Study On High Ammonia-Nitrogen Wastewater Treatment With Short-cut Nitrification-Denitrification Process

With the development of industry and agriculture, water environment has been seriously polluted in recently years. Many rivers and lakes are eutrophic due to large amount of N and P which come from production and life. It is very efficiency and energy-saving using short-cut nitrification and denitrification to removal nitrogen in wastewater.Influencing factors of short-cut nitrification and denitrification and the feasibility of it to treatment anaerobically digested effluent of piggery wastewater were studied in this paper. The main results are as follows:(1)With aerobic activated sludge as the seeding sludge, short cut nitrification reactor was successfully started up. The removal of ammonia was 90% with the nitrite accumulation reach 80% after half a month reaction in nitrification reactor. The accumulation of nitrite was realized in short-cut nitrification reactor.(2)Make other factors unchanging, when pH was 7.6-8.3, the removal of ammonia overtaken 90% and the accumulation of nitrite reached 94%; when DO was 0.5-1.5mg/L, the removal of ammonia reached 90% with the accumulation of nitrite was 90.8%; when temperature was 22-30℃, the removal of ammonia was higher than that of 0-8℃and 12-15℃(3)With the same quality of aerobic activated sludge and anaerobic activated sludge as the denitrication reactor's seeding sludge, it had activity of short-cut denitrification by cultivated in 25 d. The removal of nitrite overtaken 80%.(4)Control the single factor in short-cut denitrification, we got the result that pH became higher with the reaction time and the concentration of influent substrate. The best pH range for short-cut denirification bacterial living was 7.8-8.3. The removal of nitrite can reach 100% when C/N was 3.0.The increase of the ratio of C/N had litter use for the speed of nitrite removal.The removal rate of nitrite decreased when C/N was less than 2.5 because of lock of electron donor. With the temperature increasing, short-cut denitrification bacteria activity increased gradually when the temperature was between 20-30℃. In the range of 30-37℃, there was a temperature range under which the removal rate of nitrite decreased when temperature increased. The best temperature range for short-cut denirification bacterial living was 32±1.5℃.(5) Using short-cut nitrification and denitrification process to treat effluent of piggery wastewater can cultivate the short-cut nitrification and denitrification bacterial. Experimental results showed that the removal of TN can be improve through increase the C/N, and the removal rate of TN reached 91%.