无菌和有菌体系下砷黄铁矿氧化的电化学

在无菌和有菌酸性体系下,对砷黄铁矿电化学氧化进行研究。研究结果表明:砷黄铁矿首先被氧化为As2s2,覆盖于电极表面,使电极表面发生钝化;随着电位升高,As2S2被氧化生成亚砷酸及亚砷酸被氧化为砷酸,亚铁离子被氧化成铁离子;细菌作用后增强了砷黄铁矿的反应性能,降低了其开始氧化的电位,砷黄铁矿被氧化的趋势增大,腐蚀反应速度有所提高,但细菌对砷黄铁矿电极的阳极反应过程机理并没有产生影响;在相同电位下,有细菌时的阻抗明显低于无细菌时的阻抗;在不同电位下,电极表面发生的电化学反应机理也不同,测定结果与线性扫描研究结果相吻合。

Electrochemical aspects of oxidation of arsenopyrite in the presence and absence of thiobacillus ferrooxidans

The electrochemical research of asenopyrite in the presence and absence of thiobacillus ferrooxidans in acidic growth media was investigated.The results show that asenopyrite is firstly oxidized to AS2S2,which covers the electrode and the dissolution of arsenopyrite is retarded. As2S2 is oxidized to H3AsO3, H3AsO3 to H3AsO4,and Fe2 is oxidized to Fe3 with the increase of potential.The reactive nature of arsenopyrite is enhanced and the initial oxidation potential decreases when thiobacillus ferrooxidans are in the solution.The tendency of being oxidized and the corrosion rate increase compared to that in absence of thiobacillus ferrooxidans,but the reaction mechanism of arsenopyrite of anode process is not changed.The resistance in the presence of thiobacillus ferrooxidans is obviously lower than that in the absence of thiobacillus ferrooxidans.The proposed reaction mechanism confirms the results obtained in liner polarization satisfactorily.