pH值对锌离子污染高岭土压缩及离子扩散特性影响研究

发布时间：2018-06-06 05:29

本文选题：高岭土 + 污染土　；参考：《水文地质工程地质》2017年06期

【摘要】：为了研究不同酸碱环境下锌离子对饱和高岭土压缩特性影响,以及锌离子向其中扩散特性,利用室内人工配制的重塑土开展了一维固结试验和土柱扩散试验。试验结果表明,锌离子浓度不高于0.05 mol/L时,污染土的压缩指数变化不大,但氢氧化锌沉淀量的增加会导致高岭土的压缩性略有降低。高岭土处于碱性环境时,其上部自由溶液中锌离子浓度降低最快,中性环境次之,酸性环境时最慢。溶液电导率可间接反映出其中的溶解态锌离子浓度,高岭土处于中性和碱性环境时,土柱上部自由溶液的电导率与溶液中锌离子浓度呈正相关,而当高岭土处于酸性环境时,土柱上部自由溶液的电导率与溶液中锌离子浓度呈负相关,对于这种酸碱土体环境下的反常规律,在利用溶液电导率快速评价重金属离子浓度时需引起重视。
[Abstract]:In order to study the effect of zinc ions on the compressive properties of saturated kaolin and the diffusion characteristics of zinc ions in different acid-base environments, one-dimensional consolidation tests and soil column diffusion tests were carried out using artificial remolded soils in laboratory. The results show that the compression index of contaminated soils does not change much when the concentration of zinc ion is not higher than 0.05 mol / L, but the compressibility of kaolinite decreases slightly with the increase of zinc hydroxide precipitation. When kaolin is in alkaline environment, the concentration of zinc ion in the upper free solution decreases fastest, followed by neutral environment, and the slowest in acidic environment. When kaolin is in neutral and alkaline environment, the conductivity of free solution at the top of soil column is positively correlated with the concentration of zinc ion in solution, but when kaolin is in acidic environment, the conductivity of solution can reflect the concentration of dissolved zinc ion indirectly. The conductivity of the free solution in the upper soil column is negatively correlated with the concentration of zinc ions in the solution. Therefore, attention should be paid to the use of the conductivity of the solution to rapidly evaluate the concentration of heavy metal ions in this anomalous law of acid-base soil.
【作者单位】：东南大学交通学院岩土工程研究所;城市地下工程与环境安全江苏省重点实验室;
【基金】：国家自然科学基金项目资助(41672280,41272311,41330641)
【分类号】：TU411;X53

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