地表条件下毒砂氧化作用与水溶液pH的关系

RELATIONSHIP BETWEEN OXIDATION OF ARSENOPYRITE AND pH OF THE SOLUTIONS (1.8-12.6) UNDERSURFACE WATERCONDITION

用混合流反应器研究了毒砂在溶解氧（DO）浓度为8mg/L和温度为35℃条件下的氧化作用与水溶液pH的关系。结果显示，毒砂氧化释放的溶解As浓度随溶液pH升高呈V字形变化，在pH7～8之间最低。D0氧化毒砂释放的As主要有As（Ⅲ）和As（∨），以As（Ⅲ）为主，As（Ⅲ）／As（V）的比例与溶液pH变化没有关系。

The relationship between oxidation of arsenopyrite and pH of the solutions （1.8- 12.6） was investigated using a mixed flow reactor at dissolved oxygen（DO）concentrations of 8 mg/L and temperature of 35 ~C. The results showedthat the dissolved As concentrations varied in the V-shaped modewith increasingpH of the solutions, that is, the minimum dissolved As concentrations appeared at pH 7 - 8. Speciation of dissolved As at the end of the experiments showed the presence of both As（Ⅲ） and As （Ⅴ）, although As （Ⅲ） was the dominant species （ 〉 75 % ） in the majority of the experiments. The As （Ⅲ）/As （V） ratio showed no variation with the pH ofihe solutions inthe experiment.