Molecular Mechanisms of Lead Binding to Ferrihydrite-Bacteria Composites: ITC, XAFS, and mu-XRF Investigations

doi:10.1021/acs.est.9b06288

	Molecular Mechanisms of Lead Binding to Ferrihydrite-Bacteria Composites: ITC, XAFS, and mu-XRF Investigations
	Chen, Hansong 1,3,4; Tan, Wenfeng 1,5; Lv, Wei 5; Xiong, Juan 5; Wang, Xiaoming 5; Yin, Hui 5; Fang, Linchuan 1,2
刊名	ENVIRONMENTAL SCIENCE & TECHNOLOGY
	2020-04-07
卷号	54 期号:7 页码:4016-4025
ISSN号	0013-936X
DOI	10.1021/acs.est.9b06288
通讯作者	Fang, Linchuan(flinc629@hotmail.com)
英文摘要	Binding of Pb(II) to ferrihydrite-Bacillus subtilis composites formed in the presence of bacterial cells were investigated through macroscopic and microscopic techniques. Diffuse layer model (DLM) fitting and isothermal titration calorimetry (ITC) analysis indicated that the hydroxyl group played a key role in Pb(II) sorption onto composites by masking reactive sites, such as carboxyl and phosphoryl groups of bacterial cells. Negative enthalpy (from -39.29 to -57.87 kJ mol(-1)) and positive entropy (from 135.61 to 193.47 kJ mol(-1)) of Pb(II) sorption onto composites revealed that inner-sphere complexes formed through exothermic reactions and was driven by both entropy and enthalpy. Spatial distribution of these inner-sphere species at varied Pb(II) loading demonstrated that interactions between Pb(II) and bacterial cells preceded that of mineral components in composites, using microfocus X-ray fluorescence spectroscopy (mu-XRF) maps and microfocus X-ray absorption near edge structure (mu-XANES) spectra. Combined with bulk Pb L-m-edge X-ray absorption fine structure (XAFS) spectrum, we inferred that mononuclear bidentate edge-sharing hydroxyl-Pb complexes, monodentate mononuclear carboxyl-Pb and phosphoryl-Pb complexes predominantly contributed to Pb(II) inner-sphere binding with mineral and bacterial fractions in composites, respectively. The molecular binding mechanisms obtained in this study provide further insight into the sequestration and migration of toxic metals in natural environments.
资助项目	National Natural Science Foundation of China[41425006] ; National Natural Science Foundation of China[41977031] ; CAS Light of West China Program[XAB2016A03] ; State Key Laboratory of Loess and Quaternary Geology CAS[SKLLQGZR1803] ; Education Department Foundation of Zhejiang Province[Y201738652]
WOS关键词	CADMIUM ADSORPTION ; BACILLUS-SUBTILIS ; SORPTION ; CU(II) ; SPECIATION ; PB(II) ; SPECTROSCOPY ; COPPER ; CU
WOS研究方向	Engineering ; Environmental Sciences & Ecology
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000526418000033
资助机构	National Natural Science Foundation of China ; CAS Light of West China Program ; State Key Laboratory of Loess and Quaternary Geology CAS ; Education Department Foundation of Zhejiang Province
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/159842]
专题	中国科学院地理科学与资源研究所
通讯作者	Fang, Linchuan
作者单位	1.Chinese Acad Sci & Minist Water Resources, Inst Soil & Water Conservat, State Key Lab Soil Eros & Dryland Farming Loess P, Yangling 712100, Shaanxi, Peoples R China 2.Chinese Acad Sci, CAS Ctr Excellence Quaternary Sci & Global Change, Xian 710061, Peoples R China 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 4.Zhejiang Normal Univ, Coll Xingzhi, Jinhua 321000, Zhejiang, Peoples R China 5.Huazhong Agr Univ, Coll Resources & Environm, Wuhan 430070, Peoples R China
推荐引用方式 GB/T 7714	Chen, Hansong,Tan, Wenfeng,Lv, Wei,et al. Molecular Mechanisms of Lead Binding to Ferrihydrite-Bacteria Composites: ITC, XAFS, and mu-XRF Investigations[J]. ENVIRONMENTAL SCIENCE & TECHNOLOGY,2020,54(7):4016-4025.
APA	Chen, Hansong.,Tan, Wenfeng.,Lv, Wei.,Xiong, Juan.,Wang, Xiaoming.,...&Fang, Linchuan.(2020).Molecular Mechanisms of Lead Binding to Ferrihydrite-Bacteria Composites: ITC, XAFS, and mu-XRF Investigations.ENVIRONMENTAL SCIENCE & TECHNOLOGY,54(7),4016-4025.
MLA	Chen, Hansong,et al."Molecular Mechanisms of Lead Binding to Ferrihydrite-Bacteria Composites: ITC, XAFS, and mu-XRF Investigations".ENVIRONMENTAL SCIENCE & TECHNOLOGY 54.7(2020):4016-4025.