id, W. F.. “Removal of Thiosulfate/ d Solution.” Environ. Sci. & Technol.,

, D. W., “Environmental Assessment

r Recirculation System.” Iron & Steel

, A., “Physical-Chemical Treat-

H. J., “Study of Non-U. S . Waste- at Blast Furnaces and Coke Plants.” I Pollut. Abate. Technol., EPA-600/

of Steel-Mill Wastewater.” Civil

less Steel Plant.”

., “Metal Processing Wastes: Water Pollution. (Citations from the NTIS Data Base).” NTIS

+-Part 1.” Ind. Wastes, 25, 3, 50 (1979); Hanvell

“Advanced Ozone Technology for Cyanide Destruc- troplating.” Plat. Sur/. Finish.. 67, 5 , 77 (1980). , and Helwick, R., “Cyanide Waste Treatment Tech-

r ’ /”/*

Industrial Wastes

nology-The Old, The New, and The Practical,” Plat. Surf. Fin- ish., 67, 8, 56 (1980).

56. Okubo, K., et ai., “Recovery of Valuable Components from Waste Water from Industrial Scale Low Cyanide Zinc Plating Baths by Electrolytic Method.” Kinzoku Hyomen Gqufsu (Jap.). 31, 5, 239 (1980); Chem. Abs. 93,83428q (1980).

57. OConner, A., et ai., “The Treatment and Recovery of Chemicals in the Effluent from Tinplating and Assbciated Processes.” 2nd

I

Symp. on Environ. Control in Steel Ind., Chicago, SEC2-8-144 I (i97b); Hunvell Abs., 14, 17537 (1980).

58. Heijwegen, C. P., and Van Zijll Langhout, P.,“Treatment of I z 7 J f 3

PLW

Waste Water from the Tinning Lines of Hoogovens Ijmuiden B.V.” 2nd Symp. on Environ. Control in Steel Ind., Chicago, SEC2-8-143 (1979); Hanvell Abs.. 14, 17610 (1980).

Industrial Wastes

industry. Rosenburg’ expressed a concern that the EPA eco- nomic analysis may have been overly optimistic. Instead, the author anticipated that a 10% price increase may result from the new regulations. Also, for the author’s plating shop, the estimated annual compliance cost was seven times that esti- mated by EPA for an average plating shop. Finally, the author expressed the viewpoint that the actual number of plant clo- sures may far exceed EPA estimates.

Schaffer4 discussed proposed changes to the hazardous waste regulations that affect the electroplating industry. In- cluded would be an increase in the total cyanide limitation to 1.9 mg/l, the replacement of 30-day discharge averages with 4-day averages, and revisions for the “self-monitoring” re- quirements imposed on the industry.

Skach and Williamson’ discussed a proposed mechanism for “delisting” a particular yaste material from the hazardous waste regulations. They reviewed necessary testing procedures, in-plant monitoring and sampling needed to identify the con- stituents of waste, and the pkrtinent information that must be included in a delisting petition. Boyland6 discussed the com- pliance time schedule set up by EPA with reference to haz- ardous waste handling and disposal. The author also reviewed the implications of “InteFim Status” filing under part 265 of RCRA.

UNIT PROCE2!$SES EPA published a review of the recent advances and cost

tation techniq~es.’ Included within this document were sec- tions related to sulfide process theory, alternate precipitation schemes, data from several comparative pilot plant studies, and comparative cost data. Concern was expressed for the high cost of using sulfide precipitation chemicals, the large amounts of sludge generated by the sulfide process, and the long-range stability of metal sulfide precipitates. The report presented a possible compromise system that involved initial metals re- moval by hydroxide precipitation followed by sulfide addition as a polishing step. Korchin” presented information related to the insoluble sulfide precipitation process that had the capa- bility for chromate reduction and precipitation in one treat- ment step. The use of a sludge blanket clarifier and excess quantities of ferrous sulfide allowed the system to handle surges in’ the influent chromate concentration without pro- ducin8 significant changes in treatment efficiency. Kostura’ reported on the use of both evaporative recovery and precip- itation treatment systems for anodizing and plating plant waste treatment. Plant performance data showed the treatment sys- tem was capable of meeting the 4-day average residual metals concentrations proposed by EPA for discharge to publicly owned treatment works (POTW).

Nojiri et a1.” reported on the application of an electrolytic ferrite formation system for the reduction and removal of chro- mate. After r-duction, the chromium was incorporated into the ferrite sludge that was subsequently separated by a ro- tating electromagnet. Residual sludges had solids concentra- tions that varied from 12 to 18% dry solids after dewatering. Also, suspended solids removal efficiencies continually ex- ceeded 90% with this process.

