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Matched Legal Cases: ['art 503', 'arts 413', 'art 423', 'art 423', 'art\n455', 'art\n403', 'art 403', 'art 403', 'arts 405']

Pretreatment of Industrial Wastes | Clean Water Act | Sewage Treatment
Water Environment Federation, Pretreatment of Industrial Wastes, Manual of Practice FD-3, 1994.
SalvaSalva Pretreatment of Industrial Wastes per dopo
Manual of Practice FD - 3
Manual of Practice No. FD-3
Prepared by the Task Force on Pretreatment of Industrid Wastes EIin Eysenbach, Chair
Michael R. Alheri Paul R. Anderson
Byung R.Kim Jeffrey L. Lape
Steven A. Shedroff Sam Shelby
Peter V. Cavagnaro Hany Criswell
Roger R. Hlavek
Charles D. Malloch Michael P. McGinness William 1. Mikula
Dennis P. Shelly Rao Y.SurampaJli William M. Throop
Charles Damell
Paul I. Usinowicz
Michael C. Downey Terence P. Driscoll Richard C. Grant Negib Harfouche
Larry W. Moore John L. Musterman Tom M. Pankratz David M. Philbrook Douglas L.Ralston
Gary R. Vaughan Kannan Vembu T. Viraraghavan ThomasG. Wallace Hugh E. Wise, Jr.
Herbert N. Schott
Blaine F. Severin
Under the Direction of the FacilitiesDevelopment Subcommittee of the Technical Practice Committee and sponsored by the Industrial Wastes Committee
Water Environment Federation 601 Wythe Street Alexandria, Virginia 22314-1994 USA
The Water Environment Federation is a nonprofit, educational organization composed of member and affiliated associations throughout the world. Since 1928, WEF has represented water quality specialists, including biologists, bacteriologists, local and national government officials, treatment plant opera- tors, laboratoly technicians, chemists, industrial technologists, students, aca- demics, equipment manufacturers/distributors, and civil, design, and environmental engineers.
For information on membership, publications, and conferences, contact Water Environment Federation 601 Wythe Street Alexandria, VA 22314-1994 USA (703) 684-2400
Pretreatment of industrial wastes I prepared by the Task Force on Pretreat- ment of Industrial Wastes; under the direction of the Facilities Develop- ment Subcommittee of the Technical Practice Committee and sponsored by the Industrial Wastes Committee.
of practice: no. m)-3)
-(Manual
ISBN 1-881369-89-7:$55.00 1. Factory and trade waste-Purification.
2. Sewage-Purification.
I. Water Environment Federation. Task Force on Pretreatment of Industrial Wastes. 11. Water Environment Federation. Facilities Development Subcom-
mittee. 111. Water Environment Federation. Industrial Wastes Committee. IV. Series: Manual of practice. FD; no. 3.
TD897.5.W5 1994
628.3’44~20
Copyright 0 1994 by the Water Environment Federation Alexandria. VA 22314-1994 USA
Library of Congress Catalog No. 94-30220 ISBN 1-881369-89-7 Printed in the USA 1994
Manuals of Practice for WaterPollution Control
The Watet Environment Federation Technical Practice Committee (formerly the Committee on Sewage and Industrial Wastes Practice of the Federation of Sewage and Industrial Wastes Associations) was created by the Federation Board of Control on October 11,1941.The primary function of the Commit- tee is to originate and produce, through appropriate subcommittees, special publications dealing with technical aspects of the broad interests of the Fed- eration. These manuals are intended to provide background information through a review of technical practices and detailed procedures that research and experience have shown to he functional and practical.
The contents of this publication are for general information only and are not intended to he a standard of the Water Environment Federation (WEF). No reference made in this publication to any specific method, product, process, or service constitutes or implies an endorsement, recommendation, or warranty thereof by WEE WEF makes no representation or warranty of any kind whether expressed or implied, concerning the accuracy,product, or process discussed in this pub- lication and assumes no liability. Anyone utilizing this information assumes all liability arising from such use, including but not limited to infringement of any patent or patents.
