光谱表征评价2种不同预处理工程对DOM去除特征

为探究不同类型微污染水源预处理工程对水中溶解性有机物的去除特征,采用光谱表征结合多元统计方法,对盐龙湖预处理工程和通榆河预处理工程夏季各处理单元进出水水质进行研究。结果表明:夏季蟒蛇河及通榆河原水DO含量低于Ⅲ类水标准,蟒蛇河原水中a(254)较高,而通榆河原水中COD_Mn、BOD₅较高。盐龙湖预处理工程与通榆河预处理工程对COD_Mn、BOD₅、a(254)的去除率分别为4.19%、37.50%、1.55%和10.31%、23.49%、24.88%;从分子结构来看,盐龙湖预处理工程的预处理单元与通榆河预处理工程的高密度沉淀单元对DOM的改变最为明显,使DOM的浓度下降、分子量变小、苯环C的聚合程度增加。差异性分析表明:S_R与E₄₆₅/E₆₆₅、A₂/A₁、A₃/A₁呈显著正相关,a(355)与E₂₅₀/E₃₆₅呈显著负相关。该研究结果可为微污染水源预处理工程的优化运行及保障城市饮用水安全提供数据参考。

SPECTRAL CHARACTERIZATION OF ORGANIC REMOVAL PERFORMANCE OF TWO DIFFERENT WATER SOURCE PRETREATMENT PROJECTS

Spectral characterization combined with multivariate statistical method was used to monitor and analyze the variation of organic matter concentration and spectral indexes in the inlet and outlet water of each treatment unit in the Yanlong project and Tongyu project in Yancheng. The results showed that the content of dissolved oxygen in the raw water of the Tongyu River and the Mangshe River was lower than that of the class Ⅲ in surface water quality standards in summer. In terms of organic concentration, a(254) was higher in raw water of Yanlong Lake, while COD_Mn and BOD₅ were higher in raw water of Tongyu River. The removal rates of COD_Mn, BOD₅, a(254) and a(355) in the pretreatment engineering of Yanlong Lake and Tongyu River were 4.19%, 37.50%, 1.55% and 10.31%, 23.49%, 24.88%, respectively. From the perspective of molecular structure, the pretreatment unit of Yanlong project and high-density sedimentation unit of Tongyu project had the most obvious changes on DOM, resulting in a decrease in DOM’s concentration and molecular weight, and a rise in the degree of polymerization of carbon atoms in benzene ring. The difference analysis showed that S_R and E₄₆₅/E₆₆₅ had a significant positive correlation with A₂/A₁ and A₃/A₁ at 0.01 level, while a(355) had a significant negative correlation with E₂₅₀/E₃₆₅ at 0.01 level. The research results provide a theoretical basis for optimizing the operation of micro-polluted water source pretreatment engineering and safety ensuring of urban drinking water supply.