Release kinetics of vanadium from vanadium titano-magnetite：The effects of pH, dissolved oxygen, temperature and foreign ions  

作　　者：Xingyun Hu Yuyan Yue Xianjia Peng 

机构地区：[1]National Engineering Laboratory for Industrial Wastewater Treatment, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China [2]Beijing Key Laboratory of Industrial Wastewater Treatment and Resource Recovery, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China [3]University of Chinese Academy of Sciences, Beijing 100190, China [4]School of Environment, Henan Normal University, Xinxiang 453007, China

出　　处：《Journal of Environmental Sciences》2018年第2期298-305,共8页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.21607166,41641034 and 41473113);the National Water Pollution Control and Treatment Science and Technology Major Project(No.2015ZX07205-003)

摘　　要：As part of a broader study of the environmental geochemistry behavior of vanadium（V）, the release kinetics of V from the dissolution of natural vanadium titano-magnetite under environmentally relevant conditions was investigated. In both the acidic and basic domains, the V release rate was found to be proportional to fractional powers of hydrogen ion and dissolved oxygen activities. The dependence of the rate on dissolved oxygen can also be described in terms of the Langmuir adsorption model. The empirical rate equation is given by： r= k′α（H＋）α（Kα（O2））/（1＋Kα（O2）） where, α = 0.099–0.265, k′ = 3.2 × 10-6–1.7 × 10-5, K =2.7 × 104–3.9 × 104 mol/L in acid solution（pH 4.1）, and α =-0.494-（-0.527）, k′ = 2.0 × 104–2.5 × 10-11, and K = 4.1 × 103–6.5 × 103 mol/L in basic solution（pH 8.8） at 20°C. Based on the effect of temperature on the release rate of V, the activation energies of minerals at p H 8.8 were determined to be 148–235 k J/mol, suggesting that the dissolution of vanadium titano-magnetite is a surface-controlled process. The presence of Na＋, Ca2＋, Mg2＋, K＋, NO3-, Cl-, SO42-and CO32-was found to accelerate the V release rates. This study improves the understanding of both the V pollution risk in some mine areas and the fate of V in the environment.As part of a broader study of the environmental geochemistry behavior of vanadium（V）, the release kinetics of V from the dissolution of natural vanadium titano-magnetite under environmentally relevant conditions was investigated. In both the acidic and basic domains, the V release rate was found to be proportional to fractional powers of hydrogen ion and dissolved oxygen activities. The dependence of the rate on dissolved oxygen can also be described in terms of the Langmuir adsorption model. The empirical rate equation is given by： r= k′α（H＋）α（Kα（O2））/（1＋Kα（O2）） where, α = 0.099–0.265, k′ = 3.2 × 10-6–1.7 × 10-5, K =2.7 × 104–3.9 × 104 mol/L in acid solution（pH 4.1）, and α =-0.494-（-0.527）, k′ = 2.0 × 104–2.5 × 10-11, and K = 4.1 × 103–6.5 × 103 mol/L in basic solution（pH 8.8） at 20°C. Based on the effect of temperature on the release rate of V, the activation energies of minerals at p H 8.8 were determined to be 148–235 k J/mol, suggesting that the dissolution of vanadium titano-magnetite is a surface-controlled process. The presence of Na＋, Ca2＋, Mg2＋, K＋, NO3-, Cl-, SO42-and CO32-was found to accelerate the V release rates. This study improves the understanding of both the V pollution risk in some mine areas and the fate of V in the environment.

关 键 词：VANADIUM Release rate Hydrogen ion Dissolved oxygen 

分 类 号：P574[天文地球—矿物学] X14[天文地球—地质学]