Center for Molecular Discovery, University of New Mexico, Albuquerque, NM 87131, USA.
Water Res. 2013 Feb 1;47(2):747-57. doi: 10.1016/j.watres.2012.10.048. Epub 2012 Nov 7.
The goal of this study was to quantify and demonstrate the dynamic effects of hydraulic retention time (HRT), organic carbon and various components of extracellular polymeric substances (EPS) produced by microorganisms on the performance of submersed hollow-fiber microfiltration (MF) membrane in a hybrid powdered activated carbon (PAC)-MF membrane bioreactor (MBR). The reactors were operated continuously for 45 days to treat surface (river) water before and after pretreatment using a biofiltration unit. The real-time levels of organic carbon and the major components of EPS including five different carbohydrates (D(+) glucose and D(+) mannose, D(+) galactose, N-acetyl-D-galactosamine and D-galactose, oligosaccharides and L(-) fucose), proteins, and polysaccharides were quantified in the influent water, foulants, and in the bulk phases of different reactors. The presence of PAC extended the filtration cycle and enhanced the organic carbon adsorption and removal more than two fold. Biological filtration improved the filtrate quality and decreased membrane fouling. However, HRT influenced the length of the filtration cycle and had less effect on organic carbon and EPS component removal and/or biodegradation. The abundance of carbohydrates in the foulants on MF surfaces was more than 40 times higher than in the bulk phase, which demonstrates that the accumulation of carbohydrates on membrane surfaces contributed to the increase in transmembrane pressure significantly and PAC was not a potential adsorbent of carbohydrates. The abundance of N-acetyl-d-galactosamine and d-galactose was the highest in the foulants on membranes receiving biofilter-treated river water. Most of the biological fouling compounds were produced inside the reactors due to biodegradation. PAC inside the reactor enhanced the biodegradation of polysaccharides up to 97% and that of proteins by more than 95%. This real-time extensive and novel study demonstrates that the PAC-MF hybrid MBR is a sustainable technology for treating river water.
本研究的目的是量化并展示水力停留时间（HRT）、有机碳以及微生物产生的胞外聚合物（EPS）的各种成分对浸没式中空纤维微滤（MF）膜在混合粉末活性炭（PAC）-MF 膜生物反应器（MBR）中的性能的动态影响。在使用生物过滤单元进行预处理之前和之后，这些反应器连续运行 45 天以处理地表水（河流）。在进水、污染物和不同反应器的主体相中实时定量分析了有机碳和 EPS 的主要成分（包括五种不同的碳水化合物（D(+)葡萄糖和 D(+)甘露糖、D(+)半乳糖、N-乙酰-D-半乳糖胺和 D-半乳糖、低聚糖和 L(-)岩藻糖）、蛋白质和多糖）的水平。PAC 的存在延长了过滤周期，并使有机碳吸附和去除增加了两倍以上。生物过滤改善了滤液质量并减少了膜污染。然而，HRT 影响了过滤周期的长度，对有机碳和 EPS 成分的去除和/或生物降解的影响较小。MF 表面污染物中碳水化合物的丰度比主体相中高 40 多倍，这表明碳水化合物在膜表面的积累显著增加了跨膜压力，PAC 不是碳水化合物的潜在吸附剂。在接收生物滤过处理后的河水的膜上污染物中，N-乙酰-D-半乳糖胺和 D-半乳糖的丰度最高。由于生物降解，大部分生物污垢化合物是在反应器内部产生的。反应器内的 PAC 增强了多糖的生物降解，最高可达 97%，蛋白质的生物降解超过 95%。这项实时的广泛而新颖的研究表明，PAC-MF 混合 MBR 是一种可持续的处理河水的技术。
