Huo Shouliang, Zhang Jingtian, Yeager Kevin M, Xi Beidou, Qin Yanwen, He Zhuoshi, Wu Fengchang
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China.
J Environ Sci (China). 2015 May 1;31:1-11. doi: 10.1016/j.jes.2014.12.003. Epub 2015 Mar 9.
The technique of DGT (diffusive gradients in thin films) using three diffusive gel thicknesses was applied to estimate the mobility and bioavailability of heavy metals in sediments and porewater of Lake Taihu, China. The DGT results showed significantly positive correlations between Co, Pb, Cd and Mn, and Ni and Fe concentrations in porewater. Cu and Zn showed a significantly negative correlation with Mn, due to Cu combination with carbonates and Zn derived from agricultural pollution, respectively. The rank order of average concentrations of Co, Ni and Cd at each station was DGT1.92>DGT0.78>DGT0.39, suggesting stronger resupply from sediments to porewater when using thicker diffusive gels. Comparing centrifugation and DGT measurements, Co, Ni and Cd are highly labile; Mn and Fe are moderately labile; and Cu, Zn and Pb are slightly labile. The variations of AVS concentrations in sediment cores indicate that metal sulfides in deeper layers are easily diffused into surface sediments.
采用三种扩散凝胶厚度的薄膜扩散梯度技术（DGT）来估算中国太湖沉积物和孔隙水中重金属的迁移率和生物有效性。DGT结果表明，孔隙水中的钴、铅、镉和锰以及镍和铁的浓度之间存在显著正相关。铜和锌与锰分别呈显著负相关，原因是铜与碳酸盐结合以及锌来自农业污染。各站点钴、镍和镉的平均浓度排序为DGT1.92>DGT0.78>DGT0.39，这表明使用较厚的扩散凝胶时，沉积物向孔隙水的再供应更强。对比离心法和DGT测量结果，钴、镍和镉的活性很高；锰和铁的活性中等；铜、锌和铅的活性较低。沉积物岩心中酸挥发性硫化物（AVS）浓度的变化表明，深层的金属硫化物很容易扩散到表层沉积物中。
