In somecases, accurate scale models of the full-scalesystem are used In other cases, the pilotequipment bears no physical resemblance tothe full-scale system Fifty-five gallon drumshave been successfully used for pilot scaleinvestigations

Figure 1-3(d) Photograph of a block aerator set-up for performing treatability studies in the laboratory (Courtesy of AWARE Environmental, Inc.)

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It is not unusual for equipment

manufactur-ers to have pilot scale treatment systems that

can be transported to the industrial site on a

flatbed truck trailer A rental fee is usually

charged, and there is sometimes an option to

include an operator in the rental fee It is

important, however, to keep all options open

Operation of a pilot scale treatment system that

is rented from one equipment manufacturer

might produce results that indicate that another

type of equipment (using or not using the same

technology) would be the wiser choice

Figure 1-4 presents a photograph of a pilot

scale wastewater treatment system

One of the difficulties in operating a pilot

scale treatment system is the susceptibility of

the system to upset caused by slug doses, wide

swings in temperature, plugging of the

rela-tively small diameter pipes, and lack of

famil-iarity on the part of the operator

When operating a pilot scale treatment

sys-tem for a sufficiently long period, it is critically

important to:

1 Evaluate its performance on all

combina-tions of wastes that are reasonably

expected to occur during the foreseeable

life of the prototype system

2 Provide sufficient opportunity to evaluate

all reasonable combinations of operation

parameters When operation parameters

are changed—for instance the volumetric

loading of an air scrubber, the chemical

feed rate of a sludge press, or the recycle

ratio for a reverse osmosis system—the

system must operate for a long enough

time to achieve steady state before data to

be used for evaluation are taken Of

course, it will be necessary to obtain data

during the period just after operation

parameters are changed, to determine

when steady state has been reached

During the pilot plant operation period,

observations should be made to determine

whether performance predicted from the results

of the bench scale investigations is being

con-firmed If performance is significantly different

from what was predicted, it may be prudent to

stop the pilot scale investigation work and try

to determine the cause

Preliminary Designs

The results of the pilot scale investigationsshow which technologies are capable of meet-ing the treatment objectives, but do not enable

an accurate estimation of capital and operatingcosts A meaningful cost-effectiveness analysiscan take place only after preliminary designs ofthose technologies that produced satisfactoryeffluent quality in the pilot scale investigationshave been completed A preliminary design,then, is a design of an entire wastewater treat-ment facility, carried out in sufficient detail toenable accurate estimation of the costs for con-structing and operating a wastewater treatmentfacility It must be complete to the extent thatthe sizes and descriptions of all of the pumps,pipes, valves, tanks, concrete work, buildings,site work, control systems, and labor require-ments are established The difference between

a preliminary design and a final design is cipally in the completeness of detail in thedrawings and in the specifications It is almost

prin-as though the team that produces the nary design could use it to directly constructthe plant The extra detail that goes into thefinal design is principally used to communicateall of the intentions of the design team to peoplenot involved in the design

prelimi-Economic Comparisons

The choice of treatment technology and a plete treatment system between two or moresystems proven to be reliably capable of meet-ing the treatment objectives should be based on

com-a thorough com-ancom-alysis of com-all costs over theexpected life of the system

Example: Pretreatment for a line Cellulose Manufacturing Plant

Microcrystal-By Henri Vincent

The following sections illustrate an economiccomparison of five alternatives for treatingwastewater from an industrial plant producing

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Figure 1-4 Photograph of a pilot scale wastewater treatment system (Courtesy of Paques ADI, Inc.)

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microcrystalline cellulose from wood pulp

This plant discharged about 41,000 gallons per

day (GPD) of wastewater to the local municipal

sewer system (publicly owned treatment works

[POTW]) The municipality that owned the

POTW charged the industry a fee for treatment,

and the charge was proportional to the strength,

in terms of the BOD, TSS, fats, oils, and

greases (FOG), and total daily flow (Q)

In order to reduce the treatment charges

from the POTW, the plant had the option of

constructing and operating its own wastewater

treatment system; however, because there was

not an alternative place to discharge the

treated wastewater other than the municipal

sewer system, there would continue to be a

charge from the POTW, but it would be

reduced in proportion to the degree of

treat-ment accomplished by the industry Because

the industry’s treated wastewater would be

further treated by the POTW, the industry’s

treatment system is referred to as a

“pretreat-ment system,” regardless of the degree of

treatment accomplished

Sequencing Batch Reactors

The use of sequencing batch reactors is one

alternative for pretreating the plant’s

wastewa-ters Table 1-1 presents capital costs associated

with this

Rotating Biological Contactors

Table 1-2 presents a summary of the capital

costs associated with this option Also included

in Table 1-2 is the number of each unit

required, along with its size and installed cost

Fluidized Bed Anaerobic Reactors

costs associated with this option Also included

in Table 1-3 is the number of each unit

required, along with its size and installed cost

Expanded Bed Anaerobic Reactors

Because the expanded bed is not

commer-cially available, capital costs were estimated

using the major system components fromthe fluidized bed anaerobic reactor (seeTable 1-3) and deleting the following itemsthat are not required for the expanded bedsystem:

• Two 40-ft Secondary Clarifiers

• Two 20 GPM Sludge Pumps

• One 40-ft3 Filter Press

• Two 60 GPM Filter Feed Pumps

• Two 80 GPM Sludge Transfer Pumps

• One 10 BP Sludge Tank Mixer

• One 5 HP Sludge Tank Mixer

• One 100 CFM Compressor Also, a smaller building was designed forthis option

As a result of these deletions, the estimatedcapital cost for the expanded bed anaerobicreactor system is $1,600,000

