Simultaneous treatment of methane and swine slurry by biofiltration

BACKGROUND: The piggery industry is important both worldwide and in Canada, but localized production of large quantities of swine slurry causes severe environmental problems such as aquatic pollution and greenhouse gas emissions. The main objective of this study was to determine whether it is possible to simultaneously treat methane (CH₄) and swine slurry using an inorganic biofilter. RESULTS: A novel biofilter was designed to overcome the inhibition of CH₄ biodegradation by swine slurry. The CH₄ elimination capacity increased with the inlet load and a maximum value of 18.8 ± 1.0 g m^?3 h^?1 was obtained at an inlet load of 46.7 ± 0.9 g m^?3 h^?1 and a CH₄ concentration of 3.3 g m^?3. Four pure strains of fungi were used in an attempt to improve the removal of CH₄, but no significant effect was observed. Between 0.35 and 3.4 g m^?3, the CH₄ concentration had no effect on swine slurry treatment with removal efficiencies of 67 ± 10% for organic carbon and 70 ± 7% for ammonium. The influence of the slurry supply was analyzed and the best results were obtained with a supply method of six doses of 50 mL per day. CONCLUSION: Even though the results were lower than those obtained for the biofiltration of CH₄ alone, this study demonstrated the feasibility of treating CH₄ and swine slurry with the same biofilter using a novel design. Copyright © 2012 Society of Chemical Industry