温度对高盐条件下厌氧氨氧化反应器脱氮性能的影响

Effect of temperature on the nitrogen removal efficiency of anammox reactor under high salty stress

污水温度通常受到季节和地区的限制,在寒冷地区很难达到厌氧氨氧化反应所需的最佳温度条件。为探究高盐条件下温度对厌氧氨氧化反应器脱氮性能的影响,采用上流式厌氧污泥床在15 g/L的盐度条件下进行中温(34℃)、逐步降至低温(16℃)、恢复活性并逐步降至中低温(22℃)的连续流试验,分析不同阶段反应器稳定运行的情况。结果表明:反应器在34℃条件下NH_(4)^(+)-N、NO_(2)^(-)-N的平均去除率分别为88.92%和96.47%,温度降至16℃时NH_(4)^(+)-N、NO_(2)^(-)-N去除率分别只有25.14%及30.96%;在活性恢复阶段,依次采取逐步提升温度、投加0.2 mmol/L甜菜碱和20%质量比的新泥的方法实现了反应器性能的恢复,NH_(4)^(+)-N、NO_(2)^(-)N平均去除率分别为88.18%、94.33%。性能恢复后的反应器被再次逐步降温,并通过延长水力停留时间(HRT)实现了在22℃下稳定运行,NH_(4)^(+)-N、NO_(2)^(-)-N去除率分别为82.14%、87.03%。研究表明,高盐条件下的微生物在温度降低后消耗了更多的能量,从而减少了颗粒污泥粒径及胞外聚合物含量,延长HRT能缓解降温后的盐度胁迫,温度回升后污泥性能可以恢复,甜菜碱及新泥的添加策略对活性的恢复有效。

The temperature of sewage is usually limited by seasons and regions,and it is difficult to achieve the optimal temperature conditions required for anammox reaction in cold regions.In order to investigate the effect of temperature on the denitrification performance of anammox reactors under high salt conditions,a UASB reactor was used for continuous flow experiments at a salinity of 15 g/L.The experiments were conducted under the conditions of medium temperature(34℃),gradually decreasing to low temperature(16℃),activity recovery,and gradually decreasing to medium low temperature(22℃).The stable operation of the reactor at different stages was analyzed.The results showed that the average removal rates of NH_4~+-N and NO_2~--N in the reactor at 34℃ were 88.92%,96.47%,respectively.When the reactor temperature dropped to 16℃,the removal rates of NH_4~+-N and NO_2~--N were only 25.14% and 30.96%,respectively.In the activity recovery stage,the reactor performance was restored by gradually increasing temperature,adding 0.2 mmol/L glycine betaine,and 20% mass ratio of fresh anammox granules in sequence.The average removal rates of NH_4~+-N and NO_2~--N were 88.18% and 94.33%,respectively.After performance recovery,the reactor was gradually cooled down again and stable operation at 22℃ was achieved by extending HRT,with NH_4~+-N and NO_2~--N removal rates of 82.14% and 87.03%,respectively.The research showed that microorganisms under high salinity consumed more energy after temperature reduction,leading to a decrease in particle size and EPS content.Extending HRT could alleviate salinity stress after cooling.After the temperature rose,the sludge performance could be restored,and the addition strategy of glycine betaine and fresh anammox granules was effective in restoring activity.