重力流膜生物反应器处理农村污水效能与机制

Performance and mechanism of gravity-driven membrane bioreactor for rural wastewater treatment

重力流膜生物反应器(GDMBR)具有低能耗、低维护和出水稳定的工艺特点,然而,目前关于利用GDMBR直接处理农村污水的相关研究较少,为此,探究GDMBR处理生活污水的通量变化规律、污染物去除效能以及不同膜孔径对其的影响。结果表明,GDMBR处理生活污水时可在无反冲洗条件下长期稳定运行,稳定通量为1.3~1.5 L/(m~2·h)。这是由于膜表面生物滤饼层内形成了疏松多孔结构,且膜孔内污染物含量极低。GDMBR工艺可在较低污泥质量浓度的前提下实现对COD和UV_(254)的高效去除,去除率分别为78%和85%,并有效保留污水中的氮源和磷源。此外,不同膜孔径对GDMBR工艺除污染效能的影响甚微,但微滤膜构成的GDMBR系统的稳定通量略高于超滤膜系统。

Gravity-driven membrane bioreactor(GDMBR)confers the process characteristics of low energy consumption,low maintenance and stable effluent.However,there is limited research on the direct treatment of rural domestic wastewater.This study investigates the pattern of flux variation and removal efficiency of pollutants using GDMBR process to treat domestic wastewater,as well as the influence of different membrane pore sizes on the treatment of domestic wastewater using GDMBR.The results indicate that the membrane flux of GDMBR process can be maintained at a steady state without any cleaning procedures during the long-term filtration in treating the domestic wastewater,with a steady flux of 1.3-1.5 L/(m 2·h).This is attributed to the formation of loose and porous structure within the bio-cake layer attached on the membrane surface,resulting in extremely low concentration of pollutants deposited within the membrane pores.With relatively low sludge concentration,the GDMBR process achieves high removal efficiency of COD and UV 254.The removal rates of 78%and 85%,respectively,while effectively retaining the nitrogen and phosphorus sources in the wastewater.Furthermore,different membrane pore sizes exhibits minimal effects on the removal efficiency of GDMBR process.However,the steady fluxes of the GDMBR system configured with microfiltration membranes are slightly higher than the GDMBR system integrated with ultrafiltration membranes.