Anaerobic submerged membrane bioreactor (AnSMBR) treating low-strength wastewater under psychrophilic temperature conditions

EPS and SMP dynamics at different heights of a submerged anaerobic membrane bioreactor (SAMBR)

“…Chromatographic analyses did not detect the presence of glucose at any of the points of measurement, so it appears that the glucose was completely consumed in the bottom of the reactor. Significant differences were also found between the values of points P4 and P5 under both test conditions, indicating that the membrane either removed or retained organic material, a phenomenon that has been reported in the literature in MBR [8,23,24]. Increasing the OLR produced higher percentages of COD removal at points P3, P4, and P5, whereas no significant differences occurred in the bottom of the reactor.…”

Long-term operation of a pilot scale anaerobic membrane bioreactor (AnMBR) for the treatment of municipal wastewater under psychrophilic conditions

“…During the last period with a HRT of 7 h and VLRs above 4 kg COD/m 3 d, a continuous increase in the tCOD of the effluent was observed, reaching effluent tCOD values of 125-250 mg O 2 /L and effluent BOD 5 of 40-125 mg O 2 /L at The mean value of total VFA in the effluent at a VLR of 2-2.5 kg COD/m 3 d was 21.2 ± 14.6 mg/L (composed of acetic, propionic, butyric acid at 68.5 ± 48.4%, 15.2 ± 9.5%, and 16.3 ± 11.1%, respectively). VLRs of 3.5-4.5 kg COD/m 3 d resulted in an increase of VFA, with effluent VFA concentrations of 47.2 ± 33.4 mg/L.The results obtained confirmed that AnMBR treating municipal wastewater at psychrophilic temperature (18 ± 2ºC) achieved effluent tCOD values below the legal discharge limit at HRT of 7-10 h and VLRs of 2.5 kg tCOD/m 3 d. Similar tCOD removal efficiencies were obtained byMartinez-Sosa et al, (2012), working at 20 ± 1ºC Kg COD/m 3 d and an HRT of 16 h when working with synthetic wastewater, however with municipal wastewater the COD removal efficiency averaged 69 % ± 10% Gao et al, ( 2014),. working with municipal wastewater at three temperatures (35ºC, 25ºC and 15ºC) with volumetric loading rates between 1.2-1.44 g COD/L d and a HRT of 6 h, reported a decrease in COD removal efficiency in correspondence with temperature, ranging from 74% to 67% and 51% respectively.…”

“…the work carried out byGao et al, (2014);Giménez et al, (2012);Martinez-Sosa et al,( 2012);Pretel et al, (2014) the startup was carried out at mesophilic conditions and the temperature was decreased stepwise (around 35ºC, 25ºC, 20ºC) Bae et al, (2014). indicate that the results reported were obtained after an acclimation period of 225 days at 25ºC.…”

A novel configuration for an anaerobic submerged membrane bioreactor (AnSMBR). Long-term treatment of municipal wastewater under psychrophilic conditions

“…The SMY value obtained in the current work is similar to that reported in literature. Martinez-Sosa et al (2012), using an AnSMBR and treating low-strength wastewater under psychrophilic conditions (20°C), obtained an average SMY of 0.24 N m 3 CH 4 / kg COD removed and 0.29 L CH 4 /g tCOD removed , considering the theoretical dissolved methane. Lin et al (2011) reported SMY of 0.26 L CH 4 /g tCOD removed by treating domestic wastewater in a submerged anaerobic membrane bioreactor.…”