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In mid- 1974 and mid- 1976, two Environmental Protection Agency (EPA) regulatory events occurred which led to a large research effort designed to evaluate the toxicity of textile plant wastewaters, and to determine the most effective treatment technology. The first one occurred in June 1974, when EPA’s Effluent Guidelines Division set forth guidelines for the degree of effluent reduction attainable through the application of the “Best Practicable Control Technology Currently Available” (BPCTCA), and the “Best Available Technology ELOnomically Achievable” (BATEA), to be achieved by existing textile manufacturing (SIC 22) point sources by July 1, 1977 and July 1, 1983, respectively. However, on October 1, 1974, the textile manufacturing industry, represented by the American Textile Manufacturers Institute ( A T M I ) , Northern Textiles Association, and Carpet and Rug Institute, filed a petition with the U.S. Fourth Circuit Court of Appeals, asking for a review of the proposed 1983 effluent guidelines. Grounds for the suit were that the BATEA had not been demonstrated for the textile manufacturing industry. Thus, A T M l and EPA filed a joint motion for delay of the petition, stating that additional information would be developed through a cooperative grant
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study by A T M l and EPA’s Industrial Environmental Research Laboratory a t Research Triangle Park, N.C. (IERL-RTP).
BATEA determination The objective of the A T M I I E P A Grant Study was to gather enough technical and economic data to determine the BATEA for reducing criteria pollutants from textile wastewaters. Criteria pollutants for the textile industry include 5-day biochemical oxygen demand (BODS), chemical oxygen demand (COD), color, sulfide, pH, chromium, phenol, and total suspended solids (TSS). On January 3, 1975, the Court instructed A T M l and EPA to proceed as promptly as possible to a completion and review of the study. To evaluate the best available technology, two mobile pilot plants were constructed and operated by ATMI’s contractor, Engineering Sciences, Inc. This strategy allowed for real-time flowthrough treatability studies. Each pilot plant contained five tertiary wastewater treatment unit operations. In addition, a tertiary treatment technology was laboratory tested. One of the mobile plants was scheduled to visit 12 textile plants, and the other to visit 1 I . Treatment operations in each mobile unit included a reactor/clarifier (using combinations of alum, lime, ferric chloride, and anionic and cationic polyelectrolytes), two multimedia filters, three granular activated carbon columns, ozonation, and dissolved air flotation. Powdered activated carbon treatability tests were performed in the laboratory, instead of in the field, with the pilot plant. From these six-unit operations, A T M I and EPA selected
seven treatment modes for evaluation (Figure 1). Each of the seven treatment modes was to be individually set up, with operational and pollutant data collected over a 2- to 3-day period. Based on those data, the “best” system for each plant was to be set up for 2 weeks of operational evaluation. These data were then to be forwarded for economic evaluation. Prior to pilot plant field testing, the second EPA regulatory event occurred, and formed the basis for the toxicity study. On June 7, 1976, the US. District Court of Washington, D.C., issued a consent decree (resulting from Natural Resources Defense Council, et al. us Train) requiring EPA to accelerate development of effluent standards for 21 industrial point sources, including textile manufacturing. Among other requirements, the Court’s mandate focused federal water pollution control efforts on potentially toxic and hazardous chemical compounds. The original consent decree required that “65 classes” of chemical compounds be analyzed in wastewater samples. Recognizing the difficulty of analyzing for all chemical species present in each category of compounds, EPA developed a surrogate list of 129 specific compounds representative of the classes of compounds listed in the consent decree. These compounds are referred to as “priority pollutants,” and are divided into the following fractions for sampling and analytical purposes: volatile organics, nonvolatile organics, pesticides, polychlorinated biphenyls, metals, asbestos, cyanide, and phenol. EPA also developed a sampling and analytical procedures manual to be
0013-936X/79/0913-0160$01 .OO/O @ 1979 American Chemical Society
used as a laboratory guide for the analysis of these priority pollutants. The consent decree obliges EPA to identify which priority pollutants are present in industrial wastewaters, and to determine the ability of various wastewater treatment technologies to remove priority pollutants. Therefore, EPA, with ATMI’s cooperation, decided to conduct a separate study parallel with the E P A / A T M I Grant Study designed to measure priority pollutants. Also, since the consent decree focused on the issue of wastewater toxicity, ATMI agreed to have samples collected for bioassay testing, in order to have a complete and comprehensive wastewater characterization data base. Thus, the bioassay testing program established by EPA for evaluating the reduction in toxicity of water samples by control technologies and outlined in Figure 2 was integrated into the program. The overall E P A - I E R L / R T P textile program consists of two separate projects, each with different activities running parallel in time, but converging toward the same goal: determination of BATEA for textile wastewaters. Program objectives Monsanto Research Corporation ( M R C ) collected and analyzed the samples for priority pollutant analysis and bioassay testing under EPA Contract 68-02- 1874. The fundamental objective of the textile plant wastewater toxicity study was to determine the reduction in toxicity, and priority pollutant concentrations achieved by the tertiary treatment technologies being tested at 23 plants in the EPA/ A T M I Grant Study. The study conducted a t MRC’s
