摘要
为修复受到镉砷复合污染的农田土壤,将铁锰氧化物负载于氧化石墨烯表面,制备得到了新型氧化石墨烯负载铁锰复合材料.在此基础上开展了为期60 d土壤培养试验,通过对pH、DOC含量、土壤有效态Cd和As含量动态变化,以及土壤Cd和As形态的测定,探究了氧化石墨烯(GO)和氧化石墨烯负载铁锰复合材料(GO-FM)在不同添加比例下(0.1%、0.2%和0.3%),对上虞和佛山两种理化性质和污染程度不同的土壤中Cd和As的钝化效果,并阐明其相应修复机制.结果表明,与空白对照相比,GO-FM提高了酸性上虞土的pH,但使佛山土pH降低.培养结束后,GO和GO-FM处理均增加了土壤DOC含量.GO-FM使佛山土可溶态Cd含量降低了5.08%~19.19%,有效态Cd含量降低了36.57%~42.8%,其主要钝化机制是静电吸附、络合和羟基化金属离子的形成.而酸性上虞土受静电斥力的影响使得GO-FM对Cd的钝化效果低于佛山土,但随着材料添加量的增加,GO-FM使氧化石墨烯增加土壤Cd有效性的趋势得到了抑制,添加0.2%和0.3%的GO-FM使上虞土有效态Cd含量降低了6.45%~13.56%.同时,复合材料通过锰氧化物对As的氧化作用以及As与铁氧化物表面羟基形成内表面螯合物的钝化机制,促使上虞土和佛山土的有效态As含量分别降低了4.34%~9.15%和0.87%~5.71%.总之,在佛山土中GO-FM对Cd的钝化效果优于上虞土,在上虞土中GO-FM对As的钝化效果优于佛山土.研究结果可为不同类型土壤镉砷复合污染防治提供理论依据和参考.
Novel Fe-Mn combined graphene oxide(GO-FM)material was produced and tested for its efficacy in remediating agricultural soil co-contaminated by Cd and As.In a 60-day soil incubation experiment,the remediation mechanism and immobilization effects of GO and GO-FM at different addition ratios(0.1%,0.2%,and 0.3%)were investigated in Shangyu and Foshan soils,which had varying physicochemical properties and contamination degrees.The dynamic changes in pH,DOC concentration,bioavailable Cd and As content,and morphology of Cd and As were explored to determine the remediation efficacy of the materials.The results demonstrated that compared with that in the blank control,GO-FM increased the pH in Shangyu soil but decreased the pH in Foshan soil.After culture,both GO and GO-FM increased the soil DOC content.GO-FM decreased the soluble Cd concentration by 5.08%-19.19% and the bioavailability of Cd by 36.57%-42.8% in Foshan soil,and the main immobilization mechanism was electrostatic adsorption,complexation,and hydroxylated metal ion formation.The immobilization ability of GO-FM on Cd was lower than that of Foshan soil due to the influence of electrostatic repulsion in Shangyu acidic soil.However,with the increase in the amount of GO-FM,the trend of increasing the bioavailability of Cd by graphene oxide was inhibited.The addition of 0.2% and 0.3% GO-FM decreased the bioavailability of Cd by 6.45%-13.56% in Shangyu soil.Additionally,GO-FM decreased the bioavailability of As in Shangyu soil and Foshan soil by 4.34%-9.15% and 0.87%-5.71%,respectively.This was due to the immobilization mechanism of oxidation of As by manganese oxides and inner surface chelate between As and the surface hydroxyl group of iron oxides.In summary,the immobilization effect of GO-FM on Cd in Foshan soil was better than that in Shangyu soil,and the immobilization effect of GO-FM on As in Shangyu soil was better than that in Foshan soil,which can provide a theoretical basis and reference for the prevention and control of Cd and As co-contamination in different types of soil.
作者
袁婧
吴骥子
连斌
袁峰
孙淇
田欣
赵科理
YUAN Jing;WU Ji-zi;LIAN Bin;YUAN Feng;SUN Qi;TIAN Xin;ZHAO Ke-li(College of Environmental and Resource Sciences,Zhejiang A&F University,Hangzhou 311300,China;Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province,Zhejiang A&F University,Hangzhou 311300,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2024年第2期1107-1117,共11页
Environmental Science
基金
国家重点研发计划项目(2017YFD0801302)
浙江省自然科学基金项目(LY17D010009)。
关键词
镉砷复合污染
氧化石墨烯(GO)
铁锰
钝化
土壤修复
Cd and As co-contamination
graphene oxide(GO)
Fe-Mn
immobilization
soil remediation