An Ana-Ano-MBR system for nutrient removal from brewery wastewater at various nitrate recirculation ratios

Abstract

Anaerobic and anoxic variations were combined with membrane bioreactor to form an Anaerobic/Anoxic configuration in MBR-based (Ana-Ano-MBR) system for improving the system performance in terms of organic degradation and nutrient removal from brewery wastewater. The model of Ana-Ano-MBR system made from polyacrylic with the capacity of 42 liters was operated with organic loading rate of 0.75 kgCOD/m3.day. The results showed that for the nitrate recycling ratios of 100, 200, 300%, average NH4+-N and TN removal efficiencies of the model were 95.1 and 76.6, 98.5 and 89.6, 98.9 and 90.2%, respectively, and the output values of NH4+-N and TN were within the limits of Vietnam National Standards (QCVN 40:2011/BTNMT, column A). Treatment efficiencies of COD and TP were over 90% and below 60%, respectively, during the whole experiment period. Low phosphorus removal efficiency was the drawback of Ana-Ano-MBR system due to the lack of appropriate system configuration and operational conditions for PAOs’ growth and activity.