Dissolved Organic Matter Affects Arsenic Mobility and Iron(III) (hydr)oxide Formation: Implications for Managed Aquifer Recharge
[1];
[3];
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[1]
- Washington Univ., St. Louis, MO (United States)
- Washington Univ., St. Louis, MO (United States); Missouri Univ. of Science and Technology, Rolla, MO (United States)
- Washington Univ., St. Louis, MO (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division
During managed aquifer recharge (MAR), injected water significantly alters water chemistry in an aquifer, affecting arsenic mobility. To elucidate the effects of dissolved organic matter (DOM) on arsenic mobilization during MAR, this bench-scale study examined arsenic mobilization from arsenopyrite (FeAsS, an arsenic-containing sulfide) in the presence of Suwannee River natural organic matter, humic acid, and fulvic acid (SRNOM, SRHA, and SRFA), alginate (Alg), polyaspartate (PA), and glutamate (Glu). Suwannee River DOM (SRDOM) decreased arsenic mobility in the short term (<6 h) via inhibiting arsenopyrite oxidative dissolution, but increased arsenic mobility over a longer experimental time (~7 days) via inhibiting secondary iron(III) (hydr)oxide precipitation and decreasing arsenic adsorption onto iron(III) (hydr)oxide. In situ grazing incidence small-angle X-ray scattering measurements indicated that SRDOM decreased iron(III) (hydr)oxide nucleus sizes and growth rates. A combined analysis of SRDOM and other proteinaceous or labile DOM (Alg, PA, and Glu) revealed that DOM with higher molecular weights would cause more increased arsenic mobility. Finally, these new observations advance our understanding of the impacts of DOM in injected water on arsenic mobility and secondary precipitate formation during MAR, and in other systems where interactions between DOM, arsenic, and iron(III) (hydr)oxides take place.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Scientific User Facilities Division; National Science Foundation (NSF)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1607993
- Journal Information:
- Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 24 Vol. 53; ISSN 0013-936X
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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