欢迎访问《环境科学学报》编辑部网站！

快速检索			高级检索

Removal of cadmium in aquatic environment by sulfidated nanoscale zero-valent iron(S-nZVI)

梁莉
1. 华南理工大学环境与能源学院, 广州 510006;2. 华南理工大学工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006;3. 固体废物处理与资源化广东省环境保护重点实验室, 广州 510006

李筱琴
1. 华南理工大学环境与能源学院, 广州 510006;2. 华南理工大学工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006;3. 固体废物处理与资源化广东省环境保护重点实验室, 广州 510006

摘要：由于矿山开采、工业废水排放及农业施肥等人类活动，使得我国镉污染日益突出.本研究采用液相还原法制备硫化纳米零价铁（S-nZVI），研究其对Cd的去除行为.考察了不同硫化剂、合成方法、S/Fe比（物质的量比）及pH对Cd去除的影响，并采用扫描电子显微镜（SEM）、拉曼光谱（Raman）、X-射线衍射（XRD）等技术对反应前后的材料进行表征，结合批实验结果探讨Cd的去除机理.结果表明，采用一步法以硫化钠（Na₂S）为硫化剂合成的S-nZVI对Cd的去除效率远高于其它方法，去除容量可达385.6 mg·g^-1.反应120 min后，S-nZVI对Cd的去除率随S/Fe比的增加而升高，S-nZVI反应体系受pH影响较小.材料表征结果显示，S-nZVI颗粒由Fe⁰、Fe₃O₄、FeS组成，其中，FeS的含量随S/Fe比的升高而增加.S-nZVI对Cd的去除机理主要是Cd将FeS中的Fe置换，与S结合形成稳定的CdS.

Abstract：In China, cadmium pollution has become more and more severe due to human activities such as mining, industrial wastewater discharge, and agricultural fertilization. In this study, various sulfidated nanoscale zero-valent iron (S-nZVI) was synthesized and compared for the performance of Cd removal. The effects of sulfidation reagents, synthesis method, S/Fe molar ratio and pH on Cd removal efficiency were investigated. The removal mechanism of Cd was elucidated based on scanning electron microscopy (SEM), Raman spectroscopy (Raman), X-ray diffraction (XRD), and experimental results. The results showed that the removal efficiency of Cd by presynthesized S-nZVI with Na₂S as the sulfidation reagent was much higher than other methods, and the removal capacity reached up to 385.6 mg·g^-1. After reaction 120 min, the removal efficiency of Cd increased with the increase of S/Fe molar ratio. pH had little effect on the S-nZVI reaction with Cd. Characterization of S-nZVI showed that the particles were composed of Fe⁰, Fe₃O₄ and FeS. FeS increased with the increase of S/Fe molar ratio. The mechanism of the removal of Cd by S-nZVI was mainly via Cd displacement of Fe in FeS and form stable CdS.