变基质浓度下SBR亚硝化启动试验研究

Start-up of SBR nitritation under variable substrate concentrations

采用SBR反应器,在低DO(<1.0 mg/L)及高氨氮浓度(220 mg/L)下,经过20周期(10 d)的连续运行,亚硝化率达到90%以上并且保持稳定。此后逐步降低氨氮浓度,深入研究6个不同水平下亚硝化效果和游离亚硝酸(FNA)及温度对亚硝化的影响。试验结果表明,高氨氮时,实施限时曝气且低DO、较高游离氨(FA)的联合抑制模式,低氨氮下,采取实时控制策略,避免过度曝气,经过130 d的运行,去除负荷稳定在0.301 kg NH 4+-N/(m3.d),污泥负荷稳定在0.374 kg NH4+-N/(kg MLSS.d),亚硝化率一直在95%以上,成功实现了低氨氮SBR亚硝化的启动。同时发现FNA对AOB的抑制具有可逆性,而缓慢升温对亚硝化效果影响不大。

The nitrite accumulation rate （NAR） is above 90% and stable after 20 continuous cycles （10 d） under low dissolved oxygen（ DO ） concentrations （ 〈 1.0 mg. L-I） and high ammonia concentrations （220 mg. L-1 ） in a sequencing batch reactor （ SBR ）. Then gradually decreasing the ammonia concentrations, the nitritation effect of six different levels has been deeply studied. The influence of free nitrite acid （FNA） and temperature on nitritation is also investigated. The results show that taking the measures combined by limited aeration, the inhibition of low DO concentration and high free ammonia （FA） during high ammonia concentrations and real-time control for low ammonia concentrations to avoid excessive aeration, the ammonia removal rate and sludge removal rate are steady at 0. 301 kg NH4＋ -N/（m3 -d） and 0. 374 kg NH4＋ -N/（ kg MLSS. d）,respectively, after 130 days＇ operation. The NAR is steadily above 95%. SBR nitritation of low ammonia concentration is successfully started up. Meanwhile the inhibition of FNA to ammonia oxidation bacteria （AOB） is reversible, while slowly increasing in temperatures has very little effect on nitritation.