Arsenic removal from contaminated soil using phosphoric acid and phosphate

作     者：ZENG Min LIAO Bohan LEI Ming ZHANG Yong ZENG Qingru OUYANG Bin 

作者机构：College of Resources and Environment Central South University of Forestry and Technology Changsha 410004 China. College of Biological Science and Technology Hunan Agricultural University Changsha 410128 China International College Central South University of Forestry and Technology Changsha 410004 China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2008年第20卷第1期

页      面：75-79页

核心收录：

学科分类：12[管理学] 1204[管理学-公共管理] 082803[工学-农业生物环境与能源工程] 08[工学] 0828[工学-农业工程] 120405[管理学-土地资源管理] 

基　　金：This work was supported by the National Natural Science Foundation of China(No.20677080 20477055) 

主　　题：arsenic (As) removal phosphoric acid (H3PO4), potassium dihydrogen phosphate (KH2PO4) chemical extraction 

摘      要：Laboratory batch experiments were conducted to study arsenic （As） removal from a naturally contaminated soil using phosphoric acid （H3PO4） and potassium dihydrogen phosphate （KHEPO4）. Both H3PO4 and KHEPO4 proved to reduce toxicity of the soil in terms of soil As content, attaining more than 20% As removal at a concentration of 200 mmol/L. At the same time, acidification of soil and dissolution of soil components （Ca, Mg, and Si） resulted from using these two extractants, especially H3PO4. The effectiveness of these two extractants could be attributed to the replacement of As by phosphate ions （PO4^3-）. The function of H3PO4 as an acid to dissolve soil components had little effects on As removal. KH2PO4 almost removed as much As as H3PO4, but it did not result in serious damage to soils, indicating that it was a more promising extractant. The results of a kinetic study showed that As removal reached equilibrium after incubation for 360 rain, but dissolution of soil components, especially Mg and Ca, was very rapid. Therefore dissolution of soil components would be inevitable if As was further removed. Elovich model best described the kinetic data of As removal among the four models used in the kinetic study.