2020 Volume 33 Issue 5 Pages 79-89
River water, which is the very important drinking water resources, contains a variety of dissolved organic matter (DOM), and their negative effects on water purification process and drinking water are concerned. In this research, the fate of organic pollutants such as those in treated wastewater discharged to Irumagawa river, Saitama prefecture and further in the water purification plant sourced from the river was tracked by non-target screening analysis with Orbitrap mass spectrometer. The number of DOM components detected by mass spectrometry increased in accordance with the river flow. This increase should be due to the discharge from jokaso, domestic graywater, industrial wastewater, and non-point pollution. The inflow of treated wastewater had the biggest effect on the DOM composition in the river water. In the water purification plant located at the downstream of treated wastewater discharge point, the DOM of source water was reduced by 38％ (on average of two samples) in terms of the number of DOM components. The molecular formula and structures of some DOM which remain in the finished drinking water were estimated, and some of them were supposed to be degradation products of detergent. Newly formed compounds by water purification process were also detected, and some of them were estimated to contain chlorine and/or bromide. For more advanced management of drinking water quality, this study demonstrated that the analytical approach can be useful to comprehensively monitor the trace organic pollutants in river water.
