Study on Removing Nitric Oxide by Denitrification in Bio-trickling Filter Using Hollow Ceramic Balls

The activated sludge from the secondary settling tank of municipal sewage treatment plant is cultured to obtain the denitrifying bacteria and then inoculate them to a new type of hollow ceramic balls in the bio-tricking filter to remove nitric oxide from waste gas. The effects of carbon source, gas flow, inlet concentration, spray flow and the oxygen content of waste gas on the removal efficiency of NO are investigated. The results show that glucose is more suitable than methanol as the carbon source. The removal efficiency of NO decreases with the increasing of gas flow and inlet concentration. The spray flow has little effect on the treatment efficiency of NO. The oxygen content has great influence on the removal efficiency of NO, when the oxygen content is approximately 0, the system´s removal efficiency can reach 88%; with the increase of oxygen content, the system´s removal efficiency decreases, when the oxygen content increases to 5%, the system´s removal efficiency drops to about 50%.