School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
Behaviors of simultaneous removal of NO and SO2 using the coculture of anaerobic denitrifying bacteria and sulfate reducing bacteria were investigated in a bench-scale biotrickling-filter. Approximate 20 days were required to use the landfill leachate as the microbial seed to develop the biofilm on the surface of packing material. When the combined NO/SO2 removal biotrickling-filter was operated at an empty bed residence time (EBRT) of 76 s and the NO and SO2 feed concentrations of 2 and 2 g/m3 respectively, the SO2 removal efficiency was always above 95%, while NO removal exhibited an evident periodicity of 5-6 days for the initial 60 days after the attachment phase and then a steady-state NO-removal efficiency of around 90% was obtained after 130 days of continuous operation. Contrast experimental results indicated that the coculture in the combined NO/SO2 removal biotrickling-filter showed a higher resistance to shock NO-loadings and a better tolerance of starvation than the single denitrifying bacteria in the NO removal biotrickling-filter.