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Toxic effects of pollutants on the mineralization of 4‐chlorophenol and benzoate in methanogenic river sediment
Author(s) -
van Beelen P.,
van Vlaardingen P.
Publication year - 1994
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620130706
Subject(s) - mineralization (soil science) , pentachlorophenol , environmental chemistry , chemistry , microcosm , hexachlorocyclohexane , methanogenesis , anaerobic exercise , pollutant , benzene , sediment , organic chemistry , methane , ecology , pesticide , geology , biology , nitrogen , physiology , paleontology
The toxic effects of pollutants on the mineralization of 2 μg/L [U‐ 14 C]‐4‐chlorophenol and benzoate were studied in microcosms with methanogenic sediment from a little harbor in the Rhine River In contrast with studies using a high sub‐strate concentration, no lag time was observed and the half‐lives for 4‐chlorophenol and benzoate were 1.6 and 0.55 h, respectively The effect of increasing additions of benzene, chloroform, 1,2‐dichloroethane, pentachlorophenol, and zinc on each mineralization reaction was measured. Toxicity data were fitted with a logistic dose‐effect curve. The IC10 is defined as the concentration of a toxicant inhibiting the mineralization rate for 10% The IC10 concentrations of benzene, chloroform, 1,2‐dichloroethane, pentachlorophenol, and zinc on the benzoate mineralization were 150, 0 04, 71, 6, and 842 mg/kg sediment dry weight, respectively. This latter value includes the background concentration of 800 mg Zn/kg sediment The mineralization of 4‐chlorophenol and benzoate showed similarities in the sensitivity to these toxicants. 4‐Chlorophenol can be degraded via benzoate, which might explain the similarities in sensitivity of both mineralization reactions. Chloroform proved to be extremely toxic to anaerobic mineralization reactions, which might be attributed to the formation of very toxic and reactive intermediates formed during the slow anaerobic degradation of the chloroform in anaerobic sediments Sediment quality criteria derived solely from standard toxicity tests using aerobic organisms may lead to complete inhibition of several important microbial processes in anaerobic sediments