O&M Costs

Operational and maintenance costs presentedfor each treatment alternative include the fol-lowing elements:

• Chemicals

• Power

• Labor

• Sludge disposal, if applicable

• Sewer use charges

• MaintenanceThe bases for estimating the annual operat-ing cost for each of the previous elements were(1) the quantity of chemicals required for aver-age design value; (2) power costs for runningpumps, motors, blowers, etc.; (3) laborrequired to operate the facility; (4) sludge dis-posal costs, assuming sludge would be dis-posed of at a local landfill; (5) the cost forsewer use charges based on present rates; and(6) maintenance costs at a fixed percentage oftotal capital costs The estimated sewer usecharges for each treatment alternative are given

in Table 1-4

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Table 1-1 Capital Cost Opinion; Sequencing Batch Reactors — Alternative #1

1 Total for Both Tanks

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Table 1-2 Capital Cost Opinion; Rotating Biological Contactors — Alternative #2

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Table 1-3 Capital Cost Opinion; Fluidized Bed Anaerobic Reactors — Alternative #3

Sequencing Batch Reactors

An illustration of yearly O&M costs

associ-ated with the use of sequencing batch reactors

for wastewater pretreatment is presented in

Table 1-5

Rotating Biological Contactors

Table 1-6 presents a summary of the capitalcosts associated with this treatment alternative.Also included in Table 1-6 is the estimatedquantity and unit cost for each O&M element

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Table 1-4 Estimated Sewer Use Charges

Table 1-5 Yearly O&M Cost Summary; Sequencing Batch Reactors — Alternative #1

Fluidized Bed Anaerobic Reactors

costs associated with this treatment alternative

Included in Table 1-7 is the estimated quantity

and unit cost for each O&M element Additional

information on gas recovery is also included to

show potential offsetting of O&M costs

Expanded Bed Anaerobic Reactors

Because the expanded bed is not commercially

available, O&M costs were estimated with the

O&M elements from the fluidized bed bic reactor (see Table 1-7) and adjusted for thefollowing:

anaero-• Labor Because no sludge dewatering isrequired, labor requirements can bedecreased by 75%

• Sludge Disposal None required becausecellulose can be recycled

Based on the above, the total O&M costwithout gas recovery is $400,000, and with gasrecovery is $300,000

*Based on flow, TSS, and BOD5 charges currently incurred.

*Total rounded to nearest $50,000.

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Table 1-6 Yearly Operating Cost Summary; Rotating Biological Contactors — Alternative #2

Annualized Costs

Annualized costs are a convenient method for

making economic comparisons among

treat-ment alternatives To obtain annualized costs,

the capital cost for the alternative in question is

amortized over the life of the system, which for

the purposes of this example is assumed to be

20 years The cost of money is assumed to be

10%

The five alternative treatment systems

evalu-ated in the previous sections include (1) a

sequencing batch reactor (SBR), (2) a rotating

biological contactor (RBC), (3) a fluidized bed

anaerobic reactor, (4) an expanded bed

anaero-bic reactor, and (5) the option of no

pretreat-ment, which would result in paying the POTW

for accomplishing all of the treatment The

four treatment system types are described in

a level of accuracy of plus or minus 30% forthe total estimated cost

*Total rounded to nearest $50,000.

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Table 1-7 Yearly Operating Cost Summary; Fluidized Bed Anaerobic Reactor — Alternative #3

Table 1-8 Annualized Costs

* Total rounded to nearest $50,000.

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Final Design

The final design process is both a formality

during which standardized documents

includ-ing plans and specifications are produced, and

a procedure during which all of the subtle

details of the facility that is to be constructed

are worked out The standardized documents

have a dual purpose; the first is to provide a

common basis for several contractors to

pre-pare competitive bids for constructing the

facility The second is to provide complete

instructions for building the facility, so that

what gets built is exactly what the design team

intended

Competitive Bids for Construction

The purpose of going through the competitive

bidding process is to ensure that the facility

developed by the design team is built at the

lowest achievable cost In addition, the

contrac-tors invited to participate in the bidding process

should be carefully selected on the basis of

competence, experience, workmanship, and

reliability In the end, the best construction job

for the lowest possible price will not have a

chance of being realized if the best contractor

is not on the list of those invited to submit bids

The foundation of the bidding process is the

set of documents known as the “plans and

specifications.” The first duty of the plans and

specifications is to provide all information in

sufficiently complete detail that each of the

contractors preparing bids submits cost

propos-als for exactly the same, or truly equivalent,

items It is essential that each contractor’s bid

proposal be capable of being compared on an

“apples to apples” basis That is, regardless of

which contractor builds the facility, it would be

essentially identical in all respects relating to

performance, reliability, O&M requirements,

and useful life The key to obtaining this result

is accuracy and completeness, down to the

fin-est details, of the plans and specifications

As it has developed in the United States, the

bidding process follows the block diagram

shown in Figure 1-5 Figure 1-5 illustrates that

the first of six phases is to develop a list of

potential bidders, as discussed previously This

list is developed based on past experience, erences, and discussion with contractorsregarding their capabilities Other means fordeveloping the list can involve advertising forpotential bidders in local and regional newspa-pers, trade journals, or publications issued bytrade associations In the second phase, a for-mal request for bids is issued, along with plans,specifications, a bid form, and a timetable forbidding and construction

ref-The third phase, the pre-bid conference, iskey to the overall success of the project.This phase involves assembling all potentialcontractors and other interested parties, such

