二氧化氯-接触催化氧化联合去除水中铁和锰

为了解决水体中铁锰季节性超标的问题,提出一种既能够减少化学试剂的使用又能有效去除铁锰的经济有效的方法。研究了单一方法(二氧化氯氧化法、接触催化氧化法)及两者联合对铁锰的去除效果,提出用二氧化氯氧化-锰砂过滤联合方法解决。研究表明,用ClO2氧化去除水中Fe2+的反应先发生、速率较快且效果较好,而与Mn2+反应则较慢并且不能完全转化为沉淀。单纯接触催化氧化法需要较长时间,过滤层才能达到稳定且较好的处理效果,培养过程中其除锰效果并不理想。两者联合时,利用过滤层的吸附作用去除部分铁锰,减少了氧化剂的使用。初期3个柱的除Mn2+效果都比较好,去除率均大于80%;然而采用石英砂或纤维束滤料的滤柱去除Mn2+的效果随时间变差,但采用锰砂的除锰效果在实验期间始终维持在较高水平。

Removal of Fe2+ and Mn2+ from water by chlorine dioxide oxidation-contact catalytic oxidation combined method

The experiments were carried out both in conical flask and in plexiglass columns aimed at comparing the effect of variable methods in removing excessive amounts of iron and manganese in water. Singular method (chlorine oxidation process and contact catalytic oxidation process) and combined method were investigated. And chlorine dioxide oxidation-manganese sand filtration coupled method is more efficient. The results indicated that chlorine reacted with ferrous ions firstly, so the rate of removing manganese from water took much time and the ions cannot be completely turned into precipitation. Filter bed took a long time to reach maturity during contact catalytic oxidation process and the corresponding removal rate of manganese was not ideal. As to the coupled methods (chlorine dioxide combined with filter material: quartz sand, fibrous bundle or manganese sand), removal rates were all above 80% during early stages. Whereas the effect of removing bivalent manganese decreased with time in 1^# and 2^# columns. In contrast, removal effect of manganese maintained at a higher level during the experimental period when manganese sand filtration method was applied.