Suppressing cyanobacterial dominance by UV-LED TiO2-photocatalysis in a drinking water reservoir: A mesocosm study
Carlos J. Pestana, Allan Amorim Santos, José Capelo Neto, Vânia Maria Maciel Melo, Kelly Cristina dos Reis, Samylla Oliveira, Ricardo Rogers, Ana Beatriz Furlanetto Pacheco, Jianing Hui, Nathan Skillen, Mário Ubirajara Gonçalves Barros, Christine Edwards, Sandra M. F. O. Azevedo, Peter K. J. Robertson, John T. S. Irvine, Linda A. Lawton
Abstract
immobilized onto recycled foamed glass beads by a facile calcination method, combined in treatment units with 365 nm UV-LEDs. The treatment system was deployed in mesocosms within a eutrophic Brazilian drinking water reservoir. The treatment units were deployed for 7 days and suppressed cyanobacterial abundance by 85% while at the same time enhancing other water quality parameters; turbidity and transparency improved by 40 and 81% respectively. Genomic analysis of the microbiota in the treated mesocosms revealed that the composition of the cyanobacterial community was affected and the abundance of Bacteroidetes and Proteobacteria increased during cyanobacterial suppression. The effect of the treatment on zooplankton and other eukaryotes was also monitored. The abundance of zooplankton decreased while Chrysophyte and Alveolata loadings increased. The results of this proof-of-concept study demonstrate the potential for full-scale, in-reservoir application of advanced oxidation processes as complementary water treatment processes.