水处理工艺过程中有机物分子量分布规律

针对太湖流域某湖泊水源有机物分子量分布的特性,考察饮用水处理各工艺单元对有机物的去除效应。结果表明:原水以小分子量有机物为主,小于1k Dalton的有机物占36.1%;常规工艺对大分子量有机物去除率高,尤其对分子量在10k Dalton以上的有机物去除率达32.7%以上,但对小分子量有机物去除率低,其中分子量小于1k Dalton的有机物反而增加了12.6%左右。超滤深度处理工艺中PES膜工艺对小分子量有机物,特别是分子量小于10kDalton的有机物去除率达76.4%,出水UV254值及SUVA值比砂滤出水分别下降了22.0%和11.2%;PVDF膜工艺对各分子量有机物均有较好的去除,但对大分子有机物去除效果优于小分子有机物,其出水UV254值及SUVA值比砂滤出水分别下降了28.8%和6.3%。

Molecular weight distribution of organic matter during water treatment process

In this study, the removal of organic matter was investigated during the drinking water treatment process based on the characteristics of the molecular weight distribution of organic matter in a lake in the Taihu Basin. The results show that a great majority of the raw water was characterized by low molecular weight of dissolved organic matter, in which the organic matter with a molecular weight of lower than 1 k Dalton accounted for 36.1% of the total DOC. The organic matter with high molecular weight in the water could be effectively removed by the conventional treatment. For the organic matter with molecular weight of higher than 10 k Dalton, especially, the removal rate reached 32.7% or higher, whereas there was a low removal rate for the organic matter with low molecular weight, in which the organic matter with molecular weight of lower than 1 k Dalton increased by 12.6%. The organic matter with low molecular weight could be effectively removed using the PES membrane technology. For the organic matter with molecular weight of lower than 10 k Dalton, especially, the removal rate reached 76.4%, and the values of UV2_s4 and SUVA decreased by 22.0% and 11.2%, respectively, with the PES membrane treatment, relative to the sand infiltration technology. The PVDF membrane technology could be used to effectively remove most organic matter with different molecular weights, and it was more effective when removing the organic matter with high molecular weight than that with low molecular weight. The values of UV~ and SUVA decreased by 28.81% and 6.29 %, respectively, with PVDF membrane treatment, relative to the sand infiltration technology.