Water Environment Federation Technical Practice Committee Control Group
ED. Munsey, Chair L.J. Glueckstein. Vice-Chair
C.N. Lowery
R.W. Okey
Authorized for Publication by the Board of Control Water Environment Federation
Quincalee Brown, Executive Director
This manual is a joint effort by the Federation’s Technical Practice and Indus- trial Wastes Committees to provide general guidance on treatment selection, design, facilitiesdevelopment, and pollution prevention for the pretreatment of industrial wastes. The manual is targeted for industrial users of wastewater treatment plants (WWTP) (indirect dischargers),WWTP officials implement- ing pretreatment programs, and the technical people who support pretreat- ment design and development. Industrial indirect dischargers having the most to gain from this manual are those who need to pretreat wastewater for com- pliance with pretreatment ordinances. As an alternative to pretreatment itself, the manual also discusses in-plant pollution prevention techniques. The manual begins with an overview of pretreatment regulatory require- ments, potential management strategies, and pollution prevention considera- tions. The remainder of the manual is organized by waste characteristics. Chapters address the need for pretreatment of the specific waste characteristic and the technology selection and design considerations important in treating that characteristic. This manual was produced under the direction of Elin Eysenbach, Chair. The principal authors are
Terence P. Driscoll Elin Eysenbach W. Michael Joyce Charles D. Malloch John L. Mustermau
Michael R. Alberi Don Bzdyl Peter V. Cavagnaro Richard C. Grant Charles C. Meyer Larry W. Moore
Douglas L. Ralston Herbert N. Schott Steven A. Shedroff Gary R. Vaughan George M. Wong-Chong
Thomas M. Pankratz David N. Philbrook Stephen R. Tate SteveTripmacher Hugh E. Wise, Jr.
Additional information and review were provided by
Paul R. Anderson W. Bailey Barton Charles Darnell Jim Devlin Michael C. Downey John Groenewold Samuel J. Hadeed Negib Harfoucbe Roger R. Hlavek Robert N. Kenney Byung R. Kim Jeffrey L. Lape
Michael P. McGinness William J. Mikula Stephen J. Miller Blaine Severin Sam Shelby Dennis P. Shelly Rao Y. Snrampalli William M. Throop Paul J. Usinowicz Kannan Vembu T. Viraraghavan Thomas G. Wallace
Task force members’, reviewers’, and authors’ efforts were supported by the following organizations:
Advent Group Inc., Brentwood, Tennessee Alden Environmental Management, Inc., Wayne, Pennsylvania Aponowich, Driscoll &Associates, Inc., Atlanta, Georgia Aqua-Chem, Inc., Houston, Texas Arthur D. Little, Inc., Cambridge, Massachusetts Bio-Cide International, Inc., Lincoln, Nebraska Borden Environmental Affairs, Columbus, Ohio Calderon-Grant, Inc., Columbus, Ohio City of Austin, Austin, Texas Consulting Analytical Services, Springfield,Missouri Dufresne-Henry, North Springfield,Vermont Eckenfelder Inc., Nashville, Tennessee Engineering-Science, Liverpool, New York ENSR Consulting & Engineering, Somerset, New Jersey ERM, Inc., Exton, Pennsylvania ICF-Kaiser Engineers, Pittsburgh, Pennsylvania Illinois Institute of Technology, Chicago, Illinois John Carollo Engineers, West Linn, Oregon Jordan Jones & Goulding, Snellville, Georgia McNamee Operational Services, Ann Arbor, Michigan Monsanto Company, St. Louis, Missouri Nolte & Associates, Sacramento, California OMI, Inc., Fayetteville, Arkansas Procter & Gamble, Cincinnati, Ohio Proctor Davis & Ray Engineers, Lexington, Kentucky R.E. Wright Associates, Inc., Mechanicsburg, Pennsylvania
Roy F.Weston, Inc., Edison, New Jersey RUSTE Br 1, Raleigh, North Carolina Sadat Associates, Inc., Princeton, New Jersey Seeler Associates, Rochester, New York Stanley Consultants, Muscatine, Iowa Sverdrup Corporation, Maryland Heights, Missouri US. EnvironmentalProtection Agency, Washington, D.C. Unified SewerageAgency, Hillsboro, Oregon Union Sanitary District, Fremont, California University of Houston, Pasadena, Texas University of Regina, Regina, Saskatchewan, Canada Woodard & Curran, Inc., Portland, Maine
Federation technical staff project management was provided by Eileen J. ONeill and J. Robert Schweinfurth.Technical editorial assistance was pro- vided by Matthew Hauber.
