谭媛,黄超,王平,曾峤婧,沈璐,杨雄,郑小雨.嗜水气单胞菌强化老化纳米零价铁去除水中Cr(VI)[J].环境科学学报,2021,41(8):3211-3218
嗜水气单胞菌强化老化纳米零价铁去除水中Cr(VI)
- Activation of aged nano zero-valent iron by Aeromonas hydrophila to enhance the removal of Cr(VI) from aqueous solution
- 基金项目：国家自然科学基金（No.51809293）；国家重点研发计划（No.2016YFD0800805-4）；湖南省自然科学基金（No.2019JJ50989，2018JJ3886）；湖南省重点研发计划（No.2020SK2039）；中国博士后基金面上资助项目（No.2018M633004）；湖南省教育厅优秀青年基金（No.19B588）
- 谭媛
- 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
- 黄超
- 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
- 王平
- 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
- 曾峤婧
- 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
- 沈璐
- 中南林业科技大学环境科学与工程学院, 长沙 410004
- 杨雄
- 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
- 郑小雨
- 1. 中南林业科技大学环境科学与工程学院, 长沙 410004;2. 稻米品质安全控制湖南省工程实验室, 长沙 410004
- 摘要：基于老化对纳米零价铁（NZVI）去除水中Cr（VI）的不利影响，本研究考察了接种嗜水气单胞菌（Aeromonas hydrophila）强化老化NZVI对水中Cr（VI）的去除，并分析了溶解氧、温度、pH、Cr（VI）初始浓度对其去除Cr（VI）的影响，同时利用扫描电镜（SEM）、X射线光电子能谱（XPS）等分析了反应前后材料的形貌特征及Cr的价态变化.结果表明，接种嗜水气单胞菌能显著提高无氧条件下老化NZVI对Cr（VI）的去除效果，且在酸性条件和30~40 ℃条件下去除效果较好，可能是因为该条件下更有利于老化NZVI的腐蚀和微生物的生长，此外，Cr（VI）去除效率随Cr（VI）初始浓度升高而降低.在pH=6，温度为30 ℃，老化nZVI投加量为0.1 g·L-1，Cr（VI）初始浓度为50 mg·L-1的条件下反应24 h后，Cr（VI）的去除率可达到100%.XPS分析表明，反应后NZVI表面沉积的Cr主要以Cr（III）的形式存在，可能为Cr（OH）3沉淀或FexCr1-x（OH）3共沉淀物.动力学研究发现，Cr（VI）去除过程符合准二级动力学，去除机制为Cr（VI）的吸附、还原与共沉淀，其中以还原作用为主.
- Abstract：Based on the aging effects of nano zero-valent iron (NZVI) on Cr(VI) removal from aqueous solution, this study investigated the activation of aged nano zero-valent iron by Aeromonas hydrophila to enhance the removal of Cr(VI) from aqueous solution, and examined the effects of dissolved oxygen, temperature, pH, initial Cr(VI) concentration on Cr(VI) removal, and analyzed the morphological characteristics of the material as well as the valence change of the Cr before and after the reaction by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The results showed that inoculation of Aeromonas hydrophila significantly improved the performance of aged NZVI on Cr(VI) removal under anaerobic conditions, and the removal efficiency was significantly enhanced under acidic conditions and the temperature of 30 to 40 ℃, possibly because these conditions were more conducive for the corrosion of aged NZVI and the growth of the microorganism, and the removal efficiency of Cr(VI) decreased with the initial concentration of Cr(VI). The removal efficiency of 50 mg·L-1 Cr(VI) after 24 h reached 100% at the conditions of pH 6, aged NZVI dosage of 0.1 g·L-1 and 30 ℃. XPS analysis shows that Cr(III) was the main form deposited on the surface of NZVI after the reaction, which may be Cr(OH)3 or FexCr1-x(OH)3. The Cr(VI) removal process was found to follow the pseudo second-order kinetic model, and the removal mechanism involved adsorption, reduction and co-precipitation, which was dominated by reduction.
