Co-Digestion of Orange Pulp and Cattle Manure with Different C/N Ratios and A New Modeling of Biogas Production

Abstract

In this study, the co-digestion of orange pulp (OP) and cattle manure (CM) were investigated. The anaerobic process (40 d) of five reactors prepared according to different carbon to nitrogen (C/N) ratios (17, 26, 29, 35, 43.76) was completed. Anaerobic digestion (AD) was investigated in batch reactors (1000 mL) and both biogas production measured every five days and soluble chemical oxygen demand (SCOD) value % removals were determined. The highest biogas production was observed as 373.9 mL/g TS in the reactor in which the (C/N) ratio was 29. Compatibility of biogas production measured every five days of all reactors was investigated by Wood model and Wilmink model. Model evaluation criteria were interpreted on the basis of coefficient of determination (R2), sum of remaining squares (RSS), Akaike information criterion (AIC) and Bayesian information criterion (BIC) tests. As a result, except for other studies, biogas production measured in anaerobic processes (every 5 days) was successfully completed according to Wood and Wilmink models.