Co-Digestion Of Cattle Manure And Sewage Sludge – Effects On Biodegradation Rates
Anaerobic digestion of cattle manure (CM) as single substrate and the co-digestion with sewage sludge wastewater (SSW) was conducted at mesophilic temperature (35ºC) to investigate the feasibility of the co-digestion process. The anaerobic co-digestion of CM with SSW provided a higher removal efficiency in terms of total COD (60%) when compared to anaerobic digestion of CM or SSW. However, the high values of the ratio tCOD/TKN suggest that the C/N ratio may not be proper for the biomethanation process. The organic matter biodegradation rate observed for co-digestion of SSW and CM was 0.13±0.02gO2 gVSS-1 d-1, higher than single-digestions of CM and SSW. The results obtained suggest that anaerobic co-digestion of cattle manure and sewage sludge, at mesophilic condition (35ºC), is a viable solution in terms of increased biodegradability of substrates, seeking higher quality and quantity of biogas produced.
Keywords- Anaerobic digestion, Biogas, Biodegradability, Cattle manure, Sewage sludge.