【摘要】 为了探明土壤对酸性矿山废水中Cd的吸附机理，以湖南省攸县某矿区灌溉土壤为研究对象，模拟酸性矿山废水的化学特征，通过批试验，研究灌溉土壤中Cd的吸附特征，并对其影响因素进行了探究。结果表明，在酸性条件下（模拟灌溉水溶液pH=3.7）,灌溉土壤对Cd²⁺的吸附分为两个阶段，第一个阶段快速吸附阶段发生在试验的前60 min,之后转为缓慢吸附，其吸附动力学过程符合准二级动力学模型（r²=0.999 4）;Langmuir模型、Freundlich模型和Temkin模型均能较好地描述Cd²⁺在灌溉土壤上的吸附，但Langmuir模型（r²=0.992 5）可以更好地描述土壤对Cd²⁺的吸附，其所计算出的饱和吸附量为9.85 mg/kg;通过对热力学模型进行拟合，得出灌溉土壤对Cd²⁺的吸附为自发、放热、混乱度低的反应；随着溶液pH上升，灌溉土壤对Cd²⁺的吸附量逐渐增加，pH升至6.1时，其吸附量达到最高，为0.79 mg/kg;灌溉土壤对Cd²⁺的吸附量与与离子强度呈反比；土壤有机质可显著提高灌溉土壤对Cd²⁺的吸附能力，而Pb²⁺的存在抑制了灌溉土壤对Cd²⁺的吸附。该研究结果对矿山Cd污染治理具有重要的指导意义。更多还原

【Abstract】 In order to explore the adsorption mechanism of Cd which from acid mine wastewater by soil, this paper takes the irrigated soil of a mining area in Youxian County of Hunan Province as the research object, simulates the chemical characteristics of acid mine wastewater, studies the adsorption characteristics of Cd from irrigated soil and explores the influencing factors through batch experiments.The results showed that: under acidic conditions（the pH of the simulated solution is 3.7）,the Cd²⁺ adsorption onto irrigated soil took place in two stages: the fast rapid adsorption stage occurred in the first 60min of the experiment, and then turned to slow adsorption.The rate data are best described by the pseudo-second-order kinetic model（r²=0.999 4）.Cd²⁺adsorption can be better described by the Langmuir isotherm model（r²=0.992 5）,although Freundlich, Temkin isotherm models can also give a good fit for the adsorption of Cd²⁺ onto the irrigated soil, and the maximum adsorption amount of Cd²⁺was 9.85 mg/kg.By the thermodynamic model, it is concluded that the adsorption of Cd²⁺onto irrigated soil was a spontaneous, exothermic and low chaotic reaction.With the increase of pH,the adsorption amount of Cd²⁺ by irrigated soil increased gradually, and reached the highest value of 0.79 mg/kg when pH rose to 6.1.The adsorption amount of Cd²⁺ by irrigated soil was inversely proportional to the ionic strength.Soil organic matter significantly increased the adsorption amount of Cd²⁺ by irrigated soil, while the presence of Pb²⁺ inhibited the adsorption amount of Cd²⁺ by irrigated soil.The research results have important guiding significance for the treatment of mine Cd pollution.更多还原