Effects of Operation Variables and Electrokinetic

Authors: Xinyu Mao Fengxiang X Han Xiaohou Shao Zikri Arslan Jacqueline McComb Tingting Chang Kai Guo Ahmet Celik

Publish Date: 2016/12/08

Volume: 228, Issue: 1, Pages: 15-

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Abstract

The operation variables and electrokinetic field EKF were investigated to enhance the remediation of arsenic As and cesium Cscontaminated soils with soil washing Extractant types concentrations liquid/solid L/S ratios solution pH values washing temperatures and agitation modes were important criteria to determine the efficiency of soil washing The KH2PO4 was proved to be a suitable alternative to Na2EDTA in extracting As and Cs from contaminated soils A 2h washing with KH2PO4 at concentration of 001 M and L/S ratio of 20 mL g−1 showed the most efficient washing performance In addition the lower solution pH higher temperature and ultrasound also favored soil washing of As and Cs with KH2PO4 The EKF greatly enhanced metals extraction with soil washing It offered acidic soil environment around the anode areas for the release of soluble Cs from its soil solidphase components before soil washing Moreover the alkalization around the cathode areas also benefited the desorption of stable As since labile As were mainly presented in anionic forms The effect of CA for neutralizing OH− was proved to be limited while the reversed subsequent EKF process effectively alleviated Cs precipitation generated during the initial EKF process It also effectively restored soil pH altered by the initial EKF The overall EKF 4 V cm−1 enhanced removal efficiency of As and Cs with soil washing from the anode area was 37 and 31 respectively Higher removal of As 52 was obtained in the cathode area Moreover the reversed EKF resulted in another 28 removal of Cs in the initial cathode area which showed the capacity of EKF on continuous soil metal remediationThis study was supported by US Nuclear Regulatory Commission NRCHQ8415G0042 and NRC–HQ12G380038 and US Department of Commerce NOAA NA11SEC4810001003499 Mr Mao was also supported by the Fundamental Research Funds for the Central Universities 2016B04314 the Special Fund for Hydroscientific Research in the Public Interest 201301017 the Fundamental Research Fund for the Central Universities 2014B04814 and 2015B05814 the National Natural Science Foundation of China 51509068 the Jiangsu Planned Projects for Postdoctoral Research Funds 1501043A and the China Postdoctoral Science Foundation 2015M581716

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