低强度超声波启动短程硝化及NOB抑制动力学

Start-up of Partial Nitrification and Inhibitory Kinetics on Nitrite-Oxidizing Bacteria by Low Intensity Ultrasound

在序批式生物反应器中探究低强度超声波对短程硝化启动性能的影响,考察了亚硝酸盐积累率(NAR)、亚硝酸盐氧化菌(NOB)活性、NOB动力学参数的差异。结果表明,超声组(声功率密度0.20、0.25、0.30 W/mL)在30 d时NOB活性分别为5.01、3.57、3.29 mg/(g·h),显著低于非超声波辐照的对照组(8.01 mg/(g·h)),超声组NAR均高于90%,成功实现短程硝化。NOB的底物半饱和常数(KS)分别为310.4、134.6、241.4 mg/L,显著大于对照组的25.31 mg/L。因此,低强度超声波辐照污泥,减小了NOB增殖速率的同时抑制其活性,将硝化作用控制在亚硝化阶段,从而保证短程硝化启动。

In order to investigate the effects of low-intensity ultrasound on the partial nitrification start-up performance in sequencing batch rector(SBR),the nitrite accumulation rate(NAR),nitrite-oxidizing bacteria(NOB)activity and the variation of kinetic parameters of NOB were investigated.The results showed that the NOB activity of the ultrasound group(sound power density of 0.20,0.25,0.30 W/mL)at the 30 d was 5.01,3.57,3.29 mg/(g·h),respectively,which was significantly lower than that of the control group(8.01 mg/(g·h)),the NAR of the ultrasound group was higher than 90%,and partial nitrification was successfully achieved.The substrate half-saturation constant(KS)of NOB was 310.4,134.6,and 241.4 mg/L,respectively,which was significantly greater than that of the control group(25.31 mg/L).Therefore,the low-intensity ultrasound irradiation of the sludge reduces the NOB proliferation rate while suppressing its activity,and controls the nitrification in the nitrosation stage,and ensuring the start-up of partial nitrification.