Waste effluents

Fig. 4. Schematic of a leather tanning faciUty fitted with a wastewater treatment plant. Treatment of the combined wastes using sulfide oxidation and waste effluent pH adjustment greatiy decreases the suspended soHds and BOD loading (3). Courtesy of Krieger Publishing Co.

Industrial Wastewater Treatment. Industrial wastewaters require different treatments depending on their sources. Plating waste contains toxic metals that are precipitated and insolubiHzed with lime (see Electroplating). Iron and other heavy metals are also precipitated from waste-pidde Hquor, which requires acid neutralization. Akin to pickle Hquor is the concentrated sulfuric acid waste, high in iron, that accumulates in smokeless powder ordinance and chemical plants. Lime is also useful in clarifying wastes from textile dyeworks and paper pulp mills and a wide variety of other wastes. Effluents from active and abandoned coal mines also have a high sulfuric acid and iron oxide content because of the presence of pyrite in coal. 

Environmental awareness is a prime concern in all KOH plants. Safety precautions required in KOH and chlorine operations are well documented in operating manuals and sales brochures pubUshed by all commercial producers. Discharges of waste effluents containing mercury are strictly forbidden. 

Natural-water concentrations of boron are usually well below this value, although higher concentrations can occur as a result of industrial waste effluents or cleaning agents. 

The neutralization process is not energy intensive added heat evaporates water formed in the reaction and water entering the system with the raw materials, which is 50% NaOH. The significant waste effluent contains 10—100 ppm NaCN and must be treated before disposal. 

These observations contrast with some of the results obtained in natural waters. In the experiments where contaminated sediments were equilibrated with Lake Michigan water for a number of days, the Pu(IV) that was on the sediments and was transferred to the water was oxidized to Pu(V), with the oxidation occurring either during or after desorption (15). The studies in the Irish Sea near Windscale show that although no more than 1 percent of the waste effluent stream is oxidized plutonium, approximately 5 percent of the plutonium released leaves the area in the currents of the Irish Sea as oxidized plutonium. Most of the plutonium, therefore, must be oxidized fairly rapidly in sea water. 

Sarmah AK, Northcott GL, Leusch FDL, Tremblay LA (2006) A survey of endocrine disrupting chemicals (EDCs) in municipal sewage and animal waste effluents in the Waikato region of New Zealand. Sci Total Environ 355 135-144... 

Magno, P., Reavey, T. and Apidianakis, J. (1970). Liquid Waste Effluents from a Nuclear Fuel Reprocessing Plant, Report No. BRH/NERHL-70-2, also Report No. PB-196442 (U.S. Department of Health, Education, and Welfare, Public Health Service, Bureau of Radiological Health, Rockville, Maryland). 

King DL, Ciaccio LL (1971) (eds) Sampling of Natural Waters and Waste Effluents, Marcel Dekker, New York, NY, USA, p. 451... 

Priority surfactants and their toxic metabolites in waste effluent discharges an integrated study (pristine), Progress report No. 1, Feb. 1st, 1998-July 31st, 1998. 

Chattaraj S, Das A. 1991. Indirect determination of free cyanide in industrial waste effluent by atomic absorption spectrometry. Analyst (London) 116(7) 739-741. 

Dichlorobenzidine was not deteeted in the ambient air at production facilities at deteetion limits of 0.1-5.0 ng/m (Narang et al. 1982 Riggin et al. 1983). The median concentration of 3,3 -diehloro-benzidine in waste effluents (<10 ppb), groundwater (<10 ppb), surface water (<10 ppb), and soils (<1 ppb) is very low, although significant contamination may be associated with hazardous waste sites (Staples et al. 1985). Moreover, the production and use of 3,3 -diehlorobenzidine-based dyes has decreased to zero over the last 30 years, while environmental and health regulations have been implemented to reduce the release of 3,3 -dichlorobenzidine to the environment. 

