Effect of Adsorption Behavior for Biological Surfactants on Organic Polarities in Loess

Adsorption behaviors about organic polarities of phenol and benzoic acid in natural loess and distribution behavior between water and soil on condition that both of biosurfactant saponin and chemical surfactant TritonX 100 exist were studied.It turned out that，first，the distribution coefficient of phenol and that of benzoic acid average higher than those in pure water when the concentration of saponin and that of TritonX 100of get to 100 mgL，that is to say，when the concentrations of saponin and that of TritonX 100 were below the critical micelle concentrations，it was adsorption in loess itself that contributed to the adsorption of phenol and that of benzoic acid.Second，when the concentrations of both phenol and benzoic acid almost reached 500 mgL（approximately three or four times of their critical micelle concentrations），distribution coefficient of phenol and that of benzoic acid average were lower than those in pure water.In the adsorption experiment of phenol and benzoic acid with initial concentration 20 mgL，the adsorption ability of benzoic acid in loess was bigger than that of phenol in loess regardless of the existence of saponin or that of TritonX 100.Adsorptions of phenol and that of benzoic acid in saponin solution were lower than those in TritonX 100 solution on equal conditions.When saponin concentration reached 1 000 mgL，and initial concentration was 20 mgL，the apparent solubility of and that of benzoic acid solubility in the aqueous phase table view were 1835 mgL，1557 mgL，however 9175% of phenol and 7785% of benzoic acid were dissolved in the water.