title: The role of rainwater-borne hydrogen peroxide in the release of arsenic from arsenopyrite.
abstract: A microcosm experiment was conducted to examine the effects of hydrogen peroxide (at a concentration range of 5-50 μM) on the release of arsenic from the dissolution of arsenopyrite, a dominant arsenic-bearing mineral occurring in natural environments. This was to simulate the reaction between rainwater-borne hydrogen peroxide and arsenopyrite grains exposed on the land surfaces during rainfall events. The results showed that the release of arsenic from arsenopyrite was enhanced by the H2O2 at this concentration range. It was also evident that H2O2 played an indirect role in the transformation of arsenite into arsenate in the solutions, which might affect the fate of the liberated arsenic species due to the formation of FeAsO4 precipitates. The preliminary study sheds some light on the possible role of rainwater-borne H2O2 in the weathering of arsenopyrite, which could complicate the geochemical processes governing the release, transport and fate of arsenopyrite-derived arsenic in natural environments. This provides a rationale for conducting additional laboratory-based investigations to obtain further insights into the chemical mechanisms and kinetics, and the subsequent field-scale study to validate the research findings.
authors: National Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors: Yingqun
authors: Y
authors: Ma
authors: National Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
authors: Yanwen
authors: Y
authors: Qin
authors: School of Environment and Life Science, University of Salford, Salford M5 4WT, UK; Australian Centre for Sustainable Catchments, University of Southern Queensland, Toowoomba QLD 4350, Australia. Electronic address: C.Lin@salford.ac.uk.
authors: Chuxia
authors: C
authors: Lin
mesh_terms: D001152:Arsenicals / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D058085:Iron Compounds / Q000737:chemistry*; D007700:Kinetics; D008903:Minerals / Q000737:chemistry*; D011891:Rain / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*
chemical_list: D001152:Arsenicals; D058085:Iron Compounds; D008903:Minerals; D013440:Sulfides; C064510:arsenopyrite; D006861:Hydrogen Peroxide
keywords: Arsenate; Arsenite; Arsenopyrite; Fenton reaction; Hydrogen peroxide; Rainwater