反硝化滤池的数值模拟与模型校正

建立了反硝化滤池中试系统,在滤速8m/h,进水C/N分别为4和5两种工况条件下运行,考察其反硝化处理效果,结果表明在进水C/N=5条件下,出水TN浓度由14.52mg/L下降为7.14mg/L.应用BioWin软件,构建了反硝化滤池中试系统的模型,基于滤速8m/h,进水C/N=5条件下的运行数据,应用常规灵敏度分析法(Si,j)和均方根灵敏度分析法( ),对BioWin软件中的412个参数进行了灵敏度分析,结果表明,对反硝化滤池中试系统模拟结果影响最为显著的两类参数为:与甲基营养菌有关的计量学参数及与生物膜有关的参数.根据灵敏度分析结果,选取5个灵敏度最高的参数,通过调整参数值对所构建的反硝化滤池模型进行了校正,应用于滤速8m/h,进水C/N=5条件下的运行模拟取得了较好的效果.最后应用校正模型对滤速8m/h,进水C/N=4条件下的运行结果进行模拟,结果表明模拟值与实测值同样能够较好地吻合.由此得出结论,本研究所构建的反硝化滤池中试系统模型及基于灵敏度分析的模型校正方法是有效的,可用于实际反硝化滤池工艺的模拟.

Simulation and model calibration of denitrification biological filter

A pilot-scale DNBF was built and operated under two different conditions, filtration velocity was 8m/h, C/N of influent was 4 and 5 respectively by adding methanol as external carbon source to study its denitrification performance. The results of experiments show that the concentration of effluent TN decreased from 14.52mg/L to 7.14mg/L under the condition of influent C/N=5. BioWin software was used to simulate the pilot-scale DNBF, based on the operation data of filtration velocity of 8m/h and influent C/N of 5, normalized sensitivity coefficient measure (Si,j) and mean square sensitivity measure ( ) were used to conduct sensitivity analysis for the 412 parameters of BioWin software. The sensitivity analysis results indicated that the most sensitive parameters were the stoichiometric parameters related to methylotrophs and the parameters related to biofilm. According to the sensitivity analysis results, five most sensitive parameters were selected for model calibration by adjusting their values to obtain proper simulation of the operating condition of filtration velocity at 8m/h and influent C/N of 5. The operating condition of filtration velocity of 8m/h and influent C/N of 4 was simulated using the calibrated model for model validation after model calibration. The results of experiments and simulations showed that the presented model of pilot-scale DNBF and the model calibration protocol of this study could be used for the simulations of practical DNBFs.