Bioremediation of arsenic-contaminated groundwater by sequestration of arsenic in biogenic pyrite

Saunders, James A.; Lee, Ming‐Kuo; Dhakal, Prakash; Ghandehari, Shahrzad Saffari; Wilson, T. A.; Billor, M. Zeki; Uddin, Ashraf

doi:10.1016/j.apgeochem.2018.07.007

Cited by 42 publications

(20 citation statements)

References 75 publications

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“…However, the mechanisms at the molecular level of this incorporation during pyrite formation at ambient temperature is still unclear. Some studies that have addressed solid-solution interactions of As with FeS suggested that As sorbs onto this phase rather than being incorporated in its structure (Kirk et al, 2010;Saunders et al, 2018). Saunders et al (2018) proposed that sorption of As(III) involves inner-sphere complexation, inducing long-term arsenic retention.…”

Section: Matamorosmentioning

confidence: 99%

“…Some studies that have addressed solid-solution interactions of As with FeS suggested that As sorbs onto this phase rather than being incorporated in its structure (Kirk et al, 2010;Saunders et al, 2018). Saunders et al (2018) proposed that sorption of As(III) involves inner-sphere complexation, inducing long-term arsenic retention. Farquhar et al (2002) suggested outer-sphere complexation of As on both mackinawite and pyrite surfaces and reported As 2 S 3 precipitation in some of their experiments.…”

Section: Matamorosmentioning

confidence: 99%

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Influence of trace level As or Ni on pyrite formation kinetics at low temperature

Baya

Pape

Brest

et al. 2021

Geochimica et Cosmochimica Acta

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Pyrite formation at low temperature during early diagenesis in (sub-)surface sediments is an essential step of Fe and S biogeochemical cycles and the presence of this ubiquitous mineral of surface environments is often used as an indicator of paleo-redox conditions. Pathways of pyrite formation are usually discussed in environmental settings by involving a variety of nanosized Fe-S mineralogical precursors as a function of the local geochemical conditions. However, the influence of trace element impurities such as Ni and As in the solution at the time of pyrite formation has been poorly studied, whereas specific chemical signatures of trace elements are commonly observed in sedimentary pyrites.A better understanding of the impact of Ni and As incorporation at trace levels on pyrite formation is essential to help refining the use of these elements as paleo-redox indicators and to evaluate the role of pyrite as a sink regulating the biogeochemical cycle of potentially toxic trace elements. In this study, we have performed syntheses of pyrite at low temperature by the polysulfide pathway using aqueous Fe(III) and H 2 S in the presence of trace amounts of Ni(II) (0.001 mol%Fe) and As(III) (0.001 mol%Fe). Analysis of the solids collected at different time steps over the course of the experiments using X-Ray absorption spectroscopy at both the Fe and S K-edges shows that pyrite starts to precipitate within 5 days in presence of Ni(II) and within 32 days in presence of As(III), while the control experiment showed an intermediate precipitation rate of 14 days. Shell-by-shell analysis of Fe K-edge EXAFS data shows that the initial mineralogical precursors are the same whatever the experimental conditions and correspond to poorly-crystalline FeS (3.

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Section: Matamorosmentioning

confidence: 99%

Section: Matamorosmentioning

confidence: 99%

Influence of trace level As or Ni on pyrite formation kinetics at low temperature

Baya

Pape

Brest

et al. 2021

Geochimica et Cosmochimica Acta

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“…The high abundance of Fe in the system and the formation of pyrite, and possibly other iron sulfides at the PRB and downgradient of it (e.g., location 5M), has implications for metal removal. This process, which was previously described in PRBs (biobarriers with sulfate reduction; e.g., Herbert et al, ), not only reduces the concentration of Fe in the groundwater (Table ) but could also lead to the sorption and coprecipitation of contaminants onto Fe sulfide phases, for example, As (Saunders et al, ) and Cu (Yang et al, ). Natrolite, a zeolite detected by XRD, could also contribute to the removal of As and transition metals.…”

Section: Discussionmentioning

confidence: 85%

Biogeochemical Behavior of Metals Along Two Permeable Reactive Barriers in a Mining‐Affected Wetland

