Thursday, October 04, 2012, 4:30PM - 5:30PM
Terry Legg and Hana Fancher
RL-1 room 269
Full title of talk: "Evaluating the potential for clean energy production based on greenhouse gas emissions and bacterial community composition at an palm oil wastewater treatment system in southwestern Costa Rica."
Palm oil is the fastest growing agricultural commodity in the world. The rapid expansion of oil palm agriculture is driving of deforestation, and is replacing farming and husbandry practices pantropically. Policy debates to date have focused primarily on the loss of carbon and biodiversity due to plantation establishment, with less focus on the greenhouse gas (GHG) emissions from palm oil mill effluent (POME). A large volume of POME, which contains high levels of degradable organic matter, is generated during palm oil extraction and must be treated under environmental regulations. The goal of our research was to evaluate the magnitude of GHG fluxes from an oil palm wastewater treatment system, and the potential for clean energy generation through biogas capture. We found that the highest biogas fluxes occurred early in the POME treatment process, and that 61% of the biogas was methane whereas 39% was carbon dioxide. Nitrous oxide represented less than one percent of the total greenhouse gas fluxes from the POME treatment lagoons. Also, greenhouse gas emissions were highly variable at the beginning of the treatment process, but were more consistent at later treatment stages. The composition of the bacterial community supports our hypothesis that the composition of the biogas (methane versus carbon dioxide) changes according to stages in the microbial degradation of POME. The magnitude of biogas emissions we measured during this study suggests that this facility would be a good candidate for using biogas as clean energy. In addition, our research shows that nearly 100% of the organic matter initially present in the POME was removed during the treatment process.