摘要：In order to know the behavior of linear alkylbenznesulfonate (LAS) and their complexes (LAS-CS) with cationic surfactants (CS), alkyltrimethylammonium chloride (TM) and dialkyldimethylammonium chloride (DM), in the aquatic environment, the formation of LAS-CS, their adsorption on the river sediment and primary biodegradation in the river water were studied. The formation of LAS-CS reached to the equilibrium within thirty minutes, and no effects of pH and reaction temperature were observed. It was confirmed that LAS formed LAS-CS with TM and DM at molar ratios from 1 : 1 to 6 : 1 and from 1 : 1 to 2 : 1, respectively. The adsorption isotherms of LAS and LAS-CS with TM or DM at molar ratios of 1 : 1 and 2 : 1 followed to the Freundlich's equations. The adsorption capacities of LAS-CS were smaller than that of LAS. Their order was LAS>LAS-TM>2LAS-TM>LAS-DM>2LAS-DM. The adsorption capacities of LAS, LAS-TM and 2LAS-TM increased with increasing the alkyl chain length of LAS, whereas those of LAS-DM and 2LAS-DM showed little variation among the alkyl chain length homologues. The primary biodegradation rates of LAS-CS with TM or DM at molar ratios of 1 : 1 and 2 : 1 were slower than that of LAS. Their order of biodegradation (% decreased during 14 days) was LAS (100%)>2LAS-TM (56%)>LAS-TM (36%)>2LAS-DM (31%)>LAS-DM (29%). The biodegradation of LAS and LAS-CS also decreased with increasing the alkyl chain length of LAS.
