You are here:
EVALUATION OF CHLORPYRIFOS UPTAKE IN STERILIZED AND NON-STERILIZED SEDIMENT
Citation:
Block, D. S., D. B. Huggett, J. C. Allgood, AND W H. Benson. EVALUATION OF CHLORPYRIFOS UPTAKE IN STERILIZED AND NON-STERILIZED SEDIMENT. SETAC 20th Annual Meeting, Philadelphia, PA, 14-18 November 1999.
Description:
In order to evaluate chemical interactions in sediment, initial experiments were designed to assess the role of microbial activitiy on chemical fate of chlorpyrifos. In these initial experiments, sediment uptake of chlorpyrifos was evaluated using Enzyme Linked Immunosorbent Assay (ELISA) measurements of overlying water and whole sediment in sterilized and non-sterilized sediments. Samples were collected at 0, 3, 12 and 24 hours following direct addition of chlorpyrifos (2.0 mg/L) to overlying water. Chlorpyrifos concentrations in sterilized sediment were 11.6 |g/kg(4.1 SE), 22.3 |g/kg(10.1 SE) and 270 |g/kg(50 SE) for 3, 12 and 24 hours, respectively. Respective chlorpyrifos concentrations in non-sterilized sediment were 7.5 (0.7), 72.2 (64.9) and 139 |g/kg(16.0) for 3, 12 and 24 hours. The above data indicate no significant difference in uptake rates between sterilized and non-sterilized sediment 3 and 12 hours after direct addition of chlorpyrifos, while concentrations of chlorpyrifos in sterilized sediment was 51% greater than concentrations found in non-sterilized sediment at 24 hours. In addition, it appears the majority of chlorpyrifos uptake into sediment occurs between 12 and 24 hours. The above data indicate that microbial activity significantly affects the fate of chlorpyrifos in sediments.