-f/EPA United States Environmental Protection Agency Industrial Environmental Research Laboratory Research Triangle Park NC 27711 Research and Development EPA-600/S2-80-107 May 1981 Project Summary Physical/Chemical Treatment of Blast Furnace Wastewaters Using Mobile Pilot Units R. Osantowski, A Gemopolos, J Kane, and G. Rollinger This project was initiated to provide an evaluation of the effectiveness of existing treatment technology for upgrading steel mill wastewaters to Best Available Technology (BAT) Eco- nomically Achievable limits for Blast Furnace Category scrubber waste- waters. The wastewater tested was a blast furnace effluent from an operat- ing steel mill treatment system that met 1977 Effluent Guidelines for Best Practical Control Technology (BPT) Currently Available. This wastewater contained residual concentrations of suspended solids, BOD, oils and greases, phenols, cyanides, fluorides, ammonia compounds, sulfides, and dissolved solids. The in-depth pilot plant study was performed using mobile facilities designed especially for treating steel plant wastes. Treatment processes evaluated during the study included: alkaline chlorination, chemical treatment, dual media filtration, magnetic filtration, reverse osmosis, ozonation and acti- vated carbon. Based on the performance results of the pilot program, it was concluded that the physical/chemical technology investigated (alkaline chlorination, ozonation, and reverse osmosis) was effective in reducing influent blast furnace scrubber wastewater contam- inants to below BAT levels. Evaluation and comparison of the treatment train capital and operating costs determine that alkaline chlorination was the least-cost alternative. The study also concluded that significantly less space was required for the treatment train utilizing ozonation than for treatment trains involving alkaline chlorination or reverse osmosis. This Project Summary was devel- oped by EPA's Industrial Environ- mental Research Laboratory. Research Triangle Park. NC. to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction In 1972, the Federal Water Pollution Control Act (PL92-500) was enacted by the U.S. Congress. The Act directed the U.S. Environmental Protection Agency (U.S. EPA) to develop effluent limitation guidelines for all major industrial groups, among them the steel industry. EPA was also mandated to recommend appropriate levels of treatment and estimate costs to meet the proposed limitations. As part of its overall mission, the EPA's Industrial Environmental Research Laboratory of Research Tri- angle Park, NC, funded this study to determine the feasibility of treating steel plant wastewater to Best Available Technology (BAT) Economically Achiev- able levels. This particular project was ------- concerned with the treatment of blast furnace scrubber blowdown wastewater. The project objective was achieved through the performance of a program consisting of the three phases outlined below: PHASE I - Bench Scale Investiga- tions of a Blast Furnace Scrubber Blowdown Wastewater. PHASE II - Design and Fabrication of the Mobile Treatment Facilities to House the Pilot Scale Equipment. PHASE III - Operation and Evaluation of the Advanced Waste Treatment Pilot Plant Sys- tems at a Blast Furnace Site. The purpose of the first phase (bench- scale work) was to provide information concerning the treatment methods to be studied for the Phase II design and the Phase III pilot plant investigation (opera- tion and evaluation). Of particular interest were such items as the pre- treatment requirements, magnitude of operating variables, expected magnitude of treatment efficiency and effluent quality, selection of equipment and media, and pilot plant system design. The second phase objective (System Design and Fabrication) was to provide a mobile pilot testing system for evaluating several advanced waste treatment tech- nologies. The portable treatment system developed included the technology needed to remove the residual contami- nants from the blast furnace BPT waste- water to the extent that this wastewater was upgraded to meet BAT requirements as proposed in 1974. Schematic repre- sentations of the mobile testing systems are shown in Figures 1 and 2. Trailer No. 1 housed the alkaline chlorination, chemical treatment, magnetic filtration, and dual media filtration systems. The ozonator, activated carbon, and reverse osmosis technologies were located in Trailer No. 2. The mobile system con- tained a high degree of automation which greatly assisted the operators during the study. All of the treatment technologies were designed to treat a nominal flow of 18.9 l/min (5 gpm). The advanced waste treatment meth- ods, both singularly and in combination, investigated on a pilot basis in Phase III, included the following: 1. FIL + O + CT 2 ACL + CT + AC 3 CT + FIL + RO + O (on ROB) 4. CT + FIL + RO + ACL (on ROB) Chemical Tanks Magnetic Dual Media Air Filter Filter Compressor Flocculator Trailer 45'L x8'W x 13'-6"H Four Chamber Rapid Mix Tank Clarifier Figure 1. Steel plant mobile treatment system-trailer No. 1. Trailer 45'L x8'W x 13'-6"H Sample Carbon Refrigerator Columns Ozone Generator Clarifier Reverse