Biodegradation, chlorinated organic compounds

The biodegradability of organic compounds is strongly affected by chlorine substitution in the molecule as shown by the DDT-related compounds, Table 21b. 

Arisoy, M. Biodegradation of chlorinated organic compounds by white-rot fungi. Bull Environ. Contam. Toxicol, 60(6) 872-876, 1998. 

Haggblom, M. Salkinoja-Salonen, M. Biodegradability of chlorinated organic compounds in pulp bleaching effluents. Water Set Technol. 1991, 24 (3/4), 161-170. 

Biodegradation of Chlorinated Organic Compounds by Phanerochaete chrysosporium, a Wood-Rotting F ingus... 

The following example illustrates anaerobic biodegradation of a chlorinated organic compound that, because of its density, sinks to the bottom of a lake and dissolves in sediment pore water. 

Biodegradation. Under aerobic conditions, biodegradation results in the mineralization of an organic compound to carbon dioxide and water and—if the compound contains nitrogen, sulfur, phosphorus, or chlorine—with the release of ammonium (or nitrite), sulfate, phosphate, or chloride. These inorganic products may then enter well-established geochemical cycles. Under anaerobic conditions, methane may be formed in addition to carbon dioxide, and sulfate may be reduced to sulhde. 

The feasibility of applying solar radiation as a source of UV-visible radiation has made the photo-Fenton system an economical and competitive process. Within this context an alternative method has been developed based on solar photocatalytic oxidation and natural processes of wastewater treatment [5], as well as sunlight-driven degradations of many compounds, such as EDTA [30], phenols [7,13], pesticides [31-33], surfactants [34], diclofenac [24], formic acid [22], azo-dyes [19], non-biodegradable chlorinated solvents [35], nitroaniline [16], and other organic compounds [21, 36]. 

Lorah M. M. and Olsen L. D. (1999b) Natural attenuation of chlorinated volatile organic compounds in a freshwater tidal wetland held evidence of anaerobic biodegradation. Water Re sour. Res. 35, 3811-3827. 

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