Dynamics of the Fouling Layer Microbial Community in a Membrane Bioreactor

Abstract

Membrane fouling presents the greatest challenge to the application of membrane bioreactor (MBR) technology. Formation of biofilms on the membrane surface is the suggested cause, yet little is known of the composition or dynamics of the microbial community responsible. To gain an insight into this important question, we applied 16S rRNA gene amplicon sequencing with a curated taxonomy and fluorescent in situ hybridization to monitor the community of a pilot-scale MBR carrying out enhanced biological nitrogen and phosphorus removal with municipal wastewater. In order to track the dynamics of the fouling process, we concurrently investigated the communities of the biofilm, MBR bulk sludge, and the conventional activated sludge system used to seed the MBR system over several weeks from start-up. As the biofilm matured the initially abundant betaproteobacterial genera Limnohabitans, Hydrogenophaga and Malikia were succeeded by filamentous Chloroflexi and Gordonia as the abundant species. This study indicates that, although putative pioneer species appear, the biofilm became increasingly similar to the bulk community with time. This suggests that the microbial population in bulk water will largely determine the community structure of the mature biofilm.

Treatment of Palm Oil Mill Effluent Using Membrane Bioreactor: Novel Processes and Their Major Drawbacks

“…This implies that the TMP and flux have strong correlations with the fouling mechanism. From Figure 6, at the initial stage of the filtration process, as the flux increases at a steady d(TMP)/dt rate, the fouling rate (blue curve) is almost constant [206]. However, the maximum permeability was attained at a critical flux of 12 LMH, in which further increase yielded a steep declination of permeability and a sharp increase in membrane fouling (red line).…”

“…However, the membrane is more susceptible to fouling under an anaerobic condition at high MLSS concentration. This is because as the activated sludge aged (SRT), the viscosity increases and the foulants such as particulates, EPS and SMP easily get polarized on the membrane to form cake layer [206,207]. However, some of the noticeable approach used to mitigate fouling in AnMBR system includes BAF [62] and intermittent frequent filtration-relaxation [201] which have presented some improvement in terms of steady filtration and pollutants removals, particularly the COD and TSS.…”

Genomic profiling of four cultivated Candidatus Nitrotoga spp. predicts broad metabolic potential and environmental distribution

“…Recent 16S rRNA-based molecular surveys have identified Ca. Nitrotoga-like sequences in a wide range of habitats, including: glacial soils [14][15][16][17], an underground cave [18], a freshwater seep [19], drinking water [20,21], a subglacial Antarctic lake [22], Yellow Sea seawater [23], salt marsh sediments [24], rivers [25,26], and various wastewater treatment plants (WWTPs) or sequence batch reactors [13,[27][28][29][30][31][32]. The relative abundance of Ca.…”

The Best-Practice Organism for Single-Species Studies of Antimicrobial Efficacy against Biofilms Is Pseudomonas aeruginosa

“…Biofouling is also considered the “Achilles heel” of RO because even if 99.9% of the microorganisms are removed from the membrane, the remaining microorganisms can re-form a biofilm [ 9 ]. Moreover, treating biofilms is a complex problem because the components of biofilms vary depending on the type of microorganisms in the water and on the environmental and operational conditions [ 25 ].…”