Figure 1-5 Illustration of the bidding process

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as potential subcontractors, vendors, and

sup-pliers, for a meeting, preferably at the project

site This site visit normally includes a guided

and annotated tour, a presentation of the

engi-neer’s/owner’s concept of the project, and a

question-and-answer period This meeting can

result in identification of areas of the design

that require additional information or change

If this is the case, the additional information

and/or changes are then addressed to all parties

by issuance of formal addenda to the plans and

specifications

The final three phases—receipt and opening

of bids, bid evaluation, and award of contract—

are highly interrelated Upon receipt, the bids

are reviewed to determine accuracy,

complete-ness, and the lowest responsible bidder If all

bids are higher than was expected, the

indus-try’s management and engineers have the

opportunity to explore alternatives for redesign

of the project Finally, the project is awarded to

the contractor submitting the lowest

responsi-ble bid Construction or implementation can

now begin

Management of Solid Wastes from

Industries

By Janet Robinson

Industrial wastes that are discharged to neither

air nor water are classified as solid, industrial,

or hazardous waste At the federal level, these

wastes are regulated primarily by the Resource

Conservation and Recovery Act (RCRA),

which contains specific design and

manage-ment standards for both hazardous wastes

(Subtitle C of the Act) and municipal solid

wastes (Subtitle D)

Solid Waste

Solid waste (i.e., trash) includes such routine

wastes as office trash, unreusable packaging,

lunchroom wastes, and manufacturing or

pro-cessing wastes that are not otherwise classified

as “hazardous” under RCRA These wastes are

normally deposited in trash cans and dumpsters

and collected by a local trash hauler for disposal

in a municipal landfill or treatment at a pal incinerator Although RCRA contains designand other standards for municipal waste man-agement facilities, these facilities are normallygoverned primarily by state and local regulation General solid waste management has comeunder increasing scrutiny in recent yearsbecause of a recognition of the relatively highproportion of hazardous household compoundsthat solid waste contains As a result, technicaldesign standards for solid waste landfills arenow approaching those for industrial and haz-ardous waste landfills In addition, a reduction

munici-in the amount of available landfill space wide has caused a steady increase in tippingfees (the fees charged for using municipal land-fills) and has prompted energetic recyclingefforts by many industries and communities

nation-Industrial or Special Wastes

Industrial or special wastes are nonhazardousmanufacturing wastes that are barred frommunicipal waste treatment or disposal facili-ties, but do not meet the regulatory definition

of “hazardous waste.” Examples of thesewastes include tannery leather scraps, feathersand other wastes from poultry processing, non-hazardous sludge, and asbestos These materi-als are normally disposed of in an industriallandfill, which is generally more strictly regu-lated, more highly designed, and more closelymonitored than municipal landfills Prior wastetesting and approval are necessary before anindustry can ship waste to the site

Industrial wastes are normally regulated onthe state and local levels, and most facilities arelicensed to accept only certain kinds of waste.Special state approval is often necessary forunusual waste streams

Hazardous Waste

Hazardous waste is a type of waste that meetsspecific characteristics of toxicity, ignitability,reactivity, or corrosivity, or is specificallylisted as a hazardous waste in RCRA regula-tions Examples of wastes that are said toexhibit a hazardous “characteristic” are sludges

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Management of Industrial Wastes: Solids, Liquids, and Gases 19containing heavy metals that can be solubilized

by certain weak acids (toxic), waste gasoline

(ignitable), elemental alkali metals such as

sodium or potassium (reactive), and acid

wastes (corrosive) “Listed hazardous wastes”

include waste commercial products, wastes

from specific industrial processes, and

wastes (e.g., spent solvents) from nonspecific

sources

Hazardous waste management is arguably

among the most complex and comprehensive

arenas of environmental regulation As described

in Chapter 3, the RCRA program contains

detailed requirements for storing, handling,

transporting, treating, and disposing of

hazard-ous wastes, and mandates a “cradle-to-grave”

waste tracking system to ensure that wastes are

transported and disposed of only by properly

licensed firms Although hazardous waste

regu-lations originated at the federal level, most states

are authorized by the EPA to administer their

own programs and often promulgate standards

that are more strict than the federal standards

Hazardous waste generators are required by

the land disposal restrictions (LDRs), also

referred to as “land ban” restrictions, to

deter-mine the concentrations of certain constituents

in their hazardous wastes Depending on the

constituents present and their concentrations,

specific treatment standards, expressed as

spec-ified technologies, may be required before the

wastes can be land disposed Residues

result-ing from treatment of the waste are subject to

the same requirements and restrictions

The distinctions between each of the waste

categories (municipal, industrial, and

hazard-ous) as described are not always clear, and the

onus is on the individual industry, or

appropri-ate facility, to make the correct determination

Some states, for instance, consider waste oils to

be hazardous waste, even though federal law

does not Cans of dried paint are generally

regarded as a normal solid waste that can go in

a dumpster; however, cans of wet paint,

espe-cially those that contain lead or chromate, are

usually designated as hazardous Tannery

wastes with trivalent chrome usually can go to

an industrial landfill, but some states consider

these materials to be hazardous And, at the

present time, mixtures of listed hazardouswastes and nonhazardous wastes (e.g., rinsewa-ters containing spent plating solution, a listedhazardous waste) are hazardous in many cases.The so-called mixture rule illustrates theimportance of keeping waste streams separate

