Passive Sampling

A novel approach to water chemistry analysis

Designed by the University of Portsmouth and further developed by South West Water, Westcountry Rivers Trust has been trialling ChemCatchers on the River Tamar as part of the Upstream Thinking project. These units sit on the river bed over a set period of time and are fitted with receiving phase units tailored to the specific pollutants under analysis. These disks use the chemical potential difference to draw in and retain molecules of pollutants from the water column. ChemCatchers are capable of detecting multiple pesticides as well as pharmaceuticals such as ibuprofen, which may be entering the system via domestic waste outlets. Once recovered, the receiving phases are analysed and an accurate concentration is deduced by South West Water. Combining this high resolution information with information about local land use practices, Westcountry Rivers Trust are able to pinpoint specific areas and if necessary, mitigation methods can be put in place to prevent contamination of the river.
Chemcatchers are a novel approach to water chemistry analysis and have further potential for future projects. For more information check out our video of chemcatchers being deployed on the River Fowey.