State Key Laboratory of Urban Water Resources and Environments (SKLUWRE), School of Municipal and Environmental Engineering, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, PR China.
Water Res. 2011 Feb;45(5):2111-21. doi: 10.1016/j.watres.2010.12.023. Epub 2011 Jan 1.
This study focuses on organic membrane foulants in a submerged membrane bioreactor (MBR) process with pre-ozonation compared to an individual MBR using three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy. While the influent was continuously ozonated at a normal dosage, preferable organic matter removal was achieved in subsequent MBR, and trans-membrane pressure increased at a much lower rate than that of the individual MBR. EEM fluorescence spectroscopy was employed to characterize the dissolved organic matter (DOM) samples, extracellular polymeric substance (EPS) samples and membrane foulants. Four main peaks could be identified from the EEM fluorescence spectra of the DOM samples in both MBRs. Two peaks were associated with the protein-like fluorophores, and the other ones were related to the humic-like fluorophores. The results indicated that pre-ozonation decreased fluorescence intensities of all peaks in the EEM spectra of influent DOM especially for protein-like substances and caused red shifts of all fluorescence peaks to different extents. The peak intensities of the protein-like substances represented by Peak T(1) and T(2) in EPS spectra were obviously decreased as a result of pre-ozonation. Both external and internal fouling could be effectively mitigated by the pre-ozonation. The most primary component of external foulants was humic acid-like substance (Peak C) in the MBR with pre-ozonation and protein-like substance (Peak T(1)) in the individual MBR, respectively. The content decrease of protein-like substances and structural change of humic-like substances were observed in external foulants from EEM fluorescence spectra due to pre-ozonation. However, it could be seen that ozonation resulted in significant reduction of intensities but little location shift of all peaks in EEM fluorescence spectra of internal foulants.
本研究聚焦于采用预臭氧化的浸没式膜生物反应器（MBR）工艺中的有机膜污染物，通过三维激发-发射矩阵（EEM）荧光光谱法与单独的 MBR 进行比较。在连续以正常剂量臭氧化进水的过程中，后续 MBR 中实现了更好的有机物去除效果，且跨膜压力的增加速度明显低于单独的 MBR。采用 EEM 荧光光谱法对溶解有机物（DOM）样品、胞外聚合物（EPS）样品和膜污染物进行了表征。在两个 MBR 的 DOM 样品的 EEM 荧光光谱中可以识别出四个主要峰。其中两个峰与蛋白质类荧光团有关，另外两个峰与腐殖质类荧光团有关。结果表明，预臭氧化降低了进水 DOM 的 EEM 光谱中所有峰的荧光强度，特别是对蛋白质类物质的影响更为显著，并导致所有荧光峰发生不同程度的红移。EPS 光谱中代表蛋白质类物质的峰 T(1)和 T(2)的峰强度由于预臭氧化而明显降低。预臭氧化可以有效减轻内外两种污染。经预臭氧化的 MBR 中外部污染物的主要成分是腐殖酸类物质（峰 C），而单独的 MBR 中则是蛋白质类物质（峰 T(1)）。由于预臭氧化，在外部污染物的 EEM 荧光光谱中观察到蛋白质类物质的含量减少和腐殖质类物质的结构变化。然而，臭氧化导致内部污染物的所有峰的强度显著降低，但位置变化不大。