The removal of both cadmium and cyanide from metal fin- ishing wastewaters by seawater electrolysis was studied by

ation rerat

Poon.” Sea water was electrolyzed below a column of

tion on a particulate electrode.

with metals such as Cu+* and Ag+ being irrever

consistently less than 0.1 mg/l, even after 5 OOO bsd Katol’ evaluated the surfactant Amifat (N-acyl-L

acid) for cadmium removal. Although th i pr satisfactorily, significant improvemenis in tre were obtained through the addition of poly Elliott and Huangr6 studied the adsorptioa c copper on activated carbon. In the presen

propriate sorbent surface site. ,

ten nearby electroplating shops. the wastes generated, processes

plants would benefit to a lesser d of their waste streams or sludg

Craig’” discussed EPA’s eval

from 13 to 40%. The distance from an electro

factor affecting the expected cost savings to ea

RECOVERY Atimion” discussed in-house modifications an

recovery techniques as means of promoting the of energy, metals, and water. Modified temperatures bath and rinsing operations minimized heat 1 dragout. Evaporative recovery was utilized for

ing wastewater using an ion exchange resin (Di 180). This process removed sodium ions and ex

Journal WPCF, Volume 53,

r recovering chromic acid?2 Capital and operating reported to & better than either chemical precip

m plating solutions by the use of th graphite anodes. Cadmium was

or of 4 gal/sq f t of surface area processed. In- discussion were evaporative recovery and in-

osphite ions, with a resin requirement of 0.1

roducts such as calcium. The total cost

contaminants are present in a The author claimed a rwvery

Is of pure solvent for every

is of reseakh in the area of cyanide de- to idterfering chemicals. OWerbach2’ con- 1 cyanide method yielded erroneously high

sion with a hydroxide adsorber on-site. The in- nitrites in cyanide determinations was also re-

ure was based upon monitoring the rate of a col- reaction that utilized cyanide as the catalyst. The

ons was also presented. The use of a cyanide sensitive ced above a cyanide-containing solution has also

, electrolytic oxidation, bio-oxidation, ion exchange, erse osmosis. Stopka3’ also discussed current advance-

, / k , p

Industrial Wastes

ments in the design and technology of cyanide waste treatment systems, emphasizing the idea that ozone may be highly com- petitive with chlorine for cyanide destruction. The author noted that ozone treatment systems do not produce a residual whereas dechlorination may be necessary at treatment facil- ities that use chlorine prior to effluent discharge.

Tsuru et ~ 1 . ’ ~ examined the applicability of aetivated carbon for cyanide removal, relating mass uptake of cyanide to the activity of the cyanide ion as opposed to the actual cyanide concentration. At high pH, the rate limiting step for adsorption was found to be the mass transfer of cyanide in solution. Obari and S a ~ a b e ’ ~ studied the removal of cyanide from wastewater by passing it through a column coxitaining ferrous materials such as steel scrap. The process yielded efficient cyanide re- moval rates, with effluent cyanide concentrations in the range of 0.5 to 0.9 mg/l. H ~ n e r ’ ~ reported on an ongoing research project related to the elimination of cyanide from plating ef- fluents. The experimental approach involved heating cyanide plating solutions in a sealed container under pressure to 210°C for a few minutes, resulting in effective cyanide destructioq.

McNutt16 discussed methods for reducing dragout and min- imizing the amount of wasted chemicals and rinse water in electroplating operations. The author also cautioned against the switch from cyanide baths to acid baths just to ayoid the need for cyanide removal processes, claiming that the treat- ment of acid baths may be five to six times more expensive than the treatment of wastes for cyanide removal.

Br~nker ’~ examined the response of biolog cyanide concentrations in the range of less t above 10 mg/l. At cy included certaiq algal exposed to increased mg/l-cyanide range, the algal activity was inhibited, leaving a biota dominated by Actinomycetes, which degraded cy at a slow rate. Above 10 mg/l, no evidence of biological a or cyanide degradation was observed.

SLUDGE TREATMENT Crain3” reviewed the various methods available for concen-

trating metal finishing sludges, presenting information related to the final cake dryness and filtrate quality that may be achieved from each dewatering process. The author recom- mended that several alternate methods of dewatering be eval- uated for application based upon a consideration of cycle lengths, cake dryness, and ease of sludge handling. Heller and Roy39 reported on treatment modifications utilized to upgrade an existing treatment system to meet discharge standards. In- cluded in the discussion were data related to the use of a high- pressure (225 psi) recessed-plate filter press that produced a final cake solids concentration of 50% dry solids with a cycle time of 1 to 2 hours.

