Test And Research On Nitrogen Removal Different Operating Methods In A~2/O~2 Process

At the same time with full nitrification and denitrification and nitrification and denitrification are two processes on a Chemical Corporation Henan low-nitrogen ratio wastewater nitrogen removal pilot study after 7 months of the pilot study, the main draw the following conclusions:(1) Nitrification and denitrification using the whole deal with the company's wastewater operation, control, control of operating conditions are the following operating conditions:the amount of water 35L/h; reaction temperature above 21℃; micro-oxygen zone DO to 1.0mg/L, aerobic zone DO to 3.0mg/L; sludge concentration of 2500～3000 mg/L; aerobic zone in the mixture than 200% return; sludge return ratio 80%; adding soda ash 150～200 mg/L (wastewater); adding starch 200 mg/L (waste water). Process the long-term stable operation, the effluent ammonia concentration on average 10mg/L, the average removal rate above 90%; water CODcr average concentration of 30mg/L or so, the average removal rate above 85%; effluent total nitrogen 60mg/L about 68% of the average removal rate. The water index can reach the existing "Integrated Wastewater Discharge Standard" (GB8978-1996) in the level of emission standards.(2) Use nitrite operates processing waste water control following operating conditions:inflow 40L/h; the reaction temperature (24-28) °c; micro-oxygen area DO to 0.3mg/L, aerobic area DO to 0.6mg/L; MLSs 2000-2500 mg/L; aerobic area mixed recirculation 200%; 80% of the sludge than; dosing soda 200～300mg/L (waste), control of aerobic area pH in 7.2 to 7.5. System can implement nitrite technology stable operation, effluent ammonia nitrogen concentration averages around 14mg/L, average removal rate in 86%; the average concentration in the water CODcr 32mg/L, average removal rate in 86%; water total nitrogen 66mg/L, average removal rate at 63%; nitrite accumulation rate with an average of 78%. Its water indicators can reach existing wastewater emission standards "(GB8978-1996) in the primary emission standards.(3) ORP run as two processes running in the control parameters can effectively characterize the operational status of each pond, full nitrification and denitrification processes in the ORP at the end of the aerobic zone (85～95) mV can be achieved between the optimal control process; nitrification denitrification in the aerobic tank at the end of ORP than 40mv, you can ensure that water up to standard.(4)Nitrification and denitrification processes throughout the direct operating costs for the 1.22 yuan/m3; nitrification denitrification direct operating costs for the 0.63 yuan/m3. Nitrification denitrification than nitrification and denitrification of the whole save 48%. Nitrification denitrification process can be seen than the full nitrification and denitrification has obvious economic advantages.