Show simple item record

dc.contributor.authorvan Beelen P
dc.contributor.authorvan Vlaardingen PLA
dc.date.accessioned2017-02-20T07:47:39
dc.date.issued1993-08-31
dc.identifier714201004
dc.description.abstractThe toxic effects of pollutants on the mineralization of 2 mug/l [U-14C] 4-chlorophenol and benzoate were studied in microcosms with methanogenic sediment from 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 hours, 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 concentration of benzene, chloroform, 1,2-dichloroethane, pentachlorophenol and zinc on the benzoate mineralization was 150, 0.04, 71, 6 and 842 mg/kg sediment d.w. 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 for 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, probably due 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.<br>
dc.description.sponsorshipDGM/DWL
dc.format.extent27 p
dc.language.isoen
dc.publisherRijksinstituut voor Volksgezondheid en Milieu RIVM
dc.relation.ispartofRIVM Rapport 714201004
dc.relation.urlhttp://www.rivm.nl/bibliotheek/rapporten/714201004.html
dc.subject07nl
dc.subjecttoxische effectennl
dc.subjectverontreinigingnl
dc.subjectmineralisatienl
dc.subjectsnelheidnl
dc.subjectrivierslibnl
dc.subjecttestnl
dc.subjectmicro organismennl
dc.subjecttoxic effectsen
dc.subjectpollutionen
dc.subjectmineralizationen
dc.subjectvelocityen
dc.subjectriver sedimenten
dc.subjecttestingen
dc.subjectmicroorganismsen
dc.subject4-chlorophenolen
dc.subject4-chloorfenolen
dc.subjectcas 106-48-9en
dc.titleToxic effects of pollutants on the Mineralization of 4-chlorophenol and Benzoate in methanogenic river sedimenten
dc.title.alternative[Toxische effecten van verontreinigingen op de mineralisatie van 4-chloorfenol en benzoaat in methanogeen riviersediment.]nl
dc.typeOnderzoeksrapport
dc.date.updated2017-02-20T06:47:40Z
html.description.abstractThe toxic effects of pollutants on the mineralization of 2 mug/l [U-14C] 4-chlorophenol and benzoate were studied in microcosms with methanogenic sediment from 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 hours, 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 concentration of benzene, chloroform, 1,2-dichloroethane, pentachlorophenol and zinc on the benzoate mineralization was 150, 0.04, 71, 6 and 842 mg/kg sediment d.w. 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 for 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, probably due 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.&lt;br&gt;


This item appears in the following Collection(s)

Show simple item record