河口湿地沉积物中腐殖酸含量对外源重金属分布的影响研究

通过向不同腐殖酸含量的河口湿地沉积物添加人工配制的重金属污染海水,测定污染后沉积物的重金属总量与形态分布,以研究不同腐殖酸含量条件下外源重金属在水-沉积物系统中的转化。结果表明,腐殖酸含量对重金属在沉积物中的吸收量和形态组成有较大的影响,尤其对酸可提取态与可还原态。但是不同重金属之间有一定差别,腐殖酸含量对Cu,Pb的作用较明显,而对Zn,Cd的影响较小。此外,由于河口湿地沉积物处于较高盐度的环境,海水中的离子浓度影响有机质与金属的络合反应,因此与土壤相比,河口湿地沉积物中腐殖酸含量对重金属的生物有效性的影响有所不同。

Effects of Humic Acid on Partitioning of Extrinsic Heavy Metal for the Estuarine Wetland Sediment

Artificial heavy metal contaminated seawater was added into the sediment with different contents of humic acid(HA),and the partitioning of heavy metal was analyzed.Transformation of extrinsic heavy metals in the water-sediment system under the influence of HA was researched.The results indicate that the HA content has the obvious influence on heavy metals in the absorbing capacity and the speciation,especially on the acid extractable form and the reducible form.But the different degree of influences is showed for the different elements.The HA has the significant effect on Cu and Pb while has the inapparent effect on Zn and Cd.Because the estuarine wetland sediment is in the higher salinity environment,the ion concentrations in seawater would influence the interaction between HA and heavy metals.Therefore there are some differences for the effects of HA on bioavailability of heavy metals between estuarine wetland sediments and soils.