Knocke et ul.@ showed that, of many sludge characterization parameters, floc size distribution was most critical in deter- mining the response of metal hydroxide sludges to vacuum filtration. Of the metal sludges examined, most dewatered rap- idly when applied to a vacuum filter. When necessary, high molecular weight polymers were efficient for improving de- watering rates although no increase in final cake solids con- centrations was noted as a function of applied polymer dose. Croy and Knocke4’ examined the comparative thickening and

198 1 849

Industrial Wastes

dewatering rates of metal hydroxide and metal sulfide sludges. Variations in dewatering response were predicted based upon an evaluation of floc size and density measurements. Knocke et u I . ~ ~ presented data related to the beneficial aspects derived

C ~ u l t e r ~ ~ reviewed recent research work dealing with the leachability of metal sludges. Preliminary studies conducted a t pH 5.0 showed that many sludges would not meet the EPA criterion for d i sposa l with municipal waste. However, at higher pH values, the extraction of metals dropped sharply. Also, the author felt that the EPA Toiaf Extraction Procedure exaggerated the leachability of sludges h u s e it included the effects of metal levels in the associated or entrapped water. Further testing showed that, once the interstitial water within a sludge was washed out, little further leaching occurred. al- lowing the author to conclude that safe disposal may be un- dertaken without expe.nsive fixation procedures. Steward” pro-

REFERENCES I . “Hazardous Waste Management: Overview and Definitions; Gen-

erator Regulations; Transporter Regulations.” Federal Register. 45, 39 (Feb. 26, 1980).

2. “Hazardous Waste and Consolidated Permit Regulations.” Fed- eral Register. 45, 98 (May 19. 1980).

3. Romberg, A. J., “What Will Compliance Really Cost?” Plating a& Swfuce Nitishing, 67, 11, 26 (1980).

4. Scltaffer, R. B., “%atus of Wastewater Regulations, Including BAT Limitations.” Paper presented at 3rd EPA/AES Conference on Advanced Pollution Control for the Metal Finishing Industry (April 1980); reviewed in Plating and Surface Finishing, 67.6, ~

taction Agency Tckhndogy Transfer SummaryReport EPA 6251

8. Korchin. S. R., “Performane Report on a New Heavy Metals 8-8-80-003.

Removal System Via Sulfide Precipitation.” Proc. 26th *

Ind. Waste ConJ, Ontario Water Resources Comm..

11. Poon, C. P. C., “A Proass for Simultaneous Remova mium and Cyanide.” Ind. Water Eng., 17,2,28 (1 980); Absrrucrs, 11,80-07559 (1980).

12. Bryson, A. W., “Treatment of Dilute Metal Effluents in a trolytic Precipitator.” Water S. A, 6, 85 (1980); P o h stracrs, 11, 80-06157 (1980).

13. Srivastava, S. K., et ai., “Studies on the Use of in the Removal of Heavy Metals.” Water Res. ( (1980).

14. “Heavy Metal Removal from Wastewater.“ Jep Patent (1980); Chem. Ah. , 93, 155451s (1980).

21. Kosaka, V., “R

pis of Cyanide Ions in Surfact Finishing, 67, 8,

30. “Apparatus for Cyanide (1980); Chem.’ Abs., 93,

jected to reflect a decrease in real spending.' An 8% increase was also expected among U. S. industries as a whole. A p

annual water pollution control costs for the chemical industry are projected to reach $653 million. Pollution control spending, expressed as a percentage of capital spending, Was expected to hold at 7.4% in 1980 and increase to an average of 1 1.1% for the next 3 years.' Chemicals and allied products companies

It Presentable." paper prescntd on Advan& Pollution Control for (April 1980); reviewed in Pluting

Con!, 216

"'- ears.^ EPA-proposed effluent guidelines for inorganic chem- ical producers were estimaked to result in a cost of $41.2 mil- lion, with total annual costs including interest and depreciation at $33.8 million. Industry estimated that proposed regulations

proc. 980); ,--hem ~ b ~ . ,

year program by Swiss chemical companies has cost approx- imately $377 million.' Tax-exempt bonds have been used to finance approximately 9.5% of chemical company pollution control spending. In 1979, chemical companies used approx- imately 25 pollution control bond issues to raise more than $ 1 17 million. Present regulations prohibit tax-exempt status when dealing with hazardous waste^.^

A review of the change in emphasis from conventional to

was presented, along with a discussion of biological and phys- ico-chemical treatment techniques that could be used to meet the new regulations." A brief discussion of priority pollutant analytical methods was also included, along with a discussion of analytical quality control procedures. Five federal agencies developed plans to regulate collectively specific substances.'' Attention was initially centered on 6 chemical groups: asbes-

e m i ca S an d a 1 1 i e d priority pollutants in regulating the organic chemical industry