Elution Of PCB138 In Soil By Three Kinds Of Surfactants And Degradation Of Pollutants In Soil And Water Afterwards

Polychlorinated biphenyls(PCBs)are a type of persistent organic pollutants widely present in the environment,with a triple effect.Studies have shown that the concentration of residual pollution in the environment is high,and the properties are stable and difficult to degrade.In this paper,three different types of biodegradable green surfactants are selected,and the surfactants that have the best elution effect on PCB138 in soil are selected through experiments.After elution,PCB138 in the soil and the eluent were selected from P.chrysogenumn white rot fungi and ferrate for degradation analysis,and the factors affecting degradation were analyzed.The experimental results show that the selected three types of green surfactants: sodium lauroyl(anionic surfactant),dodecyl dimethyl betaine(amphoteric surfactant)and octylphenol polyoxyethylene ether(Nonionic surfactant)has a certain elution effect on PCB138 in the soil.Among them,the anionic surfactant sodium lauroyl acid has the best elution effect.When the concentration is 5000 mg / L,the elution rate is 33.94%.Octylphenol polyoxyethylene ether is next,and the elution effect of dodecyl dimethyl betaine is relatively weak.The modified potassium ferrate has obvious degradation effect on PCB138 in the soil eluate.The kinetic analysis results show that the degradation process of PCB138 in soil eluate by potassium ferrate,citric acid complex potassium ferrate,coated potassium ferrate and slow-release potassium ferrate conforms to the first-order reaction kinetic equation,and the reaction rate The constants are: 0.0149 h-1,0.0128 h-1,0.0048 h-1,and 0.0154 h-1.The degradation rate of PCB138 in the soil increases first and then decreases with the increase of potassium ferrate dosage.The trend is that when the p H of the reaction system is moderately acidic,the degradation effect of PCB138 is relatively good.The greater the eluent concentration,the lower the degradation rate of PCB138.The results of the degradation experiment of P.chrysogenum on PCB138 in the soil after elution showed that P.chrysogenum had a certain degradation effect on PCB138,and the degradation rate of PCB138 was 17.26% after 4 weeks of degradation.