超声强化作用下厌氧氨氧化工艺启动运行性能

通过批式实验，得到超声波强化Anammox菌活性的最优工作参数，超声频率25kHz、超声时间3min、超声强度0.2 W/cm²，而后在此最优超声强化条件下采用固定床反应器接种传统活性污泥启动Anammox工艺.整个试验过程，温度维持在35℃.在启动阶段，水力停留时间（HRT）为2d，控制进水NH₄⁺-N和NO₂^--N浓度为70mg/L.反应器运行至第38d，首次表现Anammox活性.运行至53d时，NH₄⁺-N、NO₂^--N去除速率和去除率分别为30.81，34.97mgN/（L·d）和88.03%、99.91%，总氮去除速率和去除率达60.34mgN/（L·d）和86.20%.R₁和R₂分别稳定在1.14和0.18.在负荷提升阶段（53~135d），当进水NH₄⁺-N和NO₂^--N负荷维持在最高值380mg/（L·d）时，NH₄⁺-N和NO₂^--N平均去除效率分别为82.74%和97.89%.NH₄⁺-N和NO₂^--N最大去除速率分别为320.67和379.85mgN/（L·d），最大总氮去除速率和去除率为698.00mgN/（L·d）和91.84%.负荷提高阶段末，R₁稳定在1.18左右，R₂接近于0.反应器内Anammox菌占主导，存在少量反硝化菌强化总氮去除.

Start-up and operation performance of anammox process enhanced by ultrasound irradiation

By batch experiment, the optimal working parameters of ultrasonic enhancement of Anammox bacteria activity were obtained:ultrasound frequency of 25kHz, ultrasound time of 3 min and ultrasound intensity of 0.2 W/cm²; afterwards a fixed-bed reactor was inoculated with the traditional activated sludge to start up Anammox process under the optimal ultrasound enhancing conditions. During the whole experiment, the temperature was maintained at 35℃. In the start-up stage, the hydraulic retention time (HRT) was 2 days and the influent NH₄⁺-N and NO₂^--N concentrations were both controlled at 70mg/L. After 38days operation of the reactor, the Anammox activity appeared for the first time. After 53days operation, NH₄⁺-N and NO₂^--N removal rates were up to 30.81mgN/(L·d) and 34.97mgN/(L·d) and their corresponding removal efficiencies reached 88.03% and 99.91% respectively, and the total nitrogen removal rate and removal efficiency reached 60.34mgN/(L·d) and 86.20% respectively. R₁and R₂ were stabilized at 1.14 and 0.18. In the nitrogen loading enhancement stage (day 53~135), when the influent NH₄⁺-N and NO₂^--N loading rates were both maintained at 380mg/(L·d), the average removal efficiencies of NH₄⁺-N and NO₂^--N were 82.74% and 97.89%. The max NH₄⁺-N and NO₂^--N removal rates were up to 320.67mgN/(L·d) and 379.85mgN/(L·d), while the max total nitrogen removal rate and efficiency were 698.00mgN/(L·d)and 91.84% respectively. At the end of the nitrogen loading enhancement stage, R₁ was stabilized at 1.18 while R₂ was close to 0. In the reactor, Anammox bacteria predominated and a small amount of denitrifying bacteria coexisted with them so as to improve the total nitrogen removal.