两种铁改性生物炭对微碱性砷镉污染土壤的修复效果  

Remediation Effect of Two Iron-modified Biochars on Slightly Alkaline Arsenic and Cadmium Contaminated Soil

作　　者：梁欣冉 何丹 郑曌华 付庆灵[1] 胡红青[1] 朱俊[1] LIANG Xin-ran;HE Dan;ZHENG Zhao-hua;FU Qing-ling;HU Hong-qing;ZHU Jun(College of Resources and Environment,Huazhong Agricultural University,Wuhan 430070,China;Palm Eco-Town Development Co.,Ltd.,Zhengzhou 450000,China)

机构地区：[1]华中农业大学资源与环境学院,武汉430070 [2]棕榈生态城镇发展股份有限公司,郑州450000

出　　处：《环境科学》2023年第7期4100-4108,共9页Environmental Science

基　　金：国家自然科学基金项目(U21A20237)。

摘　　要：改性生物炭作为良好的重金属钝化剂,已被广泛应用于环境修复.为探究不同改性方法对生物炭钝化土壤砷-镉(As-Cd)的影响,采用共沉淀法和浸渍热解法制备铁改性生物炭,通过吸附试验和土壤培养试验,对生物炭性质、吸附As-Cd以及钝化土壤As-Cd的能力进行分析.结果表明,两种改性方法均可提高生物炭铁含量和零电荷点,且共沉淀法制备的铁改性生物炭(FeBC-1)负载的铁矿物主要为Fe_(3)O_(4)、FeO(OH)和γ-Fe_(2)O_(3)等,而浸渍热解法制备的铁改性生物炭(FeBC-2)主要为α-Fe_(2)O_(3)和γ-Fe_(2)O_(3)等铁氧化物.FeBC-1对As和Cd均展现出很强的吸附去除能力,去除率达21.40%~34.14%,可显著促进土壤中非专性吸附态As向残渣态As转化,而FeBC-2仅对As具有较好的吸附效果.BC、FeBC-1和FeBC-2对Cd的吸附能力与自身的阳离子交换量(CEC)呈正比,其中,BC对Cd的吸附去除效果优于FeBC-1和FeBC-2,可显著促进土壤酸溶态Cd向稳定的残渣态Cd转化.As a good passivation agent for heavy metals,modified biochar has been widely used in environmental remediation.In order to explore the effects of different modification methods on arsenic(As)and cadmium(Cd)passivation in soil by biochar,this study used co-precipitation and impregnation pyrolysis to prepare iron-modified biochar.Through adsorption experiments and soil culture experiments,the properties of biochar,adsorption capacity,and the As and Cd passivation ability in soil were analyzed.The results showed that both modification methods could increase the iron(Fe)content and zero charge point of biochar,and the Fe minerals supported by Fe-modified biochar(FeBC-1)prepared by co-precipitation were mainly Fe_(3)O_(4),FeO(OH),and γ-Fe_(2)O_(3).The Fe-modified biochar(FeBC-2)prepared by impregnation pyrolysis mainly consisted of α-Fe_(2)O_(3) and γ-Fe_(2)O_(3).FeBC-1 showed strong adsorption and removal ability for As and Cd,with a removal rate of 21.40%-34.14%,which could significantly promote the conversion of non-obligate adsorbed As to residual As in soil,whereas FeBC-2 only had a good adsorption effect on As.The adsorption capacity of BC,FeBC-1,and FeBC-2 for Cd were proportional to their CEC.The adsorption and removal effect of BC on Cd was better than that of FeBC-1 and FeBC-2,which could significantly promote the conversion of soil acid-soluble Cd to stable residue Cd.

关 键 词：砷(As) 镉(CD) 土壤污染修复 铁改性生物炭 改性方法 

分 类 号：X53[环境科学与工程—环境工程]