膜材料对膜曝气生物膜反应器性能影响的比较

Effects of membrane materials on performance of membrane aerated biofilm reactor

选择聚偏氟乙烯(PVDF)和聚丙烯(PP)中空纤维曝气膜作为膜曝气生物膜反应器(MABR)的膜组件材料,比较两种膜材料由于亲疏水性能、表面形态、生物相容性等性质的差别,对MABR挂膜启动速度、生物附着量、脱氮除碳及膜污染等性能的影响。研究显示,运行末期PVDF和PP膜纤维生物附着量分别为35.62 g·m^(-2)和30.63 g·m^(-2)。通过场发射扫描电子显微镜观察两种膜表面生物污染情况,PVDF膜纤维表面呈鱼鳞状结构,有效保护了膜孔不被微生物完全堵塞。在90 d的运行周期内以PVDF为曝气膜材料的MABR获得了90%以上的COD去除率和78%的TN去除率;而以PP为曝气膜的MABR由于运行后期曝气膜纤维污染严重仅得到了76.5%的COD去除率和49.1%的TN去除率。因此,PVDF曝气纤维更适于作膜曝气生物膜反应器的曝气膜。

Polyvinylidene fluoride（PVDF） and polypropylene（PP） were chosen as membrane materials to compare the effects of membrane materials on the start-up time, biomass, performance for nitrogen and carbon removals as well as membrane fouling in membrane aerated biofilm reactor（MABR）, resulting from their different hydrophilic and hydrophobic properties, surface morphology and biocompatibility. The results showed that the biomass on PVDF and PP membrane fibers were 35.62 g·m^-2 and 30.63 g·m^-2, respectively. The membrane fouling by microorganism was observed by using scanning electron microscope（SEM）. The surface of PVDF membrane fibers with scaly structure was found, which prevented the pores from being blocked by microorganism on the surface effectively. MABR equipped PVDF membrane fibers achieved COD removal efficiency of above 90% and TN removal efficiency of 78% during 90 days operation, while COD and TN removal efficiencies of MABR occupied with PP membrane fibers were kept 76.5% and 49.1%, respectively,owing to membrane fouling. It was suggested that PVDF membrane fibers should be more suitable for MABR.