利用 DGT 技术研究大型植物根际中磷的迁移转化动力学及其对湖泊沉积物的植物去除性能。
Transfer kinetics of phosphorus (P) in macrophyte rhizosphere and phytoremoval performance for lake sediments using DGT technique.
机构信息
College of Water Sciences, Beijing Normal University, Beijing 100875, China; National Engineering Laboratory for Lake Water Pollution Control and Ecological Restoration Technology, Research Center of Lake Eco-Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012 China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 China.
College of Water Sciences, Beijing Normal University, Beijing 100875, China; National Engineering Laboratory for Lake Water Pollution Control and Ecological Restoration Technology, Research Center of Lake Eco-Environment, Chinese Research Academy of Environmental Sciences, Beijing 100012 China; State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012 China.
出版信息
J Hazard Mater. 2018 May 15;350:189-200. doi: 10.1016/j.jhazmat.2018.02.005. Epub 2018 Feb 7.
DGT (diffusive gradients in thin films) technique and DIFS (DGT induced fluxes in sediment) model are firstly designed for macrophyte-rhizobox system and in-situ macrophytes in Lake Erhai. Dynamics of phosphorus (P) transfer in Zizania latifolia (ZL) and Myriophyllum verticiilatur (MV) rhizosphere is revealed and phytoremediation performance for P in sediment is evaluated. Dynamic transfer process of P at DGT/sediment interface includes (i) diffusion flux and concentration gradients at DGT(root)/porewater interface leading to porewater concentration (C) depletion and (ii) P desorption from labile P pool in sediment solid to resupply C depletion. Fe-redox controlled P release from Fe-bound P (BD-P2) and then NHCl-P1 in rhizosphere sediment resupplies porewater depletion due to DGT (root) sink. K (labile P pool size in solid phase), r (resupply ratio) and kinetic exchange (Tc and k) lead to change characters of DIFS curves of (1) r against deployment time and (2) C (dissolved concentration) against distance at 24 h. They include two opposite types of "fast" and "slow" rate of resupplies. Sediment properties and DIFS parameters control P diffusion and resupply in rhizosphere sediment. Phytoremoval ability for sediment P in lake is estimated to be 23.4 (ZL) or 15.0 t a (MV) by "DGT-flux" method.
DGT（薄膜扩散梯度）技术和 DIFS（DGT 诱导的沉积物通量）模型最初是为大型植物-根盒系统和洱海原位大型植物设计的。揭示了磷（P）在菰（ZL）和竹叶眼子菜（MV）根际中的迁移动力学，并评价了沉积物中 P 的植物修复性能。DGT/沉积物界面上 P 的动态迁移过程包括：（i）DGT（根）/孔隙水界面上的扩散通量和浓度梯度导致孔隙水浓度（C）耗尽，（ii）从沉积物固相中的可利用 P 库中解吸 P 以补充 C 耗尽。铁氧化还原控制 P 从 Fe 结合态 P（BD-P2）和根际沉积物中的 NHCl-P1 释放，从而补充 DGT（根）吸收造成的孔隙水消耗。K（固相中可利用 P 库的大小）、r（补给比）和动力学交换（Tc 和 k）导致（1）r 与部署时间和（2）C（溶解浓度）与 24 h 时距离的 DIFS 曲线的变化特征。它们包括两种相反类型的“快速”和“缓慢”补给速率。沉积物性质和 DIFS 参数控制根际沉积物中 P 的扩散和补给。通过“DGT 通量”法估计湖泊沉积物中 P 的植物去除能力为 23.4（ZL）或 15.0 t a（MV）。
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