Optimization of radiofrequency-oxidation treatment of dairy manure

A novel technology involving radiofrequency heating and hydrogen peroxide (RF/H2O2) was used for the treatment of dairy manure. RF/H2O2 process efficacy was affected by power intensity, hydrogen peroxide dosage and holding time. The optimal conditions for nutrient release and solids disintegration were determined: for orthophosphate release, power intensity of 3 kW/L (kW/L substrate treated), holding time of 65 min and H2O2 dose of 1%; and power intensity of 1.9 kW/L, holding time of 53 min and H2O2 dose of 1.2% for soluble chemical oxygen demand concentration. The results indicated that the treatment efficacy of radiofrequency process was comparable to microwave process. However, the radiofrequency process required a longer holding time than microwave process. Nevertheless, energy required by the radiofrequency was lower than microwave as the radiofrequency system was capable of handling higher volumes of manure with higher solids content at a given time.