场地铬污染的微生物治理及资源化实验  

Microbial Remediation and Resource Utilization for Chromium Pollution in Sites

作　　者：化天赐 李艳[1] 黎晏彰 鲁安怀[1] 丁竑瑞[1] 王长秋[1] 姬翔 HUA Tianci;LI Yan;LI Yanzhang;LU Anhuai;DING Hongrui;WANG Changqiu;JI Xiang(Key Laboratory of Orogenic Belts and Crustal Evolution,Ministry of Education,Beijing Key Laboratory of Mineral Environmental Function,School of Earth and Space Sciences,Peking University,Beijing 100091,China)

机构地区：[1]北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室,矿物环境功能北京市重点实验室,北京100091

出　　处：《硅酸盐学报》2024年第10期3115-3121,共7页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金项目(92351302);国家重点研发计划项目(2019YFC1805900)。

摘　　要：中国是世界最大的铬资源消耗和铬污染排放国,每年产生万吨级的高毒性六价铬铬渣。现有修复技术存在易氧化“返黄”、含铁添加剂污染等难题,无法实现铬污染的长效治理与资源化再利用。本工作对实际铬污染场地土壤开展了碱性条件下的微生物矿化实验,探讨了矿化产物的稳定性、可回收性与反应机理。结果表明,该方法能高效还原铬渣中的六价铬和三价铁产生含三价铬的矿化物。与空气充分接触长达60 d后,矿化产物仍未出现再氧化和再分解等现象,且具有弱磁性,具备磁选回收潜力。本工作为解决场地铬污染与铬资源回收再利用问题提供了一种低成本、高效率的原位、长效治理方案。Introduction In China,thousands of tons of highly toxic hexavalent Cr slags are produced annually.The existing remediation technologies face challenges due to the facile oxidation,“re-yellowing”effects,and contamination from iron additives,hindering the achievement of sustained governance and resource recycling for Cr pollution.This study conducted microbial mineralization experiments on soil at actual Cr-contaminated sites,delving into the stability,recyclability,and reaction mechanisms of mineralization products.The results indicate that this method can efficiently reduce Cr6+and Fe3+in Cr slag to form precipitates.After 60 d extensive air exposure,the mineralized products exhibited little reoxidation or re-decomposition,and demonstrated weak magnetism,indicating a potential for recovery by magnetic separation.This paper was to investigate a low-cost,efficient in-situ,and long-term governance solution for treatment of Cr pollution on-site and facilitation of the recovery and reuse of Cr resources.Methods Cr-contaminated soil samples were collected in Henan province,China.The pH value,total Cr,and total Fe concentrations of the soil were measured.Shewanella oneidensis MR-1(S.MR-1)was cultured and acclimated to high concentrations of Cr6+and alkaline conditions to enhance its reduction capabilities.In the microbial reduction experiments,S.MR-1 was added into Cr-contaminated soil at different concentrations of Cr6+,Cr3+,and Fe^(2+).The microbial morphology and surface elemental composition of the samples were determined by scanning electron microscopy with energy dispersive X-ray spectroscopy(SEM-EDS).The microstructure of the samples was analyzed by transmission electron microscopy with energy dispersive X-ray spectroscopy(TEM-EDS).The concentrations of Cr6+and Fe^(2+)were measured by ultraviolet-visible spectrophotometry(UV-Vis).The magnetic properties of the eaction products were characterized by vibrating sample Magnetometry(VSM).The Cr valence states before and after remediation were analyzed by X-ray pho

关 键 词：铬污染 微生物 生物矿化 长期稳定 资源回收 

分 类 号：X53[环境科学与工程—环境工程] X17