Selected abstracts by topic
Selected abstracts by topic
Our list is presented without preference. It was compiled by Simon Judd in July 2023, and may be updated in future as new papers are published.
The recently-announced commemorative Special Issue in the journal Membranes prompted us to consider research publications generally. Below is listed a 'top ten' of topical MBR research papers worth highlighting from the past ten years. Many of these address subjects that have been substantially overlooked in the academic literature, but they all provide useful information of some significance to MBR practitioners.
Note that all these publications are index-linked and have been captured via the SCOPUS database. Links to the abstracts are given below, together with a brief comment on each. Topics covered include:
- Sludge foaming
- Ragging
- Membrane ageing
- Life cycle analysis (LCA) and environmental impact assessment (EIA)
- Cost-benefit analysis
- PFAS
- Petroleum effluent treatment
- MBR sludge
- Pathogen rejection
- MABRs
Enjoy.
- Selected research papers:
Abstract
Read the abstract:
https://www.sciencedirect.com/science/article/abs/pii/S1369703X16303187Our comment: Two common operational challenges in municipal MBRs are membrane channel sludging and foaming. There’s almost no practical research at all into the former, and not a huge amount into the latter. The Campo et al (2017) paper provides a correlation between foaming propensity and EPS concentration (and therefore fouling), corroborating outcomes of previous research by the same authors but extending the study to different biochemical conditions produced by intermittent aeration.
Full Reference
Campo, R., Capodici, M., Di Bella, G., and Torregrossa, M. (2017). The role of EPS in the foaming and fouling for a MBR operated in intermittent aeration conditions. Biochemical Engineering Journal, 118, 41−52. doi:10.1016/j.bej.2016.11.012
Abstract
Read the abstract:
https://iwaponline.com/wst/article-abstract/67/4/810/17274/Ragging-phenomenon-characterisation-and-impact-in?redirectedFrom=fulltextOur comment: Ragging − the agglomeration of fibres into rags in the process or membrane tank of an MBR − is a widely observed phenomenon in full-scale municipal MBRs. Yet it's hardly mentioned in the literature. The Gabarrón et al (2013) paper is interesting since it demonstrates that over 90% of the fibres in the feed are below 1 mm in length, passing through the inlet screens and agglomerating to form rags around the membranes.
Full Reference
Gabarrón, S., Gómez, M., Monclús, H., Rodríguez-Roda, I., and Comas, J. (2013). Ragging phenomenon characterisation and impact in a full-scale MBR. Water Science and Technology, 67(4), 810-816. doi:10.2166/wst.2012.633
Abstract
Read the abstract:
https://www.sciencedirect.com/science/article/abs/pii/S1383586621014039Our comment: How long will MBR membranes last? A few laboratory-scale papers have demonstrated some correlation between loss of membrane integrity and chemical cleaning, but establishing such correlations at full scale is more challenging. Robinson & Berube demonstrated this for potable water plants, and it appears Oliveira Filho et al(2021) have achieved the same for MBRs treating wastewater − and reached similar conclusions regarding the impact of the loss of PVP.
Full Reference
Oliveira Filho, M., Mailler, R., Rocher, V., Fayolle, Y., Causserand, & C. (2021). Comprehensive study of supported PVDF membrane ageing in MBR: A direct comparison between changes at bench scale and full scale. Separation and Purification Technology, 279, 119695.
Abstract
Read the abstract:
https://www.mdpi.com/2077-0375/10/12/421#Our comment: Only 15 papers combine 'MBR' or 'membrane bioreactor' with the terms 'life cycle' or 'environmental impact assessment/analysis' in the title. Of these, perhaps the most exhaustive is the comparison between anaerobic and aerobic MBRs by Cashman et al, but the only straight LCA comparison between the MBR and CAS technologies seems to be this Banti et al (2020) paper, which concluded the MBR to be favoured environmentally.
Full Reference
Banti, D. C., Tsangas, M., Samaras, P., & Zorpas, A. (2020). LCA of a membrane bioreactor compared to activated sludge system for municipal wastewater treatment. Membranes, 10(12), 1-15.
Abstract
Read the abstract:
https://www.sciencedirect.com/science/article/abs/pii/S0959652621012038Our comment: In one of the very few cost analyses focused on MBR technology, the Gao et al(2021) paper calculates the 'net profit' in terms of the costed environmental benefit (from pollutant removal and water reclamation) minus the total costs incurred based on 35 large (>10,000 m3/d capacity) municipal MBRs in China. It appears to be quite exhaustive, and the authors calculated an NP of around $5/m3, reflecting the overall environmental benefit of MBRs.
