电絮凝除铊工艺的响应曲面优化  

Optimization of Electrocoagulation Process for Thallium Removal from Aqueous Solutions by Response Surface Methodology

作　　者：付向辉 张立刚[2] 李立[2] 杨国超 Fu Xianghui;Zhang Ligang;Li Li;Yang Guochao(School of Metallurgy and Environment,Central South University,Changsha 410083,China;Changsha Research Institute of Mining and Metallurgy Co.,Ltd.,Changsha 410012,China)

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083 [2]长沙矿冶研究院有限责任公司,湖南长沙410012

出　　处：《稀有金属》2020年第5期530-539,共10页Chinese Journal of Rare Metals

基　　金：“十三五”国家重点研发计划重点专项项目(2016YF0304105-03);企业自主创新基金项目(2018HB-A5-01)资助。

摘　　要：铊(Tl)是一种剧毒的稀有金属元素。近年来,频发的铊污染及铊中毒事件引起了人们对铊污染控制的重视。铊在环境中的迁移性强,含Tl(I)废水是铊向环境进行迁移和释放的重要途径。以铁极板为牺牲阳极,利用曝气电絮凝工艺处理低浓度含Tl(I)废水(<200μg·L^-1)。通过探索性单因素实验,筛选出对Tl(I)去除率影响较为显著的影响因子。以初始pH值、处理时间和电流密度作为考察因子,Tl(I)去除率为响应值进行响应曲面优化,得到相应的二次响应曲面模型。以满足出水标准低于2μg·L^-1为目标,在处理效率最高(12 min)的情况下,最优运行条件为初始pH值10.82,电流密度14.61 mA·cm^-2,Tl(I)的实际去除率(99.23%),与模型预测值(99.09%)接近。验证实验表明,相同工艺条件下真实废水的Tl(I)去除率与模拟废水并无显著差异。能谱(EDS)分析显示铊被有效富集到了絮凝污泥中。电絮凝工艺处理效率高,污泥产生量少,是一种可对含Tl(I)废水进行深度处理的有效方法。Thallium(Tl)is a highly toxic rare metal.In recent years,the frequent occurrence of Tl pollution and Tl poisoning has aroused attention to the Tl pollution control.Tl has a strong mobility in the environment.Tl(I)containing wastewater is a primary way to migrate and release Tl to the environment.In this study,aeration electrocoagulation using iron electrode for removal Tl(I)from simulated and real wastewater contaminated with low concentration of Tl(I)(<200μg·L^-1)was investigated.The significant factors on Tl(I)removal efficiency were screened out through exploratory single factor experiments.Afterwards,a response surface methodology(RSM)named Box-Behnken was employed to establish quadratic response surface model,the effect of process parameters such as initial pH,treatment time and current density were optimized on the Tl(I)removal efficiency of simulated wastewater.Tl(I)removal efficiency(99.23%)under optimal conditions(initial pH=10.82,12 min and 14.61 mA·cm^-2)aimed to Tl(I)concentration of effluent less than 2μg·L^-1,was close to the predicted one by RSM model(99.09%).Validation experiments showed that the Tl(I)removal efficiency had no significant difference between the real and simulated wastewater under same process conditions.Energy dispersive spectrum(EDS)showed that Tl element was effectively enriched in the settled sludge.Electrocoagulation was a sustainable treatment technology with high efficiency and minimum sludge generation,which could be used for the advance treatment of low concentration Tl wastewater.

关 键 词：电絮凝 铊污染 废水 曝气 深度处理 响应曲面法 

分 类 号：X703.1[环境科学与工程—环境工程]