TY  - JOUR
AB  - The release of arsenic (As) adsorbed onto iron oxide (Fe-oxide) surfaces is affected by dissolved organic matter (DOM), phosphate (hereafter referred to as PO4), and silicic acid (H4SiO4). Further, the reductive dissolution of As from Fe-oxide phases is also affected in reduced soils and sediments. Thus, the aim of this study was to understand the adsorption competition and redox-related mechanisms by which DOM affects As mobilization from Fe-oxide in a complex system containing both H4SiO4 and PO4. The results demonstrated that the DOM-driven, microbially mediated As biotransformation, and, thus, mobilization of As significantly increased when both dissolved inorganic H4SiO4 and PO4 were present, as the co-presence of H4SiO4 and PO4 decreased As adsorption sites on Fe-oxides. The availability of DOM in the co-presence of H4SiO4 and PO4 increased the microbial activity in the system by providing more substrates for microbial metabolism, which also decreased the redox potential (reducing conditions) and consumed acidity, causing the pH to increase from 4 to 6.8. In addition, DOM, H4SiO4, and PO4 competed with As for sorption sites on Fe-oxides. The effects of DOM on As mobility by DOM-mediated or -triggered redox reactions were apparently stronger in the co-presence of H4SiO4 and PO4 than DOM competition with arsenate for sorption sites on Fe-oxide alone. These findings advance our understanding of As mobilization processes in natural systems and can provide information for soil As management.
AU  - Aftabtalab, Adeleh
AU  - Moreno-Jiménez, Eduardo
AU  - Henschel, Jonas
AU  - Nowak, Sascha
AU  - Schaller, Jörg
AU  - Knorr, Klaus-Holger
DA  - 2022-09-22
DO  - 10.17879/22049445235
KW  - arsenic
KW  - DOM
KW  - Fe-oxide
KW  - goethite
KW  - phosphate
KW  - redox reaction
KW  - silicic acid
LA  - eng
N1  - Water 14 (2022) 19, 2975, 1-15
N1  - Finanziert durch den Open-Access-Publikationsfonds der Westfälischen Wilhelms-Universität Münster (WWU Münster).
N1  - Förderer: Deutsche Forschungsgemeinschaft / Projektnummer: 327633020
N1  - Funding organisation: Deutsche Forschungsgemeinschaft / Project number: 327633020
PY  - 2022-09-22
TI  - The Impact of Dissolved Organic Matter on Arsenic Mobilization from Goethite in the Presence of Silicic Acid and Phosphate under Reducing Conditions
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:6-92039533155
Y2  - 2024-11-22T05:59:19
ER  -