摘要
为了降低U(Ⅵ)在水中的溶解性,缩小铀污染的可迁移范围,将蒙脱石改造为铁氧化物/蒙脱石并与希瓦氏菌MR-1(Shewanella oneidensis MR-1)构成联合体系,以实现在厌氧条件下对U(Ⅵ)的生物还原。制备了铁氧化物/蒙脱石复合体并对其形貌结构进行了表征;分析了矿物-微生物联合还原体系中U(Ⅵ),Fe(Ⅱ)含量的变化和矿物-微生物-腐殖酸联合体系中U(Ⅵ),Fe(Ⅱ)含量的变化;讨论了矿物-微生物联合体系对U(Ⅵ)的生物还原过程及还原途径。结果表明:蒙脱石在合成为铁氧化物/蒙脱石后,其层状结构变化不大,但引入了含量不等的Fe,其中纤铁矿中引入的Fe原子含量最高(67.71%);在矿物-微生物联合体系中,纤铁矿/蒙脱石联合希瓦氏菌MR-1体系对U(Ⅵ)的还原能力最高,在铀浓度50 mg·L^(-1)处理组中的还原率为85.8%,Fe(Ⅱ)的含量与U(Ⅵ)浓度呈反比关系,在反应的0~3 h时迅速上升;在矿物-微生物-腐殖酸复合体系中,腐殖酸浓度对还原U(Ⅵ)的影响表现为“完全促进”“低促高抑”和“高促低抑”3种现象,对联合体系中的Fe(Ⅱ)的影响主要分为抑制和促进两种类型。铁氧化物/蒙脱石与希瓦氏菌MR-1构成的联合体系在厌氧条件下能够实现对U(Ⅵ)的生物还原。
In order to reduce the solubility of U(Ⅵ)in water and the migratory range of uranium pollution,montmorillonite was transformed into iron oxide/montmorillonite and formed a consortium with Shewanella oneidensis MR-1 to achieve bioreduction of U(Ⅵ)under anaerobic conditions.The iron oxide/montmorillonite composite was prepared and its morphology and structure were characterized.The changes in U(Ⅵ)and Fe(Ⅱ)contents in the mineral-microbe consortium and mineral-microbe-humic acid consortium were analyzed.The bioreduction process and pathway of U(Ⅵ)in the mineral-microbe consortium were discussed.The results show that after synthesizing montmorillonite into iron oxide/montmorillonite composite,the layer structure of montmorillonite has little change,but different amounts of Fe are introduced.And the highest content of Fe atoms is introduced by lepidocrocite(67.71%).In the mineral-microbe consortium,the lepidocrocite/montmorillonite consortium with Shewanella oneidensis MR-1 has the highest U(Ⅵ)reduction ability,and the reduction rate is 85.8%at a uranium concentration of 50 mg·L^(-1).The content of Fe(Ⅱ)is inversely proportional to the concentration of U(Ⅵ),and it rises rapidly from 0 to 3 hours of reaction.In the mineral-microbe-humic acid composite system,the effect of humic acid concentration on the reduction of U(Ⅵ)exhibits three phenomena:“complete promotion”“low promotion and high inhibition”and“high promotion and low inhibition”.The impact on Fe(Ⅱ)in the composite system is mainly divided into two types:inhibition and promotion.The consortium of iron oxide/montmorillonite and Shewanella oneidensis MR-1 can achieve the bioreduction of U(Ⅵ)under anaerobic conditions.
作者
谢龙悦
郑志勤
翟帆帆
胡璇
杜小波
马瑛
边亮
XIE Longyue;ZHENG Zhiqin;ZHAI Fanfan;HU Xuan;DU Xiaobo;MA Ying;BIAN Liang(School of Life Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;Key Laboratory of Medical Transformation of Nuclear Technology,NHC,Mianyang Central Hospital,Mianyang 621000,Sichuan,China;Fundamental Science on Nuclear Wastes and Environmental Safety Laboratory,Mianyang 621010,Sichuan,China;School of Environment and Resource,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China;State Key Laboratory of Environment-friendly Energy Materials,Mianyang 621010,Sichuan,China)
出处
《西南科技大学学报》
CAS
2023年第3期48-57,共10页
Journal of Southwest University of Science and Technology
基金
国家自然科学基金项目(42007281)
国家卫生健康委核技术医学转化重点实验室开放课题(2021HYX007)。
