TY - JOUR
T1 - Achieving arsenic concentrations of <1 μg/L by Fe(0) electrolysis
T2 - The exceptional performance of magnetite
AU - van Genuchten, Case M.
AU - Behrends, T.
AU - Stipp, S.L.S.
AU - Dideriksen, Knud
N1 - Funding Information:
We gratefully acknowledge funding provided by the Dutch Organization for Scientific Research in a Veni Grant to CMvG (Project No. 14400). We thank Marcel Ceccato for assistance with FI-HG-AAS measurements. Synchrotron experiments were performed partly at the DUBBLE beamline at the ESRF, Grenoble, France, with assistance from Dipanjan Banerjee. We also thank Ryan Davis and Sharon Bone for technical support during synchrotron data collection at SSRL. Use of SSRL, SLAC National Accelerator Laboratory, was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Contract No. DE-AC02-76SF00515.
Funding Information:
We gratefully acknowledge funding provided by the Dutch Organization for Scientific Research in a Veni Grant to CMvG (Project No. 14400 ). We thank Marcel Ceccato for assistance with FI-HG-AAS measurements. Synchrotron experiments were performed partly at the DUBBLE beamline at the ESRF, Grenoble, France, with assistance from Dipanjan Banerjee. We also thank Ryan Davis and Sharon Bone for technical support during synchrotron data collection at SSRL. Use of SSRL, SLAC National Accelerator Laboratory, was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences , under Contract No. DE-AC02-76SF00515 . Appendix A
Publisher Copyright:
© 2019 The Authors
PY - 2020/1/1
Y1 - 2020/1/1
N2 - Consumption of drinking water containing arsenic at concentrations even below the World Health Organization provisional limit of 10 μg/L can still lead to unacceptable health risks. Consequently, the drinking water sector in the Netherlands has recently agreed to target 1 μg/L of arsenic in treated water. Unfortunately, in many poor, arsenic-affected countries, the costs and complexity of current methods that can achieve <1 μg/L are prohibitive, which highlights the need for innovative methods that can remove arsenic to <1 μg/L without costly support infrastructure and complicated supply chains. In this work, we used Fe(0) electrolysis, a low cost and scalable technology that is also known as Fe(0) electrocoagulation (EC), to achieve <1 μg/L residual dissolved arsenic. We compared the arsenic removal performance of green rust (GR), ferric (oxyhydr)oxides (Fe(III) oxides) and magnetite (Mag) generated by EC at different pH (7.5 and 9) in the presence of As(III) or As(V) (initial concentrations of 200–11,000 μg/L). Although GR and Fe(III) oxides removed up to 99% of initial arsenic, neither Fe phase could reliably meet the 1 μg/L target at both pH values. In contrast, EC-generated Mag consistently achieved <1 μg/L, regardless of the initial As(V) concentration and pH. Only solutions with initial As(III) concentrations ≥2200 μg/L resulted in residual arsenic >1 μg/L. As K-edge X-ray absorption spectroscopy showed that Mag also sorbed arsenic in a unique mode, consistent with partial arsenic incorporation near the particle surface. This sorption mode contrasts with the binuclear, corner sharing surface complex for GR and Fe(III) oxides, which could explain the difference in arsenic removal efficiency among the three Fe phases. Our results suggest that EC-generated Mag is an attractive method for achieving <1 μg/L particularly in decentralized water treatment.
AB - Consumption of drinking water containing arsenic at concentrations even below the World Health Organization provisional limit of 10 μg/L can still lead to unacceptable health risks. Consequently, the drinking water sector in the Netherlands has recently agreed to target 1 μg/L of arsenic in treated water. Unfortunately, in many poor, arsenic-affected countries, the costs and complexity of current methods that can achieve <1 μg/L are prohibitive, which highlights the need for innovative methods that can remove arsenic to <1 μg/L without costly support infrastructure and complicated supply chains. In this work, we used Fe(0) electrolysis, a low cost and scalable technology that is also known as Fe(0) electrocoagulation (EC), to achieve <1 μg/L residual dissolved arsenic. We compared the arsenic removal performance of green rust (GR), ferric (oxyhydr)oxides (Fe(III) oxides) and magnetite (Mag) generated by EC at different pH (7.5 and 9) in the presence of As(III) or As(V) (initial concentrations of 200–11,000 μg/L). Although GR and Fe(III) oxides removed up to 99% of initial arsenic, neither Fe phase could reliably meet the 1 μg/L target at both pH values. In contrast, EC-generated Mag consistently achieved <1 μg/L, regardless of the initial As(V) concentration and pH. Only solutions with initial As(III) concentrations ≥2200 μg/L resulted in residual arsenic >1 μg/L. As K-edge X-ray absorption spectroscopy showed that Mag also sorbed arsenic in a unique mode, consistent with partial arsenic incorporation near the particle surface. This sorption mode contrasts with the binuclear, corner sharing surface complex for GR and Fe(III) oxides, which could explain the difference in arsenic removal efficiency among the three Fe phases. Our results suggest that EC-generated Mag is an attractive method for achieving <1 μg/L particularly in decentralized water treatment.
KW - Arsenic treatment
KW - Electrocoagulation
KW - EXAFS spectroscopy
KW - Mineral formation
KW - Oxyanion incorporation
UR - http://www.scopus.com/inward/record.url?scp=85073604481&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2019.115170
DO - 10.1016/j.watres.2019.115170
M3 - Article
C2 - 31655435
AN - SCOPUS:85073604481
SN - 0043-1354
VL - 168
JO - Water Research
JF - Water Research
M1 - 115170
ER -