Effects of Industrial Waste on Municipal Wastewater Treatment Plants
Significant Industrial User Requirements
SignificantNoncategorical Industrial Users
Management Strategies for Pollution Prevention and Waste Minimization
Categorical Waste Streams
Identifying Wastewater-generatingOperations
Preparing Mass Balances
Cross-media Pollutants Safety Considerations Off-site Pretreatment Process Monitoring Cost Analysis
Flow Equalization Processes
Altemating Flow Diversion IntermittentFlow Diversion Completely Mixed Combined Flow Cumulative Flow Curve
Mixing Requirements Baftling Mechanical Mixing Aeration Draining and Cleaning
Suspended Solids Classifications
Removal Methods-Mainstream
Straining Coarse Screens Fine Screens Rotary Drum Screens Tangential Screens Vibratory Screens Gravity Separation Grit Removal Plain Sedimentation Chemical Coagulation Flotation Filtration
Sludge Handling and Processing
Disposal Practices and Technology
Grit and Screenings
Oily Sludge and Residues
Sludge Classified as Toxic
Nonhazardous Wastewater Solids
Chemical Wastewater Solids
The Need for Fats, Oil, and Grer
Pretreatn
Collection System Interferences
Treatment Plant Interferences
Characteristics of Fats, Oil, and Grease
Total Fats, Oil, and Grease
Floatable Fats, Oil, and Grease Combined US.Environmental Protection Agency Methods
413.2and418.1
Sources of Fats, Oil, and Grease
Coalescing Gravity Separators
Chemically Enhanced Separation
Options for Recovered Oil and Grease
Transport to Anaerobic Digestion
Titration Curves and Analysis
Effects of Flow and Load Variability Sludge Production
Alternative Neutralizing Agents
Basic Agents Lime Caustic Soda Sodium Bicarbonate Sodium Carbonate Magnesium Hydroxide Acidic Agents SulfuricAcid Carbon Dioxide and Flue Gas Other Acids Cost Per Unit Acidity/Alkalinity Bulk Storage Requirements
Design of pH-control Systems
Batch-control Systems
Raw Materials Handling and Safety Process Control Scale Formation Annual Cost Side Reactions and Byproducts Equipment and Structural Effect
8 Heavy Metals Removal
Effects on Wastewater Treatment Plants
Hydroxide Precipitation/Coagulation
Solids-separation Process Options
Sedimentation Pond Conventional Clarifier Solids Contact Clarifier Plate Settler Filtration Systems Operational Considerations Chemical Conversion Hexavalent Chromium Reduction Cyanide Destruction
Ion Exchange Adsorption Activated Carbon Soluble Sorbent Clarification Membrane Processes Ultrafiltration Reverse Osmosis Electrodialysis
Evaporation Ponds Mechanical Evaporators Vertical Tube Falling Film Horizontal Tube Spray Film Forced Circulation Combined Systems
9 Treatment of Organic Constituents
Selection of Pretreatment Technology
Biological Treatment Process Configuration Secondary Emissions Biological Pretreatment Assessment Methodology Case Histones Case 1 Case 2 Case 3 Case 4 Chemical Oxidation Case Histones
Effects of Nutrients on Treatment
Effects of Nutrients on Receiving Streams
Air or Steam Stripping of Ammonia
Other Stripping Options
Ion Exchange for Ammonia and Nitrate Removal
Synthetic Resins System
Clinoptilolite System
Pollutants regulated by pretreatment standards.
Priority pollutants-metals.
Priority pollutants-volatile
Priority pollutants-semivolatile
Priority pollutants-pesticides.
Pesticide active ingredients regulated by pretreatment standards.
Technologies applicable to pollutants regulated by pretreatment standards.
Activated sludge inhibition threshold levels.
Trickling filter inhibition threshold levels.
Nitrification ignition threshold levels.
Anaerobic digestion threshold inhibition levels.
Industries with categorical pretreatment standards.
Regulated pollutants in Part 503 eligible for a removal credit.
Additional pollutants eligible for a removal credit.
Processes applicable to industrial wastewater treatment.
Industrial facility daily flow profile.
Selection of cumulative standard normal for desired confidence level.
Hourly influent chemical oxygen demand data for 4-day period.
Flow data for example problem.
WeighVvolume reduction fmm dewatering and drying a typical biological sludge.
Industries that aremajor contributors of fats, oil, and grease to wastewater treatment plants.
