Show simple item record

dc.contributor.advisorHong, Pei-Ying
dc.contributor.authorCheng, Hong
dc.date.accessioned2019-10-16T13:15:43Z
dc.date.available2019-10-16T13:15:43Z
dc.date.issued2019-10
dc.identifier.citationCheng, H. (2019). Biofouling in anaerobic membrane bioreactors: To control or not to? KAUST Research Repository. https://doi.org/10.25781/KAUST-V9XB2
dc.identifier.doi10.25781/KAUST-V9XB2
dc.identifier.urihttp://hdl.handle.net/10754/658645
dc.description.abstractAnaerobic membrane bioreactor (AnMBR) serves as a more sustainable form of wastewater treatment. However, biofouling is particularly detrimental to the performanceof AnMBRs. This dissertation focuses on understanding more about the biofouling in nMBR, and to devise strategies to control or make use of these biofoulant layers. First, we aim to investigate the microbial community structure of sludge and biofilm from 13 different AnMBRs. Our findings indicate 20 sludge core genera and 12 biofilm core genera (occurrence ≥ 90% samples) could potentially account for the AnMBR performance. Sloan neutral model analysis indicates the anaerobic microbial consortium between sludge and biofilm is largely affected by stochastic dispersal and migration processes (i.e., neutral assembly), suggesting that the majority of these core genera are not selectively enriched for biofilm formation. Therefore, the second part of this dissertation aims to minimize the growth of the overall bacterial cells attached on the membranes. For this, membranes embedded with zinc oxide (ZnO) and copper oxide (CuO) nanoparticles were examined for their antifouling efficacies. Our findings indicate both CuO and ZnO nanoparticles embedded membranes could delay biofouling formation without significantly triggering the overall expression/abundance of antibiotic resistance genes (ARGs) and metal resistance genes (MRGs) in biofilm. Furthermore, CuO and ZnO nanoparticles could inhibit the expression of quorum sensing associated genes, resulting in lower quorum sensing signal molecules production. Despite the positive results demonstrated from this study as well as those from others, we recognize that no control strategies are likely to achieve total prevention of anaerobic biofouling. Therefore, the last part of this dissertation focuses on exploring the effects of different foulant layers on antibiotic-resistant bacteria (ARB) and ARGs removal. Our findings suggest both ARB and ARGs could be absorbed by membrane foulant. Transmembrane pressures and the foulant layer synergistically affected ARB removal, but the foulant layer is the main factor that contributed to ARG removal through adsorption. Overall, the collective findings could bring new insights to the anaerobic membrane biofouling phenomenon, and offer pragmatic approaches to minimize biofouling without compromising the post-AnMBR effluent quality.
dc.language.isoen
dc.subjectAnaerobic membrane bioreactor
dc.subjectbiofouling
dc.subjectantifouling
dc.subjectmicrobial community
dc.subjectnanoparticles
dc.titleBiofouling in anaerobic membrane bioreactors: To control or not to?
dc.typeDissertation
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Division
dc.rights.embargodate2020-10-16
thesis.degree.grantorKing Abdullah University of Science and Technology
dc.contributor.committeememberNunes, Suzana Pereira
dc.contributor.committeememberMoran, Anxelu
dc.contributor.committeememberSmith, Adam
thesis.degree.disciplineEnvironmental Science and Engineering
thesis.degree.nameDoctor of Philosophy
dc.rights.accessrightsAt the time of archiving, the student author of this dissertation opted to temporarily restrict access to it. The full text of this dissertation will become available to the public after the expiration of the embargo on 2020-10-16.
refterms.dateFOA2020-10-16T00:00:00Z
kaust.request.doiyes


Files in this item

Thumbnail
Name:
Hong Cheng Dissertation.pdf
Size:
19.16Mb
Format:
PDF
Description:
Hong Cheng Dissertation

This item appears in the following Collection(s)

Show simple item record