Department of Environmental Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
Environ Sci Pollut Res Int. 2015 Sep;22(18):14269-79. doi: 10.1007/s11356-015-4652-y. Epub 2015 May 15.
The effects of algal bloom (AB) on the physicochemical and biochemical properties of water and sediment in lakes have been widely studied. However, limited attention has been directed toward the effects of the processes of AB formation, outbreak, and extinction on heavy metal fractionation in sediment. In this study, water and sediment samples were collected from the AB and free algal bloom (FAB) regions of Chaohu Lake from May to September in 2012. The chemical fractionation of seven heavy metals (Cd, Cr, Cu, Mn, Ni, Fe, and Pb) in sediment was determined by using a modified three-step sequential procedure. Evident processes of AB formation, outbreak, and extinction were observed in the AB region, but not in the FAB region. The TN and TP concentrations in water and sediment in the AB region were significantly higher than those in the FAB region. The water DO concentration was higher in the AB region than that in the FAB region before the early stage of the AB outbreak, but an opposite trend was observed in the stages that followed. Metal fractionation in sediment showed that except for Mn and Cu, the majority of metals were in the residual fraction regardless of the AB process. The AB process slightly altered the concentrations of metal fractions, except for reducible Fe and oxidizable Cu. The result showed that AB formation, outbreak, and extinction slightly affected heavy metal fractionation in sediment though water properties were significantly different among AB processes.
富营养化（Algal Bloom，AB）对湖泊水和沉积物的理化及生化性质的影响已得到广泛研究。然而，人们对 AB 形成、爆发和消亡过程对沉积物中重金属形态的影响关注较少。本研究于 2012 年 5 月至 9 月采集了巢湖富营养化（AB）区和无富营养化（FAB）区的水样和沉积物样品。采用改良的三步连续提取法对沉积物中 7 种重金属（Cd、Cr、Cu、Mn、Ni、Fe 和 Pb）的化学形态进行了分析。AB 区出现了明显的 AB 形成、爆发和消亡过程，而 FAB 区则没有。AB 区的水和沉积物中的 TN 和 TP 浓度明显高于 FAB 区。AB 爆发前的早期，AB 区的水中 DO 浓度高于 FAB 区，而随后的阶段则相反。沉积物中金属形态分析表明，除 Mn 和 Cu 外，大部分金属均处于残渣态，与 AB 过程无关。AB 过程仅略微改变了金属形态的浓度，除可还原态的 Fe 和可氧化态的 Cu 外。结果表明，尽管 AB 过程中水的性质存在显著差异，但 AB 的形成、爆发和消亡过程对沉积物中重金属形态的影响较小。
