Clustering micropollutants based on initial biotransformations for improved prediction of micropollutant removal during conventional activated sludge treatment

Abstract

The lack of fundamental insights on the fate of micropollutants during activated sludge treatment presents one of the biggest challenges in optimizing their removal in wastewater treatment plants.

Effect of concentration and hydraulic reaction time on the removal of pharmaceutical compounds in a membrane bioreactor inoculated with activated sludge

“…The removal efficiencies reported in Figure 1 are in line with previous studies, except for metformin, whose removal in WWTPs has been reported much higher (usually more than 80%) (Briones et al, 2016;Oosterhuis et al, 2013). Acetaminophen is known to be removed very well and carbamazepine is known for its high persistence in WWTPs all around the world (Falås et al, 2016;Joss et al, 2005;Wang et al, 2020). Metoprolol and diclofenac removal is variable in WWTPs, but their removal is often slightly higher than carbamazepine removal (Falås et al, 2016;Wang et al, 2020).…”

“…Fluoxetine removal was highly variable, between 25% and 70%, and the influent concentration was around 10 times lower than expected, probably due to its high sorption behaviour to several surfaces, including glass (Peake et al, 2015). For pharmaceuticals with Kd (solid-water distribution coefficient) values lower than 0.5 L/g, sorption is considered insignificant in WWTPs (Ternes et al, 2004;Wang et al, 2020). For this reason, sorption was only considered as a removal mechanism for fluoxetine and it was calculated using Equation 3.…”

“…Acetaminophen is known to be removed very well and carbamazepine is known for its high persistence in WWTPs all around the world (Falås et al, 2016;Joss et al, 2005;Wang et al, 2020). Metoprolol and diclofenac removal is variable in WWTPs, but their removal is often slightly higher than carbamazepine removal (Falås et al, 2016;Wang et al, 2020). Diclofenac removal during nitrification has been recently reported to be higher (~84%) than during heterotrophic processes or conventional activated sludge treatment (~50%) (Tran et al, 2009;Wu et al, 2020).…”

“…For example, charged compounds are less biodegradable than neutral compounds probably due to a cellular uptake limitation Nolte et al, 2018). In addition to chemical properties, the higher the concentration of pharmaceuticals and other OMPs in the influent of WWTPs, the more these compounds seem to be removed (Nolte et al, 2018;Wang et al, 2020). The same compound can also have different removal rates/efficiencies in different WWTPs which may depend on the operational parameters and the active microbial community present (Kassotaki et al, 2018;Lautz et al, 2017;Wang et al, 2020).…”

“…In addition to chemical properties, the higher the concentration of pharmaceuticals and other OMPs in the influent of WWTPs, the more these compounds seem to be removed (Nolte et al, 2018;Wang et al, 2020). The same compound can also have different removal rates/efficiencies in different WWTPs which may depend on the operational parameters and the active microbial community present (Kassotaki et al, 2018;Lautz et al, 2017;Wang et al, 2020). For example, nitrifying activities have been correlated to the biodegradation of several OMPs which might be due to the promiscuity of the ammonia monooxygenase enzyme (Fernandez-Fontaina et al, 2012;Men et al, 2017;Tran et al, 2009) Currently, WWTPs are not very effective at removing OMPs because microorganisms do not share an evolutionary history with these compounds that have only been introduced into the environment in the last decades.…”