微塑料对土壤磷吸附的影响OA北大核心CSTPCD

Microplastics are emerging pollutants widely present in soil,and their effects on soil phosphorus(P)adsorption are still unclear.This paper examined the effects of 0.1%to 10%microplastics on soil P adsorption and the underlying mechanisms.The results showed that microplastics could significantly increase the rate of liquid film diffusion stage in the first stage of the adsorption process(p<0.05).Compared with the pure soil(qe= 6.456 mg/g),the soil P adsorption capacity was significantly reduced by microplastics with less than 1%concentration(p<0.05).However,the soil P adsorption capacity was significantly increased by microplastic with concentrations higher than 5%(p<0.05).Additionally,the smaller the particle size of microplastics,the greater the P adsorption capacity of soil with the same microplastic concentration.Microplastics could compete with P for adsorption sites,which reduced the adsorption of P in the microplastic-soil system.However,microplastics could also directly adsorb P,leading to an increase in the P adsorption capacity of microplastic-soil system when microplastic concentration were more than 5%.Therefore,microplastics pollution in soil could significantly change P adsorption characteristics,which closely related to the microplastics concentration and particle size.