摘要
为了探究锰改性生物炭(MBC)对砷-镉(As-Cd)复合污染土壤的修复效果和机制,采用室内培养试验,在微碱性As-Cd复合污染土壤中添加原始生物炭(BC)和MBC,研究其对土壤TCLP提取态As/Cd含量和As/Cd形态分布的影响,并进行土壤As/Cd生态风险评估。结果表明:改性后MBC的电荷零点升高且表面负载MnO_(2)。与不加生物炭相比,添加3%BC可使土壤TCLP提取态As和Cd显著降低35.3%和33.4%,而MBC可降低75.5%~84.2%和43.3%~49.9%,显著高于BC处理。同时,MBC施入土壤可降低土壤As和Cd的生态风险,且土壤Cd生态风险随着MBC施用量增加而降低。此外,MBC可通过减少复合污染土壤中非专性吸附态As、酸溶态Cd和可还原态Cd的含量,增加残渣态As和Cd的含量来实现土壤中As-Cd的钝化。
In order to explore the remediation effect and mechanism of manganese-modified biochar(MBC)on the arsenic/cadmium(As/Cd)composite polluted soil,a laboratory culture experiment was used to add original biochar(BC)and MBC to the slightly alkaline As/Cd composite polluted soil.The effects of MBC on the TCLP extracted As/Cd content and As/Cd speciation distribution in soil were explored,and the As/Cd ecological risk was assessed.The results show that the zero charge point of MBC after modification increases and MnO_(2) is loaded on the surface of MBC.Comparatively,the addition of 3%BC can significantly reduce the TCLP extracted As and Cd by 35.3%and 33.4%in soil,while MBC can reduce 75.5%—84.2%and 43.3%—49.9%,respectively,which are obviously higher than those of the former.Simultaneously,the ecological risks of As and Cd in soil decrease after applying MBC into the soil,and the ecological risk of Cd decreases with the increase of MBC application amount.In addition,MBC can achieve the passivation of As-Cd in soil by reducing the content of non-specifically adsorbed As,acid-soluble Cd,and reducible Cd in the As-Cd-contaminated soil,and increasing the content of residual As and Cd.
作者
梁欣冉
郜紫依
付庆灵
刘永红
朱俊
胡红青
LIANG Xin-ran;GAO Zi-yi;FU Qing-ling;LIU Yong-hong;ZHU Jun;HU Hong-qing(College of Resources and Environment,Huazhong Agricultural University,Wuhan 430070,China;College of Science,Huazhong Agricultural University,Wuhan 430070,China)
出处
《湖南师范大学自然科学学报》
CAS
北大核心
2022年第4期96-103,共8页
Journal of Natural Science of Hunan Normal University
基金
国家自然科学基金资助项目(U21A20237)。
关键词
生物炭
锰改性
砷镉复合污染
土壤修复
生态风险
biochar
manganese-modification
arsenic and cadmium composite pollution
soil remediation
ecological risk
