基于EEM-PARAFAC解析厌氧生物滤池对城市污染河流中DOM的转化特性

为探究厌氧生物滤池(AF)处理城市污染河流的最佳工况和运行效能，以新河河水为研究对象，运用三维荧光光谱结合平行因子法(EEM-PARAFAC)，研究AF中试试验系统在不同水力停留时间(HRT)及温度条件下对溶解性有机物(DOM)的转化特性. 结果表明:①河水中DOM主要包含3种荧光组分，其中，C1为类腐殖质物质，C2为类蛋白物质，C3为类腐殖质物质，类蛋白和类腐殖质物质平均占比分别为53.45%和46.55%. ②AF运行稳定后COD平均去除率为30.75%，出水UV₂₅₄降低19.80%；荧光组分分析表明，DOM的降低主要归因于C2和C3的有效转化，且提高温度和HRT有助于DOM的进一步降低. ③UV₂₅₄和<10 kDa的DOM沿程逐步减小，3~10 kDa和<3 kDa的DOM去除率分别为64.29%和22.81%；沿程出水三维荧光光谱显示，AF前端微生物活性较高，C1和C3变化较小，C2先升高后逐步下降，最终出水DOM总荧光强度出现明显的降低，表明AF第1级滤层是DOM去除和转化的主要区域. 研究显示，常温且HRT=24 h工况下，AF能够在一定程度上将难降解有机物转化为易降解有机物，有效去除城市污染河流中的DOM，可作为处理城市污染河流的潜在预处理手段. 

Analysis of DOM Transformation in Polluted Urban Rivers by Anaerobic Biofilter Based on EEM-PARAFAC

In order to explore the optimal operating conditions and performance of anaerobic biofilters (AF) for treating polluted urban rivers (Xin River), the transformation characteristics of dissolved organic matter (DOM) in a pilot-scale AF at different hydraulic retention time (HRT) and temperatures were studied by using three-dimensional fluorescence spectroscopy and parallel factor analysis (EEM-PARAFAC). The results showed that: (1) DOM in the Xin River mainly contained three fluorescent components (C1, C2, C3), corresponding to humus-like, protein-like and humus-like substance, respectively. Protein-like and humus-like substances accounted for 53.45% and 46.55%, respectively. (2) When the AF was stable, 30.75% COD and 19.80% UV₂₅₄ were removed. Also, the analysis of fluorescent components indicated that the effective removal of C2 and C3 contributed to the transformation of DOM, and the increase of temperature and HRT increased the removal of DOM. (3) UV₂₅₄ and DOM with molecular weight <10 kDa gradually decreased along the filter. The removal rates of DOM with molecular weights 3-10 kDa and <3 kDa were 64.29% and 22.81%, respectively. Moreover, three-dimensional fluorescence spectrum of the effluent along the filter indicated that the microbial activities in the front of AF was higher. C1 and C3 changed slightly, C2 increased at first and then decreased gradually, the fluorescence intensity of DOM in the final effluent decreased significantly. It further demonstrated that DOM removal occurred mainly in the first filter layer of AF. In summary, AF could convert refractory organic matter into easily degradable organic matter and effectively remove DOM in polluted urban rivers under normal temperature and HRT=24 h, and could be used as an effective potential pretreatment to treat polluted urban river.