Anaerobic membrane bioreactor coupled with gac fluidization for wastewater treatment -

Abstract

An experimental program consisting of the operation of an AnFMBR and AnFMBR-MEC reactors was conducted for a period of 273 days. The work done consisted of gas, fouling, energy, effluent and microbial analysis. The first part of the results which includes the two AnFMBR reactors performance will be presented in Lea Issa’s thesis titled Anaerobic Membrane bioreactor coupled with GAC fluidization for wastewater treatment. The second part of the results which includes the AnFMBR-MEC reactors performance will be presented in Olga El Kik’s thesis. The membrane technology has evolved into an effective treatment technology, with the anaerobic membrane bioreactor (AnMBR) offering a potential for energy sustainability, pollution control, and waste management. However, these systems are still associated with several operational challenges such as membrane fouling and loss of energy through dissolved methane. This paper aims at improving the AnMBR process by proposing a new configuration with a hollow fiber membrane (HFM) and Granular Activated Carbon (GAC) fluidization. The configuration was operated at room temperature and was fed with synthetic wastewater for a period of 264 days. Two identical AnFMBRs were operated at a hydraulic retention time (HRT) of 1.5 day and an organic loading rate (OLR) of 0.43-0.31 Kg substrate-m3.day. The membrane flux was set to 6.5 L-m2-h throughout the experiment and the transmembrane pressure (TMP) was around 5 KPa after 87 days of start-up. TMP increased slightly after that period and reached a TMP value of 10 kpa by day 134 for AnFMBR1 and day 166 for AnFMBR2 without any chemical cleaning for the membrane which is considered a long period compared to reported literature. The methane yield of the two AnFMBRs was on average 0.26 and 0.13 L-g.COD removed at an OLR of 0.43 and 0.31 Kg substrate-m3.day respectively. The COD removal ranged between 80-99 percent for both reactors. The energy needed to operate the AnFMBR (0.06 kWh-m3) was significantly less than that required in an AnMBR