Osmosis System Ozone Contact Tanks Figure 2. Steel plant mobile treatment system-trailer No. 2. Key AC: activated carbon ACL: alkaline chlorination CT: chemical treatment FIL: filtration-dual media or magnetic 0: ozonation RO: reverse osmosis ROB: reverse osmosis brine A schematic illustration of the process trains investigated for treatment of the blast furnace wastewater is shown in Figure 3. For each treatment train investigated, samples and operational data were ob- tained for later use in assessing, evalu- ating, appraising, and comparing the adequacy of the individual advanced waste treatment methods. ------- (11 Filtration, Ozonation Clarification NaOH Air Poly Raw DMF MF ~*. -*. | 03 Acid C Y ^ — » Product Sludge (2) pH Adjustment, Alkaline Chlorination, Chemical Treatment, Clarification, Filtration, Carbon Adsorption Metal NaOH Acid Salt \NaOCI\NaOCI\ Poly Alkaline Chlorination (3) Chemical Treatment, Clarification, Filtration, Reverse Osmosis, Alkaline Chlormation (on brine). Carbon Adsorption Metal Salt Poly , , Acid NaOH Acid NaOCI I Poly Alkaline Ch/orination (4J Chemical Treatment, Clarification, Filtration, Reverse Osmosis, Ozonation (on brine). Clarification Metal Salt Poly Acid Air Poly NaOH I Acid j i_ToLi_i Key AC: Carbon Adsorption C: Clarification DMF. Dual Media Filtration MF. Magnetic Filtration O3. Ozonation RO: Reverse Osmosis Figure 3. Process trains investigated for treatment of the blastfurnace wastewater. Conclusions This report was concerned with the investigation and evaluation of the effectiveness of selected physical/ chemical treatment technology on Blast Furnace category scrubber wastewaters. Effectiveness was measured using the criteria: performance, costs and space requirements. Physical/chemical treat- ment technology investigated included: chlorination, ozonation, reverse osmosis, chemical treatment, clarification, acti- vated carbon, and filtration. General conclusions from this pilot scale investi- gation are listed below: 1 The results of the pilot program indicated that alkaline chlorination, ozonation, and reverse osmosis were effective in reducing influent contaminants to below BAT levels in the treatment of blast furnace scrubber blowdown. a. Pretreatment requirements. 1. For alkaline chlorination none 2. For reverse osmosis: chem- ical clarification and filtra- tion 3. For ozonation. filtration b. Post-treatment requirements 1 For alkaline chlorination chemical clarification and possibly activated carbon. The activated carbon might be required where free chlorine discharge limita- tions are in effect. Other methods of chlorine re- moval were not investi- gated. 2. For reverse osmosis: brine treatment by alkaline chlo- rination or ozonation. (a) Following alkaline chlo- rination of the reverse osmosis brine, the wastewater would re- quire clarification with polymer and dechlon- nation by activated carbon (where dechlo- rination is required prior to discharge). (b) After reverse osmosis brine treatment by ozonation, clarification with polymer is re- quired. 2. Alkaline chlorination was the least-cost alternative treatment train investigated Expected capital investment for a 5,678 mVdav (1.5 mgd) train is $1,171,300. Tr i US GOVERNMENT PRINTING OFFICE 1981 -757-C ------- corresponding operating costs including amortization of capital are estimated at $2 68/3,785 liters ($2.68/1,000 gal.). 3. Ozonation has the lowest system area requirement of 676m2(7,100 ft2). This compared to 938 m2 (10,100 ft2) for the alkaline chlo- rination treatment train. 4. The three treatment trains investi- gated (alkaline chlormation, ozon- ation, and reverse osmosis) were all able to reduce the priority pollutant to metals to 10/ug/l except for zinc and selenium. BIS- (2 ethylhexl) phthalate (BEP) was the only organic reported above the 10/yg/l verification limit. Bibliography 1. Perry, J. H., Chemical Engineers' Handbook, 4th Edition, McGraw-Hill Book Company, New York, 1963. 2. Singer, P. C. and Zilli, W. B., "Ozon- ation of Ammonia In Wastewater," Water Research, Volume 9, pp. 127- 134, 1975. 3. Eisenhauer, H. R., "Increased Rate and Efficiency of Phenolic Waste Ozonation," Journal WPCF, Volume 43, No. 2, February, 1971. 4. Selm, R. P., "Ozone Oxidation of Aqueous Cyanide Waste Solutions In Stirred Batch Reactors and Packed Towers," Advances In Chemistry, Series No. 21, American Chemical Society. 5. Permasep Technical Information Manual, Permasep Permeators, Du- Pont, July 15, 1974. R. Osantowski, A. Geinopolos, J. Kane, and G. Rolliriger are with Rexnord, Inc., Milwaukee, W I 53201. Robert V. Hendriks is the EPA Project Officer (see below). The complete report, entitled "Physical/Chemical Treatment of Blast Furnace Wastewaters Using Mobile Pilot Units,"(Order No. PBS 1-159 386; Cost:$24.50, subject to changej will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Industrial Environmental Research Laboratory U.S. Environmental Protection Agency Research Triangle Park, NC 27711 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati OH 45268 Postage and Fees Paid Environmental Protection Agency EPA 335 Official Business Penalty for Private Use $300 U O !,,MV1K M'Ai lu -- *•> f 23u S ------- |