Investigating the effect of colloids on the performance of a biofilm membrane reactor (BF-MBR) for treatment of municipal wastewater

Abstract

Performance of membrane reactor in combination with moving-bed-biofilm reactor (BF-MBR) for treatment of municipal wastewater was investigated in relation to different organic loading rates; high and low rates. The membrane was operated with a constant flux of 50 LMH and 96% recovery. The fouling rate was evaluated as development of the trans-membrane pressure (TMP) during the operational time. Suspended solids (SS) concentrations, organic matter (COD/FCOD), particle size distributions (PSD), capillary suction time (CST) and time to filter (TTF) were measured daily and further related to TMP in order to determine major fouling factors. A higher fouling potential was observed for high-rate operating conditions. A fraction of organic matter below 1.2 μm was mostly related to changes in TMP. Furthermore, a higher amount of particulate fraction below 0.1 μm in membrane reactors during high-rate operating conditions presented a dominant contribution to membrane fouling and colloidal fouling.

Optimizing the MBBR System and Integrating Nanoparticles to Improve Wastewater Treatment Efficiency

“…One of the most important operation conditions is the carrier filling ratio which produces the amount of surface area available for biofilm growth and is considered a critical factor for the removal of pollutants in the MBBR system (Zhao, Liu, et al, 2019). Typically, MBBR performance depends on a filling percentage of about 60% to 70% of the empty reactor (Leiknes & Ødegaard, 2001). However, a high filling percentage can reduce efficiency due to mixing issues and carrier discrepancies, leading to a lack of biofilm formation on the outer surface of the carriers.…”