Effect of water quality on mercury toxicity to Photobacterium phosphoreum: Model development and its application in natural waters
Effect of water quality on mercury toxicity to Photobacterium phosphoreum: Model development and its application in natural waters
复制标题
水质对磷光杆菌汞毒性的影响：模型开发及其在天然水中的应用
DOI：
10.1016/j.ecoenv.2014.03.029
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发表时间：
2014
影响因子：
6.8
通讯作者：
Wang Zunyao
中科院分区：
文献类型：
--
作者：
Wang Xinghao;Qu Ruijuan;Wei Zhongbo;Yang Xi;Wang Zunyao
汞（Hg）化合物是广泛分布的有毒环境和工业污染物，可能给水生生物的生长发育带来危险。使用化学平衡模型 Visual MINTEQ 计算了 3% NaCl 溶液中 Hg 的形态分布，结果表明，在 pH 值 5.0~9.0 范围内，Hg 主要与氯化物络合，HgCl42−、HgCl3− 和 HgCl2(aq) 的比例达到总 Hg 的 95%。然后，在标准化的 15 分钟急性毒性试验中，评估了阳离子（Ca2+、Mg2+、K+ 和 H+）、阴离子（HCO3−、NO3−、SO42− 和 HPO42−）和络合剂（乙二胺四乙酸 (EDTA) 和溶解有机物 (DOM)）对磷光杆菌汞毒性的影响。在 5.0-8.0 的测试 pH 范围内观察到 EC50 数据随着 pH 值的增加而显着增加 6.3 倍，这表明羟基和带负电的氯络合物之间可能存在竞争。相比之下，发现主要阳离子（Ca2+、Mg2+和K+）对Hg对P的毒性影响不大。磷。一个有趣的发现是，HPO42的添加显着增加了汞的毒性，这可能意味着磷酸盐的添加增加了可溶性汞-氯络合物的种类。在暴露水中添加络合剂（EDTA 和 DOM）可通过络合汞来增加汞的生物利用度。最后，开发了一个模型，该模型结合了 pH、HPO42−、HCO3−、SO42− 和 DOM 对汞毒性的影响，以预测磷的急性汞毒性。磷，这可能是为不同类型的水制定实际水质标准的有用工具。
Mercury (Hg) compounds are widely distributed toxic environmental and industrial pollutants and they may bring danger to growth and development of aquatic organisms. The distribution of Hg species in the 3 percent NaCl solution was calculated using the chemical equilibrium model Visual MINTEQ, which demonstrated that Hg was mainly complexed by chlorides in the pH range 5.0–9.0 and the proportions of HgCl42−, HgCl3−and HgCl2(aq) reached to 95 percent of total Hg. Then the effects of cations (Ca2+, Mg2+, K+and H+), anions (HCO3−, NO3−, SO42−and HPO42−) and complexing agents (ethylene diamine tetraacetic acid (EDTA) and dissolved organic matter (DOM)) on Hg toxicity to Photobacterium phosphoreum were evaluated in standardized 15 min acute toxicity tests. The significant increase of 6.3-fold in EC50data with increasing pH was observed over the tested pH range of 5.0–8.0, which suggested the possible competition between hydroxyl and the negatively charged chloro-complex. By contrast, it was found that major cations (Ca2+, Mg2+and K+) have little effect on Hg toxicity toP. phosphoreum. An interesting finding was that the addition of HPO42−significantly increased Hg toxicity, which may imply that the addition of phosphate increased the soluble Hg–chloro complex species. Additions of complexing agents (EDTA and DOM) into the exposure water increased Hg bioavailability via complexation of Hg. Finally, a model which incorporated the effect of pH, HPO42−, HCO3−, SO42−and DOM on Hg toxicity was developed to predict acute Hg toxicity forP. phosphoreum, which may be a useful tool in setting realistic water quality criteria for different types of water.