活性污泥水热碳化法制备磁性炭及对水体Cd^2+及Pb^2+的去除  

REMOVAL OF CADMIUM AND LEAD IN WATER BY MAGNETIC CARBON PREPARED FROM ACTIVATED SLUDGE WITH HYDROTHERMAL CARBONIZATION

作　　者：袁健 钱雅洁 薛罡[1] 张权 李前 刘自豪 李贤英[1] YUAN Jian;QIAN Ya-jie;XUE Gang;ZHANG Quan;LI Qian;LIU Zi-hao;LI Xian-ying(College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620

出　　处：《环境工程》2020年第2期55-62,共8页Environmental Engineering

摘　　要：以含有FeSO4的活性污泥为原料,采用水热碳化法,在220℃,4 h条件下,制备得到磁性炭(Fe-SSBC),并实现污泥减量。以Cd^2+和Pb^2+为模型污染物,探究了Fe-SSBC的投加量、起始酸碱度对Cd^2+和Pb^2+吸附的影响以及吸附机理。采用元素分析(EA)、X射线能谱分析(EDS)、傅里叶红外光谱分析(FTIR)、比表面积(BET)、X射线光电子能谱分析(XPS)、磁滞回线对样品进行表征。研究结果表明:在投加量为0. 2 g,pH为5的条件下,Fe-SSBC对Cd^2+的吸附效果最好,在10 h后去除率接近100%;投加量为0. 3 g,pH为6时,对Pb^2+的吸附效果最佳,在8. 5 h后Pb^2+去除率接近100%。Fe-SSBC对Cd^2+和Pb^2+的吸附动力学拟合结果更符合准二级动力学模型,Langmuir吸附等温线模型能够更好地反映Cd^2+和Pb^2+在Fe-SSBC上的单分子层吸附,化学吸附为控制吸附过程,同时存在物理吸附。制备磁性炭在实现污泥减量的同时,具有有效去除水中Cd^2+和Pb^2+的作用。Magnetic biochar (Fe-SSBC) was prepared from activated sludge containing ferrous sulfate by hydrothermal carbonization at 220 ℃ for 4 h,achieving sludge reduction at the same time. Using Cd^2+ and Pb^2+ as the model pollutants,the effect of the Fe-SSBC dosage and the initial pH on the adsorption of Cd^2+ and Pb^2+ were studied,then the adsorption mechanism was investigated by adsorption kinetics and adsorption isotherm experiments. The samples were characterized by elemental analysis (EA),X ray spectroscopy (EDS),Fourier transform infrared spectroscopy (FTIR),specific surface area (BET),X ray photoelectron spectroscopy (XPS) and hysteresis loop. The results showed that optimal condition for the best Cd^2+ adsorption by Fe-SSBC was dosage of 0. 2 g under pH = 5,after 10 h,and the removal rate was close to 100%;while that for Pb^2+ adsorption was dosage of 0. 3 g under pH = 6,after 8. 5 h,and the removal rate was close to 100%. The adsorption kinetics of Cd^2+ and Pb^2+ by Fe-SSBC fitted the second-order kinetic model. The adsorption isotherm model of Langmuir could better fit the monolayer adsorption of Cd^2+ and Pb^2+ on Fe-SSBC. Chemisorption controlled the rate of adsorption process,and there was physical adsorption at the same time. In this study,sludge reduction was achieved by hydrothermal carbonization,meanwhile,a adsorbent was prepared to remove Cd^2+ and Pb^2+ effectively from water.

关 键 词：磁性生物炭 CD^2+ PB^2+ 吸附 水处理 

分 类 号：X703[环境科学与工程—环境工程]