Microwave enhanced advanced oxidation treatment of dairy manure

Abstract

The microwave enhanced advanced oxidation process (MW-AOP) was used to treat dairy manure in a continuous-flow 915 MHz microwave wastewater treatment system. The treatment efficiency increased with an increase in temperature, as well as hydrogen peroxide dosage. The settling property was also improved in all treated sets, regardless of temperature applied. The system operated at temperatures >100 °C had a much higher soluble chemical oxygen demand than at temperatures <100 °C. The highest soluble carbonaceous compounds, orthophosphate and ammonia were obtained at 110 °C and 0.6%H₂O₂ per % of total solids content. The process should be operated at higher temperatures and higher hydrogen peroxide dosages for maximizing solids disintegration, nutrient release and energy efficiency. An energy fingerprint correlating the cumulative energy consumption and temperature rise was developed. The results demonstrated that the custom designed MW-AOP system is suitable for the effective treatment of dairy manure. The system can readily be scaled up and integrated into a dairy farm manure treatment and resource recovery system.

Keywords:

• Dairy manure
• energy consumption
• MW-AOP
• nutrient release
• solids disintegration

Additional information

Funding

This research was funded by the Natural Science and Engineering Research Council (NSERC) of Canada, as well as Growing Forward 2, Canada-BC Agri-Innovation Program (CBCAIP), A federal-territorial initiative of Government of Canada and Province of British Columbia. A. Srinivasan would like to acknowledge Mitacs – Accelerate Postdoctoral Fellow Internship Program along with Opus DaytonKnight Consultants Ltd., North Vancouver for their financial support. In addition, technical assistance provided by Tim Ma is recognized.