| Nitric oxide (NO) is a major source of atmospheric pollutant. The traditional technologies for NO removal has some shortcomings such as costly, unsuitable to waste gas in low concentration condition or produced secondary pollutant. However, biofilter has become more concerned these days for its easily design, low cost, fitness for low concentration pollutants.Lava and a new kind of material named Carbon Foam were applied in this experiment which had characters of filming quickly, considerable superficial area, high rate of interspaces, nontoxic, good mechanic performance and so on. The microbe from active sludge was cultured by nitrite which is supplied as the only nitric source. After that the microbe were inoculated on the surface of packing material to develop the biofilm. The liquid phase nitrification test was conducted to determine the variability and the potential of performance among the three biofilters. The moisture in the filter was maintained by ultrasonic aerosol equipment, which can also minimize the thickness of the liquid film. The main effectors such as the concentration of inlet gas, pH, humidity, EBRT (empty-bed residence time) on biofilter were investigated respectively. The results show that the performance of 24PPC (Pores Per Centimeter) Carbon Foam-based biofilter was best in the NO removal precess.A steady removal efficiency of 48%~74% was attained for the 24PPC carbon foam-based biofilter at specified NO inlet concentrations of 61.5~123.0mg/m3 and an EBRT of 3.5minutes. The other two biofiltes haven't obtain such performance results. The experiment was restarted and the 24PPC carbon foam quickly raise the removal rate from 32% to 74%. This experiment result is useful for polit-scale experiment and the design of project. Finally, the effect of chemical oxidation on nitrification process was investigated and the mechanism of NO removal was discussed.
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