Facilitated arsenic immobilization by biogenic ferrihydrite-goethite biphasic Fe(III) minerals (Fh-Gt Bio-bi-minerals). (June 2019)

• Record Type: Journal Article
• Authors: Xiu, Wei; Yu, Xiaonuo; Guo, Huaming; Yuan, Wenjie; Ke, Tiantian; Liu, Guangyao; Tao, Jing; Hou, Weiguo; Dong, Hailiang
• Is Part Of: Chemosphere. Volume 225(2019)
• Page Start: 755
• Page End: 764
• Publication Date: 2019-06
• Subjects: Biphasic minerals -- Biomineralization -- Iron-oxidizing bacteria -- Immobilization -- Groundwater -- Fe(II) oxidation; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2019.02.098
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Biogenic iron(III) minerals (BIM) widely occur in aquatic systems. However, characteristics and mechanisms of As sequestration by biogenic biphasic Fe(III) minerals (Bio-bi-minerals) are not clearly understood. We investigated characteristics of Bio-bi-minerals induced by Pseudogulbenkiania sp. strain 2002 and explored their As sequestration mechanisms by monitoring particle morphology, mineralogical composition, and As binding properties. Results showed that Fe(II) oxidation (about 3 mM) by Pseudogulbenkiania sp. strain 2002 under growth condition produced biogenic ferrihydrite-goethite biphasic Fe(III) minerals (Fh-Gt Bio-bi-minerals), which showed better performance in As immobilization compared to corresponding biogenic monophasic Fe(III) minerals (Bio-mono-minerals). Decreased particle size, increased abundance of ferrihydrite and occurrence of bidentate mononuclear edge-sharing ( 2 E ) and monodentate mononuclear edge-sharing As complexes ( 1 V ) contributed to enhanced As immobilization by Fh-Gt Bio-bi-minerals. We suggest that the Bio-bi-minerals have the potential to illuminate As biogeochemical cycles in aquatic systems and to remediate As and nitrate co-contaminated groundwater. Graphical abstract: Image 1 Highlights: Fe(II) oxidation by strain 2002 induced the formation of biogenic biphasic minerals. Biogenic ferrihydrite-goethite biphasic minerals enhanced As immobilization. Lower Fe/As led to smaller particle size and a higher fraction of ferrihydrite. Arsenic tended to be associated with ferrihydrite with decreasing initial Fe/As. Occurrence of mononuclear As complexes contributed to facilitated As immobilization.