Industries that produce acid andor alkaline wastewater.
Neutralization factors for common alkaline and acid reagents.
Summary of properties for typical neutralization chemicals.
Industries with possible occurrence of certain metals in industrial wastewater.
Theoretical solubilities of various metals in pure water.
Industrial wastewater characteristics.
Pretreatment alternatives for compatible organics in selected industrial wastes.
Bioacclimatioddegradation of priority pollutants.
Removal of organic priority pollutants in biological treatment systems.
Organic priority pollutant removal in activated sludge systems.
Criteria for selecting an aerobic 01 anaerobic pretreatment process.
Criteria for choosing between fixed film and suspended growth.
Bleachery wastewater pretreatment plant performance.
Oxidation potential of various oxidizing agents.
Summary of generalized guidelines for hydrogen peroxide oxidation processing of organic compounds.
General process characteristicsand application of chemical oxidation processes.
Average performancedata for the chemical manufacturingplant carbon adsorption system.
Chemical coagulants for phosphorus precipitation.
Design criteria for the Upper Occquan Sewage Authority,Virginia.
Strategy for wastewater management at a manufacturing complex.
Alternating flow diversion equalization system.
Intermittent flow diversion system.
Completely mixed combined flow system.
Completely mixed fixed flow system.
Maximum effluent values as a function of equalization time and confidence level.
Cumulative flow curve.
Catenary bar screen.
Rotary drum screen.
Inclined self-cleaning static screen.
Circular vibratory screen.
Typical grit dragout tank.
Center-fed circular clarifier.
Rectangular clarifier with wood flights mounted on parallel chains.
Rectangular clarifier with traveling bridge sludge collector.
Continuous backwash upflow filter.
Classification of sludge-handling and -disposal options commonly available for pretreatment systems.
Qpical gravity thickener.
Schematic of operating dissolved air flotation system with recycle flow pressurization.
Continuous countercurrent solid howl conveyor discharge centrifuge.
Schematic diagram of a typical screw press.
Schematic of a typical three-phase centrifuge system for handling oily sludge.
qpical dissolved air flotation system.
Titration curve of strong acid titrated with a strong base.
Titration curve of strong acid titrated with a weak base.
pH control schematic for batch neutralization system for acid wastewater.
Simple on-off control switch.
Simple multimode control system.
Cascade control system with feed-back and feed-forward control loops.
Schematic for two-stage neutralization system with equalization.
Total and dissolved copper concentrations in supernatant versus pH for an electroplating and electroless plating wastewater.
Comparison of pH versus total zinc concentration in supernatant for various wastewaters.
Comparison of pH versus total nickel concentration in supernatant for various wastewaters.
metal hydroxides versus pH.
Relative solubilities of metal sulfides versus pH.
Generalized schematic of metal hydroxide precipitatiodcoagulation facility unit processes
Schematic drawings of examples of solids separation processes used in metals removal.
Multiple-effect evaporator.
Spray film evaporator.
Forced-circulation evaporator.
Schematic flow diagrams of typical biological treatment systems.
Schematic diagram of adsorption system.
a typical two-column carbon
Schematic diagram of solvent extraction of wastewater.
Three-stage chemical treatment system
Equilibrium solubility diagram for ferric, aluminum,
Temperature effects on gas-liquid requirements
and calcium phosphate precipitates.
for ammonia stripping.
Effects of hydraulic loading on ammonia removal at various depths.
Process for ammonia removal and recovery.
Ammonium nitrate recovery system.
10.7 Clinoptilolite regenerant concentration effects on regeneration efficiency.
10.8 Theoretical breakpoint chlorination curve.
Industrial WastewaterCharacteristics
Effects of Industrial Waste on Munldpal Wastewater lkeatmentPlants
The objective of this manual is to provide guidance in the selection of designs and processes for the pretreatment of industrial wastes. It is directed toward industrial users of municipal wastewater treatment plants (WWTP) (indirect dischargers), WWTP officials implementing pretreatment programs, and tech- nical personnel who support pretreatment design and development. Industrial indirect dischargers who should benefit most from this manual are those who must pretreat wastewater for compliance with pretreatment ordinances. Al- though this manual includes general discussions of design and operations, de- sign details and operational specifics are beyond its scope. As an alternative to meet pretreatment objectives, the manual also discusses in-plant pollution prevention techniques. The first three chapters set the stage for pretreatment process selection by discussing the background and issues applicable to pretreatment in general. The first chapter demonstrates the need for pretreatment information and guidance and provides a framework for later waste-specificdiscussions. Although the manual is not a legal or regulatory advisory, a basic under- standing of the US.regulatory status regarding Pretreatment, as discussed in Chapter 2, sets the stage for understanding the need for pretreatment and the driving forces for technology selection. Those seeking situational clarifica- tion should refer to relevant regulations.
