聚乙烯残膜破碎过程对土壤水分入渗的影响

Effect of decomposition of polyethylene residue film on soil water infiltration

为探究残膜-微塑料破碎过程对土壤水分入渗能力的影响,通过室内土柱试验,设置5组残膜-微塑料比例(100%~0,75%~25%,50%~50%,25%~75%,0~100%)来模拟不同的残膜破碎程度,研究了残膜-微塑料破碎对湿润锋运移和累积入渗量的影响,并评价了主要入渗模型在不同破碎程度土壤中的适用性.结果表明,湿润锋运移速率和累积入渗量随着残膜-微塑料破碎程度的增大而增大,当入渗时间为300min时,残膜完全破碎组(T4)较未破碎组(CK)的湿润锋运移距离增大48.72%(P<0.05),累积入渗量增大46.77%.随着残膜破碎程度的增大,各模型拟合效率呈现上升的趋势.湿润锋推进模型的参数B随着残膜破碎程度的增大呈现增大的趋势.Kostiakov模型的参数α,Philip模型中的参数S和C随残膜破碎程度增大而增大.总体上,Kostiakov模型对土壤累计入渗量的模拟效果优于Philip模型.本研究可为残膜污染土壤的水分入渗规律和模拟研究提供参考.

To explore the effect of decomposition of residual film into microplastics on soil water infiltration, laboratory column experiments, which five residual film microplastics ratios(100%~0,75%~25%,50%~50%,25%~75%,0~100%) were included in,were conducted to study the effects on wet front and cumulative infiltration, and evaluate the applicability of the main infiltration models in soil with different degrees of decomposition. The results showed that the migration rate of wet front and cumulative infiltration increased with the degree of residual film decomposition. When the infiltration time was 300min, wet front position of completely decomposed residual film(T4) increased by 48.72%(P<0.05) compared with primary residual film(CK), and the cumulative infiltration increased by 46.77%(P<0.05). As the degree of residual film decomposition increased, model performance in simulating wetting front and cumulative infiltration appeared to be an upward trend. The parameter B of wetting front propulsion model increased with the degree of residual film decomposition. The parameter α of Kostiakov model and parameter S and C of Philip model increased with the degree of residual film decomposition. This study can provide a reference for soil water infiltration and simulation research in residual film polluted soil.