Development and performance of a dynamic membrane for anaerobic wastewater treatment – an analysis with different mesh pore sizes and configurations

Abstract

Recent studies have focused on proposing materials with larger pores and lower cost to replace conventional membranes. This study aims to investigate the performance of an anaerobic dynamic membrane bioreactor (AnDMBR) at pilot scale, acting as a post-treatment for an Upflow Anaerobic Sludge Blanket (UASB) reactor treating sewage, for the removal of complementary organic matter, focusing on the module design, dynamic layer formation and process performance. The configurations tested on this study were: UASB followed by stone filter and three AnDMBRs in series with polyester pore sizes of 100 μm, 50 μm, and 5 μm; UASB followed by disc filter and the three AnDMBRs in series; UASB followed by the three AnDMBRs in series; and UASB reactor with only one AnDMBR module. Regarding the studied configurations, high removals of total suspended solids, chemical oxygen demand, and turbidity were achieved in all experimental setups. The use of stone and disc filters did not bring clear benefits to the system concerning the direct application of filtration with dynamic membranes, therefore, their removal in the system was favorable. The dynamic membrane formation was faster in the 50 μm mesh, and only a few hours were necessary to obtain a permeate quality with a total suspended solids concentration and a turbidity lower than 15 mg·L−1 and 30 NTU, respectively. Thus, the dynamic membrane technology proved to be a potential solution in the post-treatment of UASB reactor effluents. HIGHLIGHTS Dynamic membranes are promising alternatives for the post-treatment of UASB wastewater.; Polyester mesh pore sizes of 50 μm are an inert and low-cost material for the fabricate of dynamic membranes.;

Keywords

• domestic wastewater
• dynamic layer
• filtration
• polyester mesh
• post-treatment
• uasb reactor