Arsenic Removal from Contaminated Groundwater by Zero Valent Iron: a Mechanistic and Long-Term Performance Study

Abedin, Anwarul; Tanaka, Katsumi; Inui, Tomoyuki; Kamon, Masashi

doi:10.3208/sandf.51.369

Cited by 16 publications

(10 citation statements)

References 30 publications

(25 reference statements)

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“…[1][2][3] The interactions of ZVI or iron oxides or (oxy-)hydroxides with arsenic have been widely studied during the last decade. Most of these studies were based on batch experiments, but several treatments were based on column ltration using ZVI or iron oxides alone [4][5][6] or mixed with various supporting media 5,[7][8][9][10][11][12][13] can also be found. The trapping properties of ZVI involve complex mechanisms, including coprecipitation or adsorption 14 onto its corrosion by-products.…”

Section: Introductionmentioning

confidence: 99%

Long-term influence of aeration on arsenic trapping in a ZVI/sand bed reactor

et al. 2016

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Section: Introductionmentioning

confidence: 99%

Long-term influence of aeration on arsenic trapping in a ZVI/sand bed reactor

et al. 2016

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“…As groundwater in Bangladesh does generally not contain sufficient Fe for the removal of naturally present As and phosphate, the CIM as a source for additional Fe is crucial for As removal. Previous studies of As removal with ZVI showed that corrosion of Fe(0) yields dissolved Fe(II) and various mixed-valence Fe(II/III) and Fe(III)-phases that are excellent sorbents for arsenate (As(V)) and arsenite As(III). − Thus, the advantage of the SONO filter over other filter types is that the sorbent for As is continuously formed by corrosion of inexpensive and locally available surplus iron . Additionally, oxidation of dissolved Fe(II) with dissolved oxygen (DO) produces reactive intermediates such as H 2 O 2 , which, together with Fe(II), can oxidize As(III) to the more strongly sorbing As(V). ,,, Similar oxidation and sorption processes were found in As removal by electrocoagulation. , Consequently, As(III) is oxidized to As(V) in the corrosion process without the need for added oxidants, and SONO filters are expected to have a long functional lifetime without replacement of adsorbent, as is necessary in many other filters.…”

Section: Introductionmentioning

confidence: 99%

Arsenic Removal with Composite Iron Matrix Filters in Bangladesh: A Field and Laboratory Study

Neumann

Kaegi

Voegelin

et al. 2013

Environ. Sci. Technol.

175

125

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The main arsenic mitigation measures in Bangladesh, well-switching and deep tube wells, have reduced As exposure, but water treatment is important where As-free water is not available. Zero-valent iron (ZVI) based SONO household filters, developed in Bangladesh, remove As by corrosion of locally available inexpensive surplus iron and sand filtration in two buckets. We investigated As removal in SONO filters in the field and laboratory, covering a range of typical groundwater concentrations (in mg/L) of As (0.14-0.96), Fe (0-17), P (0-4.4), Ca (45-162), and Mn (0-2.8). Depending on influent Fe(II) concentrations, 20-80% As was removed in the top sand layer, but As removal to safe levels occurred in the ZVI-layer of the first bucket. Residual As, Fe, and Mn were removed after re-aeration in the sand of the second bucket. New and over 8-year-old filters removed As to <50 μg/L and mostly to <10 μg/L and Mn to <0.2 mg/L. Vertical concentration profiles revealed formation of Fe(II) by corrosion of Fe(0) with O2 and incorporation of As into forming amorphous Fe phases in the composite iron matrix (CIM) of newer filters and predominantly magnetite in older filters. As mass balances indicated that users filtered less than reported volumes of water, pointing to the need for more educational efforts. All tested SONO filters provided safe drinking water without replacement for up to over 8 years of use.

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“…Studies of similar intention with respect to arsenic removal exists, but are very few. 124,173) A clear white space is available for investigating the viability of various kinds of IP, especially industrially or commercially available grades, for arsenic removal. Special focus on physico-chemical properties of powders influencing the removal at real time applications needs attention.…”

Section: Commercial Presence Of Iron Powders In Water Remediation Applicationsmentioning

confidence: 99%