Investigation of the photolysis of emerging contaminants in the Western Treatment Plant lagoons

This project focused on understanding how sunlight can break down emerging contaminants (ECs) in wastewater held in large, shallow lagoons at Melbourne’s Western Treatment Plant (WTP). By studying how sunlight interacts with substances in water to produce reactive intermediates, which in turn degrade pollutants, the research aimed to better predict the effectiveness of sunlight in removing harmful chemicals from wastewater.

The research examined the reaction rates of ten selected ECs with four photochemically produced reactive intermediates (PPRIs) commonly found in WTP lagoons: hydroxyl radical, singlet oxygen, triplet excited chromophoric dissolved organic matter, and carbonate radical. The research revealed varying levels of reactivity between the ECs and PPRIs, with strong correlations found between reaction rates and the molecular structure of certain compounds. However, minimal reaction was observed with carbonate radicals.

This research highlights the importance of experimentally determining reaction rates in lagoon conditions. The findings suggest that with further study, a predictive model could be developed to forecast the removal of contaminants based on their molecular structure. This model, once refined, could be applicable to other wastewater lagoon systems, enhancing treatment processes and environmental protection.

This research was conducted exclusively for Melbourne Water.