Model for the formation of arsenic contamination in groundwater. 1. Datong Basin, China

• Published in: Geochemistry international Vol. 47; no. 7; pp. 713 - 724
• Main Authors: Wang, Yanxin, Ma, Teng, Ryzhenko, B. N., Limantseva, O. A., Cherkasova, E. V.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01-07-2009; Springer Nature B.V
• Subjects: Arsenic; Carbon dioxide; Carbonate rocks; Earth and Environmental Science; Earth Sciences; Geochemistry; Geology; Groundwater pollution; Meteoric water; Organic matter; China, People's Rep; Carbonate Rock; Arsenic; Goethite; Geochemistry International; Siderite
• ISSN: 0016-7029; 1556-1968
• DOI: 10.1134/S0016702909070052

Mineral equilibria were analyzed in the system As-bearing rock-meteoric water. It was shown that carbonate rocks are the most probable source of As and Sr in the waters of the Datong Basin (People's Republic of China). The reason for groundwater enrichment in As is the shift of the equilibrium FeCO
3
(siderite) + H
2
O = FeOOH(goethite) + CO
2
(g) + H
2
(g) to the left (toward siderite formation) owing to organic matter oxidation by atmospheric oxygen and an increase in the equilibrium partial pressure of CO
2
, while the Eh of the system remains below −0.30 ± 0.06 V.