Significant diethyl phthalate (DEP) degradation by combined advanced oxidation process in aqueous solution

Area of Science:

• Environmental Chemistry
• Water Treatment Technologies
• Advanced Oxidation Processes

Background:

• Diethyl phthalate (DEP) is a common environmental pollutant found in aqueous solutions.
• Effective removal of DEP is crucial for water purification and environmental protection.
• Conventional treatment methods may not fully address DEP contamination.

Purpose of the Study:

• To investigate the efficacy of combined ultrasound (US), UV irradiation, and titanium dioxide (TiO2) photocatalysis for DEP removal.
• To elucidate the synergistic effects and degradation mechanisms of these combined processes.
• To optimize US frequency for DEP degradation.

Main Methods:

• Experiments were conducted using single processes (sonolysis, photolysis, photocatalysis) and combined processes (sonophotolysis, sonophotocatalysis).
• The optimal US frequency for DEP degradation was determined to be 283 kHz.
• Degradation rates and total organic carbon (TOC) reduction were measured to assess DEP removal and mineralization.

Main Results:

• The sonophotolytic and sonophotocatalytic processes showed significant DEP degradation and mineralization (TOC reduction).
• Synergistic effects were observed, with enhancement factors of 1.29 for sonophotocatalysis and 1.95 for sonophotolysis.
• High hydrogen peroxide (H2O2) formation rate of approximately 0.32 mM min(-1) was noted at the optimal US frequency.

Conclusions:

• The combination of US, UV, and TiO2 offers a highly effective method for removing DEP from aqueous solutions.
• Synergistic interactions between US, UV, and the photocatalyst enhance DEP degradation efficiency.
• This integrated approach holds promise for advanced water treatment applications.