Enhancement effect of ionizing radiation pretreatment on biogas production from anaerobic fermentation of food waste

Anaerobic digestion has become an important technology in the treatment of food waste and the acquisition of renewable energy. However, the physicochemical properties of the fermentation substrate have a great influence on the fermentation process. The present study examined the use of radiation technology for the anaerobic digestion pretreatment of food waste. Food waste was irradiated with different doses of radiation from a Co-60 gamma source and then subjected to anaerobic digestion to produce biogas. The effects of ionizing radiation pretreatment on the dissolution of organics were also investigated. The results revealed that, for food waste that had been subjected to 8.28-kGy irradiation pretreatment, the soluble chemical oxygen demand (SCOD) increased by 70.6% from 140.1 g/L to 239.1 g/L while the biogas yield was 504 ml/g VSadd, which was an increase of 14.3% over the non-irradiated pretreatment group. Therefore, radiation technology is a novel and efficient means of pretreatment for the anaerobic digestion of food waste.