A fundamental analysis of continuous flow bioreactor models governed by Contois kinetics. II. Reactor cascades.
A fundamental analysis of continuous flow bioreactor models governed by Contois kinetics. II. Reactor cascades.
复制标题
DOI：
10.1016/j.cej.2009.01.028
复制
发表时间：
2009-07
影响因子：
15.1
通讯作者：
M. Nelson;A. B. Holder
中科院分区：
文献类型：
--
作者：
M. Nelson;A. B. Holder
现在已知许多生物过程的速率决定步骤由康托瓦生长动力学描述。特别地，已经发现该增长率描述了来自各种工业过程的含有可生物降解的有机材料的污染废水的处理。这种废料的有效处理是日益增长的环境问题。这一贡献是第一个稳态分析的工业废水的处理，服从Contois动力学，在一个级联的连续流生物反应器没有再循环。该模型的稳态被发现，其稳定性确定为在级联的每个反应器中的停留时间的函数。渐近解得到的流出物浓度离开一个级联的n个反应器的两种情况下，其中假设在级联的反应器具有相同的停留时间。在第一种情况下，考虑了总停留时间（τt）较大的极限情况。当n= 1、2、3和4时，发现离开反应器的流出物浓度（Sn = 1）由[式：见正文]给出。我们证明了这种关系对所有n都成立。因此，对于固定的总停留时间，增加级联中反应器的数量对离开级联的废水的质量具有显著的影响。在第二种情况下，考虑总停留时间略大于洗脱点的极限情况。在该区域中，总停留时间的小幅增加导致流出物浓度的大幅降低。通过冰淇淋废水的厌氧消化，说明了这些结果。
The rate determining step of a number of biological processes is now known to be described by Contois growth kinetics. In particular this growth rate has been found to describe the treatment of contaminated wastewaters containing biodegradable organic materials from a variety of industrial processes. The efficient treatment of such waste materials is of ever growing environmental concern. This contribution is the first steady-state analysis for the treatment of industrial wastewaters, obeying Contois kinetics, in a cascade of continuous flow bioreactors without recycle. The steady-states of the model are found and their stability determined as a function of the residence time in each reactor of the cascade. Asymptotic solutions are obtained for the effluent concentration leaving a cascade of n reactors for two scenarios, in which it is assumed that the reactors in the cascade have the same residence time. In the first scenario the limiting case of large total residence time (τt∗) is considered. The effluent concentration leaving the reactor (Sn∗) is found to be given by [Formula: see text] , when n=1,2,3 and 4. It is conjectured that this relationship holds for all n. Thus, for a fixed total residence time increasing the number of reactors in the the cascade has a dramatic effect on the quality of the wastewater leaving the cascade. In the second scenario, the limiting case when the total residence time is slightly larger than the washout point is considered. In this region, a small increase in the total residence time leads to a large decrease in the effluent concentration. These results are illustrated by considering the anaerobic digestion of ice-cream wastewater.