MONITORING LINEAR ALKYL BENZENE SULFONATE IN THE ENVIRONMENT - 1973-1986

Results from extensive monitoring from 1973 to 1986 indicate that linear alkyl benzene sulfonate (LAS) is extensively removed by sewage treatment with resulting river water concentrations in the low ppb range. Wastewater treatment plant removal efficiencies exceed those for biochemical oxygen demand (BOD); they average 98% for activated sludge, 80% for trickling filters and 27% for primary clarification. Concentrations in influent sewage (x̄ = 3.5 mg/L), effluent sewage (x̄ = 0.06–2.1 mg/L), and in river waters (<0.005–0.3 mg/L) are in agreement with predicted concentrations and measurements by other investigators. Levels of LAS in soil cores analyzed shortly after sludge amendment range from <3 to 47 mg/kg and are consistent with sludge loading rates and biodegradation of LAS from the previous year's sludge application. Removal of LAS occurs by biodegradation in all compartments and sorption/settling from the water column. Longer chain length, more sorptive LAS homologs are relatively enriched in sludge solids and in river sediments, thus the average LAS chain length was found to be higher in those compartments. Results obtained from long‐term monitoring support the rapid removal of LAS by biodegradation in the environment. Copyright © 1990 SETAC