Pyrolyzed carbon derived from red soil as an efficient catalyst for cephalexin removal

Area of Science:

• Environmental Chemistry
• Materials Science
• Catalysis

Background:

• Red soil, common in Southern China, is often considered infertile.
• Developing effective catalysts for pharmaceutical wastewater treatment is crucial.

Purpose of the Study:

• To utilize red soil as a substrate for preparing catalysts for cephalexin degradation.
• To investigate the efficiency of these catalysts in catalytic wet peroxide oxidation (CWPO).

Main Methods:

• Preparation of red soil-derived catalysts (RC500) via pyrolysis at 500°C.
• Application of RC500 in CWPO for cephalexin degradation.
• Analysis of catalyst properties, reaction parameters, and degradation pathways.

Main Results:

• The catalyst pyrolyzed at 500°C (RC500) achieved 95.23% cephalexin and 60.58% TOC removal.
• High iron content and Fe(II) on RC500 facilitated H2O2 decomposition into hydroxyl radicals (·OH).
• RC500 demonstrated efficiency in treating hospital wastewater in a pilot device.

Conclusions:

• Red soil can be effectively repurposed to create active catalysts for pharmaceutical wastewater treatment.
• The catalyst's porous structure, iron content, and mineral composition contribute to its high activity.
• A degradation pathway for cephalexin was elucidated, offering insights for advanced oxidation processes.