NO_2对颗粒污泥甲烷化动力学特性的影响

Effects of NO_2 on methanogenesis kinetics of granular sludge

采用间歇试验方法,以乙酸和乙酸盐混合物为基质,对取自EGSB反应器具有厌氧甲烷化反硝化与厌氧氨氧化活性的颗粒污泥的甲烷化动力学以及NO2影响进行研究。无NO2时,最大比基质降解速率为0.158 mg COD/mg VSS.h,半饱和常数为464 mg COD/L,甲烷的产率系数为0.254 mL CH4/mg COD。添加微量NO2对甲烷化有抑制作用,抑制程度随着微量NO2浓度的增高而增大,在NO2浓度为30.36 mg/m3、50.6 mg/m3、101.2 mg/m3、202.4 mg/m3和303.6 mg/m3条件下,甲烷化抑制程度分别为7.40%、11.87%、27.56%、39.75%和43.24%,外推得NO2的甲烷化半抑制浓度IC50值为383.8 mg/m3。NO2气氛下甲烷化动力学可用反竞争性抑制动力学进行描述,最大比基质降解速率为0.148 mg COD/mgVSS.h,半饱和常数为396 mg COD/L,NO2抑制系数为250 mg/m3。

The methanation kinetics of HAc-NaAc substrate with the granular sludge from EGSB reactor, in which methanogensis, denitrification and anaerobic ammonium oxidation were integrated, was investigated by batch experiment. The maximum specific degradation rate, half saturation constant and yield coefficient were 0. 158 mg COD/mg VSS · h, 464 mg COD/L and 0. 254 mL CH4/mg COD respectively. The trace NO2 inhibited the substrate degradation, the inhibition increased with the NO2 concentration. Under the condition of 30.36 mg/m^3 ,50.6 mg/m^3, 101.2 mg/m^3, 202.4 mg/m^3 and 303.6 mg/m^3, the inhibition degrees were 7.40% , 11.87% ,27.56% ,39.75% and 43.24% respectively. The IC50 value was 383.8 mg/m^3 determined by extrapolation for the NO2 inhibition to methanogenesis. Under the atmosphere of NO2 , methanogenesis kinetics could be described by uncompetitive inhibition model, the maximum specific degradation rate, half saturation constant and inhibition coefficient were 0. 148 mg COD/rag VSS · h, 396 mg COD/L and 250 mg/m^3 respectively.