Chapter 3 addresses wastewater management alternatives and pollution prevention (in-plant controls).The remaining chapters offer specific selection and implementation guidance for meeting pretreatment requirements. They are organized by waste characteristics, as follows:
Chapter 4 Flow Equalization Chapter 5: Solids Separation and Handling Chapter 6 Fats, Oil, and Grease Removal Chapter 7 Neutralization Chapter 8: Heavy Metals Removal Chapter 9: Treatment of Organic Constituents Chapter 10 Nutrient Removal
Allowing for some overlap, Chapters 4 to 6 generally address physical processes; Chapters 7 and 8, chemical; and Chapters 9 and 10,biological. Although wastewater conveyed to a WWTF’ may include process waste- water from industrial users, in-sewer dilution by domestic wastewater typi- cally will substantially reduce the original concentrations of chemicals in the industrial discharges. Overall treatment efficiency, however, may be tempo- rarily diminished by higher concentrations (slugs) of chemicals to which the biomass in the WWTP’s treatment process have not previously adapted. Tem- porary operational problems may also occur when slugs enter the sewer too close to the WWTP for adequate dilution or during periods of the day when the flow of domestic wastewater is low. For the purposes of this manual, the US.regulatory definition will be used for pretreatment. If is “the reduction of the amount of pollutants, the elimination of pollutants, or the alteration of the nature of pollutant properties in wastewater prior to, or in lieu of, discharging or otherwise introducing such pollutants into a waste treatment plant.” A manufacturing facility discharging to a WWTP may have to pretreat water to
Comply with the General Pretreatment Regulations issued by the U.S. Environmental Protection Agency (U.S.EPA); Comply with Categorical Pretreatment Standards, if applicable; Comply with local ordinances (limits); Reduce user fees, when the surcharge (by the WWTP) is based in part on the mass loading of one or more pollutants; and Improve its public image or reduce the stigma associated with pub- licly reported releases such as the ‘Toxics Release Inventory” under the Superfund Amendment and Reauthorization Act (SARA).
The emphasis of this manual is on indirect discharges with final treatment done by the WWTP in conjunction with the treatment of residential sanitary
Pretreatment of Zndustrinl Wastes
wastes. Most of the technologies discussed are also applicable to industrial wastes treated within the industrial facility (direct discharger) or by an off- site, privately owned wastewater treatment facility. Specific wastewater management alternatives and strategies for pretreat- ment are discussed in Chapter 3. Although they are not new to industry, em- phasis has been placed recently on pollution prevention techniques. These techniques are in-plant process designs or redesigns that avoid or reduce wastewater discharge before and, to the extent possible, instead of effluent treatment. Although not pretreatment as such, pollution prevention is critical to a sound wastewater management strategy. For the many affected industrial facilities to meet these requirements, sub- stantial investments in the construction and operation of pretreatment facili- ties has been,and will continue to be, necessary. This manual provides general treatment selection and design guidance, and facilities development information for the pretreatment of industrial wastewater. The reader should refer to detailed wastewater design texts for additional information. Several of these are included in the reference lists provided by chapter. The reader is cautioned against applying general values taken from this
manual to specific industrial applications.To ensure proper
specific evaluations and appropriate treatability testing will he needed.
design, site-
Industrial processes generate a variety of wastewater pollutants, some of which are difficult and costly to treat. Wastewater characteristics and levels of pollutants vary significantly from one industry to another and sometimes vary greatly among plants within the same industry. In addition, fluctuations may occur in the wastewater’s daily and hourly flow, temperature, and composi- tion. In some cases, several manufacturing processes may discharge at the same location. Together these factors create a complex wastewater manage- ment challenge that is unique to each industrial facility. Pollutants regulated by U.S. pretreatment standards may he grouped into conventional, nonconventional, and priority pollutants, as shown in Table 1.1. Tables 1.2 to 1.6divide priority pollutants according to waste characteristics. Knowledge of potential wastewater components and awareness of these regu- lated discharges will allow assessment of the applicability of pretreatment standards to a given facility. A list of pretreatment technologies commonly ap- plied to pollutants regulated by pretreatment standards is shown in Table 1.7. Chapters 4 through IO will address the applications of such technologies.
