Comparative mechanisms of Cr(VI)adsorption on biosynthetically derived iron-minerals  

生物成因铁基矿物的Cr(Ⅵ)吸附机制对比探究

作　　者：ZHANG Ke ZENG Xiang-feng WANG Jun GAN Min ZHU Jian-yu HE Qiang HAZEN Terry C. LIU Jun-wu FANG Ying-chun 章可;曾祥峰;汪俊;甘敏;朱建裕;何强;HAZEN Terry C.;刘军武;方迎春

机构地区：[1]School of Minerals Processing and Bioengineering,Key Laboratory of Biometallury of Ministry of Education,Central South University,Changsha 410083,China [2]Key Laboratory of Pollution Ecology and Environment Engineering,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China [3]Department of Civil and Environmental Engineering,The University of Tennessee,Knoxville,Tennessee,USA [4]Hunan Engineering Technology Research Center for Treatment and Recycling of Heavy Pollution Industrial Wastewater,Changsha 410083,China

出　　处：《Journal of Central South University》2025年第2期376-391,共16页中南大学学报(英文版)

基　　金：Project(42277256)supported by the National Natural Science Foundation of China;Projects(HBKT-2021011,HBKT-2021014)supported by the Hunan Province Environmental Protection Research Program,China;Project(CDSKY-2023-05)supported by the Scientific Research of Project Hunan Provincial Urban Geological Survey and Monitoring Institute,China。

摘　　要：In this study,Schwertmannite,Akaganéite and ammoniojarosite were biosynthesized by different bacteria and characterized.The results showed that bacteria are critical in mediating the mineral formation process:the morphology,crystallinity,grain size and specific surface area of each mineral varied upon different bacteria and culturing conditions.In addition,the formed minerals’elemental composition and group disparity lead to different morphology,crystallinity and subsequent adsorption performance.In particular,adsorption difference existed in iron minerals biosynthesized by different bacteria.The maximal adsorption capacities of Akaganéite,Schwertmannite and ammoniojarosite were 26.6 mg/g,17.5 mg/g and 3.90 mg/g respectively.Cr(VI)adsorption on iron-minerals involves hydrogen bonding,electrostatic interaction,and ligand exchange.The adsorption only occurred on the surface of ammoniojarosite,while for Akaganéite and Schwertmannite,the tunnel structure greatly facilitated the adsorption process and improved adsorption capacity.Thus,the molecular structure is the primary determining factor for adsorption performance.Collectively,the results can provide useful information in selecting suitable bacteria for synthesizing heavy-metal scavenging minerals according to different environmental conditions.施氏矿物、四方纤铁矿和铵黄铁钒是常见的可由生物成矿的铁基次生矿物,在水体污染治理领域具有极大的应用潜力。因此,深入阐明其生物成矿机制及重金属吸附机制,理解其在环境中的异质性,对于这三种矿物的实际应用具有重要意义。本文探究了四种典型嗜酸微生物(A.ferrooxidans,L.ferrooxidans,L.ferriphilum YSK和S,thermosulfidooxidans)对这三种铁基次生矿物生物成矿过程特征的影响,表征了其精细矿物学性质并解析了其重金属吸附机制。结果显示,微生物种类与溶液化学组分均可以影响矿物的元素组成、基团差异、形态、结晶度、粒度和比表面积,进而显著影响矿物的吸附性能。生物成矿的四方纤铁矿、施氏矿物和铵黄铁钒具有显著不同的Cr(Ⅵ)吸附能力,最大吸附量分别为26.59 mg/g、17.53 mg/g和3.90 mg/g。此外,在具体吸附机制方面,三种铁基矿物主要通过氢键、静电相互作用和配体交换吸附Cr(Ⅵ)。其中,铵黄铁钒主要为表面吸附,而四方纤铁矿与施氏矿物不仅可以在矿物表面吸附Cr(Ⅵ),还可以通过隧道结构进行吸附,进而具备更高的Cr(Ⅵ)吸附性能。本文的研究结果为具有高吸附容量的生物成因矿物的开发与实际应用提供了理论基础。

关 键 词：iron-secondary minerals biosynthesize BIOMINERALIZATION Cr(VI)adsorption heavy-metal scavenging minerals 

分 类 号：X703[环境科学与工程—环境工程]