Moderate pre-ozonation coupled with a post-peroxone process remove filamentous cyanobacteria and 2-MIB efficiently:...

Area of Science:

• Environmental Science
• Water Treatment Technologies
• Microbiology

Background:

• Increasing global issue of taste and odor-producing cyanobacteria in water sources.
• 2-methylisoborneol (2-MIB) from filamentous cyanobacteria causes common odor events in water supply.
• Conventional water treatments show low removal rates for cyanobacteria and 2-MIB.

Purpose of the Study:

• To propose and evaluate a water treatment strategy using moderate pre-ozonation and post-peroxone processes.
• To effectively remove filamentous cyanobacteria and intracellular 2-MIB while minimizing cell damage.
• To degrade residual dissolved 2-MIB using a post-peroxone process.

Main Methods:

• Moderate pre-ozonation (0.2 mg/L O3 for 20 min) applied before coagulation.
• Post-peroxone (2.0 mg/L O3 + 2.0 mg/L H2O2 for 20 min) applied after sand filtration.
• A 0.6 m3/h pilot system operated continuously for 14 days.

Main Results:

• Pre-ozonation enhanced coagulation efficiency for algae with low cell lysis and high viability.
• Post-peroxone process degraded residual dissolved 2-MIB by nearly 100%.
• The integrated pilot system demonstrated effective and stable removal of cyanobacteria and 2-MIB.

Conclusions:

• Moderate pre-ozonation is effective for enhanced coagulation of cyanobacteria.
• Post-peroxone efficiently removes dissolved 2-MIB.
• The combined treatment process offers a stable solution for cyanobacteria and 2-MIB removal in water treatment.