Jiravut Seengenyoung - Department of Industrial Biotechnology,Faculty of Agro-Industry, Prince of Songkla University, Songkhla ۹۰۱۱۲, Thailand
Poonsuk Prasertsan - Department of Industrial Biotechnology,Faculty of Agro-Industry, Prince of Songkla University, Songkhla ۹۰۱۱۲, Thailand
Sompong O-Thong - Department of Biology, Faculty of Science, Thaksin University, Phatthalung ۹۳۱۱۰, Thailand Microbial Resource Management Research Unit, Faculty of Science,Thaksin University, Phatthalung ۹۳۱۱۰ Thailand

The effect of alkaline and acid pretreatment on solubilization of solid organic matter in palm oil mill effluent (POME) and hydrogen production by Thermoanaerobacterium-rich sludge was studied. Organicmatter solubilization of alkaline and acid pretreatments were increased up to 28 and 15.7% of initial soluble CODin POME, respectively. That corresponds to carbohydrate solubilization of 41 and 32% of initial soluble carbohydrate in POME, respectively. A maximum hydrogen production yield of 4.6 l H2/l-POME was achieved from POME pretreated with 1.5% w/v NaOH, which was 3-fold greater than raw POME and 1-fold greater thanPOME pretreated with 1.5% w/v HCl. Optimum conditions for biohydrogen production from alkaline pretreatedPOME using Thermoanaerobacterium-rich sludge was found at initial pH 5.5 and temperature of 60°C, whichgives a maximum hydrogen production yield of 5.2 l H2/l-POME and increased 51% as compared to raw POME. The biogas was mainly composed of hydrogen and carbon dioxide with the percentage of hydrogen rangingfrom 55-60% of biogas and free of methane. During the conversion of alkaline pretreated POME into hydrogen,the acetic and butyric acids were main by-products in the metabolism. The results showed that alkalinepretreatment is an effective pretreatment methods for enhancing the hydrogen production yield from POME. The use of Thermoanaerobacterium-rich sludge is promising for future engineering practice of biohydrogen production from alkaline pretreated POME

Thermoanaerobacterium-rich sludge Palm oil mill effluent Biohydrogen Thermophilic condition Alkaline pretreatment