Wang Yan, Lin Jian-Wei, Zhan Yan-Hui, Zhang Hong-Hua, Zhang Zhi-Bin, He Si-Qi, Zhao Yu-Ying, Wu Xiao-Long, Yu Yang
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
College of Environment, Zhejiang University of Technology, Hangzhou 310032, China.
Huan Jing Ke Xue. 2019 Feb 8;40(2):649-657. doi: 10.13227/j.hjkx.201806220.
A magnetic zirconium/iron-modified bentonite (ZrFeBT) was prepared, and the effect of ZrFeBT addition on the mobilization and species transformation of P in river sediments was investigated using incubation sediment core experiments. The results showed that, under anoxic conditions, P could be released from river sediments into the pore water, and then P in the pore water could be released into the overlying water. The addition of ZrFeBT into river sediments could greatly suppress the release of P from river sediments into the pore water under anoxic conditions. Therefore, the release of P from the pore water into the overlying water could be significantly suppressed by the addition of ZrFeBT. After the addition of ZrFeBT into river sediments, the transformation of loosely sorbed P (Labile-P) and BD extractable P (BD-P) to NaOH extractable P (NaOH-rP) and residual P (Res-P) in the sediments was observed. The decrease of bioavailable P (BAP) including water soluble P (WSP), readily desorbable P (RDP), NaHCO extractable P (Olsen-P), algal available P (AAP), and Fe oxide-paper extractable P (FeO-P) in the sediments was also observed. A certain amount of P in the ZrFeBT after the incubation experiment was present in the form of mobile P (Labile-P and BD-P), Olsen-P, and FeO-P, which could be re-released into the pore water and overlying water when the environmental conditions change in the future. The control of P release from river sediment into the overlying water by the addition of ZrFeBT could be mainly attributed to the reduction of P in the pore water as well as the reduction of mobile P and BAP in the sediments after ZrFeBT amendment. The results of this study inidcated that ZrFeBT is a promising amendment for the regulation of P release from river sediments into the overlying water.
制备了磁性锆/铁改性膨润土（ZrFeBT），并通过沉积物柱培养实验研究了添加ZrFeBT对河流沉积物中磷的迁移和形态转化的影响。结果表明，在缺氧条件下，磷可从河流沉积物释放到孔隙水中，然后孔隙水中的磷再释放到上覆水中。向河流沉积物中添加ZrFeBT可显著抑制缺氧条件下磷从河流沉积物释放到孔隙水中。因此，添加ZrFeBT可显著抑制孔隙水中的磷向上覆水的释放。向河流沉积物中添加ZrFeBT后，观察到沉积物中松散吸附态磷（Labile-P）和BD可提取态磷（BD-P）向氢氧化钠可提取态磷（NaOH-rP）和残余态磷（Res-P）的转化。同时也观察到沉积物中生物可利用磷（BAP）包括水溶性磷（WSP）、易解吸磷（RDP）、碳酸氢钠可提取磷（Olsen-P）、藻类可利用磷（AAP）和铁氧化物-纸可提取磷（FeO-P）的含量降低。培养实验后ZrFeBT中的一定量磷以可移动磷（Labile-P和BD-P）、Olsen-P和FeO-P的形式存在，未来环境条件变化时，这些磷可能会重新释放到孔隙水和上覆水中。添加ZrFeBT对河流沉积物向上覆水释放磷的控制作用主要归因于ZrFeBT添加后孔隙水中磷的减少以及沉积物中可移动磷和生物可利用磷的减少。本研究结果表明，ZrFeBT是一种有前景的用于调控河流沉积物向上覆水释放磷的改良剂。
