Simultaneous removal of NO_X and SO₂ in exhausted gas through landfill leachate

Abstract

Simultaneous removal of NOx and SO₂ from exhausted gas were investigated by studying co-culture of sulfate reducing bacteria and anaerobic denitrifying bacteria, separated from landfill leachate. When H₂S, generated by sulfate reducing bacteria was chosen as the sole electron donor for anaerobic denitrifying bacteria, the co-culture system demonstrated a faster NO removal rate, higher stability and better permanence. When the feed gas flow rates of N₂ and SO₂ were maintained constant at 0.1 m³/h and 16 ml/min respectively, the maximum NO-removal rate could be achieved at over 92% with NO feed gas kept between 2-6 ml/min, while the SO₂ removal rate was always above 95%. Long-term continuous removal of NO exhibited an evident periodicity of five days, however, the fluctuation range of NO-removal was decreasing. Moreover, the decrease of the gas flow rate and the increase in NO inlet concentration could contribute to a higher NO-removal rate