Priority pollutants Asbestos (as TSS)
Ammonia (as nitrogen) Chromium VI (hexavalent) Chemical oxygen demand (COD) CODBOD, (7-day) Fluoride
Semivolatile Manganese
Total toxic organics ('ITO)* Conventional pollutants Biochemical oxygen demand, 5-day (BODS) Total suspended solids (TSS) Oil and grease Oil (animal and vegetable) Oil (mineral)
Nitrate (as N) Organic nitrogen (as N) Pesticide active ingredients (PAI)
Phenols, total Phosphorus, total (as P) Total organic carbon (TOC)
* 'IT0 is not always defined as the same organic priority pollutants (see 40 CFR Parts 413.02,464.02,467.02, and 469.12).
Priority pollutantsmetals (information taken from 40 CFR Part 423. Aooendix A).
I, 1,2,2,-Tetrachloroethane
Chloroethane 2-Chloroethylvinyl ether
1,I,I-Trichloroethane
1,I-Dichloroethane
I, 1,2-Trichloroethane
I ,I-Dichloroethylene
Priority pollutants-semivolatile organics.
Acenaphthylene Antracene Benzidine Benzo(a)anthracene Benzo(b)fluoranthene Benzo(a)pyrene
Di-n-octyl phthalate 1,2-Diphenylhydrazine(as azohenzene) Fluoranthene Fluorene Hexachlorobenzene Hexachlorohutadiene
4-Bromophenylphenyl ether
Indene(1,2,3-cd)pyrene
1,2-Dichlorohenzene
1,4-Dichlorohenzene
Di(2-ethylhexy1)phthalate
2,3,7,8-Tetrachlorcdibenzo-p-dioxin(TCDD)
1,2,4-TrichIorobenzene
Priority pollotants-pesticides 40 CFR Part 423, Appendix A).
p-BHC
6-BHC
P-Endosulfan
Pesticide active ingredients regulatedby pretreatment standards (FR 57 at 12598 [April 10,19921 and 40 CFR Part
455.2O[dl).
A1dicarb
Benfluraliu
Feuthion
Pyrethrin I1
KN methyl
Carham-S
Carhofuran
Tebuthiron
Terhacil
Terhufos
Terhuthylazine
* Priority pollutant.
Technologies applicableto pollutants regulated by pretreatment standards.
Physical Carbon adsorption Distillation Filtration Ion exchange Membranes Microfiltration (MF) Ultrafiltration (UF) Reverse osmosis (RO) Oil and grease skimming Oil and water separation Sedimentation (clarification) Steam stripping Solvent extraction
Chemical Chemical oxidation Chemical precipitation Chromium reduction Coagulation Cyanide destruction Dissolved air flotation Electrochemical oxidation Flocculation Hydrolysis Neutralization (pH control) Biological Extended aeration Rotating biological contactor Sequencing batch reactor Trickling filter
Of some 15 500 municipal wastewater treatment facilities in the US.,ap- proximately 75% have at least secondary treatment (US. EPA, 1987). Understanding the potential effects of some uncontrolled industrial dis- charges on WWTP operation will help determine the need for pretreatment in specific situations. In addition to hydraulic overloads or temperature extremes, potential con- cerns may include excess amounts of the following:
Highly acidic or alkaline wastewaters;
Inorganic wastes;
Explosive and flammable materials; and
Wastewater containing volatile, odorous, or corrosive gases.
