College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation of Ministry of Education, Beijing Normal University, Beijing 100875, China.
College of Water Sciences, Beijing Normal University, Beijing 100875, China; Engineering Research Center of Groundwater Pollution Control and Remediation of Ministry of Education, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2022 Aug 25;836:155725. doi: 10.1016/j.scitotenv.2022.155725. Epub 2022 May 5.
Exploring the relationships between heavy metal release and salinity can help address the problems of combination of toxic heavy metals and salinization in contaminated soils. Therefore, in this study, the release characteristics of heavy metals (Cd, Cu and Zn) under different salt types and mass concentrations were investigated through batch desorption experiments. Spearman's correlation analysis was performed to assess the effects of typical physicochemical properties on metal release under salt stress. The results indicated that the types and concentration gradients of salt had notably different impacts on the release of different metals; specifically, there were significant impacts for Cd but slight impacts for Cu and Zn. MgCl and CaCl had more obvious promoting effects on Cd release, followed by a salt mixture and NaCl, and this pattern was similar for Zn release. Most salts could slightly restrain the release of Cu, except for MgCl and NaSO, which had slight promoting effects. Moreover, low levels of CaCl could effectively restrain the release of Cu. The results showed that the release capacities of metals followed the order of Cd > Cu > Zn, possibly attributed to the competitive adsorption among cations. Ferromanganese oxides in the soil favored the release of Cd and Zn under salt treatments, and redox potential was an important factor affecting Cu release. The results also suggested that the background values of metals could affect metal release, but the effects were varied under different salt treatments for Zn. The reason for this may be that the addition of different salts changed the effects of certain soil properties on the metal release. Overall, this study can serve as an important reference for controlling heavy metal pollution in soils in salinization and coastal areas.
探讨重金属释放与盐度之间的关系有助于解决污染土壤中有毒重金属与盐渍化结合的问题。因此，本研究通过批式解吸实验研究了不同盐类型和质量浓度下重金属（Cd、Cu 和 Zn）的释放特征。采用 Spearman 相关性分析评估了典型理化性质在盐胁迫下对金属释放的影响。结果表明，盐的类型和浓度梯度对不同金属的释放有显著不同的影响；具体而言，Cd 受到显著影响，Cu 和 Zn 受到轻微影响。MgCl 和 CaCl 对 Cd 释放具有更明显的促进作用，其次是盐混合物和 NaCl，Zn 释放也呈现出类似的模式。除了 MgCl 和 NaSO 具有轻微的促进作用外，大多数盐对 Cu 的释放有轻微的抑制作用。此外，低浓度的 CaCl 可以有效地抑制 Cu 的释放。结果表明，金属的释放能力顺序为 Cd > Cu > Zn，这可能归因于阳离子的竞争吸附。盐处理下土壤中的铁锰氧化物有利于 Cd 和 Zn 的释放，氧化还原电位是影响 Cu 释放的重要因素。结果还表明，金属的背景值会影响金属的释放，但在不同盐处理下对 Zn 的影响不同。原因可能是添加不同的盐改变了某些土壤性质对金属释放的影响。总的来说，本研究可为控制盐渍化和沿海地区土壤重金属污染提供重要参考。
