Pinanong Tanikkul. Improvement of biohydrogen production from palm oil mill effluent using ozonation process. Master's Degree(Environmental Technology). King Mongkut's University of Technology North Bangkok. Central Library. : King Mongkut's University of Technology North Bangkok, 2010.
Improvement of biohydrogen production from palm oil mill effluent using ozonation process
Abstract:
This research was focused on the biological fermentative production of hydrogen
from the raw and the ozonated palm oil mill effluent (POME). The experiment was
conducted in 500 mL batch reactors using UASB mixed culture as a microbial seed.
Experimental conditions including pH 4.0-6.0, varied POME concentrations of 5,000 -
37,000 mg L-1 and temperatures of 37, 55 and 70°C. The preliminary results showed
that pH 6.0 is optimal for the seed since the highest hydrogen production yield (Y) of
28.31 ± 2.11 mL g-1CODremoved was observed. Comparative results of hydrogen
production from the raw POME versus the ozonated POME indicated that the ozone
pretreatment of POME (mg COD: mg ozone = 102.78) elevated the biodegradability
of the POME constituents and enhanced effectively the hydrogen production yield
and rate for most cases. Under mesophilic condition (37°C), hydrogen production
using ozonated POME concentration of 30,000 mg L-1 displayed the maximal kinetic
parameters for the hydrogen production. The maximal hydrogen production potential
(Hmax) was 349.75±13.96 mL (13.74 mmol) and the maximal hydrogen production
yield (Y) was 182.32±7.17 mL g-1 CODremoved (7.96 mmol g-1 CODremoved).
Meanwhile the maximal hydrogen production rate (Rmax) was 43.12±2.49 mL h-1
(0.92 mmol h-1) and the specific hydrogen production rate (Rmax) was 6.18±0.36 mL
h-1 g-1 TVS (0.24 mmol h-1 g-1 TVS) was observed at COD concentration 25,000 mg
L-1. Maximal CODT removal was 44% at COD concentration of 15,000 mg L-1.
Volatile fatty acid analysis showed that the concentrations of acetic, butyric, valeric,
propionic acids and ethanol were 56.42±1.20, 37.63±0.86, 3.52±0.01, 3.08±0.13 and
2.73±0.09 mM, respectively, and an undissociated acid concentrations of 14.68±1.17
mM.