College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China; Centre for Research on Environmental Ecology and Fish Nutrition of Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, China.
College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai 201306, China.
Water Res. 2023 May 15;235:119899. doi: 10.1016/j.watres.2023.119899. Epub 2023 Mar 20.
This study developed novel active capping systems with recycling convenience using ferrihydrite (Fh) combined with magnetite (Mag), and investigated the effectiveness and mechanism for the restriction of endogenous phosphorus movement from sediment into overlying water (OW) by the combined use of Fh and Mag. The Fh/Mag combined amendment effectively hindered endogenous phosphorus release from sediment to OW in dissolved oxygen (DO)-deficit environment, and the immobilization of diffusion gradient in thin film-labile phosphorus (LP) and mobile phosphorus in the sediment played a key role in the control of endogenous phosphorus liberation by the Fh/Mag combined amendment. Combined capping sediment with Fh and Mag effectively hindered endogenous phosphorus release from sediment to OW in anoxic environment, and the inactivation of LP in the upper sediment played a key part in the control of sediment phosphorus release by the Fh/Mag mixture capping. The stability of phosphorus immobilized by the Fh/Mag combined covering layer was related to its construction way, and the majority (around 90%) of P immobilized to the Fh/Mag mixture covering layer had low risk of release in common pH (5-9) and DO-deficit environments. The Fh/Mag mixture amendment or capping did not increase the risk of sediment iron release, and it also did not produce a large impact on the diversity and richness of bacterial community in the sediment. The combined utilization of Fh and Mag as a composite amendment or capping material to prevent the internal phosphorus from being moved to OW can make full use of their respective advantages. The Fh/Mag mixture capping wrapped by permeable fabric has high potential to reduce the risk of endogenous phosphorus from sediment into OW due to its advantages of high internal phosphorus release suppression efficiency, environmental friendliness, application convenience and sustainability.
本研究开发了一种新型的活性封盖系统，利用磁赤铁矿（Fh）与磁铁矿（Mag）结合，具有回收便利性，并研究了联合使用 Fh 和 Mag 限制内源磷从沉积物向表层水（OW）迁移的效果和机制。Fh/Mag 联合添加物可有效抑制溶解氧（DO）缺乏环境中内源磷从沉积物向 OW 的释放，薄膜不稳定磷（LP）和沉积物中可移动磷的扩散梯度固定在 Fh/Mag 联合添加物控制内源磷释放中起关键作用。Fh 和 Mag 联合封盖沉积物可有效抑制缺氧环境中内源磷从沉积物向 OW 的释放，上覆沉积物中 LP 的失活在控制 Fh/Mag 混合封盖沉积物磷释放中起关键作用。Fh/Mag 联合覆盖层固定磷的稳定性与其构建方式有关，在常见 pH（5-9）和 DO 缺乏环境中，固定到 Fh/Mag 混合物覆盖层中的大部分（约 90%）磷释放风险较低。Fh/Mag 混合物添加或封盖不会增加沉积物铁释放的风险，也不会对沉积物中细菌群落的多样性和丰富度产生很大影响。联合利用 Fh 和 Mag 作为复合添加剂或封盖材料来防止内部磷向 OW 迁移，可以充分利用它们各自的优势。由于具有高的内部磷释放抑制效率、环境友好性、应用便利性和可持续性，用渗透性织物包裹的 Fh/Mag 混合物封盖具有降低沉积物内源磷向 OW 迁移风险的巨大潜力。
