Environmental monitoring for linear alkylbenzene sulfonates, dialkyltetralin sulfonates and their biodegradation intermediates

Concentrations of linear alkylbenzene sulfonates (LAS), dialkyltetralin sulfonates (DATS), and their biodegradation intermediates are reported for the influents and effluents of 10 U.S. domestic wastewater treatment plants as well as upstream and downstream river waters and sediments. Three types of treatment facilities in 10 U.S. states were sampled and analyzed. Removals were calculated based on initial concentrations of LAS and DATS. A derivatization electron capture/gas chromatography/mass spectrometry method was employed. Its increased sensitivity and selectivity permitted the determination of environmental levels of LAS, DATS, and their biodegradation intermediates at low micrograms per liter (ppb) concentrations. The removal from four activated sludge and five trickling filter wastewater treatment facilities averaged 99.5% and 82.9% for LAS and 99.1% and 97.3% for LAS intermediates, respectively, for the activated sludge and trickling filter facilities. In the same plants, percent removals for DATS averaged 95% and 63.2% and DATS intermediates 59.1% and 58.7%, respectively. The removals obtained by a rotating biological contactor were similar to those observed in the activated sludge wastewater treatment facilities.