生物炭固定化微生物对U、Cd污染土壤的原位钝化修复  

In situ remediation of U-and Cd-contaminated soils by immobilized microorganisms and biochar

作　　者：戚鑫[1] 陈晓明[1,2] 肖诗琦 张祥辉[1] 田甲[1] 勾佳磊 卓驰夫 罗学刚[1] QI Xin;CHEN Xiao-ming;XIAO Shi-qi;ZHANG Xiang-hui;TIAN Jia;GOU Jia-lei;ZHUO Chi-fu;LUO Xue-gang(College of Life Science and Engineering,Southwest University of Science and Technology,Mianyang 621010,China;Deibnse Key Labo-ratory,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学生命科学与工程学院,四川绵阳621010 [2]西南科技大学国防重点实验室,四川绵阳621010

出　　处：《农业环境科学学报》2018年第8期1683-1689,共7页Journal of Agro-Environment Science

基　　金：国家核设施退役及放射性废物治理科研重点项目(16ZG6101);国家重点基础研究发展计划项目(2014CB846003);四川省科技厅项目(18YYJC0927)~~

摘　　要：为考察固定化微生物对铀(U)、镉(Cd)污染土壤的钝化效果,研究筛选出对U、Cd都有较高去除率的微生物组合,以生物炭为固定化载体,通过吸附和包埋两种固定方法制作成复合钝化剂,探究施加两种复合钝化剂和单独施加生物炭3种处理对土壤理化性质和可提取态U、Cd的影响。研究结果表明:四种微生物组合对U、Cd都有去除作用,综合考虑枯草芽孢杆菌、柠檬酸杆菌和蜡样芽胞杆菌等比组合的去除率最优,用于进一步研究。各钝化处理后,土壤的pH值升高,且随着钝化剂添加量的增加,pH呈上升趋势。各钝化处理组中土壤阳离子交换量与有机质含量均有所升高,其中,生物炭处理组对土壤阳离子交换量的提高效果最为显著。3个处理组相比,生物炭处理组和吸附固定微生物生物炭处理组中有机质增加较包埋固定微生物生物炭处理组效果显著。各钝化处理后,土壤中可提取态的U、Cd含量均有所下降,且随着钝化时间的延长,可提取态的U、Cd含量持续降低。3种钝化剂的钝化效果有所差异,即吸附固定微生物生物炭处理组>生物炭处理组>包埋固定微生物生物炭处理组,随着添加量的增加,钝化效果显著。该研究结果表明,固定化微生物方法在修复土壤重金属污染方面有着很大的潜在应用价值。The objectives of the current study are to investigate the effects of immobilized microorganism technology on passivation of uranium（U）and cadmium（Cd）. For these effects, this study screened the mixture of certain proportions of three bacteria on U and Cd for high removal efficiency. In addition, three kinds of passivators, including（ⅰ）biochar,（ⅱ）bacterial mixture adsorbed fixation by biochar, and（ⅲ）embedded fixation with sodium alginate after biochar adsorption, were applied to assess the effects on soil physicochemical properties and extractable U and Cd. The results showed that U and Cd were effectively removed from aqueous solutions by four kinds of bacterial mixtures; particularly, a mixture of equal amounts of Bacillus subtilis, Citrobacter, and Bacillus cereus resulted in the best removal rate. Soil pH increased after passivation treatments. Moreover, with an increase in the amount of the passivator applied, the soil pH increased. Soil cation exchange capacity and organic matter content increased in the passivation treatments. In addition, soil cation exchange capacity was highest in the biochar treatment than that in other treatments. Soil organic matter content was significantly higher for the biochar treatment and adsorption fixation treatment than that in the embedding fixation treatment. Extractable U and Cd content in soils showed a steady decrease with an increase in passivation time in the passivation treatments. The effects were significantly different when the different passivation treatments were used, and they could be ordered as follows：Adsorption fixation treatmentbiochar treatmentembedding fixation treatment;moreover, as the amount of passivator increased, the passivation effects increased. The results show that the immobilized microorganism technology has potential applications in the remediation of heavy metal pollutants present in soil.

关 键 词：U、Cd污染 生物炭 固定化微生物 可提取态 

分 类 号：X53[环境科学与工程—环境工程]