Phosphate Rock Grinding. Phosphate rock is mined and mechanically ground to provide the optimum particle size required for phosphoric acid production. There are no hquid waste effluents. 

Wet Process Phosphoric Acid. A production process flow diagram is shown in Figure 8. Insoluble phosphate rock is changed to water-soluble phosphoric acid by solubilizing the phosphate rock with an acid, generally sulfuric or nitric. The phosphoric acid produced from the nitric acid process is blended with other ingredients to produce a fertilizer, whereas the phosphoric acid produced from the sulfuric acid process must be concentrated before further use. Minor quantities of fluorine, iron, aluminum, sUica, and uranium are usually the most serious waste effluent problems. 

As previously mentioned, fertilizer manufacturing may create problems within all environmental media, that is, air pollution, water pollution, and solid wastes disposal difficulties. In particular, the liquid waste effluents generated from phosphate and mixed and blend fertilizer production streams originate from a variety of sources and may be summarized [17,27] as follows (a) ammonia-bearing wastes from ammonia production (b) ammonium salts such as... 

The use of solvent extraction as a unit process operation is common in the pesticide industry however, it is not widely practised for removing pollutants from waste effluents. Solvent extraction is most effectively applied to segregated process streams as a roughing treatment for removing priority pollutants such as phenols, cyanide, and volatile aromatics [7]. One pesticide plant used a full-scale solvent extraction process for removing 2,4-D from pesticide process wastewaters. As a result, 2,4-D was reduced by 98.9%, from 6710 mg/L to 74.3 mg/L. 

When boiler firesides are washed, the waste effluents produced contain an assortment of dissolved and suspended solids. Acid wastes are common for boilers fired with high-sulfur fuels. Sulfur oxides absorb onto fireside deposits, causing low pH and a high sulfate content in the waste effluent. 

Municipal waste effluents are characterized by high concentrations of sterols, fatty acids, and fatty acid esters (24). These compounds (no. 4-11) were found at high levels in most of the samples from the Delaware River. For example, cholesterol was usually one of the most abundant compounds in the water. The concentration profile for cholesterol in the August water samples showed a maximum at river mile 93 which is consistent with the location of municipal sewage plants in the Philadelphia-Camden area. Fatty acids were not quantitated due to their poor chromatographic resolution, but they were present at very high levels in all samples. 

Sixteen microorganisms isolated from soil exposed to the waste effluent from 1,3-DNB manufacture had the ability to effectively degrade 1,3-DNB in synthetic media and 1,3-DNB waste under aerobic conditions (Dey et al. 1986). The percentage degradation of 1,3-DNB ranged from 32% to 87% and from 35% to 92% under stationary and shake culture conditions respectively, in a synthetic medium. 

The situation with regard to ethanol is much clearer there is long industrial experience in the manufacture of ethanol from wood, by fermentation of the sugars in the waste effluents of pulp mills, or of the sugars made by wood hydrolysis ( ). In the years following World War II, wood hydrolysis plants have been unable to compete economically with petroleum-based ethanol synthesis, mainly by hydration of ethylene, and they have been shut down in most countries. However, in the Soviet Union, we understand, there are still about 30 wood hydrolysis plants in operation (10). Many of these are used for fodder yeast production (11) but the wood sugars are also available for ethanol production. 

The river and waste effluent is illustrated in Figure E5.3.1. The river has a discharge of <2o, a cross-sectional mean velocity of U, a mean stream width of b, and an ambient pollutant concentration of Q. The effluent discharge is Qi, with a pollutant concentration of Q. We will solve for a vertical mean concentration, C, which varies spatially across the river (y-axis) and in the direction of flow (x-axis), or... 

The use of alkylhalides, or dimethylsulphate or acylhalides as co-reactants, with co-production of waste effluents containing inorganic salts, which have to be disposed. 

Strolle, E. O., Aceto, N. C., Stabile, R. J., Turkot, V. A. (1980). Recovering useful by-products from potato starch factory waste effluents - feasibility study. Food TechnoL, 34, 90-95. 

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