颗粒型生物膜反应器在污水处理中的应用

介绍了颗粒型生物膜反应器在污水处理中的应用情况,对比了不同反应器结构和技术特点。与传统的活性污泥法和静态生物膜反应器相比,颗粒型生物膜反应器具有沉降速度快、污泥浓度高、比表面积大等特点,可以达到很高的负荷,节省占地面积。另外,颗粒型生物膜反应器的污泥产率也非常低、不存在污泥膨胀的问题,日常维护也非常简单。并指出随着对该领域进一步的深入研究和新型反应器的开发,颗粒型生物膜反应器将得到更为广泛的应用。

Prediction of Core-Annulus Solids Mass Transfer Coefficient in Gas-Solid Fluidized Bed Risers

Based on analysis of energy dissipation in the core region of gas-solid fluidized bed risers, a simplified model for determination of core-annulus solids mass transfer coefficient was developed according to turbulent diffusion mechanism of particles. The simulation results are consistent with published experimental data. Core-annulus solids mass transfer coefficient decreases with increasing particle size, particle density and solids circulation rate,but generally increases with increasing superficial gas velocity and riser diameter. In the upper dilute region of gas-solid fluidized bed risers, core-annulus solids mass transfer coefficient was found to change little with the axial coordinate in the bed.