to minimize the volume of hazardous waste fordisposal

In addition to these wastes, most industriesproduce by-products, scraps, or spent materialsthat can be reused, reclaimed, or recycled foruse on or off site Depending on their charac-teristics, these materials may be regulated ashazardous wastes even during the recyclingprocess, or they may become wastes if thedemand for them decreases to the point wherereprocessing becomes unprofitable A goodworking knowledge of the solid waste manage-ment laws, or the advice of a reputable consult-ant or attorney, is imperative to avoid violations

of waste RCRA regulations

Waste management and disposal often sent significant and constantly increasing costsfor industry In order to minimize these costsand reduce the likelihood of enforcementactions by regulators, environmental managersmust ensure that a sound program is in placeand that all personnel, from laborers to topmanagers, are vigilant in carrying it out Thefollowing guidelines are often helpful:

repre-• Know the facility waste streams Like trial wastewaters, these are seldom the samefor different plants As a first step, facilitiesmust know how much of each type of solidwaste they are producing

indus-• Keep wastes segregated Heavy fines, aswell as criminal sentences, are the penaltiesfor improper waste disposal Facilities mustensure that hazardous wastes are not put inthe trash dumpster, that listed hazardouswastes are not mixed with other nonhazard-ous materials, and generally that wastes arehandled as they’re supposed to be

• Choose waste disposal firms carefully.Because facilities can be held responsiblefor clean-up costs of the waste facilities theyuse, waste transporters and facilities should

be chosen carefully

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• Institute a pollution prevention program that

includes a vigorous wastes minimization

effort Where possible, reduce the quantity

or toxicity of materials used in production

• Keep areas clean Frequent spills or releases

not only present safety hazards, but also will

increase the amount of facility

decontami-nation necessary at closure

• Keep good records Industrywide, a great

deal of money is wasted on testing and

disposing of unknown materials or in

inves-tigating areas with insufficient historical

data Good recordkeeping is essential to

keep both current and future waste

manage-ment costs to a minimum

Excellent texts that discuss in detail the

many aspects of solid, industrial, and

hazard-ous waste management are available; these

ref-erences are listed in the bibliography at the end

of this chapter and can be consulted for specific

information

Management of Discharges to the Air

The discharge, or release, of substances to the

air, no matter how slight, is regarded as air

pol-lution Such discharges can be classified in one

of only two categories, within compliance or not

within compliance A federal permit as well as a

state license or permit must cover all discharges

over a certain quantity per unit time Local

ordi-nances or regulations may also apply

Discharges to the air can be direct, by means

of a stack, or by way of leaks from a building’s

windows, doors, or other openings The latter

are referred to as “fugitive emissions.”

Volatil-ization of organic compounds, such as solvents

and gasoline from storage containers, transfer

equipment, or even points of use, are important

sources of air discharges Another source of

discharge to the air of volatile organics is

aer-ated wastewater treatment systems

Management of discharges to the air is

almost always interrelated with management of

discharges to the water and/or the ground

because air pollution control devices usually

remove substances from the air discharge

(usu-ally a stack) and transfer them to a liquid

solution or suspension, as with a scrubber, or to

a collector of solids, as with a bag house.Therefore, a total system approach to environ-mental pollution control is preferred, and thisapproach should include a pollution preventionprogram with vigorous waste minimization There are three phases to the air pollutioncycle: (1) the release, or discharge, at thesource; (2) the dispersal of pollutants in theatmosphere; and (3) the reception of pollutants

by humans, animals, or inanimate objects.Management of the first phase is a matter ofengineering, control, and operation of equip-ment The second phase can be influenced bystack height, but meteorology dictates the path

of travel of released pollutants Because themotions of the atmosphere can be highly vari-able in all dimensions, management of the thirdphase, which is the ultimate objective of airpollution control, requires knowledge of mete-orology and the influence of topography Chapter 3 presents a detailed synopsis oflaws and regulations that pertain to protection

of the nation’s air resources Because theselaws are constantly being revised and replaced

by new legislation, an updated supplement tothis book is published every five years

Analysis of Manufacturing Process

Successful and cost-effective air pollution trol has its foundation in complete awareness

con-of all con-of the individual sources, fugitive as well

as point sources The process of cataloguingeach and every individual air discharge within

an industrial manufacturing or other facility ismost efficiently done by developing detaileddiagrams of the facility as a whole Depending

on the size and complexity of the facility, itmay also be advantageous to develop separatediagrams for point sources and sources of fugi-tive emissions Next, a separate block diagramfor each air discharge source should be devel-oped The purpose of each block diagram is toillustrate how each manufacturing process andwastewater or solid wastes treatment or han-dling process contributes unwanted substances

to the air Figures 1-6 through 1-8 are examples

of these diagrams

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Figure 1-6 Block diagram of a cement manufacturing plant.

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Figure 1-7 Flowsheet for the manufacture of Portland Cement (Taken from the EPA Development Document PB-238

610, 1974.)

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Figure 1-8 Kiln dust collection and handling.

