Combined use of calcium nitrate addition and anion exchange resin capping to control sedimentary phosphorus release and its nitrate‑nitrogen releasing risk.
Combined use of calcium nitrate addition and anion exchange resin capping to control sedimentary phosphorus release and its nitrate‑nitrogen releasing risk.
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DOI：
10.1016/j.scitotenv.2019.06.406
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发表时间：
2019-11
期刊：
影响因子：
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通讯作者：
Yanhui Zhan;Xiaolong Wu;Jianwei Lin;Zhe Zhang;Yuying Zhao;Yang Yu;Yan Wang
中科院分区：
文献类型：
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作者：
Yanhui Zhan;Xiaolong Wu;Jianwei Lin;Zhe Zhang;Yuying Zhao;Yang Yu;Yan Wang
添加硝酸钙 (Ca(NO3)2) 可用于控制沉积物中磷的释放，但它也会导致水柱中硝酸盐氮 (NO3−-N) 浓度的增加。通过放置阴离子交换树脂 (AER) 覆盖层，可以降低注入 Ca(NO3)2 的沉积物中 NO3−-N 释放的风险。在本研究中，研究了结合使用Ca(NO3)2添加和AER封盖防止磷从沉积物中释放的有效性，并评估了AER封盖降低从Ca(NO3)2注入沉积物中释放NO3−-N风险的效果。 Ca(NO3)2添加和AER封顶的联合应用可以极大地减少上覆水中可溶性活性磷(SR-P)的含量，SR-P的减少率为75.9%~98.7%。此外，它还可以减少沉积物中高分辨率扩散梯度薄膜（DGT）不稳定磷的含量，从而导致上部沉积物中磷静态层的形成。 Ca(NO3)2和AER联合处理对沉积物中可移动磷含量的影响相对较小，但可以大大增加表层30 mm沉积物中的残留磷量（增加27.7%~42.9%）。沉积物修复初期，Ca(NO3)2与AER联合处理方法作用下的上覆水中NO3−-N含量远低于单一Ca(NO3)2处理作用下的NO3−-N含量。综上所述，无论是从沉积物磷释放控制效率还是添加硝酸盐释放风险的角度来看，Ca(NO3)2添加和AER封顶联合使用是比单一使用Ca(NO3)2添加更有前景的沉积物磷释放控制策略。
Calcium nitrate (Ca(NO3)2) addition can be used to control the release of phosphorus from sediments, however it can also cause an increase in the concentration of nitrate‑nitrogen (NO3−-N) in the water column. The risk of NO3−-N release from the Ca(NO3)2-injected sediments may be reduced by the placement of the anion exchange resin (AER) capping layer. In this study, the effectiveness of the combined use of Ca(NO3)2addition and AER capping to prevent the liberation of phosphorus from sediments was investigated, and the reduction of the risk of NO3−-N released from the Ca(NO3)2-injected sediment by the AER capping was also evaluated. The combined application of Ca(NO3)2addition and AER capping could tremendously reduce the amount of soluble reactive phosphorus (SR-P) in the overlying water, with SR-P reduction rates of 75.9–98.7%. Furthermore, it could cut down the contents of high-resolution diffusive gradients in thin films (DGT)-labile phosphorus in the sediments, resulting in the formation of phosphorus static layer in the upper sediments. The combined treatment using Ca(NO3)2and AER had a relatively small effect on the contents of mobile phosphorus in the sediments, but it could greatly increase the amount of residual phosphorus in the top 30 mm sediments (increased by 27.7–42.9%). The amount of NO3−-N in the overlying water under the action of the combined treatment method using Ca(NO3)2and AER was much lower than that under the action of the single Ca(NO3)2treatment during the early stage of sediment remediation. In conclusion, the combined use of Ca(NO3)2addition and AER capping is a more promising strategy for the control of sedimentary phosphorus release than the single use of Ca(NO3)2addition from the point of view of both the control efficiency of P release from sediments and the releasing risk of the added nitrate.