Anaerobic co-digestion of organic waste has attracted attention as a promising technology for waste management and biogas recovery. Several parameters need to be considered for the proper operation of this technology including the feedstock selection and their ratios. This research was aimed to investigate the influence of mixing and lipids: proteins: carbohydrates ratios on biomethane production in anaerobic co-digestion of thickened waste activated sludge (TWAS), manure and source separated organics (SSO). The digestion reactors operated in batch mode under hemophilic condition. The results showed that the maximum methane yield was 356 mL CH4/g CODadded corresponding to TWAS: manure: SSO mixing ratio of 2:4:4 and lipids: proteins: carbohydrate ratio of 1: 3.5: 18.5. In comparison, 134, 299, and 332 mL CH4/g CODadded were obtained by mono digestion of TWAS, manure, and SSO. The trend of the methane yield variations in response to the COD: N and to the lipids: proteins ratios relatively conform to each other excluding some of the ratios. On the contrary, the methane yields demonstrated different responses to the ratios of lipids: carbohydrates and proteins: carbohydrates compared to COD: N ratios. Synergistic effect increased the methane yield by 19% in co-digestion of TWAS/manure/SSO.
Keywords: Biomethane Potential, Manure, Thickened Waste Activated Sludge, Mixture RatioPDF
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