温度变化对不同污泥形态厌氧氨氧化菌活性的影响

以Ca. Brocadia为主要种属的厌氧氨氧化颗粒污泥和生物膜为研究对象,通过测定不同温度下厌氧氨氧反应活化能以探讨温度对以不同污泥形态存在的厌氧氨氧化菌的短期影响。结果表明,在15~25 ℃和25~35 ℃,以颗粒污泥及生物膜形态存在的厌氧氨氧化菌的反应活化能不同。在15~25 ℃,颗粒污泥和生物膜中的厌氧氨氧化反应活化能分别为105.60 kJ·mol⁻¹和88.25 kJ·mol⁻¹,而在25~35 ℃,对应的活化能分别为62.15 kJ·mol⁻¹和56.78 kJ·mol⁻¹,均低于同温度条件下以游离态存在的厌氧氨氧化菌的反应活化能。这说明不同污泥形态对Anammox菌的温度效应不同,以生物膜和颗粒污泥形态存在的厌氧氨氧化菌具有较强抵抗温度变化的能力。在15~25 ℃,颗粒污泥和生物膜中厌氧氨氧化菌的温度系数θ分别为1.14和1.12,在25~35 ℃,对应的温度系数θ分别为1.09和1.08。与硝化菌或反硝化菌相比,厌氧氨氧化菌的温度系数$ theta $偏大。这表明厌氧氨氧化菌对温度的变化更为敏感,使得厌氧氨氧化在低温条件下首先将成为限制步。

Effect of temperature change on anammox activities with different sludge morphology

To investigate the short-term effects of temperature on Ca. Brocadia anammox bacteria with granular sludge and biofilm, ex-situ batch experiments were conducted to test the reaction activation energy (Ea) of anammox. The results showed that the Ea of granular sludge and biofilm increased with decreasing temperature. The Ea values of granular sludge and biofilm were 105.60 kJ·mol−1 and 88.25 kJ·mol−1 between 15~25 ℃ and 62.15 kJ·mol−1 and 56.78 kJ·mol−1 between 25~35 ℃, respectively, they were lower than that of anammox existed in suspended state at the same temperature. This result indicated that the temperature effect was dependent on the sludge morphology. Anammox bacteria in granular sludge and biofilm had a better ability to resist temperature changes than that of anammox bacteria in suspended state. Notably, at 15~25 ℃ and 25~35 ℃, the temperature coefficient (θ) of anammox bacteria in granular sludge and biofilm were 1.14, 1.12 and 1.09, 1.08, respectively. Compared to nitrifying bacteria or denitrifying bacteria, the obtained θ values of anammox bacteria were relatively higher, indicating that anammox bacteria were more sensitive to temperature changes. Therefore, anammox process will be the limiting step when the temperature drops.