胡敏酸在土壤中的迁移

The transport of humic acid in soils

研究了不同条件下胡敏酸在土壤中的迁移过程.结果表明,其迁移过程表现出较大的差异,在溶液pH值、胡敏酸浓度和溶液流速均较高时,胡敏酸迁移的阻滞因子和在土壤中的吸附系数均较低,有利于胡敏酸在土壤中的迁移;在溶液pH值、胡敏酸浓度和溶液流速均较低时,土壤对胡敏酸迁移的阻滞作用较大.胡敏酸的迁移还与土壤性质有关,土壤黏粒含量和阳离子交换量越高,胡敏酸在土壤中吸附的越多,越不利于迁移.在土壤中的吸附是胡敏酸迁移的主要控制因素,在预测胡敏酸在水土环境中迁移时,应该充分考虑不同条件下胡敏酸在不同性质土壤中的吸附.

The transport of humic acid in different soils at various conditions was studied. The transport of humic acid varied markedly with experimental conditions. Under the conditions of high solution pH values, high humic acid concentrations and fluid velocities, the retardation and humic acid adsorption on soil particles were less than that at the condition of low solution pH values, low humic acid concentrations and fluid velocities, indicating that the transport of humic acid was favored with the increase of solution pH values, humic acid concentrations and fluid velocities. The transport of humic acid was also related with soil properties. The high clay content and cation exchange capacity enhanced the adsorption of humic acid in soils, thus retarded the transport in soils. Humic acid adsorption was the major process controlling the transport of humic acid in soils. The adsorption of humic acid varied with solution chemical properties and soil properties and should be considered in predicting humic acid behaviors in soil and water environment.