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Figures 1-6 through 1-8 are block diagrams

that pertain to a facility that manufactures

cement from limestone Figure 1-6 is a diagram

of the facility as a whole, showing the cement

manufacturing process as well as the physical

plant, including the buildings, parking lots, and

storage facilities

Cement, manufactured for use in making

concrete, is produced by grinding limestone,

cement rock, oyster shell marl, or chalk, all

principally calcium carbonate, and mixing it

with ground sand, clay, shale, iron ore, and

blast furnace slag, as necessary, to obtain the

desired ingredients in proper proportions This

mixture is dried in a kiln and then ground again

while mixing with gypsum The final product is

then stored, bagged, and shipped Each of the

individual production operations generates, or

is otherwise associated with, dust or

“particu-lates” and is a potential source of air pollutant

emissions exceeding permit limits

Figures 1-6 and 1-7 illustrate that raw

mate-rials are received and stockpiled at the plant,

and are potential sources of particulate

emis-sions because of the fine particles of dust that

are generated during the mining,

transporta-tion, loading, and unloading processes Their

susceptibility to being blown around if they are

out in the open is also a factor In order to

control emissions from these sources, it is

nec-essary to conduct all loading, unloading,

grind-ing, and handling operations within enclosures

that are reasonably air-tight, to prevent fugitive

emissions, and are also ventilated, for the

health and safety of employees Ventilation

requires a fresh air intake and a discharge The

discharge requires a treatment process

Candi-date treatment processes for this application

include bag houses, wet scrubbers, and

electro-static precipitators, possibly in combination

with one or more inertial separators Each of

these treatment technologies is discussed in

Chapter 10

A very important aspect of air pollution

con-trol is to obtain and then maintain a high degree

of integrity of the buildings and other

enclo-sures that have as at least one of their purposes

that of containment of potential air pollutants

Doors and windows and vents must be kept

shut The building or enclosure must be kept ingood repair to avoid leaks In many cases, it isnecessary to maintain a negative pressure(pressure inside building below atmosphericpressure outside building) in order to preventthe escape of gasses or particulates Maintain-ing the integrity of the building or enclosurebecomes very important in this case to mini-mize costs for maintaining the negative pres-sure gradient

As further illustrated in Figure 1-6, the nextseries of processing operations constitutes thecement manufacturing process itself, and startswith crushing, then proceeds through mixing,grinding, blending, and drying in a kiln Each ofthese processes generates major amounts of par-ticulates, which must be contained, transported,and collected by use of one or more treatmenttechnologies, as explained in Chapter 10 Insome cases, it may be most advantageous frompoints of view of reliability or cost effectiveness,

or both, to use one treatment system for all pointsources In other cases, it might prove best totreat one or more of the sources individually Continuing through the remaining pro-cesses illustrated in Figures 1-6 and 1-7, thefinished product (cement) must be cooled, sub-jected to finish grinding, cooled again, stored,then bagged and sent off to sales distributionlocations Again, each of these operations is

a potential source of airborne pollutants, inthe form of particulate matter, and it is neces-sary to contain, transport, and collect the partic-ulates using hoods, fans, ductwork, and one ormore treatment technologies as explained inChapter 10

The next step in the process of identifyingeach and every source of air pollutant dischargefrom the cement manufacturing plant beingused as an example is to develop a block dia-gram for each individual activity that is a majoremission source Figure 1-8 illustrates this step.Figure 1-8 is a block diagram of the processreferred to as the “kiln,” which dries the unfin-ished cement using heat This diagram pertains

to only the manufacturing process and does notinclude sources of emissions from the physicalplant, most of which are sources of fugitiveemissions

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Management of Industrial Wastes: Solids, Liquids, and Gases 25Figure 1-8 shows that the inputs to the kiln

include partially manufactured (wet) cement

and hot air The outputs include dry partially

manufactured cement and exhaust air, laden

with cement dust, or particulates The diagram

then shows that there are four candidate

tech-nologies to treat the exhaust gas to remove the

particulates before discharge to the ambient air

The four candidate technologies are:

• Electrostatic precipitator

• Cyclone

• Bag house

• Wet scrubber

Each of these technologies is worthy of

fur-ther investigation, including their technical

fea-sibility and cost effectiveness Also, each of

these technologies results in a residual, which

must be handled and disposed of properly

For instance, the bag house technology

pro-duces a residual that can be described as a dry,

fine dust that is essentially “raw” cement This

material can be stored in a “dust bin” (the dust

bin must be managed as a potential air

pollu-tion source), and from there can be:

• Returned to the kiln in an attempt to increase

the yield of the manufacturing process

• Buried

• Hauled (as a by-product) to another point of

use

• Mixed with water to form a slurry

The first of the aforementioned options is

only a partial solution, at best, because there

must be some “blow down,” if only to maintain

quality specifications for the finished product

The second option, “burial,” is a final solution,

but it must be accomplished within the

parame-ters of good solid waste disposal practice, and

the third option, “water slurry,” is only an

interim treatment step Forming a water slurry

transforms the air pollution potential problem

into a water pollution potential problem

(“cross-media” effect) The slurry can be

trans-ported to another location without risk of air

pollution, but it must then be dewatered by

sed-imentation before final disposal within the

bounds of acceptable solid waste and ter disposal practices

wastewa-The foregoing example illustrates how anentire manufacturing facility must be analyzedand diagrammed to define each and everysource of discharge of pollutants to the air as anearly step in a technically feasible and cost-effective air pollution control program Thenext steps are presented as follows

Wastes Minimization and Characterization Study

After all potential sources of air pollutants havebeen identified, the objectives of the industry’spollution prevention program should beaddressed As explained in Chapter 7, wastesminimization is only one aspect of a pollutionprevention program, but it is a critical one.Each source should first be analyzed to deter-mine if it could be eliminated Next, materialssubstitution should be considered to determine

if there are opportunities to use able substances in place of currently usedobjectionable ones Then, it should be deter-mined whether a change in present operations,for instance, improved preventive maintenance

nonobjection-or improved equipment, can significantlyreduce pollutant generation Finally, it should

be determined whether improvements in dent and spill prevention as well as improvedemergency response are warranted

acci-After a prudent wastes minimization gram has been carried out, a period should beallocated to determine if the changes madeappear to be permanent This phase of the over-all air pollution control program is importantbecause, if the determination of air pollutantflow rates and concentrations is made on thebasis of improved maintenance and operationalprocedures, and if the facility regresses to theway things were done previously, the handlingand treatment equipment designed on the basis

pro-of the improved procedures will be overloadedand will fail

Once all air pollution flows and loads havebecome stabilized, each of the sources should

be subjected to a characterization program todetermine flow rates and target pollutant