Because municipal wastewater treatment typically involves complex bio- chemical processes, an upset affecting one design parameter will likely affect others as well. Industrial waste characteristics potentially affecting municipal collection systems may include seasonal fluctuations, odorous wastes, corrosiveness, viscous solids precipitation, and explosion hazards. Special care must be exer- cised to prevent discharge of volatile or flammable chemicals that may result in explosive concentrations in sewer head space. Industrial-waste-related difficulties likely to affect preliminary or primary treatment facilities may result from overloading or high variability of otber- wise acceptable waste materials. Special wastes may result in predictable problems if the WWTP is not designed to handle them. An example may be organic solids from food-processing or meat-packing wastes that become trapped at a point of reduced flow, causing septic odors. This can occur in typical WWTP equipment, such as a grit chamber, or as a result of solids sepa- ration equipment plugging. Unless waste composition is well understood, WWTPs may be underds signed for not only industrial discharges of solids, including such organics, but also sand or large debris. Well-run industrial facilities, however, can nor- mally collect and dispose of most gross solids, such as rags, as solid waste. A comprehensive cost evaluation may be needed to determine whether the WWTP should address the needed additional capacity or pretreatment is re- quired. It is important for effective operation that actual waste loads and com- position be within the design tolerance. As additional dischargers apply to connect to the WWTP, the WWTP staff must constantly reassess potential waste streams and their anticipated effects on treatment effectiveness. Potential effects on secondary treatment systems may result from materials or circumstances that interfere with, or upset, biochemical activity.These in- clude high variability in waste organic content or flow (shock loading), high organic loading for extended time periods, waste components at potentially toxic levels, nutrient imbalance, and temperature or pH extremes. Tables 1.8 through 1.11provide US. EPAestimates of thresholds of inhibition on bio- logical treatment processes. When waste characteristics are compatible with WWTP processes, shock loadings can be handled with equalization by the re- sponsible waste discharger or by modification of the WWTP, perhaps at the expense of the responsible discharger. Community user-fee-based solutions often allow for appropriate treatment while optimizing complementary characteristics of different dischargers. An example would be combining alkaline and acidic wastes with a minimum chemical dosage to neutralize pH in the influent. In at least one WWTP agree- ment, the industrial user assists the WWTP by controlling pH to a level speci- fied daily by the WWTP. This results in reduced WWTP costs and user-fee savings.
Pretreatment of Zndustrial Wastes
Activated sludge inhibition threshold levels* (US.EPA,
Metaldnonmetal inorganics
level, mgL
2.5 as Hg (11)
1,4-Dicblorobenzene
Activated sludge inhibition threshold levels* (continued).
Organics (continued) Naphthalene
Laboratoly
5&100
* References did not distinguish between total of dissolved pollutant inhibi- tion levels.
'Mckling filter inhibition threshold levels* (US.EPA 1987).
Laboratory, pilot
level, mpn
3.5-67.6
Referencedid not distinguish between total or dissolved pollutant inhibi- tion levels.
Nitrification inhibition threshold levels* (US.EPA, 1987).
Metalshonmetal inorganics
level, mg/L.
0.25-1.9
(Trickling filter)
(as Cr0k2.)
Chloride Organics
* References did not distinguish between total or dissolved pollutant inhihi- tion levels.
When WWTP operations require industrial pretreatment, the user must fully understand the basis and success criteria for pretreatment design. It is lit- tle consolation for the user to meet the specified criteria only to find the proh- lem unresolved or the standard not met. Jointly prepared periodic waste load projections are useful in both industrial and WWTP pretreatment planning. Potential adverse effects on sludge management processes may result from shock loading of normally compatible waste components such as sand, silt, or industrial process waste solids. Perhaps the most important interference of this type is the possibility of sludge contamination, particularly by metals. Sweeping changes in US. EPAregulation of sludge disposal may require ex- tensive additional pretreatment. Some industrial wastes may interfere with disinfection processes by, for example, exerting chlorine demand. If accounted for in system design and user fees, this is not likely to be
Anaerobic digestion threshold inhibition levels' (USEPA,
Minimum reported inhibition Reported range of Laboratory,
Metalsinonmetal inorganics Cadmium
13-6Sb
2.9-159.4
0.23-3.8
3.3-536.4
Anaerobic digestion threshold inhibition levels' (continued).
Reported range of
a Total pollutant inhibition levels, unless otherwise indicated Dissolved metal inhibition levels.
problematic. If, on the other hand, waste components increase over time or fluctuate widely, the WWTPmay be unprepared to address needs. As in all need-based cases, consideration of WWTP changes should be weighed against pretreatment options to resolve the concerns. The most common WWTP concerns relating to industrial waste loading in excess of plant capacity are potential interferences, accumulation, pass- through, and facility damage.
