Start‐Up Study on Biohydrogen from Palm Oil Mill Effluent in a Pilot‐Scale Reactor

Abstract

A start-up study for biohydrogen production from palm oil mill effluent (POME) is carried out in a pilot-scale up-flow anaerobic sludge blanket fixed-film reactor (UASFF). A substrate with a chemical oxygen demand (COD) of 30 g L −1 is used, starting with molasses solution for 30 days and followed by a 10% v/v increment of POME/molasses ratio. At 100% POME, a hydrogen content of 80%, hydrogen production rate of 36 L H 2 per day, and maximum COD removal of 48.7% are achieved. Bio-kinetic coefficients of Monod, first-order, Grau second-order, and Stover-Kincannon kinetic models are calculated to describe the performance of the system. The steady-state data with 100% POME shows that Monod and Stover-Kincannon models with bio-kinetic coefficients of half-velocity constant (K s) of 6000 mg COD L −1 , microbial decay rate (K d) of 0.0015 per day, growth yield constant (Y) of 0.786 mg volatile suspended solids (VSS)/mg COD, specific biomass growth rate (max) of 0.568 per day, and substrate consumption rate of (U max) 3.98 g/L day could be considered as superior models with correlation coefficients (R 2) of 0.918 and 0.989, respectively, compared to first-order and Grau's second-order models with coefficients of K 1 1.08 per day, R 2 0.739, and K 2s 1.69 per day, a = 7.0 per day, b = 0.847.

Bioenergy recovery from food waste through dark fermentation direction

“…Phenol-sulfuric method with glucose as a standard was used to measure the total carbohydrate [20]. All the equipment and methods used in this study is same as our previous study [12][13][14]. Lipids were measured by Soxhlet method [21].…”

“…For biohydrogen production, the activity of methanogens bacteria must be prevented; hence, operation the system at short hydraulic retention time (HRT), low pH, or applying heat treatment of the sludge are the approaches to overwhelm the methanogens bacteria and increase the yield of H 2 production [10,11]. Among these methodologies, heat treatment has been considered as an alternative to enrich the community of hydrogenase bacteria from anaerobic inoculum culture [12,13]. The in uence of the required fermentation pH of 5.5 to 6.0 as an effective range on the e ciency of biohydrogen production has been demonstrated in several studies [9,13,14].…”