Effects of Total Solid Content on Anaerobic Fermentation Performance and Biogas Productivity of Tail Vegetables

A large amount of vegetable waste generated by farms is currently damaging the environment and public health. Anaerobic fermentation is a mature technology that significantly contributes to the recovery of energy and resources from tail vegetables and the control of environmental pollution. However, most vegetable wastes have not been utilized due to poor performance of biogas production, lack of optimal solid contents, and multiple other reasons. Herein, the anaerobic digestion biogas production performance of tail vegetables treated with different total solid (TS) content was studied using solanaceous and leafy vegetables as raw materials. Results showed that there was no acidification in all trials except for treatment with TS of 6%. The optimal TS for anaerobic fermentation of vegetable waste was determined to be around 20% in terms of methane production and biogas production efficiency. The cumulative methane production per unit of volatile solids (VSs) reached 241.7 mL CH4/g of VS, and the methane content was about 65% during the peak period of biogas production. Theoretically, the value of methane production based on anaerobic fermentation of tail vegetables is as high as 1.8 × 1013~4.6 × 1013 L in China. This research provides advice for screening specific and efficient parameters to promote the biogas production rate by tail vegetable anaerobic fermentation.