Optimal combination of food waste and maize husk for enhancement of biogas production: Experimental and modelling study

This study was focused on the optimization of biogas production from the co-digestion of food waste (FW) and maize husk (MH). The co-digestion of FW and MH at various mixture ratios was carried out in digesters A to E at 37 +/- 1 degrees C. Digesters A, B, C, D and E contained FW: MH of (100:0; 75:25; 50:50; 25:75; 0:100) respectively. Results obtained showed that average biogas yields of 0.50 +/- 0.04, 0.71 +/- 0.07, 0.54 +/- 0.05, 0.30 +/- 0.03, and 0.24 +/- 0.02 L/gVS were obtained from digesters A, B, C, D, and E respectively. The modified Gompertz modelling of the experimental data showed that digesters A, B, C, D, and E had latency (lambda) of 4.1, 4.9, 6.9, 7.4, and 10.6 days respectively. Digester B had the highest maximum specific biogas production R-m, and maximum biogas production potential (A) of 0.50 L/gVS/day and 20.7 L/gVS respectively. The R-2 values between experimental and simulation data ranged from 0.9913 to 0.9989 in all digesters. The Post hoc Test in ANOVA using the Least Significant Difference (LSD) confirmed that there were significant differences in the mean biogas yield from the different digesters. The study therefore shows that the best combination of FW and MH for enhanced biogas production occurred in digester B. (C) 2015 Elsevier B.V. All rights reserved.