环境温度下短程硝化的低氧启动与维持

采用序批式反应器(SBR)处理模拟氨氮废水,通过控制溶解氧浓度在中温下实现了短程硝化,并在较低温度下维持稳定的短程硝化。以全程硝化污泥为种泥,当溶解氧浓度从3.5～4.5 mg/L降低至0.8～1.3 mg/L时,可迅速实现NO 2--N的积累,持续运行中NO 2--N的积累率稳定在80%以上。利用随季节变化温度逐渐降低的特点,在中温下实现NO2--N的积累和氨氧化菌(AOB)的优势生长,然后随着气温的逐渐下降使AOB逐渐适应低温环境,当水温为13℃时NO 2--N的比积累速率为0.119 g/(gMLVSS.d)。单周期运行情况表明,游离氨(FA)对亚硝酸盐氧化菌(NOB)的抑制作用主要在反应前期,而游离亚硝酸(FNA)、pH值的抑制作用主要在后期。

Oxygen-limited Start-up and Maintenance of Short-cut Nitrification in SBR at Ambient Temperature

Through oxygen-limited control,short-cut nitrification was carried out in a lab-scale SBR at medium temperature and maintained stably even at low temperature.Using fully nitrified sludge as seeding sludge,NO-2-N was rapidly accumulated when DO decreased from 3.5-4.5 mg/L to 0.8-1.3 mg/L,and NO-2-N accumulation rate was maintained stably at above 80% in the subsequent operation.As the temperature decreased gradually,firstly NO-2-N accumulation and the selective enrichment of AOB were obtained at medium temperature,and then the AOB were slowly adapted to low temperature while the specific NO-2-N accumulation rate was 0.119 g/(gMLVSS·d) at 13 ℃.The single-cycle operation showed that the inhibition of NOB by FA taken place mainly in the early stage,and that by FNA and pH mainly occurred in the later stage.