Arsenic transforming abilities of groundwater bacteria and the combined use of Aliihoeflea sp. strain 2WW and goethite in metalloid removal

• Published in: Journal of hazardous materials Vol. 269; pp. 89 - 97
• Main Authors: Corsini, Anna, Zaccheo, Patrizia, Muyzer, Gerard, Andreoni, Vincenza, Cavalca, Lucia
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 30-03-2014; Elsevier
• Subjects: Adsorption; Aliihoeflea; Applied sciences; Arsenate; Arsenicals - chemistry; Arsenite; Bio-oxidation; Chemical engineering; Drinking water and swimming-pool water. Desalination; Exact sciences and technology; Goethite; Groundwater; Groundwater - microbiology; Groundwaters; Metals - chemistry; Metals - isolation & purification; Natural water pollution; Oxidation-Reduction; Phyllobacteriaceae - chemistry; Phyllobacteriaceae - genetics; Phyllobacteriaceae - metabolism; Pollution; Polymerase Chain Reaction; Reactors; RNA, Ribosomal, 16S - chemistry; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - toxicity; Water treatment and pollution; Groundwater; Bio-oxidation; Arsenate; Arsenite; Goethite; Aliihoeflea; Pseudomonadales; Drinking water; Arsenic; Arsenates; Oxidant; Pseudomonas; Modeling; Arsenites; Health and environment; Adsorption; Pseudomonadaceae; Bacteria; Oxidation; Water pollution; Public health; Ground water
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2013.12.037

•Resting cells of Aliihoeflea sp. strain 2WW oxidize 200μg/L As(III) in 32h.•Goethite is 100-fold higher efficient in adsorbing 200μg/L As(V) than As(III).•The combined 2WW-goethite system is tested in buffer solution for As removal.•2WW-goethite system remove 95% of the As(III) present, meeting World Health Organization limit adequately.
Several technologies have been developed for lowering arsenic in drinking waters below the World Health Organization limit of 10μg/L. When in the presence of the reduced form of inorganic arsenic, i.e. arsenite, one options is pre-oxidation of arsenite to arsenate and adsorption on iron-based materials. Microbial oxidation of arsenite is considered a sustainable alternative to the chemical oxidants. In this contest, the present study investigates arsenic redox transformation abilities of bacterial strains in reductive groundwater from Lombardia (Italy), where arsenite was the main arsenic species. Twenty isolates were able to reduce 75mg/L arsenate to arsenite, and they were affiliated to the genera Pseudomonas, Achromobacter and Rhodococcus and genes of the ars operon were detected. Three arsenite oxidizing strains were isolated: they belonged to Rhodococcus sp., Achromobacter sp. and Aliihoeflea sp., and aioA genes for arsenite oxidase were detected in Aliihoeflea sp. strain 2WW and in Achromobacter sp. strain 1L. Uninduced resting cells of strain 2WW were used in combination with goethite for arsenic removal in a model system, in order to test the feasibility of an arsenic removal process. In the presence of 200μg/L arsenite, the combined 2WW-goethite system removed 95% of arsenic, thus lowering it to 8μg/L. These results indicate that arsenite oxidation by strain 2WW combined to goethite adsorption is a promising approach for arsenic removal from contaminated groundwater.