界面活性剤の河川水中での生分解

Abstract

To predict the behavior of the surfactants used in the new domestic phosphate-free-built detergents in natural waters, the effect of water temperature and chemical structure of the surfactants on primary biodegradation was examined by a river die-away test using the water collected from Tama River. The extent of biodegradation was dependent on water temperature and varied between the surfactant types tested. Alkyl sulfates or alkyl poly(oxyethylene) ethers were biodegraded rapidly at high to low water temperature. Decreased biodegradation rates were observed for alkylpoly(oxyethylene) sulfates and α-olefin sulfonates. Linear alkylbenzenesulfonates (LAS) or alkylphenyl poly(oxyethylene) ethers were biodegraded moderately at high water temperature, but were poor at low water temperature.These results suggest that large quantities of LAS, being most widely used until now, may persist in natural waters at lower water temperature. The use of the new detergent surfactants may reduce a surfactant concentration in natural waters, as they would biodegrade more rapidly than LAS.