Contaminated water: better monitoring for better detection

With the OPTIWATER project ("Emerging pollutants in water and wastewater: innovative detection methods"), LIST researchers spent almost two years addressing the question of water quality and detecting water contamination incidents from micropollutants, especially from pesticides. These polluting substances present in very weak concentrations, in particular, in water, prove to be potentially harmful, as much for human health as for ecosystems. The detection of them in the vital resource that water represents is therefore at the heart of the research questions.

Fluorescence as an indicator

With OPTIWATER, LIST researchers, specialized in monitoring chemical pollution and the evaluation of its impact on water, in particular, spent time developing a spectrographic methodology using dissolved organic matter (DOM) fluorescence in order to be able to detect water contamination incidents from these micropollutants. A necessary identification to be able to take, afterwards, measures to isolate the contaminated water.

With the ambition of developing a methodology based on easy-to-detect signals that are measurable both in the field and continuously, the researchers spent time on a micropollutant detection method based on the fluorescence signal changes of a proxy, the DOM. To ensure the effectiveness of the method put in place to detect the contamination incidences, the researchers carried out preliminary tests in real settings. For this, in partnership with several Luxembourgish water and wastewater companies, they were able to put fluorescence-measuring probes in place and install automatic samplers on a number of pilot sites: drinking water catchment basins and water treatment plants. Alongside this fieldwork, LIST researchers measured DOM fluorescence and the pesticide contents in the water samples collected in the lab, as well as carrying out an analysis of the raw data, before comparing their results to those obtained by the probes used in the field.

A method to be confirmed

The results obtained were very promising. From the sampling to the data analysis, the complete method developed by LIST now needs to be validated at the sites. A project enabling the innovative methodology to be tested on several pilot sites from 2019 is currently being defined.

>> Below, an animated GIF on the fluorescence of dissolved organic carbon according to the molecular size