Application Study On Embedded Immobilized Microorganisms Technology Efficient Nitrification Treatment In Industrial Wastewater

The latest national twelfth five planning about environmental protection listed the ammonia nitrogen as the important reduce emissions index at the first time. The efficient ammonia nitrogen treatment technology is required in both new treatment plants and the reconstruction of the old plants. This thesis focuses on treating the mixed industrial wastewater and high ammonia nitrogen chemical wastewater, studies on the application of embedded immobilized microorganisms technology effect on nitrification treatment in industrial wastewater. The purpose of the research is to provide a new thinking for improving ammonia nitrogen removal efficiency and to popularize the embedded immobilized technology application of industrial wastewater. The main conclusions are as follows:1. Embedded pellets is easy to acclimation by synthetic wastewater, 21 days later, the nitrification ability of the embedded pellets is increased from 8.3mgNH₄⁺-N/L-pellet?h to 23.4mgNH₄⁺-N/L-pellet?h.2. The mixed system combined embedded pellets with activity sludge can well adapt to the mixed wastewater. The removal rate of NH₄⁺-N is more than 97% and the removal rate of COD is more than 86%.3. Temperature had a less influence on the removal rate of NH₄⁺-N in mixed system combined embedded pellets with activity sludge than traditional activated sludge process. And with the system continued operated, embedded pellets will be slowly adapted to the low temperature conditions.4. In the mixed system, DO had a great influence on the removal rate of NH₄⁺-N, The removal rate of NH₄⁺-N could meet the requirement when DO>4. 5. Contrast experiment between MBBR carrier and embedded pellets shows that the removal rate of NH₄⁺-N is 95% with the stable embedded pellets mixed system, better than the MBBR(Moving Bed Biofilm Reactor) carrier which is 80%, and removal rate of TN is 90%, better than about MBBR reactor which is 75%.6. The experiment of treating the high ammonia chemical wastewater with immobilized microorganisms combined with A/O process indicated that: on the condition of enough carbon sources and alkalinity, the removal rate of NH₄⁺-N is more than 98% and the removal rate of COD is more than 95%. The effluent meets the first level criteria specified in Integrated Wastewater Discharge Standard(GB8978-1996).7. With the Dosing the embedded pellets into the aeration zone of A/O process, the removal rate of NH₄⁺-N is increased from 70% to 98% after 22 days'acclimation and HRT can be decreased from 36h to 24h when meet the same effluent NH₄⁺-N. Dosing the embedded pellets can effectively improve the removal rate of NH₄⁺-N, and carrier additive is simple. It is suitable for the reconstruction of the old plants. The effluent can meet criteria without reconstructing the tank.