基于响应面法的尾矿重金属离子溶出研究

Leaching of Heavy Metal Ions from Tailings Based on Response Surface Method

随着环境或条件的改变,尾矿中的重金属元素会缓慢溶出至尾矿库地下水中,大量的重金属的溶出会对土壤以及地下水环境造成危害.本文考虑了影响尾矿重金属溶出的3个关键因素:降雨量、雨水酸碱度以及尾矿的粒径组成,研究了3种影响因素对尾矿中重金属离子溶出的影响作用,并采用响应面法探究了3种影响因素之间的交互作用关系及影响程度.进行了单原因静态淋溶实验,分别得出固液比、淋溶液pH值及尾矿粒径3种影响因素对尾矿中铜离子溶出的影响规律;依据Box Benhnken中心组合试验方法,在单原因试验的基础上进行响应面试验,试验数据通过Design-Expert 13软件进行拟合分析.试验表明在静态淋溶试验情况下,3种影响因素对铜离子的溶出影响主次顺序为:淋溶液pH值>固液比>尾矿粒径;利用响应面法拟合尾矿中铜离子溶出的回归模型适应性较好;淋溶液pH值与固液比和尾矿粒径之间存在显著的交互作用.本文将响应面分析方法引入到尾矿重金属溶出的研究中,丰富了该领域的研究方法,为防治土壤及地下水污染提供了理论依据.

With changes in the environment or conditions,heavy metal elements in tailings slowly leach into the groundwater in tailings ponds,and the leaching of a large amount of heavy metals can cause harm to the soil and groundwater environment.This study considers three key factors affecting the leaching of heavy metals in tailings:rainfall,acidity and alkalinity of rainwater,and particle size composition of tailings.It investigates the effects of these three influencing factors on the leaching of heavy metal ions in tailings and uses response surface methodology to explore the interaction relationships and degrees of influence among these three influencing factors.(1)Single-factor static leaching experiments were conducted to determine the influence of three factors,namely,solid-liquid ratio,leachate pH,and tailings particle size,on the leaching of copper ions in tailings.(2)Based on the Box Behnken central composite experimental method,response surface experiments were conducted on the basis of single-factor experiments,and the experimental data were analyzed by Design-Expert 13 software.The experiments showed that under the conditions of static leaching experiments,the primary and secondary effects of the three influencing factors on the leaching of copper ions were as follows:leachate pH>solid-liquid ratio>tailings particle size.The regression model for the leaching of copper ions in tailings fitted using response surface methodology was found to be well-adaptive,and there was a significant interaction between leachate pH and solid-liquid ratio as well as tailings particle size.This paper introduces response surface analysis into the study of heavy metal leaching in tailings,enriching the research methods in this field and providing a theoretical basis for the prevention and control of soil and groundwater pollution.