Dayton Laboratory was divided into two phases, in order to gather the most information in a cost-effective manner. Phase I was designed to collect baseline toxicity and priority pollutant data on secondary effluents from the 23 plants before the pilot plant program began. In this manner, 23 samples were to be subjected to the battery of bioassay tests. Only those plants with toxic secondary effluents would be selected to determine reduction in toxicity by tertiary treatment systems. Also, appropriate bioassays could be selected, instead of performing the entire battery of tests for Phase 11. Phase I I was designed to collect samples before and after each tertiary treatment unit operation to determine reduction in toxicity and priority pollutant concentrations at the plants selected from Phase I . In addition to collecting samples for priority pollutant analysis and bioassay testing, EPA included the new Level I environmental assessment technology developed by EPA’s Process Measurements Branch, IERL/RTP. Level 1, the first part of a three-phased en-
vironmental assessment approach, was designed to focus available resources on emissions that have a high potential for causing measurable health or ecological effects. Based on the results of the pilot test, approaches for Levels 2 and 3 could be developed.
Field sampling The basic textile plant wastewater treatment plant consisted of an aeration lagoon with several surface aerators, followed by conventional clarifiers and chlorination. Raw waste and secondary effluent samples were collected at the points indicated in Figure 3. Secondary effluent samples were collected between the clarifier and chlorination, because that is the stream that would flow into a tertiary treatment system. Raw waste samples were collected over an eight-hour period during a normal working day, with automatic composite samples. Eight individual secondary effluent samples were collected by grab sampling techniques, by use of a 3-gal Teflon@-linedstainless steel bucket. Aliquots were removed
FIGURE 1
Tertiary treatment nodes for “best availqble technology” evaluation Mode A: Reactwlclarifier -+Multimedia filter activated carbon columns Mode 8: Multimedia filter *Granular Mode C: Multimedia filter -+Ozonator Mode D:Ozonator filter -Granular activated (Optional) Mode E: Reactoriclarifier-+Multimedia carbon +Ozonator Mode F: Coagulation-+ Multimedia filter Mode G: Dissolved air flotation
FIGURE 2
Bioassay testing Water sample 4
Marine or freshwater
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Freshwater fathead minnow toxicity al ae bottle QaFJfnia toxicity
Marine: sheepshead minnow algae grass shrimp
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from the bucket, and poured into appropriate sample containers. Care was taken to ensure that the sample remained homogeneous throughout each of the IO-min pouring sessions. Containers for volatile organics analysis were filled first, and sealed to minimize possible evaporation losses. All samples were preserved in the field according to EPA specifications. Samples were then packed in ice and shipped via commercial air freight to the appropriate laboratory for analysis.
Priority pollutants detected Analysis of raw waste and secondary effluent samples (totaling 64 samples) for the 129 priority pollutants were performed by M R C in accordance with the analytical methodology recommended by EPA. It is important to realize that the purpose of EPA's analytical scheme is to screen samples to determine which of the I29 chemical species are present, and to estimate their general concentration range. With a narrowed list of species, later verification studies will more accurately quantify species concentrations in a cost-effedtive manner. Currently, the recommended analytical protocol is in the developmental stage and requires further verification and validation. Therefore, the analytical results of textile plant wastewater
samples must be looked upon as reliable estimates of which priority pollutants were present, with concentrations accurate to within a factor or two. The 1 14 organic priority pollutants are divided into four categories for analysis: voltatile organics, base/ neutral organics, acid organics, and pesticides and PCB's. Volatile organics were sparged from the sample with helium and adsorbed onto a Tenax column. Adsorbed species were later thermally desorbed for identification and quantification with a HewlettPackard 598 1 gas chromatograph/ mass spectrometer ( G C / M S ) with a 5934 Data System. Base/neutral and acid organics were determined by extracting the sample with methylene chloride first at pH > I 1, and then the aqueous phase at pH
