为了揭示土壤剖面中含氧非烃污染物的迁移特征,以及TOC和淋滤水量等因素对迁移作用的影响,选择了部分典型的含氧非烃开展了纵向迁移的土柱淋滤实验,对原土及添加污染物的土柱淋滤实验后样品中含氧非烃的含量及组成进行了对比分析.结果表明,土柱淋滤实验后,土柱表层添加的含氧非烃主要残留在土柱表层0~5 cm范围内,但相比所添加的化合物的量均有不同程度的降低,土柱深部(〉10 cm)土壤中含氧非烃含量仍然很低,甚至低于原土中的,在TOC较高的土柱中,这种现象尤为突出.说明土柱淋滤实验过程中,不同剖面含氧非烃均存在向下迁移的现象,且以水溶方式迁移为主.不同含氧非烃单体含量均有随深度增加而降低的趋势,表明其在土壤剖面淋滤过程中均具有一定的迁移性,但不同性质的含氧非烃单体在表层土中残留量及组成差别较大,说明不同化合物迁移能力存在差别,其中,胆甾醇、β-谷甾醇、正构十六烷酸和邻苯二甲酸二丁酯迁移性较强.土壤TOC和淋滤水量对含氧非烃在土壤剖面的迁移作用都有不同程度的影响,淋滤水量相同时,TOC含量越高,土壤中有机质越丰富,越容易富集含氧非烃;TOC相同时,淋滤水量越大,含氧非烃迁移量越大,迁移的深度越大,尤其在TOC含量较低时更明显.
To reveal the characteristics and influence factors of the migration of oxygen nonhydrocarbons in soil profiles, soil column leaching experiments were carried out, and the contents and composition of the oxygen nonhydrocarbons in both the natural soil and pollutant-added soil were analyzed. The results indicate that: after leaching, the oxygen nonhydrocarbons added in the topsoil (2 cm) are mainly enriched in the topsoil (0 -5 cm), but lower than those prior to leaching. The contents of oxygen nonhydrocarbons are low in the deep soil ( 〉 10 cm), even lower than the contents in the natural soil. The content drop becomes more significant when the TOC is high. This indicates that during the soil column leaching experiments, oxygen nonhydrocarbons among different soil profiles can migrate downward, and the most important way of migration is water dissolution; in most cases, the contents of monomers decrease with the increase of soil depth in different soil columns after leaching, indicating the ability of migration. However, the amount of residue and composition of the monomers in topsoils are different, and the migration capabilities are also different, with cholesterol, fl-sitosterol, n-hexadeeane acid and dibutyl phthalate capable of migration deeper in the soil profiles. Both TOC of soil and volume of leaching water significantly influence the migration of the compounds in soil profiles. Under the same condition of leaching water, the enrichment degree of soil organic matter for these compounds increases with the increase of TOC. Under the same condition of TOC, the migration amount of oxygen nonhydrocarbons increase with the increase of leaching water amount, especially when the TOC is low. In addition, the migration of nonhydrocarbons in soil is related to soil textures and their contents in the natural soil.