Dynamics and steady state operation of a nitrifying fixed bed biofilm reactor: mathematical model based description

The operation of a fixed bed biofilm reactor for nitrification colonized by Nitrosomonas europaea and Nitrobacter winogradskyi has been characterized in terms of steady state operation but also studying the dynamics of the system in front of disturbances of ammonium load. The nitrifying reactor is used in a biological life support system (BLSS) in which it is necessary to assure high conversion to nitrate and to avoid nitrite production. In order to enhance the knowledge on the system and also as a simulation and control tool, a mathematical model has been developed, calibrated and validated for both steady state and dynamic conditions of continuous mode operation. The results presented demonstrate the applicability of the model to the experimental system, providing a simple and useful mathematical tool to be further applied to the control of the reactor and to maintain the long-term stability of a loop of interconnected bioreactors in the BLSS.

[1]  F Gòdia,et al.  MELISSA: a loop of interconnected bioreactors to develop life support in space. , 2002, Journal of biotechnology.

[2]  J W Wimpenny,et al.  Individual-based modelling of biofilms. , 2001, Microbiology.

[3]  Peter A. Vanrolleghem,et al.  A simplified mixed-culture biofilm model , 1999 .

[4]  Julio Pérez,et al.  Nitrification by immobilized cells in a micro‐ecological life support system using packed‐bed bioreactors: an engineering study , 2004 .

[5]  J J Heijnen,et al.  Mathematical modeling of biofilm structure with a hybrid differential-discrete cellular automaton approach. , 1998, Biotechnology and bioengineering.

[6]  S. Okabe,et al.  Analyses of Spatial Distributions of Sulfate-Reducing Bacteria and Their Activity in Aerobic Wastewater Biofilms , 1999, Applied and Environmental Microbiology.

[7]  L Poughon,et al.  kLa determination: comparative study for a gas mass balance method , 2003, Bioprocess and biosystems engineering.

[8]  Octave Levenspiel,et al.  The chemical reactor minibook , 1979 .

[9]  J. Heijnen,et al.  Population distribution in aerobic biofilms on small suspended particles , 1995 .

[10]  B. Rittmann,et al.  Accurate pseudoanalytical solution for steady-state biofilms. , 1992, Biotechnology and bioengineering.

[11]  Dimitrios V. Vayenas,et al.  On the design of nitrifying trickling filters for potable water treatment , 1995 .

[12]  C. Dussap,et al.  Dynamic model of a nitrifying fixed bed column: Simulation of the biomass distribution of Nitrosomonas and Nitrobacter and of transient behaviour of the column , 1999 .

[13]  W Gujer,et al.  A multispecies biofilm model , 1986, Biotechnology and bioengineering.

[14]  J Tramper,et al.  Co‐immobilized Nitrosomonas europaea and Nitrobacter agilis cells: validation of a dynamic model for simultaneous substrate conversion and growth in κ‐carrageenan gel beads , 1994, Biotechnology and bioengineering.