温度对UASB厌氧氨氧化反应器运行性能的影响及其过程动力学特性

Effect of Temperature on Nitrogen Removal Preformance of UASB Anammox Reactor and Process Kinetics

本研究通过阶梯降温方式考察了温度对上流式厌氧污泥床(UASB)厌氧氨氧化反应器脱氮性能的影响。试验结果表明,23℃是UASB反应器脱氮效能的转折点,温度大于23℃时UASB反应器可稳定高效运行,容积氮去除率(NRE)维持在87%左右;温度小于23℃时,NRE大幅度下降,但适当延长污泥驯化时间及降低容积氮负荷(NLR),NRE均缓慢回升且大致保持稳定在85%.温度由8℃提高至13℃时,逐渐提高系统进水NLR(由3.55 kg/(m 3·d)提高至5.16 kg/(m 3·d)),系统可实现良好的脱氮性能(NRE大致为84.19%).动力学分析表明,长期降温过程中的容积氮去除负荷(NRR)与温度之间的关系较好地符合改进的Stover-Kincannon模型,且活化能(E a)随温度的降低而增加。但长期处于最适温度条件下的厌氧氨氧化菌受温度变化的影响更大,而低温驯化有助于提高厌氧氨氧化菌对温度的适应性。

In this study,a long term dynamic change in anammox reaction in response to the gradiently decreased and recovered temperature was evaluated in an upflow anaerobic sludge blanket(UASB).Results show that the temperature of 23℃was the turning point for the nitrogen removal performance of UASB reactor.Anaerobic ammonia oxidation reaction in the UASB reactor remained stable and total nitrogen removal efficiency(NRE)was maintained around 87%at 23,28,33℃.NRE was reduced significantly when temperature was lower than 23℃(18,13,8℃),but with appropriately extended sludge domestication time and reduce NLR,NRE was recovered slowly and generally remained stable at 85%.However,the total nitrogen removal efficiency was recovered to 84.19%at 13℃in an upflow anaerobic sludge blanket.Kinetic analysis shows that,the relationship between NRR and temperature was well consistent with the improved Stover-Kincannon model in gradient cooling process.In addition,specific ANAMMOX activaty(SAA)always decreased with the decrease of temperature,while the apparent activation energy(E a)value increased with the decrease of temperature.The temperature change had the greatest impact on anammox bacteria at the optimal temperature for a long time,and low temperature acclimation could improve the adaptability of microorganisms to temperature.