水铁矿/坡缕石复合材料吸附水中Sb(Ⅴ)、As(Ⅴ)的效果与机制  

Effect and mechanism of adsorption of aqueous Sb(Ⅴ)and As(Ⅴ)by ferrihydrite/palygorskite composites

作　　者：闫安 陈帅宇 朱影影 王俊欢 侯红 YAN An;CHEN Shuaiyu;ZHU Yingying;WANG Junhuan;HOU Hong(College of Resources and Environment,Shanxi Agricultural University;Chinese Research Academy of Environmental Sciences)

机构地区：[1]山西农业大学资源环境学院 [2]中国环境科学研究院

出　　处：《环境工程技术学报》2025年第1期203-217,共15页Journal of Environmental Engineering Technology

基　　金：国家重点研发计划项目(2020YFC1807700)。

摘　　要：为开发廉价、高效的水体Sb(Ⅴ)、As(Ⅴ)去除材料,以煅烧温度、盐酸浓度、铁氧化物负载量为主要影响因素,设计正交实验以制备铁氧化物/坡缕石复合材料(Fh-ACPal),探讨其最佳改性方式,并研究Fh-ACPal在不同环境条件下对单溶质和双溶质体系水溶液中As(Ⅴ)、Sb(Ⅴ)的吸附效果,通过X射线衍射(XRD)、傅里叶红外光谱(FTIR)、BET孔隙结构分析、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)对Fh-ACPal进行表征,探讨其吸附机制。结果表明:在灼烧温度350℃、盐酸浓度2.0 mol/L、氯化铁浓度2.0 mol/L的改性条件下,制备的Fh-ACPal具有最好的吸附能力;在pH为4、Fh-ACPal投加量为1 g/L时,Fh-ACPal对As(Ⅴ)、Sb(Ⅴ)的最大单层吸附容量分别为26.44和42.38 mg/g。在单一吸附质条件下,Freundlich和Langmuir等温吸附模型均能较好地拟合Fh-ACPal吸附Sb(Ⅴ)的过程,而Fh-ACPal吸附As(Ⅴ)的过程仅能较好地被Freundlich模型描述;As(Ⅴ)和Sb(Ⅴ)共存体系中,Sb(Ⅴ)可在已被Fh-ACPal优先吸附的As(Ⅴ)表面上进一步形成多分子层吸附,BET等温吸附模型能较好地拟合该过程。实验以及各项表征结果证明,负载的铁氧化物为水铁矿(Fh),改性后Fh-ACPal的比表面积达到224.84 m^(2)/g,同时大部分的Sb(Ⅴ)以共沉淀的方式进入Fh-ACPal晶体内部被稳定结合,而大部分的As(Ⅴ)主要以表面络合形成内球络合物的方式被Fh-ACPal吸附;As(Ⅴ)、Sb(Ⅴ)共存时,As(Ⅴ)优先占据Fh-ACPal表面的吸附位点,阻碍Sb(Ⅴ)与Fh-ACPal的共沉淀作用,从而抑制Sb(Ⅴ)的去除。研究证明了水铁矿/坡缕石复合材料对水体中Sb(Ⅴ)、As(Ⅴ)去除的有效性,为水体中锑、砷重金属污染治理提供了理论参考。To develop inexpensive and efficient Sb(Ⅴ),As(Ⅴ)removal materials for water bodies,an orthogonal experiment was designed to prepare ferrihydrite/palygorskite composite material(Fh-ACPal),taking calcination temperature,acid concentration,and iron oxide loading as the main influencing factors.The optimal modification method was explored,and the adsorption behavior of Fh-ACPal for As(Ⅴ)and Sb(Ⅴ)in both single and double solute aqueous solutions across varying environmental conditions was investigated.To elucidate its adsorption mechanism,Fh-ACPal was characterized by using X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),BET pore structure analysis,X-ray photoelectron spectroscopy(XPS),and scanning electron microscopy(SEM).The results showed that under the modified conditions of calcination temperature of 350℃,hydrochloric acid concentration of 2.0 mol/L,and ferric chloride concentration of 2.0 mol/L,the prepared Fh-ACPal had the best adsorption capacity.When pH was 4 and the dosage of Fh-ACPal was 1 g/L,the maximum monolayer adsorption capacities of Fh-ACPal for As(Ⅴ)and Sb(Ⅴ)were 26.44 and 42.38 mg/g,respectively.In a single solute system,both Freundlich and Langmuir isotherm adsorption models could well fit the process of Fh-ACPal adsorbing Sb(Ⅴ),while the process of Fh-ACPal adsorbing As(Ⅴ)could only fit Freundlich model well.In a dual solute system,Sb(Ⅴ)further formed multi-layered adsorption on As(Ⅴ)surface that had been preferentially adsorbed by Fh-ACPal.The BET isothermal adsorption model could fit this process well.Based on the experimental and characterization results,it has been proven that the loaded iron oxide is ferrihydrite(Fh),and the modified Fh-ACPal has a specific surface area of 224.84 m^(2)/g.At the same time,most of Sb(Ⅴ)enters the interior of Fh-ACPal crystal through co-precipitation and is stably bound.Most of As(Ⅴ)is mainly adsorbed by Fh-ACPal through surface complexation to form inner spherical complexes.When As(Ⅴ)and Sb(Ⅴ)coexist,the inha

关 键 词：坡缕石 二线水铁矿 锑(Sb) 砷(As) 吸附 共沉淀 表面络合 

分 类 号：X703[环境科学与工程—环境工程]