MIEX预处理技术对长江原水中有机物的去除效能

利用烧杯试验研究了磁性离子交换树脂（magnetic ion exchange resin，MIEX）预处理对长江原水中有机物的去除效能，以总溶解有机碳(DOC)、254 nm紫外吸收值(UV254)、有机物相对分子质量分布、有机物分级、紫外扫描以及消毒副产物生成量等指标进行表征.结果表明，长江水源水中的有机物主要为小分子亲水性有机物，其含量占有机物总量的50%以上；MIEX预处理可以有效降低水中有机物的含量，投加量为10 mL/L、接触时间为15 min时，DOC的去除率超过35%，相对分子质量和分级的测定结果表明，小分子亲水性部分有机物的去除导致了DOC去除效果的改善；从紫外扫描结果可看出，MIEX预处理对在190～250 nm波长时有强吸收的有机物去除效果非常明显，但对在高于250 nm波长处有吸收的有机物去除效果与混凝阶段的效果相近.

Removal Effect of Organics in Yangtze River Raw Water by MIEX Resin Pretreatment

Jar-tests were used to study the removal effect of organics by MIEX pre-treatment from Yangtze River raw water, in which molecular weight, fractionation, UV scan, disinfection by-products, DOC and UV₂₅₄were used to estimate the removal effect. The results showed that organics in raw water were mainly composed of low-molecular weight and hydrophilic fraction, which accounted for above 50% of total organics. Above 35% DOC was removed by MIEX pretreatment with a dosage of 10 mL/L and contact time of 15 min, which due to the removal of low molecular weight and hydrophilic organics. The results of UV scan showed that organics which had high adsorption between 190 nm and 250 nm were significantly removed by MIEX pretreatment, while the part that had high adsorption on wavelength above 250 nm could be removed similar to coagulation alone.