永寿大骨节病区硒的氧化还原电位及腐殖酸等的影响

以大骨节病病区土壤溶液环境为背景,研究了土壤溶液中E_HSe(Ⅵ)/Se(Ⅳ)]—pH关系及天然环境中主要的氧化还原剂腐殖酸、MnO_2、Fe~(2+)等对硒氧化还原性质的影响。腐殖酸和Fe~(2+)可提高Se(Ⅵ)/Se(Ⅳ)体系的还原能力,MnO_2对Se(Ⅳ)有一定的氧化作用,而腐殖酸和Fe~(2+)只有在低pH条件下才对Se(Ⅵ)有弱的还原作用。几种含硫化合物还原Se(Ⅵ)的能力依次为:硫代乙醇酸>L-半胱氨酸>硫化物。

REDOX POTENTIAL OF SELENIUM IN YONGSHOUKASCHIN-BECK DISEASE REGION AND THE INFLUENCEOF HUMIC ACID ON EH [Se(VI)/Se(IV)]

The relation between EH Se(VI)/Se(IV)] and pH of soil solution in Kaschin-Beck Disease region and the effects of natural redox agents, namely humic substances, MnO2 and Fe2+, on the redox property of the system were studied. The results indicated that both humic acid and Fe2+ could enhance the reducibility of Se(VI)/Se (IV) and MnO2 had a limited dxidisability for Se(IV). Fe2+ showed a week reducibility only at low pH value. The reducibilities of three sulfur-containing compounds for Se(VI) were in following order. sulfo-ethanol acid > L-cystine > sulfide.