Biogas production from anaerobic co-digestion of durian shell with chicken, dairy, and pig manures

Highlights: • Methane yield on the co-digestion of DS and PM possessed synergistic effect. • The optimal mixing ratio for the co-digestion of DS and PM was 1:1. • Co-digestion kinetics of DS and PM could be fitted well by modified Gompertz and Cone models. • Co-digestion enriched microbial community compared to mono-digestion. • Overall energy produced from the co-digestion of DS and PM was estimated to be 2.1 × 10⁹ MJ/year. -- Abstract: Durian shell (DS), a kind of fruit waste with a very large annual production yield, is mainly discarded in Asia. Currently, finding a reasonable method to utilize this bioresource is urgently needed. The effective technique of anaerobic digestion (AD) for the utilization of DS has seldom been reported. In this study, the anaerobic co-digestion of DS with chicken manure (CM), dairy manure (DM), and pig manure (PM) at different ratios was performed. The results showed that significant synergistic effects were observed in the co-digestion of DS and PM at 1:1 and 1:3 ratios, respectively. The highest cumulative methane yield of 224.8 mL g_VS⁻¹ and biodegradability (B_D) of 48.3% were obtained at the optimal DS to PM ratio of 1:1. The kinetics of the anaerobic co-digestion of DS and PM were well described by the modified Gompertz and Cone models. High-throughput sequencing (HTS) demonstrated that the co-digestion of DS and PM was highly beneficial to the growth and richness of microorganisms in AD. The energy conversion performance of the co-digestion of DS and PM was also preliminarily evaluated. The validated findings in this research confirmed that the anaerobic co-digestion of DS and PM was a promising way to not only achieve the bioconversion of bioresources into clean energy but also explore broad prospects for their future industrial application.