Metformin Degradation by Advanced Oxidation Processes: Performance, Limitations, and Environmental Concerns

Area of Science:

• Environmental Chemistry
• Pharmaceutical Science
• Water Treatment Technologies

Background:

• Metformin, a widely prescribed biguanide for type 2 diabetes, is frequently detected in aquatic environments.
• Incomplete human metabolism leads to metformin's excretion and subsequent environmental contamination, posing ecological risks.
• Metformin is classified as an emerging contaminant due to its growing environmental presence.

Purpose of the Study:

• To review the environmental presence and risks of metformin.
• To evaluate advanced oxidation processes (AOPs) for metformin degradation.
• To identify research gaps and future directions for sustainable metformin removal.

Main Methods:

• Descriptive analysis of metformin's environmental occurrence.
• Evaluation of various AOPs: photolysis, photocatalysis, electrolysis, and ozonation.
• Assessment of degradation rates and by-product toxicity.

Main Results:

• UV photocatalysis and ozonation achieve high metformin degradation rates (99.9% and 100%).
• These effective methods can generate toxic by-products harmful to aquatic ecosystems.
• Solar photocatalysis offers a lower degradation rate (74.22%) but uses no artificial energy and produces fewer hazardous by-products.

Conclusions:

• Current AOPs for metformin degradation have limitations regarding efficiency and environmental safety.
• There is a critical need for developing clean and sustainable methods for metformin removal.
• Future research should focus on enhancing photocatalytic and biological treatments to improve efficiency and minimize ecological impact.