et al. 2019

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The biogeochemistry of two alkaline permeable reactive barriers (PRBs) installed for remediation in a mining-affected wetland was investigated in order to assess the importance of colloidal particles on metal removal processes in such systems. At the time of investigation, both PRBs were effective in removing U, Cu, and Zn (>95%) from groundwater but were slightly less efficient for Ni and Co (<90%). Previously installed groundwater wells allowed an in-depth analysis of groundwater passing through the first PRB. Here, in an alkaline environment (pH 6.0-9.7), 11-14% of Ni, 36-37% of Co, 77-81% of Cu, 14-17% of U, and 10-19% of Fe were associated with organic matter and inorganic colloids, while upgradient in the more acidic environments (pH <6.0), ionic species and complexes (e.g., Co 2+ , Ni 2+ , Cu 2+ , and UO 2 H 3 SiO 4 + ) dominated. Copper and U preferentially bound to larger colloidal fractions (>1 kDa), which might have promoted their sequestration. Uranium removal was likely further enhanced by U (VI) reduction in the alkaline and oxygen-depleted conditions of the PRBs. The less efficient removal of Ni and Co, being target metals for remediation, was explained by a combination of their high solubility, unfavorable redox and pH conditions created by the alkaline PRBs, and their limited association with colloidal particles. These considerations are critical in the design of future PRBs for the remediation of similar systems.Plain Language Summary Permeable reactive barriers are a technology often applied to treat contaminated groundwater. In this study, the biogeochemistry of two alkaline barriers, placed in a wetland near a decommissioned uranium mine, was investigated. At the time of investigation, both reactive barriers were effective in removing uranium, copper, and zinc from groundwater but were less efficient for nickel and cobalt. Using previously installed groundwater wells, we conducted an in-depth analysis of groundwater passing through the first barrier. The alkaline and oxygen-depleted environment promoted the formation of colloids, which potentially contributed to the effective removal of copper and uranium, while the surrounding acidic wetland promoted the transport of ionic metal species. At the reactive barriers, uranium removal was further enhanced by uranium reduction to more immobile uranium forms through reduced chemical species and the activity of bacteria. The less efficient removal of nickel and cobalt was explained by their high solubility, unfavorable conditions created by the alkaline reactive barriers, and their limited association with colloids. This work provides new insights into future uses of permeable reactive barrier technology for metal remediation in wetlands.

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“…These conditions would enhance the potential denitrifying activity of Dechloromonas and/or Sulfuricurvum bacteria, which showed a marked increase in population in the anaerobic environment promoted by nZVI, while the abundance of other hydrogen-oxidizing bacteria such as Hydrogenophaga significantly decreased. Under reducing conditions, sulfate-reducing bacteria (SRB) can modulate the concentration of metallic pollutants and arsenic through the use of organic metabolites (or nZVI, as a direct source of Fe(II) and hydrogen reductants) and the generation of biogenic pyrite, which can remove dissolved arsenic from contaminated groundwater through adsorption and co-precipitation ( Saunders et al, 2018 ).…”

Section: Resultsmentioning

confidence: 99%

“…The information obtained will allow a deeper understanding of the extraordinary adaptations and metabolic networks of bacteria in these complex contaminated brownfield sites, and such knowledge would contribute to optimizing remediation treatments on a rational basis. Despite this and based on the data already available, a possible improvement in the remediation strategy would be the use of organic amendments that stimulate the growth of facultative/anaerobic SRB bacteria that participate in the sequestration of arsenic ( Saunders et al, 2018 ; Zacarías-Estrada et al, 2020 ). However, in this case, it would be necessary to maintain an available proportion of Fe(II) in the groundwater for iron sulfide formation, since an excess of dissolved H 2 S may produce more soluble thioarsenic compounds ( Saunders et al, 2018 and references therein).…”

Section: Resultsmentioning

confidence: 99%

Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic

et al. 2021

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Nanoscale Zero-Valent Iron (nZVI) is a cost-effective nanomaterial that is widely used to remove a broad range of metal(loid)s and organic contaminants from soil and groundwater. In some cases, this material alters the taxonomic and functional composition of the bacterial communities present in these matrices; however, there is no conclusive data that can be generalized to all scenarios. Here we studied the effect of nZVI application in situ on groundwater from the site of an abandoned fertilizer factory in Asturias, Spain, mainly polluted with arsenic (As). The geochemical characteristics of the water correspond to a microaerophilic and oligotrophic environment. Physico-chemical and microbiological (cultured and total bacterial diversity) parameters were monitored before and after nZVI application over six months. nZVI treatment led to a marked increase in Fe(II) concentration and a notable fall in the oxidation-reduction potential during the first month of treatment. A substantial decrease in the concentration of As during the first days of treatment was observed, although strong fluctuations were subsequently detected in most of the wells throughout the six-month experiment. The possible toxic effects of nZVI on groundwater bacteria could not be clearly determined from direct observation of those bacteria after staining with viability dyes. The number of cultured bacteria increased during the first two weeks of the treatment, although this was followed by a continuous decrease for the following two weeks, reaching levels moderately below the initial number at the end of sampling, and by changes in their taxonomic composition. Most bacteria were tolerant to high As(V) concentrations and showed the presence of diverse As resistance genes. A more complete study of the structure and diversity of the bacterial community in the groundwater using automated ribosomal intergenic spacer analysis (ARISA) and sequencing of the 16S rRNA amplicons by Illumina confirmed significant alterations in its composition, with a reduction in richness and diversity (the latter evidenced by Illumina data) after treatment with nZVI. The anaerobic conditions stimulated by treatment favored the development of sulfate-reducing bacteria, thereby opening up the possibility to achieve more efficient removal of As.

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Bioremediation of arsenic-contaminated groundwater by sequestration of arsenic in biogenic pyrite

Cited by 42 publications

References 75 publications

Influence of trace level As or Ni on pyrite formation kinetics at low temperature

Influence of trace level As or Ni on pyrite formation kinetics at low temperature

Biogeochemical Behavior of Metals Along Two Permeable Reactive Barriers in a Mining‐Affected Wetland

Effects of in situ Remediation With Nanoscale Zero Valence Iron on the Physicochemical Conditions and Bacterial Communities of Groundwater Contaminated With Arsenic

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