Bio-hydrogen Production By Enzymic Hydrolysis of Sunflower Oil Sludge

Bio-hydrogen was produced from different agro-industrial wastes by Hypocrea lixii SS1 isolated from fouled soil. The alkaline pre-treatment of sunflower oil sludge resulted in a bio-hydrogen potential of 405mL H-2/g volatile solids (VS). The role of sunflower oil sludge on the bio-hydrogen production by H. lixii SS1 was investigated. It was inferred that xylose enhances the bio-hydrogen production when compared to other monomeric carbohydrates in sunflower oil sludge. A maximum bio-hydrogen potential of 430 mL H-2/g VS was achieved with 7.2 mg/mL of xylose formation for a 168 h incubation period. The bio-hydrogen production was carried out under optimized conditions of 80 g/L inoculum, pH 5 and 50 degrees C, and a maximum bio-hydrogen potential of 494.26 mL H-2/g VS was obtained. A cumulative bio-hydrogen production of 450 mL was achieved with modified Gompertz model. The maximum chemical oxygen demand (COD) removal efficiency (93%) and maximum fermentative products (2182.60 mg COD/L) with total volatile fatty acids of 2032.82 mg COD/L were obtained when 120 and 80 g/L of inoculum were added to the reactor, respectively. Hence, enzymatic hydrolysis led to a marked improvement in the overall bio-hydrogen yield of 400-500 mL H-2/g VS suggesting the potential use of sunflower oil sludge for bio-hydrogen production in a cost effective manner.