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concentrations (flows and loads) for the

pur-pose of developing design criteria for handling

and treatment facilities Examples of handling

facilities are hoods, fans, and ductwork

Examples of treatment equipment are

electro-static precipitators and fabric filters (bag

houses, for instance) The characterization

study is essentially the process of developing

estimates of emission rates based on historical

records of either the facility under

consider-ation or those of a similar facility For instance,

materials balances showing amounts of raw

materials purchased and products sold can be

used to estimate loss rates

Treatment Objectives

Treatment objectives are needed to complete

the development of design criteria for handling

and treatment equipment The air discharge

permit, either in hand or anticipated, is one of

the principal factors used in this development

Another principal factor is the strategy to be

used regarding allowances, i.e., whether or not

to buy allowances from another source or to

reduce emissions below permit limits and

attempt to recover costs by selling allowances

This strategy and its legal basis are discussed in

Chapter 3 Only after all treatment objectives

have been developed can candidate treatment

technologies be determined; however, it may

be beneficial to employ an iterative process,

whereby more than one set of treatment

objectives and their appropriate candidate

technologies are compared as competing

alter-natives in a financial analysis to determine the

most cost-effective system

Selection of Candidate Technologies

After the characteristics of air discharges, in

terms of flows and loads, have been determined

(based on stabilized processes after changes

were made for wastes minimization), and

treat-ment objectives have been agreed upon,

candidate technologies for removal of

pollut-ants can be selected The principles discussed

in Chapters 2 and 8 are used as the bases for

this selection The selection should be based on

one or more of the following:

• Successful application in a similar set ofconditions

• Knowledge of chemistry

• Knowledge of options available, as well asknowledge of capabilities and limitations ofthose alternative treatment technologiesThe next step is to conduct bench scaleinvestigations to determine technical and finan-cial feasibility

Bench Scale Investigations

Unless there is unequivocal proof that a giventechnology will be successful in a given appli-cation, a rigorous program of bench scalefollowed by pilot scale investigations must becarried out Such a program is necessary forstandard treatment technologies as well asinnovative technologies The cost for this type

of program will be recovered quickly, as aresult of the equipment being appropriatelysized and operated Under-designed equipmentwill simply be unsuccessful Over-designedequipment will cost far more to purchase,install, and operate

The results of a carefully executed benchscale pollutant removal investigation providethe design engineer with reliable data on which

to determine the technical feasibility of a givenpollutant removal technology, as well as a pre-liminary estimate of the costs for purchase,construction and installation, and operation andmaintenance Without such data, the designengineer is forced to use very conservativeassumptions and design criteria The result,barring outrageous serendipity, will be unnec-essarily high costs for treatment throughout thelife of the treatment process

Pilot Scale Investigations

Bench scale investigations are only the firststep in a necessary procedure for determiningthe most cost-effective treatment technology.Inherent scale-up problems make it inadvis-able, to say the least; imprudent, to beconservative; and negligent, to be truthful, todesign a full-scale treatment system based only

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on data from bench scale work The next step

after bench scale investigations is the pilot

scale work A pilot plant is simply a small

ver-sion of the anticipated full-scale treatment

system

A good pilot plant should have the capability

to vary operational parameters It is not

suffi-cient to merely confirm that successful

treat-ment, in terms of compliance with discharge

limitations, can be achieved using the same

operating parameters as was determined by the

bench scale investigations Again, it would be

outrageous serendipity if the results of the

bench scale investigations truly identified the

most cost-effective, as well as reliable,

full-scale treatment system design and operating

parameters

The pilot scale investigation should be

carried out at the industrial site, using a

por-tion of the actual gas stream to be treated A

pilot scale treatment unit, for instance a wet

scrubber, or an electrostatic precipitator, can,

in many cases, be rented from a

manufac-turer and transported to the site on a flatbed

truck

The pilot plant should be operated

continu-ously, over a representative period, so as to

include as many of the waste stream variations

that are expected to be experienced by the

full-scale unit as is reasonably possible One

diffi-culty in carrying out a pilot scale study is that

smaller units are more susceptible to upset,

fouling, plugging, or other damage from slug

doses caused by spills or malfunctions in

pro-cessing equipment Also, unfamiliarity on the

part of the pilot plant, either with the gas

stream being treated, the processing system

from which the stream is generated, or the pilot

plant itself, can result in the need for prolonged

investigations

Similar to wastewater treatment pilot plant

investigations, it is critically important to

oper-ate a pilot scale treatment system for a

suffi-ciently long period to:

