基于DO控制实现SBR短程硝化过程

Shortcut nitrification process controlled by dissolved oxygen in a sequencing batch reactor

采用序批式反应器(SBR)处理模拟氨氮废水,研究了固定供氧模式下氨氮降解过程和溶解氧变化规律,并对DO控制实现短程硝化机理进行了探讨。实验结果表明,当DO<1 mg/L时,体系产生亚硝酸盐积累,当亚硝化反应结束后,DO出现跃升现象,并且p H值对短程硝化有一定影响,充足的碱度和较高的p H值有利于建立以DO为控制参数实现短程硝化过程控制。短程硝化启动后,亚硝酸盐积累率达90%以上,并且经过度曝气5 d后,系统仍保持稳定运行。

The experiment was carried out in a sequencing batch reactor( SBR) treating simulated ammonia wastewater. The performance of removal of ammonia and variations of dissolved oxygen( DO) was investigated under fixed oxygen supply,and the mechanism of shortcut nitrification process controlled by dissolved oxygen also was researched. The results showed that a steady nitrite accumulation would be obtained at low DO concentration lower than 1 mg / L. Moreover,the DO concentration in the SBR increased sharply at the end of oxidation of ammonia to nitrite. The influences of p H on shortcut nitrification were also investigated in the SBR. The results showed that sufficient alkalinity and high p H value were conducive to achieve shortcut nitrification in SBR based on the control of dissolved oxygen. After the implementation of DO control strategies,90% oxidation of ammonia to nitrite was achieved,with stable system remained even at excess aeration of 5 days.