Full Reference
Gao T., Xiao K., Zhang J., Zhang X., Wang X., Liang S., Sun J., Meng F., and Huang X. (2021). Cost-benefit analysis and technical efficiency evaluation of full-scale membrane bioreactors for wastewater treatment using economic approaches. Journal of Cleaner Production, 301 doi:10.1016/j.jclepro.2021.126984
Abstract
Read the abstract:
https://www.sciencedirect.com/science/article/abs/pii/S0045653516314564Our comment: The Fuertes et al (2017) paper is one of the few reporting influent and permeate PFAS concentrations from MBR treatment, focusing on landfill leachate since this is known to be a significant source of PFAS. According to these authors the PFAS levels actual increase following biological treatment due to biotransformation of precursor compounds like fluorotelomer alcohols and sulphonamides - a phenomenon reported previously for conventional biological treatment of leachate.
Full Reference
Fuertes, I., Gómez-Lavín, S., Elizalde, M. P., and Urtiaga, A. (2017). Perfluorinated alkyl substances (PFASs) in northern Spain municipal solid waste landfill leachates. Chemosphere, 168, 399−407. doi:10.1016/j.chemosphere.2016.10.072
Abstract
Read the abstract:
https://www.sciencedirect.com/science/article/abs/pii/S2214714421004980Our comment: Industrial effluent treatment using MBRs attracts less research than municipal effluent treatment. Rarer still are studies reporting on pilot or full scale installations. The Lebron et al (2021) study reports long-term (5 years) flux, permeability and membrane surface property trends for a pilot-scale MBR treating petroleum refinery wastewater. The trends in recovered (post cleaning) permeability and contact angle measurement with time are particularly revealing.
Full Reference
Lebron, Y. A. R., Moreira, V. R., da Costa, P. R., Alkmin, A. R., de França Neta, L. S., Cerqueira, A. C., and Amaral, M. C. S. (2021). Chemical cleaning procedures on permeability recovery and lifespan of MBR membranes treating petroleum refinery wastewater: From bench- to pilot-scale applications. Journal of Water Process Engineering, 44 doi:10.1016/j.jwpe.2021.102411
Abstract
Read the abstract:
https://doi.org/10.1061/(ASCE)EE.1943-7870.0001299Our comment: An MBR sludge property which is of practical significance is the ease with which it can be thickened/dewatered. The Pontoni et al (2018) study measured dewaterability − as well as biomethane production − of CAS and MBR sludge sampled prior to and following anaerobic digestion. The authors provided correlations of dewaterability and filterability with the key sludge quality determinants of proteins, carbohydrate, uronic acids, humic acids and extracellular polymeric substances (EPS) concentration. They also observed filterability to decrease following anaerobic digestions due to the decreased particle size.
Full Reference
Pontoni L., Papirio S., D'Alessandro G., Caniani D., Gori R., Mannina G., Capodici M., Nicosia S., Fabbricino M., Pirozzi F., and Esposito G. (2018). Dewaterability of CAS and MBR sludge: Effect of biological stability and EPS composition. Journal of Environmental Engineering (United States), 144(1) doi:10.1061/(ASCE)EE.1943-7870.0001299
Abstract
Read the abstract:
https://www.tandfonline.com/doi/full/10.1080/10643389.2020.1771889Our comment: Pathogen rejection by MBRs is an extensively researched topic. The review article by Branch et al (2021) captures a large number of log rejection datum (500 virus, 600 bacteria, and 20 protozoa LRV data points) to produce guideline values for these three pathogen groups. The recommended highly conservative threshold values, based on the 5th percentile, were >1.8 for viruses, >3.2 for all protozoa, and >3.8 for bacteria (using E Coli as a surrogate). It was this Australian study that informed the USEPA in producing its values for pathogen credits assigned to MBR technology for water reuse applications.
Full Reference
Branch, A., Leslie, G., and Le-Clech, P. (2021). A statistical review of pathogen and indicator log removal values from membrane bioreactor literature. Critical Reviews in Environmental Science and Technology, 51(16), 1866-1890. doi:10.1080/10643389.2020.1771889
Abstract
Read the abstract:
https://www.sciencedirect.com/science/article/abs/pii/S1385894723004242Our comment: A couple of reviews on MABRs were published in 2008, but then almost nothing for another 14 years. However, there have been four papers published in the past year, the most recent review by Li et al (2023) focusing on the nitrification−denitrification performance. This review includes a summary of ranges of values for the nitrogen load and corresponding air pressure for the different material types, information on trends in N2O emissions, and other useful bits and pieces.
Full Reference
Li, J., Feng, M., Zheng, S., Zhao, W., Xu, X., and Yu, X. (2023). The membrane aerated biofilm reactor for nitrogen removal of wastewater treatment: Principles, performances, and nitrous oxide emissions. Chemical Engineering Journal, 460 doi:10.1016/j.cej.2023.141693
Simon Judd has over 35 years’ post-doctorate experience in all aspects of water and wastewater treatment technology, both in academic and industrial R&D. He has (co-)authored six book titles and over 200 peer-reviewed publications in water and wastewater treatment.