effects of ultrasonic and thermo-chemical pre-treatments on methane production from fat, oil and grease (fog) and synthetic kitchen waste (kw) in anaerobic co-digestion

the effects of ultrasonic and thermo-chemical pre-treatments on the methane production potential of anaerobic co-digestion with synthetic kitchen waste (kw) or fat, oil and grease (fog) were investigated. non-linear regressions were fitted to accurately assess and compare the methane production from co-digestion under the various pre-treatment conditions and to achieve representative simulations and predictions. ultrasonic pre-treatment was not found to improve methane production effectively from either fog co-digestion or kw co-digestions. thermo-chemical pre-treatment could increase methane production yields from both fog and kw co-digestions. cod solubilization was found to effectively represent the effects of pre-treatment. a comprehensive evaluation indicated that the thermo-chemical pre-treatments of ph = 10, 55 °c and ph = 8, 55 °c provided the best conditions to increase methane production from fog and kw co-digestions, respectively. the most effective enhancement of biogas production (288 ± 0.85 ml ch₄/g tvs) was achieved from thermo-chemically pre-treated fog co-digestion, which was 9.9 ± 1.5% higher than fog co-digestion without thermo-chemical pre-treatment.