pH influence on sorption characteristics of heavy metal in the vadose zone
pH influence on sorption characteristics of heavy metal in the vadose zone
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DOI：
10.1016/s0013-7952(00)00089-2
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发表时间：
2001-06-01
影响因子：
7.4
通讯作者：
Yong, RN
中科院分区：
文献类型：
--
作者：
Elzahabi, M;Yong, RN
吸附是模拟和预测重金属在不饱和粘土屏障中运动的重要过程。本实验研究了酸性范围内 pH 变化对非饱和土壤中铅、铜和锌等重金属吸附特性的影响。使用不同的重金属溶液，在不同 pH 值的不饱和伊利土上进行了一系列一维耦合溶质和水分浸出柱试验。测量不同时间段内体积含水量（VWC）随距离的变化，并分析液相和固相中重金属的浓度。确定了土壤中每一层污染物沿土柱的分配系数分布。柱浸试验的结果表明，重金属的吸附特性受许多因素控制，应考虑到，即 VWC、润湿时间、土壤 pH 值和进水重金属浓度。将 Kd 简化为常数，将 VWC 简化为线性函数，不能被认为是一个好的假设，并且可能导致对吸附现象的不正确评估，并在预测污染物通过非饱和土壤的迁移时产生严重错误。 (C) 2001 Elsevier Science B.V. 保留所有权利。
Sorption is an important process in the modelling and prediction of the movement of heavy metals in unsaturated clay barriers. This experimental study investigates the effect of pH changes in the acidic range on the sorption characteristics of heavy metals such as: lead, copper and zinc in an unsaturated soil. A series of one-dimensional coupled solute and moisture leaching column tests, using different heavy metal solutions, were conducted on an unsaturated illitic soil at varying pH values. Variations of volumetric water content (VWC) with distance were measured for different time durations, and concentrations of heavy metals in the liquid and solid phases were analysed. Partitioning coefficient profiles of contaminants along the soil column were determined for each individual layer in the soil.Results from column leaching tests showed that the sorption characteristics of heavy metals are controlled by many factors which should be taken into consideration, i.e. the VWC, time of wetting, soil pH, and the influent heavy metal concentrations. Simplification of Kd as a constant and of the VWC as a linear function cannot be considered a good assumption and may lead to an improper evaluation of the sorption phenomena and also to serious errors in predicting contaminant transport through unsaturated soils. (C) 2001 Elsevier Science B.V. All rights reserved.