Anaerobic 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.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/658645 |
| Date | 10 1900 |
| Creators | Cheng, Hong |
| Contributors | Hong, Peiying, Biological and Environmental Sciences and Engineering (BESE) Division, Nunes, Suzana, Moran, Anxelu, Smith, Adam |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
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