초록
In this work, the application of ozone, an unexplored pretreatment to improve methane production from three mixed microalgae sources was investigated. Ozonation at various, culture-dependent dosages was employed and its impact on the efficiency of subsequent anaerobic digestion was examined in comparison with untreated biomass. Regardless of the O<SUB>3</SUB> pretreatment conditions, the methane yield in all cases could be increased by various extents (6-66%). The highest methane production (432.7mLCH<SUB>4</SUB>g<SUP>-1</SUP>VS<SUB>algal</SUB>, equaling to 259.6mLCH<SUB>4</SUB>g<SUP>-1</SUP>COD<SUB>in</SUB>) was attained with the culture composed of 35% Scenedesmus, 30% Dictyosphaerium, 15% Keratococcus, 10% Oscillatoria, 8% Monoraphidium and 2% Nitzchia, using the highest dosage of ozone (382mgO<SUB>3</SUB>g<SUP>-1</SUP>VS<SUB>algal</SUB>) for pretreatment. Electron microscopic assessment revealed the devastating effect of O<SUB>3</SUB> on algal cell wall structure and integrity, which was thus identified as the key-contributor to the improvement of CH<SUB>4</SUB> fermentation.