Hazardous events in membrane bioreactors – Part 2: Impacts on removal of trace organic chemical contaminants

Seasonal variations in fate and removal of trace organic chemical contaminants while operating a full-scale membrane bioreactor

“…In general, the detected concentrations of TrOCs were comparable with previous Australian studies ( Le-Minh et al, 2010;Trinh et al, 2016;Leusch et al, 2014;Ying et al, 2008). The day-to-day variability in influent concentrations of TrOCs in this WWTP was generally higher than in a previous study at a larger WWTP in NSW (Trinh et al, 2016).…”

“…2 also revealed that in general, the overall removal efficiencies of most of hydrophilic chemicals including caffeine, ketoprofen, paracetamol, atorvastatin, o-hydroxyatorvastatin, p-hydroxyatorvastatin, naproxen, ibuprofen, DEET, estriol, propylparaben, androstenedione by the MBR were always above 92% and comparable between the winter and the summer sampling periods. Previous MBR studies also reported similar high overall removal efficiencies (92-100%) for caffeine, ketoprofen, paracetamol, atorvastatin, naproxen, ibuprofen, DEET, estriol and propylparaben (Kim et al, 2014;Trinh et al, 2016;Radjenovic et al, 2007;Sui et al, 2011;Phan et al, 2015;Komesli et al, 2015). The high removal efficiencies noted here can be attributed to the high SRT and MLSS concentrations in MBRs (Chen et al, 2008;Clara et al, 2005;Fernandez-Fontaina et al, 2013).…”

“…Therefore, the concentrations of TrOCs in influent, MBR permeate and biomass were used together with the aqueous and biomass flow data to establish a mass balance for the fate of each chemical. The equations for mass balance calculation including equations for the percentage overall removal and the percentage removal via adsorption to biomass were reported in previous publications (Trinh et al, 2016;Trinh et al, 2011a). The percentage removal via biotransformation was equalled to the percentage overall removal minus the percentage removal via adsorption to biomass.…”

“…The majority of previous MBR work (Bo et al, 2009;Kantiani et al, 2008;Kimura et al, 2005;Tadkaew et al, 2011;Kim et al, 2007) focused on the analysis of TrOCs in the aqueous phase alone and therefore the removal via adsorption to biomass versus removal via biotransformation was not distinguished. A few recent studies have investigated the contribution of different removal mechanisms to the overall removal of TrOCs though MBR treatment (Kim et al, 2014;Trinh et al, 2016). However, seasonal effects on these removal mechanisms were not addressed.…”

Performance of secondary wastewater treatment methods for the removal of contaminants of emerging concern implicated in crop uptake and antibiotic resistance spread: A review

“…Moreover, high biomass concentrations provide higher stability, persistence to shock loads, increased contact between microorganisms and pollutants, thus facilitating their biodegradation (Cirja et al, 2007;Verlicchi et al, 2012;Trinh et al, 2016a). This may also induce microorganisms metabolism of poorly degradable compounds due to relative shortages in biodegradable substances associated with reduced F/M ratio (Verlicchi et al, 2012).…”