生物电极膜内脱氮速率模型

来源期刊：中南大学学报(自然科学版)2004年第3期

论文作者：李建平 袁兴中 渡辺智秀 黒田正和

文章页码：418 - 422

关键词：生物电极反应器;生物膜模型;电子供体;脱氮

Key words：bio-electro reactor; biofilmmodel; electron donor; denitrification

摘    要：通过研究生物电极脱氮过程中膜内物质运动和反应机理,建立了能够表现生物膜内脱氮反应过程的动力学模型。在本模型中,氢气和醋酸同时作为电子供体参与反应,在生物膜内反硝化细菌的作用下,硝酸氮被还原为氮气从而彻底将其去除。模型综合考虑了膜内物质迁移、扩散等对脱氮过程的影响,得到了氢气和醋酸同时作为电子供体参与反应时去除硝酸氮的动力学方程。在模型建立过程中,假定生物膜厚度和反硝化菌脱氮活性不受生物浓度、时间和电极位置影响,并且认为生物膜内各反应物质的有效扩散系数约为其在水中分子扩散系数的80%。采用Runge-Kutta法和Shaoting Mathal法对模型进行求解,模型计算结果和实验结果较吻合。

Abstract: Based on the research on reaction mechanism of denitrification in a electrochemically activated biofilm, a kinetic model describing the reaction process was developed. Hydrogen gas produced by electrolysis of water and acetic acid are utilized simultaneously as electron donors in the process, and under the effects of denitrifying bacteria, nitrate is deoxidized to nitrogen gas and removed. The model takes into account the effects ofmass transfer and diffusion on denitrification process. Adenitrification kinetic expression was deduced,inwhich both hydrogengas and acetic acid are utilized simultaneously. The thickness of biofilm, the activity of denitrifying bacteria are supposed to not be affected by the concentration of biomass, the time and the position of electrodes. A constant of 0.8 is taken to correct the effective diffusion coefficient in the biofilm. The model are solved by combining Runge-Kutta method and Shaoting Mathal method, and the calculated results are in fairly good agreementwith experimental results.