Start-up And Operation Of Partial Nitrification Denitrification

Partial Nitrification Denitrification is an economic and efficient nitrogen removal technology. But the process started a long time prevailing, domestic wastewater treatment ineffective, limitations and other issues form the reactor.In response to these problems, this paper mainly studied Partial Nitrification Denitrification quick start-up and investigation of high concentrations of ammonia water distribution, sewage treatment effect in the reactor while a certain form of exploration.The results show that using activated sludge from common sewage treatment plant and trained with a special culture medium, controlling DO at 1-3mg/L and temperature at 24-27℃, activated sludge with the characteristics of Partial Nitrification Denitrification only 3 days, NO₂^--N accumulation remained at 95% stablely, NO₂^--N up to 169mg / L.After the success trained of sludge, useing SBR for treatment of high concentration of ammonia wastewater, the start-up time be only 3 days, with good Partial Nitrification Denitrification characteristics. NO₂^--N accumulation in the first cycle of device is 90.5% and the NO₂^--N accumulation has remained above 90% in 1 month; controlled the aeration rate in device, the formation of distinct TN loss can reach 89 %, or even 100%; on the one hand can save a good support section of aeration, denitrification on the other hand can reduce the dosage of carbon segments. Using SBR treating domestic wastewater, Partial Nitrification Denitrification characteristics maintain about 4 months. The NO₂^--N accumulation usually at 80%, then followed by gradually decreased gradually lost nitrification characteristics; this process has the effect of ammonia removal, ammonia water stable reached the first level A standards, also has a better COD removal. In the conditions of the influent COD concentration of 174mg / L, the effluent COD concentration can be 30mg / L.Finally, the effects of Partial Nitrification Denitrification in continuous flow treatment plant to maintain nitrification characteristics in a month, then gradually reduced nitrite accumulation by nitrification into a normal complete nitrification. Nitrification characteristics lead to the loss of Partial Nitrification Denitrification factors: domestic sewage is not ideal denitrification carbon source, the device completely using domestic sewage as carbon source, in denitrification can not provide an effective carbon source, resulting in Partial Nitrification Denitrification transformed into complete nitrification and denitrification.