Open Access Statistical Optimization of Biohydrogen Production from Palm Oil Mill Effluent by Natural Microflora

Abstract: In this study, palm oil mill effluent (POME) was used as the substrate for biohydrogen production. Heat-treated POME sludge acclimated with POME incubated at 37°C for 24 hours was used as seed culture. Preliminary screening on the effects of inocula sizes, heat treatment, substrate concentration and pH of incubation by using a factorial design (FD) were conducted under mesophilic condition (37°C) using a serum vial (160 mL). The experimental results from two-level FD showed that pH and Chemical Oxygen Demand (COD) of POME significantly affected biohydrogen production. Op-timizations of the specific hydrogen production (Ps) and the hydrogen production rate (Rm) were achieved by using a cen-tral composite design (CCD). The maximum Ps of 272 mL H2/g carbohydrate was obtained under optimum conditions of pH 5.75 and substrate concentration of 80 g/L. The maximum Rm of 98 mL H2/h was calculated under the optimum condi-tions of pH 5.98 and substrate concentration of 80 g/L. The optimized conditions obtained were subjected to a confirma-tion run and it showed reproducible data with a Ps of 226 mL H2/g carbohydrate and Rm of 72 mL H2/h