CAST工艺处理城市污水的强化脱氮研究

Study on Enhanced Biological Nitrogen Removal from Municipal Wastewater by CAST Process

介绍了镇江征润州污水处理厂CAST工艺的运行情况，结合该厂实际运行状况开展了强化脱氮效果的生产性试验研究。结果表明，该工艺对COD、SS和TP的去除率均能维持在80％以上，但对氨氮的去除效果较差；在该厂运行模式下，控制进水／曝气前30min的DO〈0．5mg／L、进水／曝气后30min的DO浓度在1．0-3．0mg／L、纯曝气DO浓度在2．0-3．0mg／L，可以实现同步硝化反硝化和硝化／反硝化作用下的共同脱氮，使脱氮效率提高了57％左右；在控制进水／曝气后DO〈0．5mg／L、纯曝气DO浓度在1．0-3．0mg／L的条件下，可以实现同步硝化反硝化作用下的脱氮，但较难实现理想的脱氮效果。

The Cyclic Activated Sludge Technology （CAST） was applied to wastewater from Zhengrunzhou Wastewater Treatment Plant. The full-scale experiment on treat municipal enhanced nitrogen removal was carried out. Results show that CAST is capable of removing biodegradable COD, SS and TP, and that the average removal rates are up to 80%. However, the effect of nitrogen removal is not as good. SND and SQND can be achieved and nitrogen removal increased by 57% under the conditions： the concentration of dissolved oxygen is controlled below 0.5 mg/L for 30 minutes before inflow/aeration, 2.0 - 3.0 mg/L during pure aeration, and 1.0 - 3.0 mg/L for 30 minutes after inflow/aeration. In addition, SND can be achieved but without higher effect of nitrogen removal when concentration of DO is controlled below 0.5 mg/L after inflow/aeration and 1.0 - 3.0 mg/L during pure aeration.