The effects of irradiation intensity on the microwave-enhanced advanced oxidation process

Abstract

The microwave enhanced advanced oxidation process (MW/H₂O₂-AOP) was adopted in successfully treating a multitude of organic slurries. The factor of ramp rate was incorporated in this study to investigate its correlations with different nutrients release into solution from waste activated sludge. Besides the ramp rate, the amount of time the samples were held at the treatment temperature to a total of 10 minutes aided in the isolation of held temperature from ramp rates, since different ramp rates will yield different reaction times. It was found that with the exception of orthophosphate and chemical oxygen demand release, ammonia and volatile fatty acids depended highly on the ramp rates. All constituents, chemical oxygen demand, orthophosphate, ammonia and volatile fatty acids, solubilized better with longer reaction times coupled with the highest ramp rate. Besides treatment time and ramp rates, treatment temperature and hydrogen peroxide dosage also play important roles in the release of various nutrients into solution by the MW/H₂O₂-AOP. The results from this study can aid in design parameters for the scaling up of a continuous microwave system for the MW/H₂O₂-AOP.

Keywords:

• Microwave
• advanced oxidation process
• ramp time
• solubilization
• nutrients

Acknowledgments

The authors wish to acknowledge the research funding by the Natural Science and Engineering Research Council (NSERC) of Canada as well as the technical assistance provided by Ms. Paula Parkinson.