Abstract:
Three common surfactants that NP-10(Nonylphenol Ethoxylate 10 mol),TW-80(polysorbate-80) and SDS(sodium dodecyl sulfate) were selected as experimental materials, and the mixture of non-ionic and anionic surfactants was also taken in test.The soil column leaching test was carried out and phosphorus content in leaching solution, soil phosphorus adsorption capacity, Zeta potential and soil moisture characteristics were analyzed to explore the effects of non-ionic surfactants and the mixture surfactants on soil phosphorus loss and retention under leaching, in order to provide reference for reducing agricultural non-point source pollution.The results showed that NP-10 promoted phosphorus loss, comparing with CK,the increase of total phosphorus loss was 26.04%.Meanwhile, TW-80 had relatively little effect on soil phosphorus loss.In combined leaching of NP-10 and TW-80 with SDS respectively, though soil phosphorus loss decreased, but it was still 5.24% and 13.67% higher than CK.According to total phosphorus loss, the order of experimental groups was SDS-5>NP-10-5>TW-80+SDS>TW-80>NP-10+SDS>CK.Soil phosphorus loss was positively correlated with soil Zeta potential and soil water holding capacity.Correlation between soil phosphorus adsorption after leaching and Zeta potential was the strongest(R=0.875 0) while the correlation with total phosphorus loss was weak.Surfactants changed the surface electrical properties of soil and it had great influence on phosphorus re-adsorption and subsequent phosphorus supply.