Incineration pollutants, polychlorinated

Incineration of domestic waste is also a contributor to environmental pollution. One more source of dioxins is pulp-and-paper industry. Comparatively new ways of forming polychlorinated dibenzo-p-dioxins and furans are high-temperature processes like copper melting in electric arc furnaces, and production of magnesium, nickel and, possibly, other metals of their chlorides. 

POLYCHLORINATED DIBENZODIOXINS AND FURANS AS POLLUTANTS FORMED IN INCINERATIONS... 

SFE has also replaced many regulated solvents in analytical chemistry applications in recent years, primarily because it provides a more reliable measure of the concentrations of environmental contaminants and can play an important role in pollution assessment, abatement, and control. Advantages have been shown for using SFE compared to the conventional Soxhlet extraction with toluene for determining the presence of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in ashes from a municipal incinerator (Dolezal et al., 1995). SFE allows the complete extraction of the analytes from the sample, whereas conventional extraction results in an incomplete, and hence, inferior extraction. 

The most relevant problem originating from MSW incineration is flue gas treatment, since untreated incineration flue gas can contain large amounts of macropollutants (e.g., CO, S02, HC1, NOx, particulates) andmicropollutants (e.g., PAHs, mercury compounds, polychlorinated biphenyls, dioxins, furans). The necessity of reducing polluting emissions to levels compatible with existing regulations dictates the adoption of rather sophisticated- and expensive flue gas treatment sections in incineration plants. 

Suppose that a landfill site contains PCBs (polychlorinated biphenyls) as a pollutant and we have to reduce the average concentration of them over the site to below 1%. The effective treatment for PCB contamination is to remove the soil, incinerate it and return it to the site. 

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are the most hazardous environmental pollutants that have received prolonged attention by the scientific community and by environmental regulation. These compounds are not commercially produced but can be formed during combustion processes, such as municipal waste incineration, in which halogenated compounds are exposed to very high temperatures. Other primary sources of formation of these compounds are related to various chemical processes that result in contaminated products and waste. Although there are theoretically 75 PCDFs and 135 PCDDs, only 17 of them... 

Phenol and substituted phenols such as chlorinated phenols (CPs) and related aromatic compounds are known to be common components of industrial waste. Most of them are carcinogenic, and their presence can be harmful to humans in general. Therefore, phenols are considered to be priority pollutants by the United States Environmental Protection Agency (USEPA). CPs are present also in flue gas from waste incinerators and are noted to be the precursors of polychlorinated dibenzo p-dioxins and dibenzofurans (PCDD/F). 

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