文献类型：期刊文献

英文题名：Simultaneous immobilization of arsenic, lead and cadmium by magnesium-aluminum modified biochar in mining soil

作者：Li, Qiannan[1];Liang, Weiyu[1];Liu, Fang[2];Wang, Gehui[1];Wan, Jiang[1];Zhang, Wei[1];Peng, Cheng[1];Yang, Jie[2]

机构：[1]East China Univ Sci & Technol, Sch Resource & Environm Engn, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China;[2]Shanghai Acad Environm Sci, State Environm Protect Engn Ctr Urban Soil Contam, Shanghai 200233, Peoples R China

年份：2022

卷号：310

外文期刊名：JOURNAL OF ENVIRONMENTAL MANAGEMENT

收录：;EI(收录号：20233214514411);WOS:【SCI-EXPANDED(收录号:WOS:000781102100007)】；

基金：This research was supported by the projects of the National Key Research and Development Program of China (2019YFC1805202, 2018YFC1800606); the National Natural Science Foundation of China (21737005, 41877124).

语种：英文

外文关键词：Heavy metals; Mg -Al modified biochar; Mining soil; Remediation mechanisms; Simultaneous immobilization

摘要：Owing to the human activities such as smelting and mining, arsenic (As), lead (Pb) and cadmium (Cd) seriously polluted the soil of non-ferrous metal mining areas, thus efficient methods for the simultaneous immobilization of the three heavy metals are urgently needed. In the present study, Mg-Al modified biochars (MABs) were synthesized through a simple one-pot pyrolysis method to immobilize the three heavy metals. According to the BET (Brunauer-Emmett-Teller) test method, MABs had larger specific surface areas than biochar. Compared to the materials obtained at 300 ? and 700 ?, MAB with a pyrolysis temperature of 500 ? (MAB 500) had a significant immobilization effect on As, Pb and Cd in the Gansu mining area. Compared with BC, the removal efficiencies of As, Pb and Cd increased from-62%, 17% and 5% to 52%, 100% and 66%, respectively. And the toxicity characteristic leaching procedure (TCLP) test showed that the leaching concentrations of the three heavy metals in the treated soil were all lower than the standard value. X-ray photoelectron spectroscopy and kinetic experiments showed that there were various mechanisms in the immobilization process of the three heavy metals, and the large specific surface area and the multi-Mg/Al-OH of MABs play an important role in this process. More charges were provided by larger specific surface for ion exchange with heavy metals. In addition, larger specific surface area also provided more adsorption sites. More complex sites were provided by Mg/Al-OH to form Mg/Al-O-M then immobilize the heavy metals. In summary, the immobilization mechanism may involve electrostatic attraction, precipitation/co-precipitation, and surface complexation.