Temporal and spatial variation of perchlorate in streambed sediments: results from in-situ dialysis samplers.
The fate of perchlorate (ClO4-) in streambed sediments is becoming a concern due to the increasing number of groundwater and surface water contamination sites in the United States. Dialysis samplers were deployed at three sites over a period of 1 year to determine the vertical distribution of ClO4- in sediment pore water. Results indicated that the spatial and temporal ClO4- penetration into sediments could be affected by numerous factors, such as temperature, microbial degradation, ClO4- surface water concentration, and sediment physico-geological properties. In general, maximum ClO4- penetration into sediments at the studied sites was 30 cm below the sediment-water surface. The vertical sequential depletion of electron acceptors in sediments suggested that microbial reduction was responsible for ClO4- depletion in stream sediments. Biodegradation of ClO4- occurred over a seasonally variable active depth zone of 1-10 cm. Results implied that there was a rapid natural attenuation potential of perchlorate in saturated near-surface sediments.
Tan
Kui
K
Department of Civil Engineering, Texas Tech University, Lubbock, TX 79409, USA.
Anderson
Todd A
TA
Jackson
W Andrew
WA
D003956:Dialysis; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D019015:Geologic Sediments / Q000737:chemistry*; D010472:Perchlorates / Q000032:analysis*; D045483:Rivers; D013048:Specimen Handling; D014874:Water Pollutants, Chemical / Q000032:analysis*
D010472:Perchlorates; D014874:Water Pollutants, Chemical