| Popis: |
This work investigated, during one year, the occurrence and fate of 52 contaminants of emerging concern (CECs) in transnational river basins and coastal areas of the North of Portugal and Galicia (NW Spain) and the wastewater treatment plants (WWTPs) discharging on these environments. The different CECs investigated included pharmaceuticals, personal care products, industrial chemicals, among others, of which ca. 90 % would fulfill the persistence, mobility and toxicity criteria proposed by the German Environmental Agency. The results showed the ubiquitous presence of these CECs and an incomplete removal of over 60 % of them with current conventional WWTPs. These findings highlight the requirement of a prominent and coordinated upgrade of WWTP treatments in order to meet the future European Union regulations on urban wastewater treatment and surface water quality. In fact, even some compounds exhibiting high removals, such as caffeine or xylene sulfonate, were frequently detected in river and estuarine waters at the high ng L−1 level. Thus, our preliminary risk assessment study concluded that 18 of the CECs presented a potential risk for the environment, being caffeine, sulpiride, perfluorooctanoic acid (PFOA), diclofenac, fipronil and perfluorobutanoic acid (PFBA) the most concerning ones. Yet, additional toxicity data as well as a more robust information on persistence and mobility of CECs are necessary for better estimating the magnitude of the problem and improve risk assessment. As an example, in the case of the antidiabetic metformin, recent research has revealed toxicity for model fish species at concentration levels below those found in 40 % of the river water samples analyzed in this work This work was financed by the European Regional Development Fund through the Interreg V-A Spain-Portugal Programme (POCTEP) 2014-2020 (ref. 0725_NOR_WATER_1_P), the Agencia Estatal de Investigación MCIN/AEI/10.13039/501100011033 (ref. PID2020-117686RB-C32) and the Consellería de Cultura, Educación y Universidades da Xunta de Galicia (ref. ED431C 2021/06). The study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the projects [UIDB/04423/2020 and UIDP/04423/2020]. R.M. acknowledges Banco Santander and Universidade de Santiago de Compostela for her outstanding researcher contract, N. A. acknowledges the FCT for his Ph.D. grant DFA/BD/6218/2020 and T.N. acknowledges FCT Individual Call to Scientific Employment Stimulus 2022 (2022.02925.CEECIND). The authors also want to acknowledge Agilent Technologies for providing the equipment described in Section 2.4 and the different entities which have collaborated in the sampling campaign: VIAQUA, Augas de Galicia, Confederación Hidrográfica do Miño-Sil, Águas do Porto, Efacec and Águas do Norte SI |
