The palm oil industry generates a large volume of waste known as palm oil mill effluent (POME), which must to be treated appropriately before the final discharge. The most powerful refining treatment method is anaerobic digestion to produce hydrogen which is a promising alternative energy. This study aims to investigate and compare the hydrogen production efficiency, metabolites, and microbial community from POME obtained from two different sites, Southern (TSPOME) and the Eastern (SBPOME) parts of Thailand. Our finding suggests that TSPOME is a better hydrogen-producing inoculum than SBPOME. The TSPOME produced a hydrogen content of 34.35% and a maximum hydrogen yield of 0.74±0.10 mol-H2/mol-glucose, which is 24.63% and 0.63 mol-H2/mol-glucose higher than those of SBPOME (9.72% and 0.11±0.01 mol-H2/mol-glucose). Furthermore, the metabolite analysis in TSPOME showed the increase in butyric acid concentration had led to higher hydrogen production. In addition, the total relative abundance of potential hydrogen producer in TSPOME was 2.42% while that from SBPOME was only 0.24%. The hydrogen-producing bacteria found in TSPOME were Ruminococcus sp. (2.40 %), Bacillus sp. (0.01%), and Clostridium sp. (0.01%). Our results allow a better understanding of H2 production in different regions of Thailand and how the microbial community involved can affect H2 yield. Hence, this provides the key information for efficient selection of inoculum for future applications.
Keywords
Hydrogen, microbial community, POME, anaerobic digestion, renewable energy