养猪废水厌氧消化液SBR短程硝化系统影响因素

Main influence factors for shortcut nitrification in a SBR treating anaerobic digested piggery wastewater

针对养猪废水厌氧消化液较高残留的氨氮,为开发短程硝化-反硝化脱氮工艺,以序批式活性污泥反应器（SBR）的运行为基础,探讨温度、氨氮负荷（Rnl）和曝气时间对活性污泥系统短程硝化特征的影响.结果表明：在28和15℃条件下,将溶解氧控制为1.0~2.0 mg·L-1时,SBR系统均能实现良好的短程硝化功能;但在15℃条件下,氨氮去除率和亚硝酸盐积累率（Rna）较28℃均有显著下降,分别从71.1%和96.7%降到52.8%和85.4%;在28℃条件下,氨氮负荷由0.56 kg·m-3·d-1大幅提高到2.18 kg·m-3·d-1后,SBR系统的氨氮去除率显著降为48.6%,但Rna仍然高达96.8%,保持了良好的短程硝化性能.Rnl较高时,可适当延长曝气时间以强化SBR系统的氨氮氧化能力.但曝气时间过长会导致大量NO2--N的氧化,Rna显著下降.

To develop a shortcut nitrification process for treating anaerobic digested piggery wastewater with a high ammonia concentration,a sequencing batch reactor（ SBR） was introduced,and the temperature,ammonia nitrogen loading rate（ Rnl） and aeration time were investigated as the significant influence factors of the shortcut nitrification. The shortcut nitrification process could be established in the SBR at 28 ℃ or 15 ℃ with the identical dissolved oxygen（ DO）,ranged from 1 to 2 mg·L- 1. But the ammonia removal and nitrite accumulation rate Rna were decreased from 71. 1% and 96. 7% to 52. 8% and 85. 4%,respectively,when the temperature was dropped from 28 ℃ to 15 ℃. Though the ammonia removal rate was decreased to 48. 6% since the Rnlhad been increased from 0. 56 to 2. 18 kg·m- 3·d- 1at 28 ℃,a Rnaas high as 96. 8% was obtained,indicating that an excellent shortcut nitrification occurred in the SBR. To obtain a superior ammonia oxidation with a higher Rnl,extension of aeration time would be supportive. But an excessive aeration could result in an increase in nitrate and a decrease in Rna,which was unfeasible for the shortcut nitrification process in the SBR.