改性纳米铁氧化物对砷的吸附研究  

Adsorption Studies of Arsenic by Modified Nanosized Iron Oxides

作　　者：徐妮 吴萌 马天宇 王萍[1] Xu Ni;Wu Meng;Ma Tianyu;Wang Ping(Anhui University of Technology,Maanshan 243032,China)

机构地区：[1]安徽工业大学,安徽马鞍山243032

出　　处：《广东化工》2025年第5期29-32,58,共5页Guangdong Chemical Industry

摘　　要：天然铁氧化物来源广泛,因其对环境中的砷具有较强的亲和力而备受关注。本文以磁铁矿、赤铁矿和磁赤铁矿为基体,通过液相还原法均匀负载纳米零价铁(nZVI),并进一步以聚乙烯亚胺(PEI)修饰减轻其钝化,制得六种稳定纳米铁氧化物颗粒,结合光谱学手段研究其对砷的吸附性能及作用机理。结果表明,相同的投加量PEI-αFe_(2)O_(3)@nZVI颗粒对As(Ⅴ)的去除率最高。在弱酸性条件下,αFe_(2)O_(3)改性材料对As(Ⅴ)的吸附效果较好,且PEI进一步改性对As(Ⅴ)的去除率增加了19.17%。六种纳米铁氧化物颗粒对As(Ⅴ)的吸附均符合准二级动力学模型;等温线试验表明Fe3O_(4)改性材料对As(Ⅴ)的吸附机制为异质表面的多层吸附,理论吸附容量分别为325.10 mg/g、55.51 mg/g,αFe_(2)O_(3)改性材料对As(Ⅴ)的吸附为单层吸附,理论吸附容量分别为97.92 mg/g、132.45 mg/g。γFe_(2)O_(3)@nZVI对As(Ⅴ)的吸附符合Langmuir模型,PEI-γFe_(2)O_(3)@nZVI对As(Ⅴ)的吸附符合Freundlich模型,理论吸附容量分别为99.84 mg/g、60.94 mg/g。XRD和FTIR进一步分析表明改性材料对As(Ⅴ)的吸附机理为表面络合和静电作用。Natural iron oxides are widely available and have received much attention because of their greater affinity for arsenic in the environment.With magnetite,hematite and maghemite as surface supporting agents,six stable iron oxide nanoparticles were produced by loading nano-zero-valent iron(nZVI)uniformly by liquid-phase reduction and further modified with polyethyleneimine(PEI)to alleviate passivation,and the adsorption performance and mechanism of arsenic were investigated by spectroscopic means.The results showed that the same dosage of PEI-αFe_(2)O_(3)@nZVI particles had the highest removal rate of As(V).TheαFe_(2)O_(3) modified material showed the best adsorption of As(V)under weakly acidic conditions,and the removal rate of As(V)was increased by 19.17%with further modification by PEI.The adsorption of As(V)by six iron oxide nanoparticles all fit the pseudo-secondary kinetic model;The adsorption isotherm test showed that the adsorption mechanism of Fe3O_(4) modified materials on As(V)was multilayer adsorption on heterogeneous surfaces,with theoretical adsorption capacities of 325.10 mg/g and 55.51 mg/g,respectively;and the adsorption ofαFe_(2)O_(3) modified materials on As(Ⅴ)was monolayer adsorption,with theoretical adsorption capacities of 97.92 mg/g and 132.45 mg/g,respectively;the adsorption of As(V)byγFe_(2)O_(3)@nZVI was in conformity with the Langmuir model,while the adsorption of As(V)by PEI-γFe_(2)O_(3)@nZVI was in conformity with the Freundlich model,with theoretical adsorption capacities of 99.84 mg/g and 60.94 mg/g,respectively.Further analyses by XRD and FTIR showed that the adsorption mechanism of the modified materials on As(V)was surface complexation and electrostatic forces,respectively.

关 键 词：磁铁矿 赤铁矿 磁赤铁矿 吸附 砷 

分 类 号：TQ[化学工程]