期刊
CHEMICAL ENGINEERING JOURNAL
卷 421, 期 -, 页码 -出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.cej.2021.129683
关键词
Arsenic; Zero valent iron; Metal immobilization; Hydrothermal mineralization; Crystallization; Phase transformation
资金
- National Natural Science Foundation of China [21836002]
- National Key Research and Development Program of China [2019YFA0210401]
- Guangdong Special Support Program [2019TQ05L153]
- Guangdong Science and Technology Program [2020B121201003]
Arsenic-bearing lime-ferrate sludge (ABLFS) is a hazardous waste from nonferrous metallurgical industry, causing serious environmental pollution. A new method using zero valent iron (ZVI) and hydrothermal treatment effectively stabilized arsenic in ABLFS, converting it into a highly stable mineral form and reducing leachable arsenic concentration to far below regulatory levels. This study provides a promising treatment strategy for safe disposal of ABLFS.
Arsenic-bearing lime-ferrate sludge (ABLFS) is a common hazardous waste from nonferrous metallurgical industry. The leaching of arsenic from ABLFS during waste storage and disposal causes serious environmental pollution. In this study, a new method was developed to effectively stabilize arsenic in ABLFS by treating ABLFS with combined zero valent iron (ZVI) and hydrothermal treatment. The treatment converted the unstable arsenic adsorbed or complexed on ferrihydrite into well-crystallized lattice form in a highly stable natural mineral, Johnbaumite. When treated under the optimum conditions (ZVI dosage = 0.1 g/g-sludge, hydrothermal treatment at 150 degrees C for 12 h), the leachable arsenic concentration was decreased from 22.4 mg/L for untreated ABLFS to 0.015 mg/L, which is far below the Chinese regulatory level of 2.5 mg/L. XRD, FTIR, and TEM analyses were carried out to understand the phase evolution and the underlying arsenic stabilization mechanism. The results revealed three key steps: (i) ZVI-mediated reaction with arsenic-laden 2-line ferrihydrite (Fh) leading to the release of arsenate ions, (ii) hydrothermally facilitated phase transformation of gypsum causing the release of calcium ions, and (iii) hydrothermally enabled formation and crystal growth of Johnbaumite. This work provides a promising treatment strategy for the safe disposal of ABLFS.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据