Kinetics and Mechanism of Photopromoted Oxidative Dissolution of Antimony Trioxide

被引：56
作者：
Hu, Xingyun [1 ]
Kong, Linghao [1 ]
He, Mengchang [1 ]
机构：
[1] Beijing Normal Univ, Sch Environm, State Key Lab Water Environm Simulat, Beijing 100875, Peoples R China
来源：
ENVIRONMENTAL SCIENCE & TECHNOLOGY | 2014年 / 48卷 / 24期
基金：
美国国家科学基金会; 中国国家自然科学基金;
关键词：
NATURAL-WATERS; PHOTOINDUCED OXIDATION; SB(III); DEGRADATION; ENVIRONMENT;
D O I：
10.1021/es503245v
中图分类号：
X [环境科学、安全科学];
学科分类号：
08 ; 0830 ;
摘要：
Light (sunlight, ultraviolet, simulated sunlight) irradiation was used to initiate the dissolution of antimony trioxide (Sb(2)O3). Dissolution rate of Sb2O3 was accelerated and dissolved trivalent antimony (Sb(III)) was oxidized in the irradiation of light. The photopromoted oxidative dissolution mechanism of Sb2O3 was studied through experiments investigating the effects of pH, free radicals scavengers, dissolved oxygen removal and Sb2O3 dosage on the release rate of antimony from Sb2O3 under simulated sunlight irradiation. The key oxidative components were hydroxyl free radicals, photogenerated holes and superoxide free radicals; their contribution ratios were roughly estimated. In addition, a conceptual model of the photocatalytic oxidation dissolution of Sb2O3 was proposed. The overall pH-dependent dissolution rate of Sb2O3 and the oxidation of Sb(III) under light irradiation were expressed by r = 0.08 [OH](0.63) and r(ox) = 0.10 [OH](0.79). The present study on the mechanism of the photo-oxidation dissolution of Sb2O3 could help clarify the geochemical cycle and fate of Sb in the environment.
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页码：14266 / 14272
页数：7
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