Swette Center for Environmental Biotechnology, Biodesign Institute at Arizona State University, 1001 South McAllister Ave., Tempe, Arizona 85287-5701, United States.
Environ Sci Technol. 2012 Feb 7;46(3):1598-607. doi: 10.1021/es203129s. Epub 2012 Jan 30.
A multispecies biofilm model is developed for simultaneous reduction of nitrate and perchlorate in the H(2)-based membrane biofilm reactor. The one-dimension model includes dual-substrate Monod kinetics for a steady-state biofilm with five solid and five dissolved components. The solid components are autotrophic denitrifying bacteria, autotrophic perchlorate-reducing bacteria, heterotrophic bacteria, inert biomass, and extracellular polymeric substances (EPS). The dissolved components are nitrate, perchlorate, hydrogen (H(2)), substrate-utilization-associated products, and biomass-associated products (BAP). The model explicitly considers four mechanisms involved in how three important operating conditions (H(2) pressure, nitrate loading, and perchlorate loading) affect nitrate and perchlorate removals: (1) competition for H(2), (2) promotion of PRB growth due to having two electron acceptors (nitrate and perchlorate), (3) competition between nitrate and perchlorate reduction for the same resources in the PRB: electrons and possibly reductase enzymes, and (4) competition for space in the biofilm. Two other special features are having H(2) delivered from the membrane substratum and solving directly for steady state using a novel three-step approach: finite-difference for approximating partial differential and/or integral equations, Newton-Raphson for solving nonlinear equations, and an iterative scheme to obtain the steady-state biofilm thickness. An example result illustrates the model's features.
建立了一个多物种生物膜模型，用于在基于 H 2 的膜生物膜反应器中同时还原硝酸盐和高氯酸盐。该一维模型包括稳态生物膜的双底物 Monod 动力学，具有五个固相和五个液相组分。固相组分是自养反硝化细菌、自养高氯酸盐还原细菌、异养细菌、惰性生物量和细胞外聚合物物质 (EPS)。液相组分是硝酸盐、高氯酸盐、氢气 (H 2 )、底物利用相关产物和生物量相关产物 (BAP)。该模型明确考虑了三种重要操作条件（H 2 压力、硝酸盐负荷和高氯酸盐负荷）影响硝酸盐和高氯酸盐去除的四个机制：（1）对 H 2 的竞争，（2）由于有两种电子受体（硝酸盐和高氯酸盐）而促进 PRB 生长，（3）硝酸盐和高氯酸盐还原之间对 PRB 中相同资源的竞争：电子和可能的还原酶，以及（4）在生物膜中竞争空间。另外两个特殊功能是从膜基质中输送 H 2 并使用一种新的三步方法直接求解稳态：有限差分逼近偏微分和/或积分方程、牛顿-拉普森求解非线性方程以及迭代方案以获得稳态生物膜厚度。一个示例结果说明了模型的特点。
