新型一体化污水净化槽的水力行为及脱氮效果研究

摘要

在新型一体化污水净化槽中采用短程硝化与厌氧氨氧化联合脱氮工艺,使用NaCl示踪剂研究在不同进水流量条件下净化槽好氧区和厌氧区的流体水力行为,通过定量反应器的水力学参数为该工艺的数学建模提供基础参数.由停留时间分布所计算的水力学参数推流比率的大小,可以发现反应器中的好氧区表现出全混流的特征,而厌氧区显示出多个反应釜串联的特征;控制溶解氧和pH可以抑制硝酸根的产生,有利于短程硝化.当pH控制在8.0~8.5、好氧区的溶解氧为0.8~1.2,mg/L、进水流量为1,L/h时,好氧区出水中氨态氮和亚硝态氮的比例接近1,为后续厌氧氨氧化提供了有利的条件,净化槽终端出水的氨态氮去除率最高可达到70%,.%The process of partial nitrification combined with anammox was established in a novel purifying tank to remove nitrogen.NaCl tracer tests were performed to study the hydraulic behavior in aerobic and anaerobic zones of thepurifying tank at different water flow rates.The hydraulic parameters of this reactor were quantified to supply the basic parameters for the numerical model of this process.According to the plug flow ratio calculated by the retention time distribution,the aero-bic zone was consistent with the completely stirred tank reactor,while the anaerobic zone was consistent with the tanks-in-series model.Meanwhile,the production of nitrate was inhibited by controlling dissolved oxygen and pH,which is favorable for partial nitrification.The ratio of+4NH-N to2NO--N in the effluent of the aerobic zone approached to 1 when pH was between 8.0 and 8.5,the dissolved oxygen ranged from 0.8 to 1.2,mg/L,and the water flow rate got to 1,L/h.These are the favorable conditions for the anammox process in the following anaerobic zone.The+4NH-N removal efficiency could reach 70%, at the outlet of the purifying tank.