Monthly variation of activated sludge extracellular polymeric substances and their correlation with the removal of anthropogenic micropollutants

Extracellular polymeric substances (EPS) are produced during biological nutrient removal in wastewater treatment processes (WWTPs). EPS may have a seasonal variation, however there are only few studies available on their dynamics with temperature. Moreover, recent studies have shown that EPS may play a role in the removal of emerging contaminants of concern (ECCs) in wastewater, and this may be attributed to the organic nature of ECCs. Additionally, the tightly-bound and the loosely-bound EPS fractions may interact differently with ECCs since their composition and transport properties are different. The objective of this study is to monitor EPS and test their correlation with the removal of selected ECCs in two activated sludge WWTPs. Our results show an EPS seasonal trend and that EPS production is positively correlated with temperature. Some ECCs adsorbed to the activated sludge have significant correlation with EPS components, suggesting a preferential ECC transport to sludge digestion.