不同诱导条件对结晶产物形貌特征的影响

在流化床反应器中,以含铜废水为处理对象,重点考察了诱导条件改变对结晶系统运行效率及结晶产物形貌特征的影响。结果表明,进水200 mg/L,进药比([Cu2+]/[CO32-])1:1.2,pH为10.2的条件下,铜离子去除率可接近100%,诱导晶种表面平滑,诱导颗粒生长成致密杆状晶体结构,以碳酸盐为沉淀剂的诱导结晶系统依赖于体系的pH,高pH体系下发生的共结晶现象是影响系统运行的主要原因;随着进药摩尔比的增加,结晶产物由短杆状向球状转化,晶体机械强度显著降低大量破碎,影响出水水质;进药比1:1.2,pH为11的条件下,含铜废水浓度为500 mg/L时,系统去除率可达95%以上,微晶产率低于5%。

Influence of different induced conditions on product characteristic by induced crystallization

A fluidized bed reactor was employed to treat copper containing wastewater.The effect of induced conditions on system removal efficiency and the products characteristic was investigated.Results showed that approximate 100% copper removal efficiency could be achieved when the influent copper concentration was 200 mg/L,pH value was 10.2,the molar ratio of [Cu2+]/[CO32-]/was 1:1.2.Regular rod-like crystals can be obtained.Co-crystallization was able to account for a poor removal efficiency under the high pH value condition.With the increase of carbonate to copper molar ratio,the morphology of the crystals changed from the rod-like to spherical,the surface of copper pellets was broken which greatly influenced the effluent water quality.About 95% copper removal efficiency could be achieved when the influent copper concentration was 500 mg/L,pH value was 11,the molar ratio of [Cu2+]/[CO32-] was 1:1.2.Fine productive rate was less than 5%.