| The spiral up-flow reactor(SUFR)is a new stand pattern reaction technique of wastewater treatment, which has a mechanical leading flow system. The system is optimum designed by a single reactor technology on the base of UCT process. The mixture liquid in the reactors flows in spiral up-flow way, forming a better piston pattern flow. And the concentration of substrate has a evident gradient distribution. On the basis of prophase research, the followings were studied.â‘ The thesis investigated the effects of feed water carbon-nitrogen ratio, sludge age and dissolved oxygen on biological nitrogen and phosphorus removal in the Spiral Up-Flow Reactor system. Furthermore, the experiment was to optimize the operating conditions by analyzing on the characteristics of reactors.â‘¡The aerobic denitrifying bacteria were isolated and selected from the system to study the possibility of the existence of aerobic denitrification.â‘¢The kinetics model of biological nitrogen removal in the system is established, simulated and analyzed.According to the study above, the conclusions were as follows. The results show that the feed water carbon-nitrogen ratio, sludge age and dissolved oxygen have a greater impact on biological nitrogen and phosphorus removal.The feed water carbon-nitrogen ratio, that varied from 7 to 13, has no obvious effect on the remove of CODcr and total phosphorus, while the average removal rate is 95.2% and 93.9%, respectively. When the carbon-nitrogen ratio is lower than 9.4, the removal rate of total nitrogen increases as the carbon-nitrogen ratio rapidly. However, while the carbon-nitrogen ratio is higher than 9.4, the removal rate of total nitrogen stabilizes at 81.1%-85.6%. The nitrification of the system is more stable and the ammonia nitrogen removal rate remains at 90.5%-98.8%. Meanwhile, the denitrification of the system strengthenes with the increase of the carbon-nitrogen ratio and the effluent concentration of nitrate nitrogen decreases gradually.While the sludge age is twenty days, the removal efficiency of simultaneous nitrogen and phosphorus removal is better. The average removal efficiency of CODcr, total phosphorus, ammonia nitrogen and total nitrogen is 96.53%, 92.75%, 91.52% and 83.53%, respectively. In addition, the effluent quality reachs the first grade standard of GB18918-2002. Meanwhile, the sludge concentration is higher and the flocculation of sludge is better.To balance the demand of biological nitrogen removal and biological phosphorus removal, the concentration of dissolved oxygen should be from 2.5 to 3.0mg.L-1. The average removal efficiency of CODcr, total phosphorus, ammonia nitrogenr and total nitrogen is 94.89%, 93.54%, 94.62% and 83.28%, respectively. The effluent concentration could meet the wastewater discharge standardsTwo aerobic denitrifying bacteria, named Y3 and Y4, are selected and screened from the aerobic reactor in the SUFR system, by the aerobic denitrification medium which has nitrate nitrogen as sole nitrogen source. The experimental results show that the colony of Y3 is circular and pink, while the colony of Y4 is circular and orange-red. Both of Y3 and Y4 are gram-positive, rhapidosome. Through 16SrDNA sequencing and analysis of homology intercomparison, it is found that Y3 is identified as Rhodococcus sp, while Y4 is identified as Gordonia sp.The kinetic equations of anoxic denitrification and aerobic nitrification are derived through the establishment of material balance equations in the SUFR system. And the kinetic parameters are obtained. Meanwhile, the kinetics model of biological nitrogen removal in the system is established on the foundation. The results show that the derived kinetic models have strong ability on fitting data to simulate the process of biological nitrogen removal in the SUFR system.The research acquired the important parameters that could be used in practical design and operational control, and it provided technical support for the engineering application of the SUFR system.
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