Study on Removing Nitric Oxide from Waste Gas by Nitrification Using Bio-trickling Filter

The activated sludge from the nitrification section of secondary settling tank in municipal sewage treatment plant is cultured to obtain the nitrobacteria and then inoculates them to the columnar activated carbon in the bio-tricking filter to remove nitric oxide from waste gas. The test studies the effect of the pH of circulating fluid, the circulating fluid flow rate, the empty bed residence time, the inlet NO concentration and organic carbon source on the removal efficiency. The results show that the optimum pH of circulating fluid is 7.5, while the removal efficiency of NO can reach the best. The smaller inlet gas flow and the lower inlet NO concentration, the better the removal efficiency will be. In the experimental range, the circulating fluid flow has an effect on the bio-tricking filter s removal efficiency and the most suitable range of circulating fluid flow rate is 0.05~0.10L/h.After the addition of organic carbon source, the removal efficiency of NO increases.