Fazolo A, Pasotto M B, Foresti E, Zaiat M
Centro de Ciências Exatas e Tecnológicas, Universidade Estadual do Oeste do Paraná (UNIOESTE), Rua Universitária, 2069. 85819-110, Cascavel, PR, Brazil.
Environ Technol. 2006 Oct;27(10):1125-35. doi: 10.1080/09593332708618721.
This study presents an assessment of the kinetic, mass transfer and hydrodynamic parameters of a pilot-scale fixed bed reactor containing immobilized biomass in polyurethane matrices and fed with the effluent of a horizontal-flow fixed bed anaerobic reactor, which was used to treat domestic sewage. It was found that the liquid-solid and intra-particle mass transfer resistances significantly affected the overall oxygen consumption rate and that mechanical agitation could minimize such resistances. The volumetric oxygen transfer coefficient (kLa) values for superficial air velocities between 8.4 cm min(-1) and 57.0 cm min(-1) varied from 20.8 h(-1) to 58.8 h(-1) for tap water, and 16.8 h(-1) to 53.0 h(-1) for the anaerobic pre-treated effluent. The intrinsic oxygen uptake rate was estimated to be 19.9 mgO2 gVSS(-1) h(-1). A first-order kinetic model with residual concentration was considered to adequately represent the COD removal rate, whereas nitrogen conversion was considered to be well represented by a model of pseudo-first-order reaction in series. It was also found that the ammonium conversion to nitrite was the limiting step of the overall nitrogen conversion rate. The hydrodynamic behavior of the reactor was represented by three to four completely mixed reactors in series.
本研究对一个中试规模的固定床反应器的动力学、传质和流体动力学参数进行了评估。该反应器中固定化生物质负载于聚氨酯基质中，并以水平流固定床厌氧反应器处理生活污水后的出水为进水。研究发现，液固传质阻力和颗粒内传质阻力显著影响总耗氧速率，而机械搅拌可使这些阻力降至最低。对于自来水，表观空气流速在8.4 cm min⁻¹至57.0 cm min⁻¹之间时，体积传氧系数（kLa）值在20.8 h⁻¹至58.8 h⁻¹之间变化；对于厌氧预处理后的出水，该值在16.8 h⁻¹至53.0 h⁻¹之间变化。本征氧摄取率估计为19.9 mgO₂ gVSS⁻¹ h⁻¹。考虑含残余浓度的一级动力学模型可充分表征化学需氧量（COD）去除率，而氮转化过程则认为可用串联的拟一级反应模型很好地描述。研究还发现，铵转化为亚硝酸盐是总氮转化率的限制步骤。该反应器的流体动力学行为可用三至四个串联的全混流反应器来描述。
