Toxicity and biodegradation of chlorophenols in anaerobic propionate enrichment culture

Abstract

The fate of four trichlorophenols (TCP), six dichlorophenols (DCP), and three monochlorophenols (CP), were studied in anaerobic propionate enrichment systems. TCPs were more toxic than DCPs and CPs; 2,4,5-TCP was most toxic to the propionate users among the 13 chlorophenols studied in this research. Most chlorophenols were dechlorinated reductively to less chlorinated compounds and/or phenol. Dechlorination at the ortho position was observed most frequently. The overall removal of the selected chlorophenols by anaerobic propionate enrichment systems were in the following order: 2,3,5-TCP > 2,3,6-TCP> 3,5-DCP > 2,4-DCP > 2-CP > 3,4-DCP; 2,3-DCP; 2,5-DCP > 3-CP > 2,4,5-TCP > 2,6-DCP > 2,4,6-TCP > 4-CP. Water Environ. Res., 69, 938 (1997).

Factors affecting the biodegradation of PCP by Pseudomonas mendocina NSYSU

“…Ring cleavage can occur either before or after removal of the chlorine substituents, giving rise to a whole array of intermediates of varying toxicity [10,12]. Isolation of PCP-degrading microorganisms from the soils, sediments, or sludges has been reported [10][11][12][13][14][15]. Application of the enriched PCP-degrading microorganisms would significantly enhance the PCP removal [10,12,15].…”

Chlorophenols in leachates originating from different landfills and aerobic composting plants

“…Therefore, the characteristics of the leachate are highly variable depending on the composition of the solid waste, rate of water application, refuse moisture content, as well as landfill design, operation and age [8]. Because chlorophenols are among the most widely industrial compounds and listed as priority pollutants by the U.S. Environmental Protection Agency (U.S. EPA), toxicity of those compounds are of great importance both in natural environment and bioremediation technologies [10]. Although toxicity of chlorophenols may show variation depending on both the number and the location of chlorine atoms, it may be generalized that the toxicity of chlorophenols increases with increasing the number of chlorine atom in aerobic environment.…”

Tratamento de águas residuárias simuladas de indústrias de pasta celulósica não branqueada e branqueada

“…Os clorofenóis têm sido encontrados em efluentes de indústrias de papel e celulose, contaminando solos ao redor de indústrias, águas subterrâneas e águas superficiais, devido à lixiviação de solos contaminados e aos fluxos de escoamento ou descargas industriais diretas. Estudos têm mostrado que a persistência de clorofenóis em ambientes aquáticos e terrestres pode ser perigosa aos seres humanos e também pode ser carcinogênico (JIN & BHATTACHARYA. 1997).…”