Modeling and Evaluation of an Integrated Nitrogen Removal System with Microorganisms Co-immobilized in Double-Layer Gel Beads
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- 作者：Ví ; tor A. P. M. dos Santos ; Leonardus M. Marchal ; Johannes Tramper ; and René ; H. Wijffels
- 刊名：Biotechnology Progress
- 出版年：1996
- 出版时间：April 1996
- 年：1996
- 卷：12
- 期：2
- 页码：240 - 248
- 全文大小：262K
- 年卷期：v.12,no.2(April 1996)
- ISSN：1520-6033
文摘
A dynamic model describing integrated nitrification and denitrificationby Nitrosomonas europaea and Pseudomonas sp. co-immobilized in theseparate layers of double-layer gel beads is presented. The model describes diffusion ofcomponents, substrateutilization, and growth, all occurring simultaneously in the beads.Both internal andexternal mass transfer resistance are accounted for. The modelpredicts biomass andsolute bulk concentrations, substrate consumption rates, productformation rates, andbiomass and solute concentration profiles within the beads as afunction of time.Fluctuations in substrate load, dilution rates, or mass transferparameters can beaccommodated as well. Intrinsic kinetic parameters of themicroorganisms, internaland external mass transfer coefficients, initial conditions, beadconcentration, andparticle diameters are the input parameters. The model wasevaluated by comparingexperimental and predicted bulk concentrations and macroscopicconsumption (production) rates in air-lift loop reactors containing double-layer gel beads.The reactorswere run under both steady and dynamic operating conditions.Nitrification rateswere determined by daily analysis of influent and effluent ammonia andnitriteconcentrations, and denitrification rates were calculated frommolecular nitrogenproduction rates measured by head-space analysis. Modelpredictions agreed reasonably well with the experimental results. Fluctuations in dilutionrates and influentsubstrate concentrations were adequately described. Althoughfurther validation isstill required, the model presented here has shown to describesatisfactorily theproposed system.