抄録
The amounts of homologous series of linear Alkylbenzenesulfonates (LAS) in water and sediment were measured as free and complex LAS by using methylene blue colorimetry and high-performance liquid chromatography. The amounts of Quaternary ammonium surfactants (QAC) were also measured by Orange-II colorimetry with cation exchange column chromatography. The concentrations of free and complex LAS in the influent sewage and the river water were found at the levels varying 0.37 to 4.1 mg/l, and 0.09 to 0.58 mg/l respectively, and QAC was found at the levels of 0.05 to 0.15 mg/l. The percentages of QAC which contribute to complex LAS in the water were estimated at the value ranging from 21 to 73%. The concentrations of free and complex LAS in the river sediment were found at levels varying 0.66 to 120 μg/g, and 0.54 to 52 μg/g, and QAC was found at the levels varying 6.2 to 69 μg/g. The results obtained in this study suggest that the adsorption of complex LAS to the river sediment is more likely to that of free LAS, and, furthermore, LAS with longer alkyl chain length is preferentially adsorbed. It is considered that free QAC is adsorbed faster than complex QAC in the river sediment, and the biodegradations of LAS and QAC in the sediment are much slower than their adsorption.
