Sewage metal removal

Effluents from both dye works and dyehouses are treated both before leaving the plant, eg, neutrali2ation of acidic and alkaline Hquors and heavy metal removal, and in municipal sewage works. Various treatments are used (34). 

Other proposed mechanisms of metal removal from sewage include physical capture by microbial floes, cellular accumulation and volatilization by such organisms as Klebsiella, Pseudomonas, Zoogloea and Penicillium spp. (Brown Lester, 1979). In laboratory and pilot-scale studies, up to 98% metal removal by these mechanisms combined has been documented (Lester, 1987). 

Blais JF, Tyagi RD, Auclair JC. 1993. Metals removal from sewage sludge by indigenous iron-oxidizing bacteria. J Environ Sci Health (A) 28 443-467. 

Matsumoto N, Uemoto H, Saiki H. (2007). Case study of electrochemical metal removal from actual sediment, sludge, sewage and scallop organs and subsequent pH adjustment of sediment for agricultural use. Wafer Research 4 2541-2550. 

Brown H. C., Hensley C. P., McKinney G. L. and Robinson J. L. (1973) Efficiency of heavy metal removal in municipal sewage treatment plants. Environ. Lett. 5, 103-110. 

Yoshizaki S. and Tomida T. (2000) Principle and process of heavy metal removal from sewage sludge. Environ Sci. Technol. 34, 1572-1575. 

PermeOx is also used to improve the bioremediation of soils contaminated with creosote or kerosene (see Bioremediation (Supplement)), to deodori2e sewage sludges and wastewater (see Odormodification), and to dechloriaate wastewater and effluents. A special formulation of calcium peroxide, made by FMC and sold ia the United States under the trademark Trap2ene, is used for removing metal ions from acidic waste streams such as coal ash leachate and acid mine drainage (see Wastes, industrial). 

Elimination of metal ions is a second major function of supported chelators. And a variety of conditions may be envisioned. Electroplating firms can be faced with the need to remove metal ions from solutions as part of an EPA-approved disposal protocol. A radiator shop may be faced with a need to remove waste zinc ion before allowing water to go into a sewer, in an effort to minimize the danger of killing bacteria used in sewage treatment procedures. The Berkeley Pit (vide infra) represents an outstanding example of the need to remove waste copper. 

The removal of metals from wastewater streams and sewage relies primarily on... 

The solubility product for CuS is very low ( sp = 10 19 as written) so that the presence of sulfide in water acts to immobilize Cu (and many other metals) and reduce effective exposure. The formation of metal sulfides is important in anaerobic soil and sediment, stagnant ponds and basins, and many industrial and domestic sewage treatment plants and discharges. Co-precipitation of metals also can be a very important removal process in natural waters. In aerobic systems, the precipitation of hydrous... 

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