Long-term effectiveness of sediment dredging on controlling the contamination of arsenic, selenium, and antimony.
Long-term effectiveness of sediment dredging on controlling the contamination of arsenic, selenium, and antimony.
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DOI：
10.1016/j.envpol.2018.11.050
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发表时间：
2019-02
影响因子：
8.9
通讯作者：
Qin Sun;S. Ding;Musong Chen;Shuaishuai Gao;G. Lu;Yuexia Wu;Mengdan Gong;Dan Wang;Yan Wang
中科院分区：
文献类型：
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作者：
Qin Sun;S. Ding;Musong Chen;Shuaishuai Gao;G. Lu;Yuexia Wu;Mengdan Gong;Dan Wang;Yan Wang
本研究评估了疏浚在控制沉积物中砷（As）、硒（Se）和锑（Sb）污染方面的有效性，通过检查疏浚完成六年后沉积物中的污染物浓度。采用高分辨率薄膜扩散梯度（DGT）和透析（HR-Peeper）技术分别监测沉积物中DGT不稳定类金属和可溶性类金属的浓度。结果表明，疏浚措施仅在4月、7月和1月有效地修复了沉积物中的类金属污染。与未疏浚沉积物相比，疏浚沉积物中可溶性和DGT不稳定As、Se和Sb的浓度分别平均降低42%、52%、43%（可溶性）和54%、50%、53% （DGT）。疏浚的有效性主要是由于类金属从不稳定组分转变为惰性组分，这增加了沉积物保留类金属的能力，并且减缓了从可用固体池中补充类金属的速度。相比之下，疏浚的负面影响在10月份可以忽略不计，在疏浚的沉积物中，可溶性和不稳定的类金属浓度甚至增加了。这主要是由于藻类降解释放的类金属可能抵消了疏浚效果。
This study assessed the effectiveness of dredging in controlling arsenic (As), selenium (Se), and antimony (Sb) contamination in sediments, by examining contaminant concentrations in sediments six years after dredging was completed. High-resolution diffusive gradients in thin films (DGT) and dialysis (HR-Peeper) techniques were used to monitor the concentrations of DGT-labile metalloids and soluble metalloids in sediments, respectively. Results revealed that dredging effectively remediated metalloid contamination in sediments only in April, July and/or January. Compared to non-dredged sediments, the concentrations of soluble and DGT-labile As, Se, and Sb in dredged sediments decreased on average by 42%, 52%, and 43% (soluble), and 54%, 50%, and 53% (DGT), respectively. The effectiveness of the dredging was primarily due to the transformation of metalloids from labile to inert fractions, which increased the ability of the sediments to retain the metalloids, and the slowed rate of resupplied metalloids from available solid pools. In contrast, negligible/negative effects of dredging were seen in October, and the concentrations of soluble and DGT-labile metalloids even increased in some profiles of dredged sediments. This was mainly caused by a release of the metalloids from algal degradation, which may offset the dredging effectiveness.