Residual toxicity after biodegradation: interactions among benzene, toluene, and chloroform.
Ecotoxicol Environ Saf
; 57(2): 162-7, 2004 Feb.
Article
em En
| MEDLINE
| ID: mdl-14759662
A microbial enrichment originating from a pristine aquifer was found to aerobically biodegrade benzene and toluene, but not chloroform. This enrichment culture was used to study changes in pollutant toxicity as affected by biodegradative activity. Two assays for toxicity were used: (1) a 48-h acute toxicity test using the freshwater invertebrate Ceriodaphnia dubia and (2) microbial biodegradation activity as affected by the presence of mixed pollutants. At 20-ppm concentrations, toluene was significantly more toxic (99% mortality) to C. dubia than benzene (48% mortality) or chloroform (40% mortality). Also at 20-ppm concentrations, but before biodegradation, toluene was significantly more toxic (88% mortality) to C. dubia than benzene (33% mortality). After biodegradation of 98% of toluene and benzene, significant residual toxicity still remained in the bacterial supernatant: toluene-degraded supernatant caused 33% mortality in C. dubia and benzene-degraded supernatant caused 24% mortality. In the second toxicity assay, examining the effect of mixed pollutants on biodegradation activity, the presence of benzene slowed the biodegradation of toluene, but chloroform had no effect on either benzene or toluene biodegradation. Results indicate that significant toxicity remain after biodegradation and that halogenated aliphatic hydrocarbons may have little or no effect on aromatic hydrocarbon biodegradation at sites impacted by mixed pollutants.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Solventes
/
Tolueno
/
Poluentes Químicos da Água
/
Benzeno
/
Clorofórmio
Limite:
Animals
Idioma:
En
Revista:
Ecotoxicol Environ Saf
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Holanda