Research on Operation Efficiency and Membrane Fouling of A2/O-MBR in Reclaimed Water Treatment

Abstract

Taking the public building domestic wastewater as an example, the combination of the MBR (membrane bioreactor) process and the traditional A2/O (anaerobic-anoxic-oxic) process was established and analyzed in terms of the removal effect of the pollutants, the impact of the microbial community changes on the process, the MBR membrane fouling, the cleaning methods, and the cleaning performance. The results indicated that the effluent water quality of the domestic wastewater treated with the A2/O-MBR process was stable and met the emission requirement to the natural water body. There was good microbial diversity in raw water, the anaerobic tank, the anoxic tank, the aerobic MBR tank and the disinfection tank, and the aerobic MBR tank has a wide variety of aerobic microorganisms, which elevates the removal of organics and the nitrification of ammonia nitrogen and ensures the qualification of nitrogen and phosphorus indexes of the system effluent water. For the fouled membrane, the surface of the contaminated membrane was covered by macromolecular contaminants, causing the membrane flux to drop, and after different cleaning methods to the membrane were compared, it was discovered that the combined use of cleaning agents had better effects than the single ones, and the cleaning method of sodium hydroxide followed by hydrochloric acid showed the best effect, achieving a membrane flux restoration ratio above 80% after cleaning.

Treatment of Hydrothermal-Liquefaction Wastewater with Crossflow UF for Oil and Particle Removal

“…Increasing the pH value to 12 helped to increase the repulsive forces between the negatively charged membrane surface and the fouled organic compounds. This pH increase supports the hydrolysis and ionization of the carboxyl groups and hydroxyl groups, eventually leading to the detachment of the fouling layer [ 45 ]. The last cleaning step was chemical cleaning with an acid solution at pH 2.…”

Enhancing Rubber Industry Wastewater Treatment through an Integrated AnMBR and A/O MBR System: Performance, Membrane Fouling Analysis, and Microbial Community Evolution

“…In Phase 4, the anaerobic membrane sustained an organic loading of 7.39 ± 0.95 kg COD/m 3 /day, with the TMP marginally rising to 76 ± 5 kPa and flux stabilizing at 20 ± 3 LMH. This stabilization could be attributed to the efficiency of the in situ membrane cleaning protocols applied, such as periodic backwashing, which seems to control the fouling without leading to significant loss in permeability [ 49 ]. The oxic membrane, subjected to a lower organic loading rate throughout the phases (0.42 ± 0.11 to 4.32 ± 0.88 kg COD/m 3 /day), demonstrated a more subdued TMP increase from 24 ± 2 kPa to 30 ± 3 kPa, and the flux varied between 13 ± 2 and 9 ± 3 LMH.…”

Exploring the impact of hyper-quantity on the performance to access GHG emission in a full-scale A 2 O+MBR process: From predictions to implementation

“…The plant covered an area of approximately 2000 hectares, and severed population of around 1.65 million. The facility became functional in November 2013 with a designed treatment capability of 4.0 ×10 4 tons per day (Liu et al 2018). The daily real treated water volume was about 30,000-35,000 t/d, resulting from the membrane ux attenuation before September 2018.…”

“…The daily real treated water volume was about 30,000-35,000 t/d, resulting from the membrane ux attenuation before September 2018. In September 2018, the daily water production volume rose to 35,000-40,000 t/d, due to 16 membranes modules upgraded (Liu et al 2018). At this point the wastewater treatment process was operated with the near full designed capacity.…”