Coupling a pathway-oriented approach with tailor-made monitoring as key to well-performing regionalized modelling of PFAS emissions and river concentrations.

Surface water pollution with poly- and perfluorinated compounds (PFAS) is a well-recognized problem, but knowledge about contribution of different emission pathways, especially diffuse ones, is very limited. This study investigates the potential of the pathway oriented MoRE model in shedding light on the relevance of different emission pathways on regional scale and in predicting concentrations and loads in unmonitored rivers. Modelling was supported with a tailor-made monitoring programme aimed to fill gaps on PFAS concentration in different environmental compartments.

Occurrence and levels of micropollutants across environmental and engineered compartments in Austria.

Occurrence and concentration of a broad spectrum of micropollutants are investigated in Austrian river catchments, namely polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), organotin compounds, perfluoroalkyl acids (PFAAs) and metals. The parallel analysis across multiple environmental and engineered compartments sheds light on the ratio of dissolved and particulate transport and on differences in concentration levels between point and diffuse emission pathways. It is found that some PAHs and organotins are present in rivers, groundwater and bulk deposition at higher concentrations than in municipal wastewater effluents.

Evaluating the success of sewer reconstruction by using carbamazepine as anthropogenic marker in groundwater.

The antiepileptic drug carbamazepine is a useful anthropogenic marker in groundwater to detect and quantify sewer exfiltration. In 2003 its application on a city wide scale enabled the identification of a trunk sewer in extremely bad structural status with an exfiltration (of wastewater into groundwater) rate in the adjacent area of around 5% compared to an average of approximately 1% in other parts of the city. After a reconstruction of the trunk sewer investigations were carried out again in 2008.

Micropollutant removal during biological wastewater treatment and a subsequent ozonation step.

The design criteria for wastewater treatment plants (WWTP) and the sludge retention time, respectively, have a significant impact on micropollutant removal. The upgrade of an Austrian municipal WWTP to nitrogen removal (best available technology, BAT) resulted in increased elimination of most of the analyzed micropollutants. Substances, such as bisphenol-A, 17alpha-ethinylestradiol and the antibiotics erythromycin and roxithromycin were only removed after the upgrade of the WWTP.

Adsorption of bisphenol-A, 17 beta-estradiole and 17 alpha-ethinylestradiole to sewage sludge.

Adsorption of bisphenol-A (CAS 85-05-7), 17 beta-estradiole (CAS 50-28-2) and 17 alpha-ethinylestradiole (CAS 57-63-6) to activated and to inactivated sludge from wastewater treatment plants (WWTPs) was investigated, thus allowing to distinguish between pure adsorption and biosorption. For the investigated substances the determination of the adsorption kinetics is based on experiments performed according to the OECD guideline 106 and on free concentration measurements in the liquid phase. The description of the adsorption behaviour occurred via Freundlich Adsorption Isotherms.