Fouling mitigation through flocculants and adsorbents addition in membrane bioreactors: Comparing lab and pilot studies

The performance of pollutant removals, tetracycline (TC) and norfloxacin (NOR) removals, membrane fouling mitigation and the microbial community of three Anoxic/Oxic membrane bioreactors (AO-MBRs), including a moving bed biofilm MBR (MBRa), a fixed biofilm MBR (MBRb) and an AO-MBR (MBRc) for control, were compared in treating antibiotic-containing synthetic mariculture wastewater. The results showed that MBRb had the best effect on antibiotic removal and membrane fouling mitigation compared to the other two bioreactors. The maximum removal rate of TC reached 91.65% and the maximum removal rate of NOR reached 45.46% in MBRb. The addition of antibiotics had little effect on the removal of chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N)—both maintained more than 90% removal rate during the entire operation. High-throughput sequencing demonstrated that TC and NOR resulted in a significant decrease in the microbial diversity and the microbial richness MBRs. Flavobacteriia, Firmicutes and Azoarcus, regarded as drug-resistant bacteria, might play a crucial part in the removal of antibiotics. In addition, the dynamics of microbial community had a great change, which included the accumulation of resistant microorganisms and the gradual reduction or disappearance of other microorganisms under antibiotic pressure. The research provides an insight into the antibiotic-containing mariculture wastewater treatment and has certain reference value.

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Fouling Mitigation by Cationic Polymer Addition into a Pilot-Scale Anaerobic Membrane Bioreactor Fed with Blackwater

Polymers ◽

10.3390/polym12102383 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2383

Author(s):

Magela Odriozola ◽

Nicolás Morales ◽

Jose R. Vázquez-Padín ◽

Maria Lousada-Ferreira ◽

Henri Spanjers ◽

...

Keyword(s):

Membrane Fouling ◽

Large Scale ◽

Oxygen Demand ◽

Cationic Polymer ◽

Membrane Bioreactors ◽

Cod Removal ◽

Methanogenic Activity ◽

Filtration Performance ◽

Fouling Mitigation

Cationic polymers have proven to be suitable flux enhancers (FEs) in large-scale aerobic membrane bioreactors (MBRs), whereas in anaerobic membrane bioreactors (AnMBRs) research is scarce, and so far, only done at lab-scale. Results from MBRs cannot be directly translated to AnMBRs because the extent and nature of membrane fouling under anaerobic and aerobic conditions are different. Our research focused on the long-term effect of dosing the cationic polymer Adifloc KD451 to a pilot AnMBR, fed with source-separated domestic blackwater. A single dosage of Adifloc KD451 at 50 mg L−1 significantly enhanced the filtration performance in the AnMBR, revealed by a decrease in both fouling rate and total filtration resistance. Nevertheless, FE addition had an immediate negative effect on the specific methanogenic activity (SMA), but this was a reversible process that had no adverse effect on permeate quality or chemical oxygen demand (COD) removal in the AnMBR. Moreover, the FE had a long-term positive effect on AnMBR filtration performance and sludge filterability. These findings indicate that dosing Adifloc KD451 is a suitable strategy for fouling mitigation in AnMBRs because it led to a long-term improvement in filtration performance, while having no significant adverse effects on permeate quality or COD removal.

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Effects of a low-strength magnetic field on the characteristics of activated sludge for membrane fouling mitigation

RSC Advances ◽

10.1039/c8ra10013f ◽

2019 ◽

Vol 9 (16) ◽

pp. 9180-9186 ◽

Cited By ~ 2

Author(s):

Ren Zhijun ◽

Wang Pengfei ◽

Tian Jiayu ◽

Zhang Zhiliu

Keyword(s):

Magnetic Field ◽

Microbial Community ◽

Activated Sludge ◽

Membrane Fouling ◽

Membrane Bioreactors ◽

Sludge Characteristics ◽

Fouling Mitigation ◽

Low Strength

This study aims to investigate the performance of a low-strength magnetic field in membrane bioreactors (MBRs) for membrane fouling mitigation and its effects on sludge characteristics and microbial community.

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