Bai Xiao-Yun, Lin Jian-Wei, Zhan Yan-Hui, Chang Ming-Yue, Wu Jun-Lin, Xin Hui-Min, Huang Liang-Jun
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
Eight-Sail Instrument & Equipment(Shanghai) Co., Ltd., Shanghai 201114, China.
Huan Jing Ke Xue. 2020 May 8;41(5):2281-2291. doi: 10.13227/j.hjkx.201908135.
Understanding the effect of calcite and chlorapatite mixture (CA/ClAP) addition on the mobilization of phosphorus (P) in sediments is crucial to the application of CA/ClAP as an amendment material to control the release of P from sediments. To address this issue, batch experiments were conducted to investigate the removal performance of phosphate by CA/ClAP, and sediment incubation experiments were carried out to study the effect of CA/ClAP addition on the mobilization of P in sediments. The results showed that the removal ability of phosphate by CA/ClAP was much higher than those by calcite and chlorapatite, and the kinetics data of phosphate removal by CA/ClAP followed a pseudo-second-order kinetics model. Increasing calcite and chlorapatite dosages would be favorable for the removal of phosphate by CA/ClAP, and coexisting Ca enhanced the phosphate removal. CA/ClAP addition not only reduced the concentration of soluble reactive P (SRP) in the overlying water, but also decreased the concentration of SRP in the pore water. The addition of CA/ClAP in sediments caused an increase in the content of P in the sediments, but the increased P mainly existed in the form of calcium-bound P (HCl-P), which was difficult to be re-released into the water column under anoxic and common pH (5-9) conditions. The reduction of SRP in the pore water after the addition of CA/ClAP played an important role in the prevention of sedimentary P liberation into the overlying water by the CA/ClAP amendment. The results of this work indicate that CA/ClAP can be used as an amendment material for interception of the release of P from sediments into overlying water.
了解添加方解石和氯磷灰石混合物（CA/ClAP）对沉积物中磷（P）迁移的影响，对于将CA/ClAP用作控制沉积物中磷释放的改良材料至关重要。为解决这一问题，进行了批量实验以研究CA/ClAP对磷酸盐的去除性能，并开展了沉积物培养实验以研究添加CA/ClAP对沉积物中磷迁移的影响。结果表明，CA/ClAP对磷酸盐的去除能力远高于方解石和氯磷灰石，且CA/ClAP去除磷酸盐的动力学数据符合准二级动力学模型。增加方解石和氯磷灰石的用量有利于CA/ClAP对磷酸盐的去除，共存的钙增强了磷酸盐的去除效果。添加CA/ClAP不仅降低了上覆水中可溶性活性磷（SRP）的浓度，还降低了孔隙水中SRP的浓度。在沉积物中添加CA/ClAP导致沉积物中磷含量增加，但增加的磷主要以钙结合磷（HCl-P）的形式存在，在缺氧和常见pH值（5-9）条件下难以再次释放到水柱中。添加CA/ClAP后孔隙水中SRP的降低在通过CA/ClAP改良防止沉积物中磷释放到上覆水中方面发挥了重要作用。这项工作的结果表明，CA/ClAP可作为一种改良材料，用于拦截沉积物中磷向上覆水的释放。