US. Environmental Protection Agency (1987) 1986Needs Survey Report to Congress: Assessment of Needed Publicly Owned Wastewater Treatment Facilities in the United States. U.S. EPA 430/9-87-001, Washington, D.C.
b'UGGESTED READINGS
Anthony, R.M., and Breimhurst, L.H. (1981) Determining Maximum Influent Concentrations of Priority Pollutants for Treatment Plants. J. Water Pollut. Control Fed., 43, 10, 1457. US.Environmental Protection Agency (1978) General Pretreatment Regula- tions for Existing and New Sources ofPollution. 43 FR 27746, Washing- ton. D.C.
U.S.Environmental Protection Agency (1986) Report to Congress on the Dis- charge of Hazardous Wastesto Publicly Owned Treatment Works.Office of Water Regulation and Standards, 530-SW-86-004, Washington, D.C. US.Environmental ProtectionAgency (1991) National Pretreatment Pro- gram: Report to Congress. EN-336,21W-4004, Washington, D.C.
Pretreatment ofIndustrial Wastes
Chapter 2 Prepeahment Regulations
Signifleant Industrial User
CategoricalIndustrial Users
Significant NancategoricaiIndustrial Users
The Federal Water Pollution Control Act of 1972, amended in 1977 and 1987, gives the US.Environmental Protection Agency (US.EPA) the authority to establish and enforce pretreatment standards for the indirect discharge of in- dustrial wastewaters. The intent of these regulations is to prohibit the discharge of wastes that are incompatible with wastewater treatment plant (WWTP) processes. To be specific, the pretreatment program has three objectives (see 40 CFR Part
403.2):
To prevent the introduction of pollutants to WWTPs that will interfere with the operation of a WWTP, including interference with its use or disposal of municipal sludge; To prevent the introduction of pollutants to WWTPs that will pass through the treatment works or otherwise be incompatible with such works; and To improve opportunities to recycle and reclaim municipal and indus- trial wastewaters and sludge.
Prefrenfment Regulations
Instead of allowing each WWTP to set local limits to regulate contami- nants troublesome to its operations, the US.Congress passed legislation that requires uniform pretreatment standards to be administered nationwide through authorized pretreatment programs at WWTPs. Pretreatment require- ments were focused on controlling a list of 129 (now 126) chemicals that were negotiated in a 1975 lawsuit and became incorporated into Sec- tion 307(a) of the Clean Water Act (CWA) as amended in 1977.These pollut- ants are more commonly known as “priority pollutants.” To implement the mandate of the 1917 CWA to control priority pollutants reaching WWTPs from industrial users,US.EPA first issued the General Pre-
treatment Regulations (40 CFR
Part 403) in 1978, followed by a revised ver-
sion in 1981.These regulations became the basis for nationwidepretreatment programs by establishingprocedures, responsibilities, and requirements for US.EPA, states, local governments (WWTPs), and industries. The General Pretreatment Regulations require US.EPA to promulgate pre- treatment standards for control of priority pollutants in industrial process wastewater before its discharge to the WWTP. US. EPA has responded by es- tablishing “prohibited discharge standards” (Part 403.5) applicable to all non- domestic WWTP users and promulgating “categorical pretreatment standards” that are applicable to specific industries (40 CFR Parts 405-471). Congress assigned the primary responsibility for enforcing these standards to local WWTPs. The Water Quality Act of 1987 reinforced many of the pretreatment provi- sions of the earlier amendments. While the new law did not change the frame- work of the general pretreatment regulations, it did establish certain provisions requiring modification to the regulations and mandated that US. EPA report to Congress on pretreatment (which US.EPA sent to Congress on May 21, 1991). Perhaps the most significant provision from an industrial user standpoint dealt with “removal credits.” The Resource Conservation and Recovery Act (RCRA) Section 3018(h) contains a provision dealing with Domestic Sewage Exclusion and a required study. On February 7, 1986, US.EPA submitted its “Report to Congress on the Discharge of Hazardous Waste to Publicly Owned Treatment Works.” As a follow-up commitment made within that report, U.S. EPA promulgated
changes to the General Pretreatment Regulations (see 55 FR 30082) on July 24, 1990. These changes have a significant effect on industrial users. Readers should obtain copies of the relevant changes to the statute for an in-depth understanding. Industrial users (IU) of WWTPs with authorized pretreatment programs must meet certain requirements before industrial wastewater is allowed to be discharged to a WWTP for treatment. The regulatory framework for these re- quirements is set forth