Ding An, Wang Jinlong, Lin Dachao, Zeng Rong, Yu Shengping, Gan Zhendong, Ren Nanqi, Li Guibai, Liang Heng
State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin, 150090, PR China.
Chemosphere. 2018 Jan;191:253-261. doi: 10.1016/j.chemosphere.2017.10.034. Epub 2017 Oct 7.
Gravity-driven membrane filtration (GDM) is promising for decentralized rainwater recycling, owing to low maintenance and energy consumption. However, the organic removal by GDM process is sometimes undesirable and the quality of the permeate cannot meet the standard of water reuse. To improve this, granular activate carbon (GAC) was added as a particle layer on the membrane surface of GDM system. Additionally, a system with sand addition and a system with no particle addition were trialed as comparisons, to study the combined effects of particle hindering and adsorption on the removal efficacy of organics and the development of permeate flux. Results showed that GDM with a GAC layer improved removal efficiency of organics by 25%, and that GAC enhanced removal of florescent compounds (e.g., aromatic proteins, tryptophan proteins and humics), compared with the other two systems. Additionally, the permeate flux in three systems stabilized after Day 25, and kept stable until the end of the operation. However, the presence of GAC layer decreased the level of stable flux (3.2 L/mh) compared with the control system (4.5 L/mh). The factors responsible for the lower flux and severe membrane fouling in GAC layer assisted system were the combined effects of particle and adsorption which led to a denser bio-fouling layer with higher amount of biomass and extracellular polymeric substances contents (proteins and polysaccharides). Resistance distribution analyses revealed that GAC layer mainly increased hydraulically reversible resistance (occupied 93%) of the total resistance, indicating that the flux could be recovered easily by simple physical cleaning.
重力驱动膜过滤（GDM）由于维护成本低和能耗低，在分散式雨水循环利用方面具有广阔前景。然而，GDM工艺对有机物的去除效果有时不尽人意，渗透液质量无法达到中水回用标准。为改善这一情况，在GDM系统的膜表面添加了颗粒活性炭（GAC）作为颗粒层。此外，还试验了添加沙子的系统和不添加颗粒的系统作为对照，以研究颗粒阻碍和吸附对有机物去除效果及渗透通量发展的综合影响。结果表明，带有GAC层的GDM提高了25%的有机物去除效率，与其他两个系统相比，GAC增强了对荧光化合物（如芳香族蛋白质、色氨酸蛋白质和腐殖质）的去除。此外，三个系统的渗透通量在第25天后趋于稳定，并在运行结束前保持稳定。然而，与对照系统（4.5 L/mh）相比，GAC层的存在降低了稳定通量水平（3.2 L/mh）。GAC层辅助系统中通量较低和膜污染严重的原因是颗粒和吸附的综合作用，导致形成了一个更致密的生物污染层，其生物量和胞外聚合物物质含量（蛋白质和多糖）更高。阻力分布分析表明，GAC层主要增加了总阻力中水力可逆阻力（占93%），这表明通过简单的物理清洗即可轻松恢复通量。
