RT Journal Article T1 Seasonal and spatial evolution of trihalomethanes in a drinking water distribution system according to the treatment process A1 Domínguez Tello, Antonio A1 Arias Borrego, Ana A1 García Barrera, Tamara A1 Gómez Ariza, José Luis AB This paper comparatively shows the influence of four water treatment processes on the formation of trihalomethanes (THMs) in a water distribution system. The study was performed from February 2005 to January 2012 with analytical data of 600 samples taken in Aljaraque water treatment plant (WTP) and 16 locations along the water distribution system (WDS) in the region of Andévalo and the coast of Huelva (southwest Spain), a region with significant seasonal and population changes. The comparison of results in the four different processes studied indicated a clear link of the treatment process with the formation of THM along the WDS. The most effective treatment process is preozonation and activated carbon filtration (P3), which is also the most stable under summer temperatures. Experiments also show low levels of THMs with the conventional process of preoxidation with potassium permanganate (P4), delaying the chlorination to the end of the WTP; however, this simple and economical treatment process is less effective and less stable than P3. In this study, strong seasonal variations were obtained (increase of THM from winter to summer of 1.17 to 1.85 times) and a strong spatial variation (1.1 to 1.7 times from WTP to end points of WDS) which largely depends on the treatment process applied. There was also a strong correlation between THM levels and water temperature, contact time and pH. On the other hand, it was found that THM formation is not proportional to the applied chlorine dose in the treatment process, but there is a direct relationship with the accumulated dose of chlorine. Finally, predictive models based on multiple linear regressions are proposed for each treatment process. PB Springer Verlag SN 0167-6369 SN 1573-2959 (electrónico) YR 2015 FD 2015 LK http://hdl.handle.net/10272/12839 UL http://hdl.handle.net/10272/12839 LA eng NO Domínguez Tello, A. Arias Borrego, A., García Barrera, T., Gómez Ariza, J.L.: "Seasonal and spatial evolution of trihalomethanes in a drinking water distribution system according to the treatment process". Environmental Monitoring and Assessment. Vol. 187:662, (2015). DOI: 10.1007/s10661-015-4885-8 NO The authors wish to express their apprecia-tion to the plant managers GIAHSA (Gestión Integral del Agua deHuelva S.A.) and employees for their help and cooperation in facilitating the collection of water samples during this study. Thiswork was supported by the project CTM2012-38720-C03-01 fromthe Spanish Ministry of Economy and Competitiveness(MINECO) and by projects P009-FQM-4659 and P12-FQM-0442 from the Regional Ministry of Economy, Innovation, Sci-ence and Employment (Andalusian Government, Spain). NO The authors wish to express their appreciation to the plant managers GIAHSA (Gestion Integral del Agua de Huelva S.A.) and employees for their help and cooperation in facilitating the collection of water samples during this study. This work was supported by the project CTM2012-38720-C03-01 from the Spanish Ministry of Economy and Competitiveness (MINECO) and by projects P009-FQM-4659 and P12-FQM-0442 from the Regional Ministry of Economy, Innovation, Science and Employment (Andalusian Government, Spain). DS Repositorio Institucional de la Universidad de Huelva RD 30 may 2026