Biohydrogen production from renewable agri-waste blend: Optimization using mixer design

Biohydrogen from untreated mixed renewable agri-waste using buffalo dung compost is reported. Corn husk (CH) supported 25% higher hydrogen (H-2) production and showed the maximum value (62.38%) with p value (1.2 x 10(-6)) revealing its significance at individual and interactive level, respectively, compared to ground nut shell (GNS) and rice husk (RH). Augmented-simplex-lattice design experimentation revealed that a partial supplementation of RH or GNS to CH improves H-2 yield. Multiple-linear-regression analysis indicated that a quadratic model (low p = 0.0023, high F value = 35.99 and R-quadratic(2) = 0.99) was more significant compared to other linear, cubic and special cubic) models. Acetate and butyrate were accounted >80% of the volatile fatty acids (VFAs). A maximum accumulation of 65.78 ml H-2 g(-1) TVS was produced using agri-wastes in the ratio of CH:RH:GNS = 70:16:12. (C) 2009 Published by Elsevier Ltd on behalf of international Association for Hydrogen Energy.