Intensification of the O₃/TiO₂/UV advanced oxidation process using a modified flotation cell

Area of Science:

• Environmental Chemistry
• Chemical Engineering
• Water Treatment Technologies

Background:

• Conventional reactors for ozonation face challenges in efficiency and mass transfer.
• Intensified ozonation processes like catalytic and photocatalytic ozonation offer potential for enhanced pollutant degradation.
• Diclofenac is a persistent pharmaceutical pollutant requiring effective removal from wastewater.

Purpose of the Study:

• To evaluate a flotation cell as a reactor for ozonation and intensified ozonation processes.
• To investigate the impact of pH, ozone concentration, and catalyst loading on degradation efficiency.
• To compare the performance of the flotation cell with conventional reactors using a novel Ozone Utilized Index (OUI).

Main Methods:

• Utilized a modified flotation cell for ozonation, catalytic ozonation, and photocatalytic ozonation.
• Investigated the effects of operational parameters: pH, ozone concentration, and catalyst loading.
• Proposed and applied the Ozone Utilized Index (OUI) to assess reactor performance and ozone utilization efficiency.

Main Results:

• The flotation cell demonstrated efficient total diclofenac degradation in a short timeframe.
• The flotation cell achieved the lowest OUI, indicating high ozone consumption and minimal wastage.
• Mass transfer limitations were not observed (Ha = 7.26), and energy consumption was relatively low (1.15 kW h m-3).

Conclusions:

• A modified flotation cell is an effective reactor for ozonation, catalytic ozonation, and photocatalytic ozonation.
• The flotation cell offers superior ozone utilization efficiency compared to conventional reactors.
• This reactor design presents a promising, energy-efficient solution for pharmaceutical pollutant removal in wastewater treatment.