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The ultimate biodegradabilities of ten anionic, three cationic and five nonionic surfactants, were studied. As test surfactants, sodium linear alkylbenzenesulfonates (LAS), sodium alkyl sulfates (AS), sodium alkylpoly (oxyethylene) sulfates (AES), sodium α-olefinsulfonate (AOS), sodium N-acyl-L-glutamate (LG), sodium salt of fatty acid (Soap), alkyltrimethylammonium chloride (ATM), dialkyldimethylammonium chloride (ADM), alkylbenzyldimethylammonium chloride (ABDM), alkyl poly (oxyethylene) ether (LPE), p-alkylphenyl poly (oxyethylene) ether (NPE), N, N-bis (2-hydroxyethyl) alkanamide (LDEA), poly (oxyethylene) ester of fatty acid (PAE) and N, N-bis [poly (oxyethylene)] alkylamine (PEA) were used, and glucose was served as readily biodegradable control in each test set. The test solutions were incubated at 27°C under an aerobic condition. The rate and degree of biodegradation in the 10-d test period were followed by measuring CO2 production, total organic carbon (TOC), methylene blue active substances (MBAS) for avionics and iodobismuthate active substances (BIAS) for nonionics. The results of the comparative biodegradabilities of the surfactants, estimated by biodegradation index, were as follows; (AS, LG) >Soap> (AES, AOS, PAE) >LDEA>LPE>LAS>> (NPE, PEA, ATM, ADM, ABDM). |
