Comparative study of catalytic ozonation and Fenton-like processes using iron-loaded rice husk ash as catalyst for the removal of methylene blue in wastewater

ABSTRACT

This study intends to compare the effectiveness of catalytic ozonation and Fenton-like processes for the decolorization of methylene blue using iron-loaded rice husk ash as catalyst. In both processes, effect of initial pH, adsorption, hydroxyl radical scavenger, and chemical oxygen demand removal was studied. The results revealed that catalytic processes were found to be pH dependent with the highest activity at pH 3.0. Unlike Fenton-like process, catalytic ozonation also found to be effective at pH 7.0. It is therefore, concluded that catalytic ozonation process is more effective than Fenton-like process near wastewater pH values.

KEYWORDS:

• Catalytic ozonation
• Fenton-like process
• Methylene blue
• Rice husk ash

Highlights

• The catalytic ozonation and Fenton-like catalytic decolorization and degradation of methylene blue on rice husk ash-based catalyst was compared.

• The catalytic activity was found to be effective for the removal of methylene blue.

• The catalytic activity was found to be the maximum at initial pH 3.0.

• Unlike Fenton-like process, catalytic ozonation also found to be effective at pH 7.0.

• The effect of hydroxyl radical scavenger and catalyst dose has significant effect on the catalytic activity.

• The catalyst shows significant reuse performance in both processes.

Additional information

Funding

The financial support from the Institute of Environmental Engineering and Research, University of Engineering and Technology Lahore (Pakistan) is gratefully acknowledged.