Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798, Singapore.
Singapore Membrane Technology Centre, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore.
Water Res. 2019 May 1;154:72-83. doi: 10.1016/j.watres.2019.01.044. Epub 2019 Feb 4.
In this study, permeate quality, membrane performance, and microbial community in a gravity-driven microfiltration (GDM) reactor and a biofiltration (BF) + GDM reactor for seawater reverse osmosis (RO) desalination pretreatment were compared at both lab-scale and pilot-scale. The presence of BF column was more efficient in removing soluble organic substances by biosorption/biodegradation, leading to superior permeate quality from BF + GDM and subsequently lower RO fouling than GDM. Compared to the biofilm-saturated anthracite media, the granular activated carbon media in BF improved the assimilable organic substances removal in BF + GDM. Although less organic substances and microbial cells were accumulated on the membrane in BF + GDM, its permeate flux was 10-20% lower than GDM. Furthermore, BF lowered the amounts and diversity of prokaryotes (due to less organic substances) and eukaryotes (due to BF media rejection and lacking of prokaryotic preys) in the membrane biofilm of BF + GDM, but did not cause significant shifts of predominant species. Thus, the lower flux in BF + GDM was attributed to the limited predation and movement of eukaryotes in membrane biofilm, which may result in the formation of less porous and compact biofilm layer. The cost analysis indicated that BF + GDM-RO requires 5.2% less operating cost and 1.5% less water production cost than GDM-RO.
本研究比较了重力驱动微滤（GDM）和生物过滤（BF）+GDM 反应器在实验室规模和中试规模下用于海水反渗透（RO）淡化预处理时的渗透质量、膜性能和微生物群落。BF 柱的存在通过生物吸附/生物降解更有效地去除可溶性有机物，从而使 BF+GDM 的渗透质量更优，随后 RO 结垢程度更低。与生物膜饱和的无烟煤介质相比，BF 中的颗粒活性炭介质提高了 BF+GDM 中可同化有机物的去除率。尽管 BF+GDM 中膜上积累的有机物质和微生物细胞较少，但渗透通量比 GDM 低 10-20%。此外，BF 降低了 BF+GDM 膜生物膜中原核生物（由于有机物质较少）和真核生物（由于 BF 介质排斥和缺乏原核生物猎物）的数量和多样性，但没有引起主要物种的显著变化。因此，BF+GDM 中较低的通量归因于膜生物膜中真核生物的有限捕食和运动，这可能导致形成较少多孔和致密的生物膜层。成本分析表明，与 GDM-RO 相比，BF+GDM-RO 所需的运行成本降低 5.2%，水生产成本降低 1.5%。
