Model based analysis of fate of contaminants of emerging concern in the water column and the sediment of the Oslofjord

6 contaminants of emerging concern (CEC): clarithromycin, citalopram, tributyl phosphate, benzotriazole, octocrylene and teflubenzuron, with  differing sources, applications, and contrasting properties were selected for modeling in the water column and the sediments of the Oslofjord. The FABM family of models was used, which coupled benthic-pelagic model 2DBP together with the biogeochemical model BROM and the elaborated contaminants transformation module. This parameterized processes of CEC partitioning with organic matter, and CEC decay due to biodegradation, photolysis and hydrolysis. This combination of modules allows for the simulation of spatial and temporal variability of CEC during a period of intensive pollution and restoration. It was shown that (i) the biological pump significantly affects transformations of CECs leading to seasonal variation of concentration in the water column, (ii) During the pollution period fluxes of particulate and dissolved matter are directed to the sediments, while there is a flux of dissolved CEC from the sediments, (iii) After cessation of the pollution there can be predicted flux of dissolved CEC from the sediments for a certain period, (iv) Properties of the CEC determine the effectiveness of the biological pump and duration of CEC existence in the water column and the sediments following the cessation of pollution. This work was supported by Grant Agreement 101135037 – CONTRAST – Horizon CL6-2023.