Joint Toxicity for BS-12 of Amphoteric Surfactant and Substituted Aromatic Compounds to Photobacterium Phosphoreum

The toxicity to Photobacterium phosphoreum of different mixture systems of amphoteric surfactant of dodecyldimethyl betaine(BS-12) and three substituted aromatic compounds including phenol,toluene and nitrobenzene,according to equiconcentration ratio of 1:1,as well as individual toxicity,were determined respectively.They were evaluated by toxicity unit(TU),additive index(AI),similarity parameter(λ),and mixture toxicity index(MTI).Four evaluating methods were compared and the modes of joint action of different systems were analyzed.It was shown that the coherent results were obtained by four different evaluating methods.Conclusions can be drawn that the mixture of BS-12 and toluene was additive effect,the mixture of BS-12 nitrobenzene,BS-12 toluene nitrobenzene showed antagonistic effect,and the other mixtures exhibit synergistic effects.