改性生物炭对Cd污染农田土壤的钝化修复机制及其对土壤细菌群落的影响  

Remediation Mechanism of Chitosan-modified Biochar on Cd-contaminated Farmland Soil and Its Effect on Bacterial Community

作　　者：姜凌[1,2,3] 岳小琼 安靖玥 张思怡 孙佳园 李兆和 柴丽红 JIANG Ling;YUE Xiao-qiong;AN Jing-yue;ZHANG Si-yi;SUN Jia-yuan;LI Zhao-he;CHAI Li-hong(School of Water and Environment,Chang'an University,Xi'an 710054,China;Key Laboratory of Subsurface Hydrology and Ecological Effect in Arid Region of the Ministry of Education,Chang'an University,Xi'an 710054,China;Key Laboratory of Eco-hydrology and Water Security in Arid and Semi-arid Regions of Ministry of Water Resources,Chang'an University,Xi'an 710054,China)

机构地区：[1]长安大学水利与环境学院,西安710054 [2]旱区地下水文与生态效应教育部重点实验室,西安710054 [3]水利部旱区生态水文与水安全重点实验室,西安710054

出　　处：《环境科学》2024年第9期5557-5569,共13页Environmental Science

基　　金：中国工程院咨询研究项目(2019-RC-4);国家自然科学基金项目(42077370);大学生创新创业训练项目(S202310710061)。

摘　　要：为探究壳聚糖改性生物炭(钝化剂)对Cd污染农田土壤的钝化修复机制,通过盆栽试验,研究了钝化剂对土壤理化性质、黑麦草生物量、土壤酶活性及细菌群落结构和多样性的影响.结果表明,当钝化剂施用量从0.5%增加到3%时,土壤有效态Cd含量较对照显著降低,黑麦草地上和地下部分生物量分别较对照增加了1.08~1.56倍和1.00~1.68倍,富集和运转系数分别降低了6.15%~30.00%和10.42%~31.25%.相关分析结果表明,土壤pH、CEC、SOM、AN、AP和AK与DTPA-Cd之间呈显著负相关关系,表明钝化剂的施加通过改变土壤理化性质,促进了对土壤中Cd的钝化.高通量测序结果显示,钝化剂的施加改变了土壤细菌群落结构和多样性,表现为α多样性的显著下降,不同处理组间菌群明显分离,鞘氨醇单胞菌属(Sphingomonas)和芽球菌属(Blastococcus)等有益菌群相对丰度增加.土壤脲酶和纤维素酶活性增加,蔗糖酶和过氧化氢酶活性降低.研究结果为生物炭改性材料在Cd污染农田土壤修复中的应用提供理论依据和技术参考.To explore the remediation mechanism of chitosan-modified biochar(passivator)on Cd-contaminated farmland soil,pot experiments were conducted to determine the effects of passivator on soil physical and chemical properties,ryegrass biomass,enzyme activity,and the response of soil bacterial diversity and structure.The results showed that when the amount of passivating agent was increased from 0.5%to 3%,the content of available Cd in soil was significantly decreased compared with that in the control,and the aboveground and subsurface biomass of ryegrass was increased by 1.08-1.56 times and 1.00-1.68 times,respectively.The enrichment and running coefficients were reduced by 6.15%-30.00%and 10.42%-31.25%,respectively.The correlation analysis results showed that soil pH,CEC,SOM,AN,AP,and AK were significantly negatively correlated with DTPACd,indicating that the application of a passivating agent promoted the passivation of Cd in soil by changing the physical and chemical properties of soil.High-throughput sequencing results showed that the application of the inactivation agent changed the structure and diversity of the soil bacterial community,which was manifested as a significant decrease inαdiversity,significant isolation of bacteria between different treatment groups,and an increase in the relative abundance of beneficial bacteria such as Sphingomonas and Blastococcus.Moreover,the activities of soil urease and cellulase increased,whereas the activities of sucrase and catalase decreased with the addition of a passivator.This study provides a theoretical basis and technical reference for the application of modified biochar in the remediation of Cd-contaminated farmland soil.

关 键 词：生物炭 细菌群落 酶活性 CD污染土壤 钝化修复 

分 类 号：X171.5[环境科学与工程—环境科学]