• Include as many combinations of wastes

that are reasonably expected to occur during

the foreseeable life of the prototype system,

as is reasonably possible

• Evaluate as many combinations of operationparameters as is reasonably possible Whenoperation parameters are changed, forinstance the volumetric loading of an airscrubber, the chemical feed rate of a pHneutralization system, or the effective poresize of a bag house type fabric filter, the sys-tem must operate for a long enough time toachieve steady state before data to be usedfor evaluation are taken Of course, it will benecessary to obtain data during the periodjust after operation parameters are changed,

to determine when steady state has beenreached

Observations should be made to determinewhether performance of the pilot plant using aparticular set of parameters is in the range ofwhat was predicted from the results of thebench scale investigations If the difference inperformance is significant, it may be prudent tostop the pilot scale investigation work and try

to determine the cause

Preliminary Designs

The results of the pilot scale investigationsshow which technologies are capable of meet-ing the treatment objectives, but do not enable

an accurate estimation of capital and operatingcosts A meaningful cost-effectiveness analysiscan take place only after preliminary designs ofthose technologies that produced satisfactoryeffluent quality in the pilot scale investigationshave been completed A preliminary design,then, is a design of an entire waste treatmentfacility, carried out in sufficient detail to enableaccurate estimation of the costs for construct-ing and operating a waste treatment facility Itmust be complete to the extent that the sizesand descriptions of all of the pumps, pipes,valves, tanks, concrete work, buildings, sitework, control systems, and labor requirementsare established The difference between a pre-liminary design and a final design is principally

in the completeness of detail in the drawingsand specifications It is almost as though theteam that produces the preliminary designcould use it to directly construct the plant Theextra detail that goes into the final design is

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principally used to communicate all of the

intentions of the design team to people not

involved in the design

Economic Comparisons

The choice of treatment technology and

com-plete treatment system between two or more

systems proven to be reliably capable of

meet-ing the treatment objectives should be based on

a thorough analysis of all costs over the

expected life of the system

Bibliography

American Society of Civil Engineers, Manual

of Practice: Quality in the Construction

Project—A Guide for Owners, Designers,

and Contractors, New York, 1988

CELDS: United States Army Corps of

Engi-neers, Construction Engineering Research

Chanlett, E.T., Environmental Protection, 2nd

ed., McGraw-Hill, New York, 1979

Dunne, T., and L.D Leopold, Water in

Envi-ronmental Planning, Freeman, San

Francisco, 1978

Pruett, J.M., “Using Statistical Analysis for

Engineering Decisions,” Plant Engineering,

May 13, 1976, pp 155–157

U.S Environmental Protection Agency, Design

Criteria for Mechanical, Electric, and Fluid System and Component Reliability,

EPA-430-99-74-001, Washington, D.C.,

1974

U.S Environmental Protection Agency,

Devel-opment Document for Effluent Limitations and Guidelines and New Source Perfor- mance Standards for the Cement Manufacturing Point Source Category, EPA/

PB-238 610, January 1974

U.S Environmental Protection Agency, ISO

14000 Resource Directory, National Risk

Management Research Laboratory, EPA/625/R-97/003, Cincinnati, Ohio, 1997

Vesilind, P.A., Environmental Pollution and

Control, 10th ed., Ann Arbor Science

Pub-lishers, Ann Arbor, Michigan, 1982

Wachinski, A.M., and J.E Etzel,

Environmen-tal Ion Exchange, Lewis Publishers, New

York, 1997

Willis, J.T., (ed.), Environmental TQM, 2nd

ed., McGraw-Hill, New York, 1994

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2 Fundamentals

Introduction

Although the laws and regulations that require

industrial wastewater treatment are constantly

changing, the fundamental principles on which

treatment technologies are based do not

change This chapter presents a summarized

version of the basic chemistry and physics that

treatment technologies are based on, with the

objective of showing that a command of these

principles can enable quick, efficient

identifica-tion of very effective treatment technologies

for almost any given type of wastewater

The fundamental idea upon which the

approach suggested in this chapter is based can

be stated as follows: If the mechanisms by

which individual pollutants become

incorpo-rated into a waste stream can be identified,

ana-lyzed, and described, the most efficient

methodology of removal, or treatment, will be

obvious

As an example of the usefulness of this

approach to quickly develop an effective,

effi-cient treatment scheme, the leachate from a

landfill was to be pretreated, then discharged to

a municipal wastewater treatment facility

(publicly owned treatment works [POTW])

Because the waste sludge from the POTW was

to be disposed of by land application, a

restric-tive limitation was placed on heavy metals in

the pretreated leachate Analysis of the

leachate showed that the content of iron was

relatively high Other metals such as cadmium

(probably from discarded batteries), zinc,

cop-per, nickel, and lead were also present in excess

of the concentrations allowed by the

pretreat-ment permit, but substantially lower than iron

Knowledge of the following enabled quick

conceptualization of a treatment scheme:

• All metals are sparingly soluble in water

• Iron in the divalent state is highly soluble in

water, whereas iron in the trivalent state is

not

• Iron can be converted from the divalent state

to the trivalent state by passing air throughthe aqueous solution containing the dis-solved iron (The oxygen in the air oxidizesthe ferrous (divalent) ion to ferric (trivalent)ion.)

