MBR工艺中溶解性有机物的分子量和EEM解析

Analysis of molecular weight and EEM of dissolved organic matter in MBR process

采用凝胶过滤色谱（GFC）分子量测定技术和三维荧光（EEM）光谱技术,对平板膜-生物反应器工艺应用于餐饮废水和粪便污水处理的工程实例进行研究,对比分析2套工艺中的调节池水和出水的溶解性有机物（DOM）及污泥胞外聚合物（EPS）的性质变化。研究表明,餐饮废水处理过程的调节池水DOM中大分子（〉100 kDa）物质比例为66.6%,数均分子量（Mn）为37.7 kDa,粪便污水处理过程的调节池水DOM中中等分子（10~50 kDa）物质的比例为57.9%,Mn=7.3kDa;然而,餐饮废水处理后的出水中DOM的Mn（34.3 kDa）明显小于粪便污水处理后出水（Mn=40.3 kDa）。MBR处理餐饮废水导致出水中紫外富里酸峰值发生了15 nm的红移,且峰值被削弱了51.5%,处理粪便污水过程中将调节池水DOM中仅存的色氨酸峰值削减了69.2%;出水中荧光性DOM含量明显降低,而且性质发生变化。

The projects of the flat sheet membrane bioreactor used for restaurant wastewater and fecal wastewater treatment were studied through gel filtration chromatography（GFC） and excitation-emission matrix（EEM） fluorescence spectra analysis.The characteristic variations of dissolved organic matter（DOM） in regulation tank and membrane effluent together with extracellular polymeric substances（EPS） in sludge of the two MBRs were analyzed.Results showed that the proportion of the larger molecules（100 kDa）substances in the regulation tank of restaurant wastewater treatment process was 66.6% and the number average molecular weight（Mn） was 37.7 kDa,while the proportion of middle molecules at 10~50 kDa substances in the regulation tank of fecal wastewater treatment process was 57.9% and the Mn was 7.3 kDa.In the meantime,the effluent Mn（34.3 kDa） of restaurant wastewater treatment process was much smaller than that（Mn=40.3 kDa） of fecal wastewater treatment process.In the restaurant wastewater treatment process,the peak of UV-fulvic acid in the membrane effluent was red-shifted by 15 nm along the emission axis and its intensity was reduced by 51.5% compared to that of wastewater in the regulation tank.In the fecal wastewater treatment process,the intensity of the unique peak of tryptophan in the regulation tank was reduced by 69.2%.The concentrations of the fluorescent DOM in effluents were obviously reduced and their characteristics were also changed.