Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Toxic effects of pollutants on the mineralization of 4-chlorophenol and benzoate in methanogenic river sediment

Journal Article · · Environmental Toxicology and Chemistry; (United States)
 [1];  [2]
  1. National Inst. of Public Health and Environmental Protection, Bilthoven (Netherlands)
  2. Univ. of Amsterdam (Netherlands). Dept. of Fundamental and Applied Ecology
The toxic effects of pollutants on the mineralization of 2 [mu]g/L [U-[sup 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 substrate 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. Their 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.
OSTI ID:
7163088
Journal Information:
Environmental Toxicology and Chemistry; (United States), Journal Name: Environmental Toxicology and Chemistry; (United States) Vol. 13:7; ISSN ETOCDK; ISSN 0730-7268
Country of Publication:
United States
Language:
English