外源Ca2+对两种产脲酶细菌修复Cd-As复合污染水稻土的影响
Effect of Exogenous Ca2+ on Remediation of Cd-As Co-contaminated Paddy Soil by Two Urease-producing Bacteria
王金坪 1费藏乐 1邵梦迪 1杨润 1罗燕 1黄金富 1蔡倩 1伍钧 1徐敏1
作者信息
- 1. 四川农业大学环境学院,成都 611130
- 折叠
摘要
微生物诱导碳酸盐沉淀(Microbially induced carbonate precipitation,MICP)技术已被广泛应用于土壤重金属污染修复.为促进MICP过程,提高土壤修复效果,以Cd-As复合污染的水稻土为研究对象,利用巴氏八叠球菌(Octococcuspasteurii)和蜡样芽孢杆菌(Bacillus cereus)两种产脲酶细菌,分析比较了外源添加氯化钙(CaCl2)对两种菌株固定土壤中Cd、As效果的影响,并对修复后土壤理化性质、酶活性及微生物多样性的变化进行了检测.结果表明:两种菌株均能固定土壤Cd、As,其中,蜡样芽孢杆菌对土壤Cd、As的固定效果更佳,与巴氏八叠球菌处理相比,蜡样芽孢杆菌处理下土壤有效态Cd、As含量分别降低了 16.7％、11.1％;添加外源Ca2+后,在两种细菌处理下有效态Cd、As含量均发生显著变化,分别降低了 17.3％～22.2％、16.8％～26.7％,可见Ca2+的添加能有效促进MICP过程,促进对Cd、As的固定.此外,与未添加 Ca2+处理相比,添加Ca2+后,两种细菌处理下显著提高了土壤脲酶活性(52.6％～113.3％)、蔗糖酶活性(13.1％～28.9％)、碱解氮含量(3.4％～25.5％)、速效钾含量(2.1％～34.1％)以及微生物多样性,表明外源Ca2+可有效提高土壤肥力及土壤生态功能.综上,基于MICP作用,可通过添加外源Ca2+来增强产脲酶细菌对Cd-As复合污染土壤的修复效果,其中,蜡样芽孢杆菌修复效果更佳.
Abstract
Microbial-induced carbonate precipitation(MICP)has been widely used in the remediation of heavy metal contaminated soil.Two urease-producing bacteria,Octococcus pasteurii and Bacillus cereus,with or without exogenous Ca2+were introduced to Cd-As co-contaminated paddy soil in order to optimize the process of MICP and improve remediation efficiency.The impact of exogenous CaCl2 on the efficacy of Cd and As remediation in the soil under two strains treatments,as well as the changes of soil properties,enzyme activities and microbial diversity after remediation were studied.Results showed that two strains were able to immobilize Cd and As in soil,compared with Octococcus pasteurii,Bacillus cereus reduced available Cd and As contents by 16.7％and 11.1％,respectively.The addition of exogenous Ca2+reduced available Cd and As by 17.3％-22.2％and 16.8％-26.7％in both bacterial treatments,respectively,indicating that the addition of Ca2+accelerated MICP process and immobilized Cd and As.Compared with the treatment without Ca2+,the addition of Ca2+significantly increased soil urease(52.6％-113.3％),sucrase activity(13.1％-28.9％),alkaline hydrolysis nitrogen(3.4％-25.5％),available potassium(2.1％-34.1％)and microbial diversities in both bacterial treated soils,implying that the addition of exogenous Ca2+effectively enhanced soil fertility and soil ecological functions.In conclusion,the remediation efficiency of Cd-As co-contaminated soil by urease producing bacteria can be improved by the addition of Ca2+,with Bacillus cereus offering a higher efficiency for reducing the phytoavailability of heavy metals in soil.
关键词
微生物诱导碳酸盐沉淀(MICP)/外源Ca2+/产脲酶细菌/土壤修复Key words
Microbial induced carbonate precipitation/Ca2+from exogenous sources/Urease-producing bacteria/Soil remediation引用本文复制引用
基金项目
国家自然科学基金项目(42107017)
成都市科技项目(2020-YF09-00023-SN)
成都市科技项目(2020-YF09-00012-SN)
大学生创新训练计划项目资助()
出版年
2024
国家科技期刊平台
NSTL
万方数据