Paul Chambonniere
Doctor of Philosophy, (Environmental Engineering)
Study Completed: 2019
College of Sciences
Citation
Thesis Title
Understanding the mechanisms involved in Escherichia coli decay during wastewater treatment in High Rate Algal Ponds
Read article at Massey Research Online: 
High Rate Algal Pond (HRAP) is an established algae based wastewater treatment technology combining efficient secondary treatment with high biomass recovery. Despite knowledge from other algae ponds, evidencing that HRAP could be suited to disinfection, HRAP pathogen removal performance has been scarcely characterised. In this study, an average 98.3% removal of Escherichia coli (common pathogen removal indicator) was recorded during the two year monitoring of two pilot scale HRAPs, hence evidencing comparable performance of other algae ponds designed for disinfection. Laboratory investigations showed that most of the observed removal was caused by decay in the dark, the exact underlying mechanism(s) remaining unclear. Direct sunlight damage and temperature dependent high-pH toxicity further increased Escherichia coli removal. Because sunlight-mediated mechanisms were previously concluded to be the main drivers of disinfection in algae ponds, Mr Chambonniere's research critically challenges the existing consensus, and highlights the need to characterise 'dark' disinfection mechanisms in HRAPs.
Supervisors
Professor Benoit Guieysse
Professor John Bronlund