Institute of Environmental Sciences and Engineering (IESE), School of Civil and Environmental Engineering (SCEE), National University of Sciences and Technology (NUST), Sector H-12, Islamabad, Pakistan E-mail:
Department of Engineering Science, Centre for Sustainable Water Engineering, The University of Oxford, Parks Road, Oxford OX1 3PJ, UK.
Water Sci Technol. 2014;69(7):1403-9. doi: 10.2166/wst.2014.007.
In this study, three laboratory scale submerged membrane bioreactors (MBRs) comprising a conventional MBR (C-MBR), moving bed MBR (MB-MBR) and anoxic-oxic MBR (A/O-MBR) were continuously operated with synthesized domestic wastewater (chemical oxygen demand, COD = 500 mg/L) for 150 days under similar operational and environmental conditions. Kaldnes(®) plastic media with 20% dry volume was used as a biofilm carrier in the MB-MBR and A/O-MBR. The treatment performance and fouling propensity of the MBRs were evaluated. The effect of cake layer formation in all three MBRs was almost the same. However, pore blocking caused a major difference in the resultant water flux. The A/O-MBR showed the highest total nitrogen and phosphorus (PO4-P) removal efficiencies of 83.2 and 69.7%, respectively. Due to the high removal of nitrogen, fewer protein contents were found in the soluble and bound extracellular polymeric substances (EPS) of the A/O-MBR. Fouling trends of the MBRs showed 12, 14 and 20 days filtration cycles for C-MBR, MB-MBR and A/O-MBR, respectively. A 25% reduction of the soluble EPS and a 37% reduction of the bound EPS concentrations in A/O-MBR compared with C-MBR was a major contributing factor for fouling retardation and the enhanced filtration capacity of the A/O-MBR.
在这项研究中，三个实验室规模的浸没式膜生物反应器（MBR），包括一个传统的 MBR（C-MBR）、移动床 MBR（MB-MBR）和缺氧-好氧 MBR（A/O-MBR），在相似的操作和环境条件下，连续用合成生活污水（化学需氧量，COD=500mg/L）运行了 150 天。Kaldnes（®）塑料介质的干体积 20% 用作 MB-MBR 和 A/O-MBR 中的生物膜载体。评估了 MBR 的处理性能和结垢倾向。所有三个 MBR 中滤饼层形成的影响几乎相同。然而，孔堵塞导致水通量的差异很大。A/O-MBR 对总氮和磷（PO4-P）的去除率最高，分别为 83.2%和 69.7%。由于氮的去除率高，A/O-MBR 中的可溶性和结合态胞外聚合物物质（EPS）中的蛋白质含量较低。MBR 的结垢趋势分别为 C-MBR、MB-MBR 和 A/O-MBR 的 12、14 和 20 天过滤周期。与 C-MBR 相比，A/O-MBR 中可溶性 EPS 减少 25%，结合态 EPS 减少 37%，这是减缓结垢和提高 A/O-MBR 过滤能力的主要因素。
