1 Introduction

2 Basics
2.1 Biology of Microorganisms
2.2 Biofilms and Capillary Biofilm Reactors 
2.3 Modelling Biofilms

3 Model Development 12
3.1 Assumptions and Simplifications
3.2 Basic Biological Processes in a Biofilm Reactor
3.3 Parameters
3.4 Geometry, Materials and Mesh of the Capillary in COMSOL
3.5 Laminar Flow 
3.6 Mass Transfer
3.7 Cell Growth and Inactivation
3.8 Reactions in the Biofilm
3.9 Model Stoichiometry 
3.10 Initial Values and Model Kinetics Determination 

4 Results 30
4.1 Medium Flow through the Capillary Reactor
4.2 Implementation of Determined Parameters
4.3 Inhibition Term Reduces Biofilm Formation in the Model 
4.4 Impact of Oxygen Permeability of the Reactor Material on Oxygen Concentration, Carbonate Consumption and Biofilm Formation 
4.5 Impact of Reactor Scale-Up on Oxygen Concentrations and Biofilm
Formation
4.6 Impact of Growth Rates on Model Results

5 Discussion 
5.1 Oxygen Inhibition Reduces Biofilm Growth to Realistic Levels 
5.2 Oxygen Permeability of the Reactor Influences Oxygen Concentrations
in the Biofilm
5.3 Reactor Permeability Influences Biofilm Growth
5.4 Scale-Up Impact on Oxygen Concentrations and Biomass Production
5.5 Maximum Growth Rates can be Approached Through Iteration

6 Conclusion 

7 Summary 

8 Outlook