探讨U(Ⅵ)初始浓度、COD、SO42-、Cu2+、Fe0等对硫酸盐还原菌颗粒污泥(SRBGS)去除U(Ⅵ)的影响,讨论其去除U(Ⅵ)的稳定性,并利用XPS分析U(Ⅵ)还原产物的形态特征。结果表明:当COD为300~1500 mg/L时,随着COD浓度的升高,U(Ⅵ)的去除速率加快;SO42-浓度低于1500 mg/L对U(Ⅵ)的去除有促进作用;Cu2+浓度低于100 mg/L时,U(Ⅵ)还原未受显著影响,但当其增至200 mg/L时,U(Ⅵ)还原受到完全抑制;投加铁粉大大提高了U(Ⅵ)的去除速率,20 h内,U(Ⅵ)的去除率达到100%。SRB颗粒污泥能够长期使用,最佳水力停留时间12.5 h,NO3-能使已还原的U(Ⅵ)再氧化。XPS分析表明,颗粒污泥表面沉积或吸附了铀,且以U(Ⅳ)为主。
The effect of initial U(Ⅵ) concentration, COD, SO42-, Cu2+ and Fe0 on U(Ⅵ) removal by sulfate reducing bacteria granular sludge(SRBGS) for U(Ⅵ) removal was investigated. The removal stability was analyzed, then the deposit valence of uranium was studied. The results show that U(Ⅵ) reduction prefers a higher COD and SO42-concentration at the range of 300-1500 mg/L. U(Ⅵ) removal is accelerated with increasing COD concentration and can be promoted when SO42- concentration is less than 1500 mg/L. The existing of Cu2+ do not affect U(Ⅵ) removal appreciably when its concentration is less than 100 mg/L, but U(Ⅵ) removal can not be inhibited completely while its concentration reaches 200 mg/L. Adding iron greatly improves U(Ⅵ) removal rate, U(Ⅵ) removal rate reaches 100% within 20 h. The SRBGS sludge can be long-term used, and the optimal hydraulic stay time(HRT) is 12.5 h. U(Ⅵ) can be reoxidized by NO3-. XPS analysis results indicate that the deposition of U element on SRBGS in main valence of U(Ⅳ).