生物膜多基质模型及其对BAF处理合成污水的模拟

Biofilm multiple-substrate model and its simulating of BAF treating the synthetic domestic sewage.

将简化的活性污泥模型ASM3与传质反应方程相耦合,建立了生物膜多基质模型(BMSM),在此基础上,运用均相生物膜反应单元概念,导出了曝气生物滤池(BAF)反应器一维模型.模型方程表明,出水基质浓度与生物膜表面积相关,与反应器体积无关.灵敏度分析结果表明,出水水质对大部分动力学参数灵敏度较低,对生物膜参数如表面积、膜厚、活性附着生物量等灵敏度较高.进行了以陶球为滤料的BAF处理合成生活污水实验,测定了生物膜膜厚、生物膜干密度、生物膜面积分别为300μm、45kg/m3、5.65m2.用Matlab语言对BAF的稳态运行进行模拟,考察了COD、NH4+-N、NO3--N沿填料高度浓度上的变化.结果表明,建立的BMSM能较好地模拟BAF的稳态运行.

A biofilm multiple-substrate model (BMSM) was established through combining the simplified activated sludge model ASM3 and the equations of mass transfer reaction. Based on the BMSM, a one-dimensional model for the biological aerated filter (BAF) reactor was developed through the conception of the volume-uniform biofilm reacting unit. The model equation indicated that the concentration of effluent water substrate was related to the surface area of biofilm, and not related to the volume of the reactor. The sensitivity analysis results showed that the effluent water quality had lower sensitivity on most kinetic parameters, but higher sensitivity on biofilm parameters, such as surface area, membrane, thickness, and activated adhered biomass. The experiment of treating synthetic domestic sewage using BAF with granular ceramics as filter material was carried to determine the thickness, density and area of the biofilm, which were 300 μm, 45 kg/m3, 5.65 m2 respectively. The steady operation of BAF was simulated using Matlab language; and the changes of COD, TN, NH4+/-N and NO3--N concentration profiles relating to the height of the BAF were inspected. The BMSM established could well simulate the steady operation of BAF.