基于有机物分子质量分布的饮用水处理工艺选择

Selection of Drinking Water Treatment Process Based on Molecular Weight Distribution of Organic Matters

为应对市内运河排洪造成的出水有机物超标问题,建立了臭氧/活性炭中试装置,采用滤膜法测试了运河水、现有水厂各工艺段及臭氧/活性炭出水中有机物的分子质量分布,在此基础上对现有水处理工艺进行了评价。结果表明,由于原水受到工业污染,其大分子有机物含量较高,并且亲水性强而易被氧化,造成混凝沉淀的去除效果不好,而运河水中的溶解性小分子有机物含量较高,也不易被混凝沉淀去除,采用臭氧/活性炭深度处理工艺是一个很好的选择。臭氧和活性炭联用提高对有机物去除效果的原因在于,臭氧能有效地氧化大分子有机物为小分子有机物,有利于活性炭的吸附、降解去除。

In order to solve the problem that the organic matters in the effluent exceed the standard due to flood discharge from urban canal, the pilot plant of ozone/activated carbon was set up. The molecular weight distributions （ MWD ） of organic matters in the canal water sample, the different existing process effluents and the ozone/activated carbon effluent were measured using membrane filtration method, and the different treatment processes were evaluated. The results show that contaminated by industry, the raw water has high-concentration organic matters with high molecular weight, which cannot be removed by coagulation and sedimentation due to their strong hydropfiilic and oxidable characteristics. Furthermore, the high-concentration dissolved organic matters with low molecular weight in the canal water cannot also be removed by coagulation and sedimentation. Therefore, the ozone/activated carbon process is a good choice. The reason of enhanced removal of organic matters by ozone/activated carbon is that the ozone can effectively oxidize organic matters with high molecular weight into organic matters with low molecular weight, which is favorable for the adsorption and degradation of organic matters by activated carbon.