间歇曝气氧化沟工艺脱氮除磷和节能研究

Study on energy saving and nitrogen and phosphorus removal of intermittent aeration oxidation ditch process

为了降低氧化沟工艺的运行能耗,采用连续进水间歇曝气的运行方式对某中型氧化沟工艺污水处理厂进行了改造研究。该方式将硝化菌控制在硝化动力学的高效率段,提高了硝化菌的硝化效率,降低了曝气能耗;有效避免了过量曝气,从而降低了出水NO3--N的浓度,NO3--N对厌氧区释放磷的影响同时降低,提高了生物除磷效率。研究表明:采用间歇曝气的运行方式,使污水处理厂在出水NH3-N达标的基础上,提高了TN和TP的去除率;经过改造该污水处理厂TN和TP的去除率分别由45%、35%提高到65%和84%;该工艺在不改变原有氧化沟污水处理厂基础设施的基础上,仅对运行方式进行优化调控,使全厂的平均电耗降低了21.5%。

In order to reduce operating energy consumption of the oxidation ditch process, a medium sized oxidation ditch wastewater treatment plant （WWTP） was reconstructured and studied with intermittent aeration and continuous flow operation mode. In this way, nitrobaeteria were controlled at high efficiency phase in the kinetics of nitrification paragraph, so the efficiency of nitrification nitrification bacteria was improved and the aeration energy was reduced; excessive aeration was effectively avoided, and then the effluent NO3^--N was reduced, the effluence of NO3^--N on phosphorus release was also reduced in the anaerobic zone at the same time, which improved the efficiency of biological phosphorus removal. The results showed that： （1） in addition to the satisfaction of national wastewater plant outlet standards on NH3^ --N, the TN and TP removal efficiency was enhanced; （2） the removal rate of TN and TP was increased from 45% and 35% to 650% and 84% respectively after the reconstruction of the WWTP; （3） based on the maintenance of the original infrastructure of WWTP, this process optimized the operation mode and reduced the average power consumption by 21.5 %.