What is the principle of biological nitrogen and phosphorus removal from wastewater?

The basic principle of biological nitrogen removal from wastewater is that, on the basis of transforming organic nitrogen into ammonia nitrogen, firstly, ammonia nitrogen is transformed into nitrite nitrogen and nitrate nitrogen through nitrification in aerobic section and the synergistic effect of nitrifying bacteria and nitrifying bacteria, that is, ammonia nitrogen is transformed into nitrite nitrogen and nitrate nitrogen. Nitrate nitrogen is transformed into nitrogen by denitrification under anoxic conditions, that is, (denitrification) and (denitrification) are reduced to nitrogen, which overflows the water surface and is released into the atmosphere to participate in the natural nitrogen cycle. Nitrogen-containing substances in water are greatly reduced, which reduces the potential danger of effluent and achieves the purpose of denitrification of wastewater. \x0d\ This process can be divided into three steps: \x0d\ The first step is ammonification, that is, the organic nitrogen in water is transformed into ammonia nitrogen under the action of ammonifying bacteria. (In the ordinary activated sludge process, ammoniation is carried out very quickly, and no special measures are needed) \x0d\ The second step is nitrification, that is, under the condition of sufficient oxygen supply, ammonia nitrogen in water is first oxidized to nitrite by nitrite bacteria, and then further oxidized to nitrate by nitrate bacteria. \x0d\ The third step is denitrification, that is, under anoxic or anaerobic conditions, nitrite and nitrate produced by nitrification are reduced to nitrogen by denitrifying bacteria.