Yao Cheng, Che Feifei, Jiang Xia, Wu Zhihao, Chen Junyi, Wang Kun
National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing, 100012, China; College of Water Sciences, Beijing Normal University, Beijing, 100875, China.
National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environmental Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Anwai, Beiyuan, Beijing, 100012, China.
Chemosphere. 2021 Mar;267:128913. doi: 10.1016/j.chemosphere.2020.128913. Epub 2020 Nov 19.
Antimony is a priority environmental contaminant. Increasing attention is being paid to the behaviors and mobilities of the various Sb species in the environment. Sb speciation in the environment and the mobilities of Sb species at mining sites have been studied well, but Sb speciation and mobility in shallow lakes requires further study. Here, we studied Sb behavior in sediment of a shallow lake in the plain rivers network in Taihu Basin that suffers continual Sb inputs from textile plants. The diffusive gradients in thin films techniques (DGT) made of zirconium oxide based binding resin gel (ZrO-Chelex), agarose diffusive gel and polyvinylidene fluoride filter were deployed in water and sediment to obtain a high-resolution record in situ. The results indicated that (1) pollutants released by textile plants caused relatively high Sb(Ⅲ), Sb(Ⅴ) and organoantimony concentrations in the eutrophic shallow lake, (2) Sb was seldomly mobile in the oxic layer where Sb(Ⅲ) was sorbed on Fe(Ⅲ) oxides and gradually formed Fe-Sb complexes in the sediment, but in the anoxic environment (oxidation-reduction potential: 366 - -344 mv) Sb(V), Fe(Ⅱ) and P (V) were simultaneously released to resupply the porewater, (3) the release of Sb from solid phase is decided by the redox condition, and the rate of release is dependent on the labile Sb content of the sediment. The mobility of Sb should be given sufficient attention when the potential ecological risk of metal(loid)s in shallow lakes and wetlands sediment are evaluated.
锑是一种重点环境污染物。人们越来越关注环境中各种锑物种的行为和迁移性。环境中的锑形态以及矿区锑物种的迁移性已得到充分研究，但浅水湖泊中的锑形态和迁移性仍需进一步研究。在此，我们研究了太湖流域平原河网区一个受纺织厂持续锑输入影响的浅水湖泊沉积物中的锑行为。将由基于氧化锆的结合树脂凝胶（ZrO - Chelex）、琼脂糖扩散凝胶和聚偏二氟乙烯滤膜制成的薄膜扩散梯度技术（DGT）部署在水和沉积物中，以原位获取高分辨率记录。结果表明：（1）纺织厂排放的污染物导致该富营养化浅水湖泊中锑（Ⅲ）、锑（Ⅴ）和有机锑浓度相对较高；（2）锑在有氧层中很少迁移，在该层中锑（Ⅲ）吸附在铁（Ⅲ）氧化物上，并在沉积物中逐渐形成铁 - 锑络合物，但在缺氧环境（氧化还原电位：−366～−−344 mV）中，锑（Ⅴ）、铁（Ⅱ）和磷（Ⅴ）会同时释放以补充孔隙水；（3）固相锑的释放取决于氧化还原条件，释放速率取决于沉积物中不稳定锑的含量。在评估浅水湖泊和湿地沉积物中金属（类金属）的潜在生态风险时，应充分关注锑的迁移性。
