The Composition of Dissolved Organic Matter and its Impact on Water Treatment in a Changing Climate

This project seeks to build resilience to the water supply chain supporting economic growth. Clean drinking water that requires minimal chemical and energy to treat it, particularly as we face stress from climate change, is vital for underpinning our economy as identified by the Government's Green Paper 'Building Our Industrial Strategy' 2017. In the UK 11.4 million people rely on peatlands for their drinking water. Dissolved organic matter concentrations in rivers draining peatlands are high and result in highly coloured water; deterioration in water colour results in breaches of European Union drinking water standards and an increase in water treatment costs. It also has health implications as the chlorination of highly coloured water can result in the production of carcinogenic disinfection by-products which are strictly regulated and very costly to deal with. When water colour peaks become too severe water companies have to invest tens of millions of pounds in capital for every new treatment plant (and there are hundreds of such plants in the UK at risk) plus the additional expense of running those plants. At the same time, in-stream processing of dissolved organic matter leads to greenhouse gas emissions from water bodies that are under-represented in the Intergovernmental Panel on Climate Change (IPCC) reports. There is limited understanding of factors that control the composition and processing of dissolved organic matter and the treatability of drinking water. For water companies, policy makers and society there is now an urgent need to understand how water treatment can be made more effective, and the outcomes of this project will help to optimise water treatment performance to deal with threats posed by changes in dissolved organic matter quality and composition as a result of climate change; left unresearched, there would be limited advance in the water sector's ability to efficiently treat drinking water, and in the IPCC's ability to incorporate the peatland water emissions into its assessments of climate change.

This Fellowship will explore an interdisciplinary, innovative solution to a focused water sector need to identify the composition of dissolved organic matter in order to conduct more efficient removal of dissolved organic matter at water treatment works. The project will undertake UK-wide field sampling, laboratory experiments and analysis of very large datasets that have been pooled together for the first time. The composition and processing of dissolved organic matter originating in peatland catchments will be investigated, to identify potential improvements to the treatment processes at water treatment works, to reduce the production of carcinogenic disinfection by-productions and costs, and to future-proof the industry to the effects of climate change on changing dissolved organic matter inputs to potable water thus providing both short-term and long-term economic benefits to the water industry.