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 biofilterwas 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 +/- 0.9g 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 supplymethod of six doses of 50 mL per day. yCONCLUSION: Eventhoughthe resultswerelower thanthoseobtained for thebiofiltration of CH4 alone, this studydemonstrated the feasibility of treating CH4 and swine slurry with the same biofilter using a novel design. (C) 2012 Society of Chemical Industry