海藻酸钙凝胶固定化活性污泥反应器处理丙酮废气稳态模型的研究

Steady state model of immobilized activated sludge bioreactor for removing acetone in waste gas

建立了海藻酸钙凝胶固定化活性污泥反应器处理丙酮废气的数学模型,引入颗粒调整系数的概念以解决模型假设与真实情况的差异。在流量为1100mL/min、反应器进口丙酮质量浓度为3051mg/m3时,测定4个采样口和出气口的丙酮浓度,对反应器模型参数进行了校正,得到微生物最大比生长速率为4.17×10-5mg/(mg.s),丙酮半饱和常数为76900mg/m3,氧气半饱和常数为273mg/m3,颗粒调整系数为195,丙酮分配系数为0.0024。随后引入蒂勒模数、有效系数等表征传质阻力和反应动力学的物理量,对反应器和固定化活性污泥颗粒的传质阻力和动力学进行了计算和讨论。

A steady state model was developed for simulating a packed tower reactor of calcium alginate gel beads containing immobilized activated sludge employed for removing acetone from the gaseous feed. The model incorporates a particle adjustment factor to account for the differences between model assumptions and actual situations. For the bioreactor treating a gaseous feed of 1 100 mL/min containing 3 051 mg/m^3 of acetone and employing the adjusted typical model parameters obtained from balancing the measured acetone concentrations （at four sampling ports and the outlet） and the calculated acetone concentration on the particle surface, the estimated bio-kinetics parameters were： maximum specific growth rate （μm） =4. 17× 10^-5 mg/（mg·s）, semi-saturation constant of acetone （KSA）- 76 900 mg/m^3, semi-saturation constant of oxygen（KSO）= 273 mg/ma, bead accommodation coefficient= 195, and partition coefficient of acetone （ma）=0. 002 4. The model also incorporates the Thiele modulus and an effectiveness coefficient to characterize the reactor and particles for discussion of the mass transport processes. The distribution of acetone concentration was also calculated, and the degradation kinetics was discussed. The overall treatment performance can be improved by a lower Thiele modulus of system and/or a higher effectiveness eoefficient.