Impact of support material type on performance of dynamic membrane bioreactors treating municipal wastewater

BACKGROUND: Membrane bioreactor (MBR) applications have been limited by high cost of membrane modules and fouling problems. Dynamic membrane (DM) technology can be a solution for these problems. Low-cost filters can be used as support materials for dynamic (cake) layer formation. The characteristics of support material play an important role on dynamic layer formation behavior. Therefore, the aim of this study was to investigate the impact of support material type on dynamic membrane bioreactor (DMBR) performance for municipal wastewater treatment. Hollow fiber support materials, made of polyester fabrics and glass fiber materials, were used for DM formation. RESULTS: Similar treatment performances were obtained with each membrane achieving high removal efficiencies for chemical oxygen demand (>97%) and total suspended solids (>99%) parameters. Higher transmembrane pressure (TMP) was observed for glass fiber material in comparison to polyester material. Based on morphological analyses, dynamic layers formed on both support materials had similar composition, organic and inorganic materials. A homogeneous layer was formed on polyester support material, while fine particles were deposited between the filaments of glass fiber support material, which caused clogging. CONCLUSION: Based on TMP results and morphological analyses, polyester support material provided better formation of DM layer. Thus selection of proper support material type is very important to achieve stable DM layer in DMBRs.