The coupling of sand with ZVI/oxidants achieved proportional and highly efficient removal of arsenic  

作　　者：Sana Ullah Xuejun Guo Xiaoyan Luo Xiangyuan Zhang Yameng Li Ziyu Liang 

机构地区：[1]State Key Laboratory of Environment Simulation,School of Environment,Beijing Normal University,Beijing 100875,China [2]Department of Environmental and Conservation Sciences,University of Swat,19200,Pakistan

出　　处：《Frontiers of Environmental Science & Engineering》2020年第6期29-39,共11页环境科学与工程前沿（英文）

基　　金：Authors greatly acknowledge the support from the National Natural Science Foundation of China(Grant No.21876011);National Key Research and Development Program of China(Grant No.2017YFA0605001);Fund for Innovative Research Group of the National Natural Science Foundation of China(Grant No.51721093).

摘　　要：The coupling of zero-valent iron(ZVI)with common oxidants has recently achieved very rapid and highly efficient removal of Heavy metals from wastewater.However,the uniform activation of ZVI throughout the column and the proportional removal of target contaminants are urgently required for the prevention of premature filter clogging and the extension of the effective column operational time.In this study,we successfully achieved this objective by simply doping granular sand with ZVI at appropriate weight ratios.When pure ZVI packed column was spiked with oxidants,the majority of As trapping occurred between the column inlet and the first sampling point.In a packed column with a 1:20 mixture of ZVI and sand,the average As removal efficiency was 36(1st),13.1(2nd),18.5(3rd),19.2(4th)and 5.9%(5th outlet).The overall arsenic removal performance of the composite filling system of ZVI/sand was equally as efficient as that of the previous pure ZVI-packed system.Moreover,the leaching of Fe was significantly reduced with an increased sand ratio,resulting in clearer water with less turbidity.The results of X-ray photoelectron spectroscopy(XPS)demonstrated that more than 54%of the arsenic was reduced to As(III).X-ray diffraction(XRD)and scanning electron microscopy(SEM)confirmed the extensive corrosion of the ZVI surface,which resulted in various species of iron oxyhydroxides responsible for the highly efficient sequester of arsenic through reduction,adsorption,and coprecipitation.

关 键 词：ARSENIC ZVI Sand OXIDANTS Fixed-bed Column REMOVAL 

分 类 号：X703[环境科学与工程—环境工程]