[Vertical fractionation of dissolved organic matter and its effect on the transport of Cu in Cu-contaminated soils].

ABSTRACT

The vertical fractionation of DOM and its effect on Cu transport in acidic and calcareous Cu-contaminated soils were studied in column experiments. The results showed that the polarities of DOM derived from green manure and pig manure were obviously decreased by 11.4% and 10.72%, respectively, when they were leached through soil columns, especially in the calcareous soil. Dissolved organic matter can increase the dissolution of copper from the two copper-contaminated soils, but the dissolution effect was influenced by the properties of DOM and soils. For example, the ability of DOM derived from green manure to increase copper dissolution was stronger than that of DOM from pig manure. On average, the amounts of copper into effluent leached by green manure DOM or pig manure DOM in the column packed with a calcareous soil are 4.37 and 3.03 times higher than that in the column packed with an acidic red soil, respectively. In addition, it was observed that Cu dissolution from soils facilitated by DOM was decreased due to microbial degradation of DOM in soils.