Over the last 20 years, the kinetics of HAA formation have been well described and modelled with reaction rates and types observed and reported. General findings are that the levels of brominated HAAs are not linearly related to bromide levels indicating that other factors are influential. Reported studies are observational and descriptive and manipulation of the kinetics has not been reported in the literature.
The initial formation of HOBr and the incorporation of bromine into DBPs will be investigated at a fundamental level to advance the understanding of the reactions and the influencing factors.
The novelty of this work is in investigating the potential for manipulation of the reaction kinetics. This project will provide an understanding of how manipulating the kinetics and thermodynamics of Br-DBP formation influences the distribution and mass of DBPs formed.
This project will allow water companies to develop holistic strategies for DBP management to meet current and future regulatory requirements, especially for the Br-HAAs.
Current strategies are to reduce organic levels to reduce DBPs. This works well for the currently regulated THMs, but has been shown to increase Br-DBPs particularly HAAs. Through consideration of chemical interactions from source to tap, this project will allow the interaction of organic carbon, bromide and chlorine to be assessed. The information on these reactions will inform the best approach to minimise formation of these compounds; this could inform decisions on catchment/resource management as well as on future investment in infrastructure.
The influence of the impending HAA standards coupled with an increase in source water organics in upland sources from soil erosion and in lowland water from algae is leading water companies to invest in solutions to reduce DBP formation. These investments can include new plant such as ion-exchange processes for organics removal, reservoir treatment to reduce algal blooms and catchment management solutions to manage organics levels in the water.
Understanding current HAA levels and the potential for reducing brominated HAAs through manipulation of kinetics will allow the investments to be targeted to ensure resilience in meeting regulatory requirements