高浓度氨气去除机理及微生物增长动力学

Mechanism of removal of high concentration ammonia and kinetics of microbial growth

文中模拟实际工况,在气体流量700 L/h,气体停留时间1.2 min,循环水流量85 L/(m^3·h),循环水内营养成分COD(Cr)质量浓度40 mg/L,pH=8.5,n(N)∶n(P)=5∶1,Na Cl质量浓度400 mg/L的最佳实验条件下,通过改变氨气进气浓度来研究以沸石为填料的滴滤塔对于高浓度氨气的去除效果,得到本装置最高进气质量浓度为925mg/m3。对不同氨气负荷下塔内微生物膜上的微型动物进行鉴定与分析,可知在氨气负荷小于1 g/(L·d)时,表壳虫占优,说明了硝化菌长势良好;当氨气负荷大于1 g/(L·d),表壳虫迅速减少,摇头虫大量增多,说明硝化速率降低,硝化菌长势减弱。依照逻辑方程得到生物膜动力增长期的硝化菌挂膜量的对数与时间成线性关系,其斜率μ0=0.003 9 t-1,实验结果对实际工程中的设备设计及调试阶段提供了可靠的数据依据。

Simulating the practical engineering application process,under the optimal experimental conditions of gas flow rate 700 L/h,gas residence time 1. 2 min,circulating water flow 85 L/( m^3·h),mass concentration of COD( Cr)in the circulating water 40 mg/L,p H = 8. 5,n( N) ∶ n( P) = 5 ∶ 1,and mass concentration of NaCl 400 mg/L,the removal efficiency of high concentration NH3 with the zeolite as the filler was studied by changing the inlet concentration of NH3. The maximum inlet concentration of the device could reach 925 mg/m3. Microfauna on microbial film in filter under different NH3 load was authenticated and analysed. When the NH3 load is less than1 g/( L·d),arcellas are the most,which means nitrobacterium growing well. When the NH3 load is greater than1 g/( L · d),arcellas decreases rapidly and shaking worms increases rapidly,which means rate of nitrification reducing and nitrobacterium growing slowly. According to the logic equation,the logarithm of the biofilm quantity of nitrifying bacteria in the biofilm growth period is linear with time,and the slope μ0= 0. 003 9 t-1. The experimental results provide reliable and favorable data basis for the design and debugging of the equipment in practical engineering.