title: Evaluation of system performance and microbial communities of a bioaugmented anaerobic membrane bioreactor treating pharmaceutical wastewater.
abstract: In this study, a control anaerobic membrane bioreactor (C-AnMBR) and a bioaugmented anaerobic membrane bioreactor (B-AnMBR) were operated for 210 d to treat pharmaceutical wastewater. Both the bioreactors were fed with the pharmaceutical wastewater containing TCOD of 16,249 ± 714 mg/L and total dissolved solids (TDS) of 29,450 ± 2209 mg/L with an organic loading rate (OLR) of 13.0 ± 0.6 kgCOD/m(3)d. Under steady-state condition, an average total chemical oxygen demand (TCOD) removal efficiency of 46.1 ± 2.9% and 60.3 ± 2.8% was achieved by the C-AnMBR and the B-AnMBR, respectively. The conventional anaerobes in the C-AnMBR cannot tolerate the hypersaline conditions well, resulting in lower TCOD removal efficiency, biogas production and methane yield than the B-AnMBR seeded from the coastal shore. Pyrosequencing analysis indicated that marine bacterial species (Oliephilus sp.) and halophilic bacterial species (Thermohalobacter sp.) were only present in the B-AnMBR; these species could possibly degrade complex and recalcitrant organic matter and withstand hypersaline environments. Two different dominant archaeal communities, genus Methanosaeta (43.4%) and Methanolobus (61.7%), were identified as the dominant methanogens in the C-AnMBR and the B-AnMBR, respectively. The species of genus Methanolobus was reported resistant to penicillin and required sodium and magnesium for growth, which could enable it to thrive in the hypersaline environment.
authors.affiliation: Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore.
authors.forename: Kok Kwang
authors.initials: KK
authors.lastname: Ng
authors.affiliation: Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Shi
authors.affiliation: Centre for Water Research, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, 117576, Singapore. Electronic address: howyongng@nus.edu.sg.
authors.forename: How Yong
authors.initials: HY
authors.lastname: Ng
mesh_terms: D000693:Anaerobiosis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D059001:Aquatic Organisms; D001105:Archaea / Q000235:genetics / Q000254:growth & development; D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D056804:Biofuels; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D004345:Drug Industry; D008697:Methane / Q000096:biosynthesis; D017019:Methanosarcinaceae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D010403:Penicillin Resistance; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D054712:Salinity; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; D056804:Biofuels; D008697:Methane; D012336:RNA, Ribosomal, 16S; D062065:Wastewater
keywords: Anaerobic membrane bioreactor; Coastal sediment; Marine microorganisms; Organic removal; Pharmaceutical wastewater; Salinity