Catalytic oxidation with Al–Ce–Fe–PILC as a post-treatment system for coffee wet processing wastewater
The effluent from the anaerobic biological treatment of coffee wet processing wastewater (CWPW) contains a non-biodegradable compound that must be treated before it is discharged into a water source. In this paper, the wet hydrogen peroxide catalytic oxidation (WHPCO) process using Al–Ce–Fe–PILC catalysts was researched as a post-treatment system for CWPW and tested in a semi-batch reactor at atmospheric pressure and 25 °C. The Al–Ce–Fe–PILC achieved a high conversion rate of total phenolic compounds (70%) and mineralization to CO2 (50%) after 5 h reaction time. The chemical oxygen demand (COD) of coffee processing wastewater after wet hydrogen peroxide catalytic oxidation was reduced in 66%. The combination of the two treatment methods, biological (developed by Cenicafé) and catalytic oxidation with Al-Ce–Fe–PILC, achieved a 97% reduction of COD in CWPW. Therefore, the WHPCO using Al–Ce–Fe–PILC catalysts is a viable alternative for the post-treatment of coffee processing wastewater.