Fate and mass balance of contaminants of emerging concern during wastewater treatment determined using the fractionated approach

Abstract

Contaminants of emerging concern (CECs) are often poorly removed from wastewater using conventional treatment technologies and there is limited understanding of their fate during treatment. Inappropriate sampling strategies lead to inaccuracies in estimating removals of CECs. In this study, we used the “fractionated approach” that accounts for the residence time distribution (RTD) in treatment units to investigate the fate of 26 target CECs in a municipal wastewater treatment plant (WWTP) that includes primary, secondary and tertiary treatment steps[...] Analysis of the selected metabolites demonstrated that negative removals obtained could be explained by transformations between the parent compound and their metabolites. This study contributes to the growing literature by applying the fractionated approach to calculate removal of different types of CECs across each wastewater treatment step. An additional level of understanding of the fate of CECs was provided by mass balance calculations in primary and secondary treatments

Toxicity of extracts from municipal wastewater to early life stages of Japanese medaka (Oryzias latipes) to evaluate removals of micropollutants by wastewater treatment

“…In the present study, we used solid phase extraction (SPE) to isolate and concentrate micropollutants and their transformation products from treated and untreated municipal wastewater, and we tested these extracts for toxicity to early life stages of Japanese medaka ( Oryzias latipes ). The concentrations of selected PPCPs and drugs of abuse in extracts prepared from these wastewater samples were previously reported, and in all cases the levels of these compounds were reduced as a result of wastewater treatment (Baalbaki et al ; Baalbaki et al ; Maya et al, ).…”

“…Samples of treated and untreated wastewater were collected from 2 WWTPs with secondary and tertiary treatment, respectively. The removal of targeted PPCPs and drugs of abuse within these WWTPs has been reported previously (Baalbaki et al ; Baalbaki et al ), and samples collected at the same time were used in toxicity tests in the present study. Final effluent collected from another WWTP with secondary treatment was further treated by ozonation in a bench‐scale experiment.…”

“…Wastewater treatment plant 1 uses conventional activated sludge secondary treatment and WWTP 2 uses tertiary treatment. The treatment processes and schematics of the treatment trains are described in more detail for WWTP 1 by Baalbaki et al () and for WWTP 2 by Baalbaki et al (). However, the basic treatment trains of these WWTPs are illustrated in Supplemental Data, Figures S1 and S2 .…”

Advancement in treatment of wastewater: Fate of emerging contaminants

“…Quantities of ECs are expressed relative to value observed in the influent (%). Data taken from elsewhere …”

“…Baalbaki et al studied the fate and mass balance of ECs during primary, secondary, and tertiary treatment processes using residence time distribution in WWTPs. By considering mass balance calculations, they reported that the primary treatment process produced a 50 % reduction in these contaminants and a significant removal (99 %) in the aqueous phase during the activated sludge treatment process.…”