A paradigm-shift in water treatment: In-reservoir UV-LED-driven TiO2 photocatalysis for the removal of cyanobacteria – a mesocosm study

Start Date

27-5-2022 9:45 AM

End Date

27-5-2022 10:00 AM

Abstract

Potentially harmful cyanobacteria challenge potable water treatment with high biomass events and dissolved toxic and nuisance metabolites globally. Retrofitting existing water treatment infrastructure is often impractical, if not impossible, and often prohibitively expensive. In a paradigm-shifting move we propose in-reservoir pre-treatment of cyanobacteria-contaminated raw waters to ease the burden on existing water treatment infrastructure.

In an iterative design approach over three years, treatment modules have been designed, refined, and optimised in bench and pilot-scale studies for in-reservoir deployment. TiO2-coated beads made from recycled glass are employed in conjunction with UV-light emitting diodes (LEDs) to create highly reactive hydroxyl radicals that preferably remove cyanobacteria and subsequently released cyanotoxins from raw water. In a mesocosm study in a drinking water reservoir in Brazil water quality parameters were markedly improved within 72h of deployment and cyanobacterial presence was decreased by over 90% without affecting other phytoplankton communities. The treatment system is virtually plastic-free, low cost, utilises recycled materials and could ultimately be powered by renewable energies, thus providing a true green treatment option.

We have conclusively demonstrated that a paradigm-shift towards in-reservoir treatment is not only possible but feasible and can provide a valuable addition to conventional water treatment methods.

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May 27th, 9:45 AM May 27th, 10:00 AM

A paradigm-shift in water treatment: In-reservoir UV-LED-driven TiO2 photocatalysis for the removal of cyanobacteria – a mesocosm study

Potentially harmful cyanobacteria challenge potable water treatment with high biomass events and dissolved toxic and nuisance metabolites globally. Retrofitting existing water treatment infrastructure is often impractical, if not impossible, and often prohibitively expensive. In a paradigm-shifting move we propose in-reservoir pre-treatment of cyanobacteria-contaminated raw waters to ease the burden on existing water treatment infrastructure.

In an iterative design approach over three years, treatment modules have been designed, refined, and optimised in bench and pilot-scale studies for in-reservoir deployment. TiO2-coated beads made from recycled glass are employed in conjunction with UV-light emitting diodes (LEDs) to create highly reactive hydroxyl radicals that preferably remove cyanobacteria and subsequently released cyanotoxins from raw water. In a mesocosm study in a drinking water reservoir in Brazil water quality parameters were markedly improved within 72h of deployment and cyanobacterial presence was decreased by over 90% without affecting other phytoplankton communities. The treatment system is virtually plastic-free, low cost, utilises recycled materials and could ultimately be powered by renewable energies, thus providing a true green treatment option.

We have conclusively demonstrated that a paradigm-shift towards in-reservoir treatment is not only possible but feasible and can provide a valuable addition to conventional water treatment methods.