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Doctoral thesis2012Open access

Source, occurrence, and fate of pharmaceuticals in natural waters

Daneshvar, Atlasi

Abstract

The consumption of pharmaceuticals has increased in the last few decades. After usage, pharmaceuticals are excreted via urine and feces and transported to wastewater treatment plants (WWTPs) where they are subjected to treatment processes, and finally discharged into rivers. In order to assess aquatic risk associated with short- and long-term exposure to pharmaceuticals, temporal-spatial variability in the concentrations should be monitored in different water compartments. In this thesis, occurrence and fate of pharmaceuticals and other organic pollutants were studied in Swedish and Canadian rivers and WWTPs, and the major sources of contaminations were identified. The ranges of mean concentrations of the pharmaceuticals and personal care products (PPCPs), hormones, and pesticides were 2.4-13755 ng L-1 and 0.5-112 ng L-1 in treated wastewaters and rivers, respectively. WWTPs and combined sewer overflows (CSOs) were identified as major sources of PPCPs in rivers. However, a large gathering of people at a river shore could temporarily contribute to a high input of pharmaceuticals. A temporal study of mass flows and corresponding removal efficiencies (REs) of WWTP-derived pharmaceuticals showed winter accumulations for most of the compounds. This might reflect high water flow rates and negligible rates of bio- and phototransformation in this season. REs of beta-blockers were season-dependent, with the highest removal in the summer and fall. This was due to biotransformation, indicated by high water temperature and chlorophyll a mass flows during those seasons. Yearly median REs of nutrients were low compared to pharmaceuticals. Yet, REs of atenolol and nitrate-nitrogen (NO3-N) were related and had similar seasonal trends. Carbamazepine REs were the lowest among the pharmaceuticals. The latter combined with the persistence of carbamazepine in WWTPs and a lake showed its potential as an indicator of cumulative contamination. A correlation between caffeine concentrations and fecal coliforms in rivers confirmed caffeine as an indicator of recent urban fecal contamination. A high caffeine/carbamazepine ratio might be indicative of raw sewage discharge in a river, justified by higher concentrations of caffeine than carbamazepine in raw sewage and negligible removal of carbamazepine in WWTPs. The outcomes of the thesis show that source characteristics, water flow rates, and environmental conditions are essential factors that control detection frequency, concentrations and associated mass flows, and the fate of pharmaceuticals in aquatic environments. Also, pharmaceuticals can be used as indicators of recent and cumulative fecal contamination in drinking water sources.

Keywords

pharmaceutical; source water; treated wastewater; occurrence; fate; indicator

Published in

Acta Universitatis Agriculturae Sueciae
2012, number: 2012:67ISBN: 978-91-576-7714-3Publisher: Dept. of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences

    UKÄ Subject classification

    Analytical Chemistry
    Environmental Sciences
    Water Engineering

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/79088