• Because substances such as cadmium, zinc,and lead are so sparingly soluble, they tend

to adsorb to the surface of almost any solidparticle in an aqueous environment

In this scheme, the leachate would be veyed to a simple, open concrete tank where airwas bubbled through it In this tank, insolubleiron oxide was formed from soluble ferrouscompounds, the precipitated iron oxide parti-cles would coagulate and flocculate because ofthe gentle mixing action of the air bubbles, anddissolved species of other metals would adsorb

con-to the iron oxide particles Next, the aeratedleachate was allowed to settle, effectivelyremoving all of the heavy metals to within thelimits of the pretreatment permit

The following sections of this chapter havebeen developed to explain the fundamentalchemical and physical principles by which pol-lutants become dissolved, suspended, or other-wise incorporated into wastewater At the end

of this chapter, several simple examples, lar to that involving the leachate, are given tofurther illustrate the usefulness of the techniquewhereby fundamental concepts of chemistryand physics can be applied to efficientlydeduce optimal treatment schemes

simi-Characteristics of Industrial Wastewater

Industrial wastewater is the aqueous discardthat results from the use of water in an indus-trial manufacturing process or the cleaningactivities that take place along with thatprocess

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Industrial wastewater is the result of

sub-stances other than water having been dissolved

or suspended in water The objective of

indus-trial wastewater treatment is to remove those

dissolved or suspended substances The best

approach to working out an effective and

effi-cient method of industrial wastewater treatment

is to examine those properties of water and of

the dissolved or suspended substances that

enabled or caused the dissolution or

suspen-sion, then to deduce plausible chemical or

physical actions that would reverse those

pro-cesses Familiarity with the polar

characteris-tics of water is fundamental to being able to

make such deductions

The Polar Properties of Water

Water molecules are polar This polarity arises

from the spatial arrangement of protons and

electrons in the individual hydrogen and oxygen

atoms that make up each water molecule

Con-sidering hydrogen first, it is the smallest of the

elements Hydrogen consists of one proton

within a small, extremely dense nucleus and one

electron contained within an orbital that is more

or less spherical and surrounds the nucleus An

orbital is a region in space where, according to

the theory of quantum mechanics, an electron is

most likely to be found Figure 2-1 is a

two-dimensional portrayal of the three-two-dimensional

hydrogen atom, but is sufficient to show that, at

any given instant, the negatively charged

elec-tron is able to counteract the positively charged

nucleus within only a small region of the space

that the atom occupies

Figure 2-1 Diagram of a hydrogen atom

Figure 2-1 illustrates that, if a charge tor could be placed near the hydrogen atom, atany given instant, it would detect a negativecharge in the region near the electron and apositive charge everywhere else The positivecharge would register strongest in the regionopposite in space to the region occupied by theelectron At any given instant then, a hydrogenatom is a polar object, having a negativelycharged region and a positively charged region

detec-In this sense, at any given instant, a hydrogenatom exhibits properties of a tiny magnet; how-ever, the electron is in continual motion, and atany given instant can be found anywherewithin the approximately spherical orbital sur-rounding the nucleus The net effect of an iso-lated hydrogen atom is to appear electricallyneutral and not polar

Before proceeding to an examination of thestructure and electrically charged characteris-tics of oxygen, and then water, it is useful toexamine the construction of the six elementsthat lie between hydrogen and oxygen in size,and to consider, in a step-by-step way, howeach successive proton and its associated elec-tron influence the characteristics of each ele-ment Several “rules” govern where electronsare to be found within an atom or a molecule.The first has to do with energy level As atomsincrease in size, the additional protons alwaysreside in the nucleus, but the additional elec-trons reside in successively larger orbitals that,

in turn, exist within successively larger tric shells The electrons within orbitals that arecloser to the nucleus are of lower energy levelthan those in larger orbitals One of the strictrules of electron location is that no electron canoccupy an orbital of higher energy level untilall orbitals of lower energy are “full.” A secondrule is that only two electrons can occupy anyatomic orbital, and these electrons must haveopposite spins These electrons of oppositespin are called “electron pairs.” Electrons oflike spin tend to get as far away from eachother as possible This rule is the “Pauli exclu-sion principle” and is the most important of allthe influences that determine the properties andshapes of molecules

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concen-Fundamentals 31Figures 2-2(a) and (b) show two ways

to depict a spherical electron orbital

Figure 2-2(a) presents the orbital as a

spheri-cal cloud surrounding the nucleus Figure 2-2

(b) is simply a convenient, two-dimensional

representation of the orbital Figure 2-3 shows

the shapes of the two orbitals of lowest

energy level, which are the two smallest

orbit-als as well

Figure 2-3(a) shows that the smallest and,

therefore, lowest energy level orbital is

desig-nated the “1s” orbital and is approximately

spherical The center of the 1s orbital coincides

with the center of the atom’s nucleus Figure

2-3(b) shows that the next larger orbital is

called the “2s” orbital and is also

approxi-mately spherical, with its center coinciding

with the center of the nucleus Next in size (and

energy level) are three orbitals of equal energy

level that have two approximately spherical

lobes each, and can thus be described as having

Figure 2-2(a) Spherical electron orbital as a spherical

cloud surrounding the nucleus.

Figure 2-2(b) Two-dimensional representation of the

electron orbital.

shapes similar to dumbbells (as in ing) These orbitals, named “2p orbitals,”are shown in Figures 2-4(a), (b), and (c).Figure 2-4(a), (b), and (c) show that the threetwo-lobed orbitals are arranged so as to be asfar away from one another as possible, and arethus arranged such that the center of each lobelies on one of three axes that are perpendicular

weightlift-to one another

The center of the atomic nucleus coincideswith the origin of the three axes The axes arereferred to as the x, y, and z-axes, and the threeorbitals are called the 2px, 2py, and 2pz orbitals The electron orbitals exist within electronshells The electron shells are concentric andare numbered 1, 2, 3, 4, etc., and the smallershells, closer to the nucleus, must become fullbefore electrons will be found in orbitals inhigher, or larger, shells Shell 1 is full with one(1s) orbital The total number of electrons inshell 1, when it is full, then, is two Shell 2 is

Figure 2-3(a) 1s orbital.

Figure 2-3(b) 1s and 2s orbital.

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