Wastewater characteristics priority pollutants

Design data are available for the specific organics on the EPA s priority pollutant Hst. For mixed wastewaters, a laboratory study is necessary to determine adsorption characteristics. Wastewater is contacted with a range of concentrations of powdered carbon and adsorption occurs, as graphed ia the form of a Freundhch Isotherm, shown ia Figure 19. 

Because of the variety and uniqueness of pesticide manufacmring processes and operations, the flow and characteristics of wastewater generated from production plants vary broadly. In 1978, 1979, 1980, 1982, and 1984, the USEPA conducted surveys to obtain basic data concerning manufacturing, disposal, and treatment as well as to identify potential sources of priority pollutants in pesticide manufacmrers [7]. The results of these surveys and USEPA s interpretations and evaluations are summarized in the following. 

Phthalate esters listed as EPA priority pollutants may be analyzed in wastewaters by U.S. EPA (1984) Methods 606 (GC), 625 (GC/MS), and 1625 (isotope dilution). Soils, sediments, groundwater, and hazardons wastes may be analyzed by GC using FID or ECD (Method 8060) or by GC/MS (Method 8270 or 8250) (U.S. EPA 1986). The primary and secondary characteristic ions to identify these compounds by GC/MS (electron-impact ionization) are as follows dimethyl phthalate, 149, 177, and 150 din-butyl phthalate, 149, 150, and 104 butyl benzyl phthalate, 149, 167, and 279 and din-octyl phthalate, 149, 167, and 43. Other phthalate esters may be analyzed by GC or GC/MS techniques. A fused-silica capillary column is suitable for the purpose. 

One of the first applications of GC/FT-IR was, in 1979, the identification of alkyl-9-fluorenones in diesel exhaust particulate extracts. Some years later in the EPA laboratory of Athens, GA, USA and then in the EPA laboratory of Las Vegas, GC/ET-IR was applied to identify toxic substances in environmental-sample extracts. In the latter laboratory, the minimum identifiable quantities of 30 priority pollutants and 25 other environmental contaminants were determined. The method was shown to be applicable for the analysis of hazardous waste and industrial wastewater extracts. The gas-phase spectra of 47 compounds of environmental importance were also taken, and their characteristic absorption frequencies and specific absorbances were published. 

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