废弃香蕉皮粉末对六价铬的吸附特性与机理研究  

Study on Adsorption Characteristics and Mechanism of Cr(Ⅵ) by Waste Banana Peel Powder

作　　者：马路路 许利滢 张泽新 袁莹莹 陈锋 MA Lu-lu;XU Li-ying;ZHANG Ze-xin;YUAN Ying-ying;CHEN Feng(School of Environmental and Biological Engineering,Henan University of Engineering,Zhengzhou 451191,China;School of Environmental Science and Engineering,Donghua University,Shanghai 201620,China)

机构地区：[1]河南工程学院环境与生物工程学院,河南郑州451191 [2]东华大学环境科学与工程学院,上海201620

出　　处：《生态与农村环境学报》2024年第7期954-963,共10页Journal of Ecology and Rural Environment

基　　金：国家自然科学基金面上项目(42172189);河南省自然科学基金青年基金项目(222300420134);河南省高等学校重点科研项目(21A610002);河南省大学生创新创业训练计划项目(202311517005);2023年度河南工程学院开放实验重点项目。

摘　　要：研究了废弃香蕉皮粉末对六价铬〔Cr(Ⅵ)〕的吸附特性与机理。重点考察各种影响因素,利用等温线、动力学和热力学方程定量分析了吸附过程,并采用扫描电镜(SEM)、红外光谱(FTIR)和X射线光电子能谱(XPS)等手段探讨了吸附机理。结果表明:香蕉皮粉末是一种优良的吸附剂,对Cr(Ⅵ)的吸附性能远高于其他生物质。香蕉皮粉末对Cr(Ⅵ)吸附的最佳pH值为2,吸附24 h时达到平衡,Cr(Ⅵ)初始浓度和温度越高,吸附效果就越好。3次吸附-解吸循环后,香蕉皮粉末对Cr(Ⅵ)的吸附容量仍达到初始吸附容量的93.7%。Langmuir和Freundlich方程均能用于描述香蕉皮粉末对Cr(Ⅵ)的吸附过程,表明存在单分子层和多分子层吸附,且为有利吸附。在298、308和318 K条件下,香蕉皮粉末对Cr(Ⅵ)的最大吸附量分别为149.25、161.29和169.49 mg·g^(-1)。准二级动力学模型更适用于拟合香蕉皮粉末对Cr(Ⅵ)的吸附过程,表明化学吸附占主导,发生电子转移。热力学参数表明,香蕉皮粉末对Cr(Ⅵ)的吸附是自发吸热熵增的反应。SEM结果显示,香蕉皮粉末呈片状结构,直径几十到数百微米,表面有褶皱和孔隙,提供了多个活性位点。SEM、FTIR和XPS分析结果表明,香蕉皮粉末对Cr(Ⅵ)的吸附机理包括静电吸引、氧化还原、表面螯合和离子交换。In this study,the adsorption characteristics and mechanism of chromium[Cr(Ⅵ)]by waste banana peel powder were investigated.The research focused on various influencing factors and quantitatively by analyzing the adsorption process with isotherm,kinetic,and thermodynamic equations.The adsorption mechanism was studied through scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),and X-ray photoelectron spectroscopy(XPS).It indicate that banana peel powder is an excellent adsorbent,outperforming other biomass in terms of Cr(Ⅵ)adsorption.The optimal pH value of adsorption was found to be 2,with equilibrium achieved in 24 hours.Higher initial Cr(Ⅵ)concentrations and temperatures improved the adsorption performance.The adsorption capacity of Cr(Ⅵ)with banana peel powder remained at 93.7%after three adsorption-desorption cycles.Both Langmuir and Freundlich isotherm equations accurately described the adsorption process which indicates the presence of both monolayer and multilayer adsorption,suggesting favorable adsorption conditions.The maximum adsorption capacities of Cr(Ⅵ)at 298,308,and 318 K were 149.25,161.29,and 169.49 mg·g^(-1),respectively.The adsorption process was best described by the quasi-second-order kinetic model,implying that chemisorption was predominant and involved electron transfer.Thermodynamic parameters revealed that the adsorption was spontaneous,endothermic,and entropy-increasing.It shows that banana peel powder has a lamellar morphology with diameters ranging from tens to hundreds of microns in SEM,featuring folds and pores on the surface that provides multiple active sites.The combined results from SEM,FTIR,and XPS analyses indicate that the adsorption mechanism of Cr(Ⅵ)by banana peel powder involved electrostatic attraction,oxidation-reduction,surface chelation,and ion exchange.

关 键 词：废弃香蕉皮 六价铬 吸附特性 机理 

分 类 号：X52[环境科学与工程—环境工程]