Catalytic wet hydrogen peroxide oxidation of phenolic compounds in coffee wastewater using Al–Fe-pillared clay extrudates

Abstract

The effluents from the biological treatment of coffee wet processing wastewater (CWPW) contain non-biodegradable compounds, which are toxic to aquatic ecosystems. In this study, Al–Fe-pillared bentonite extrudates shaped into Raschig rings were used to catalyze the oxidation of the phenolic compounds in CWPW. The catalytic wet hydrogen peroxide oxidation was tested in a semi-batch basket reactor at 25 °C under atmospheric pressure. Al–Fe-pillared bentonite extrudates achieved a 62.4% total phenol conversion with a 67.5% selectivity toward CO₂ after 96 h. Catalytic performance of the Al–Fe-pillared bentonite extrudates in the oxidation of phenolic compounds shows the potential of applying this catalyst for the treatment wastewaters. The implementation of systems for wastewater treatment is essential to the conservation of natural resources and the preservation of Colombian biodiversity, therefore, this research is a contribution to the sustainable development of coffee growing.

Keywords:

• CWHPO
• Coffee wastewater
• Al–Fe-pillared clay
• Extrudates
• Phenolic compounds

Acknowledgments

The authors are grateful for the financial support provided by project DIB Code 14990 of Universidad Nacional de Colombia—Sede Bogotá. The authors also thank Hacienda Venecia for supplying the CWPW.