Skip to Main Content

Parameters for the nitrification model are reported in Table 1. While a base AOB density, assuming uniform distribution of AOB, was used in most studies, different biomass densities were also tested. For additional tests with AOB along with a constant and uniformly distributed population of NOB, the NOB were simulated using the conventional ASM model, i.e. without electron mediators (Picioreanu et al. 1997). The denitrifying model included N2O formation by heterotrophic bacteria, and was adapted from Pan et al. (2013).

Table 1

Parameters used for the nitrification model

ParameterSymbolValueUnitsSource
Concentrations in influent 
 Oxygen Cin,O2 from 0.001 to 5 (varied) mg L−1 Typical range 
 Ammonia Cin,NH3 80 mgN L−1 Chosen 
 Hydroxylamine, nitrous oxide, nitric oxide, nitrite, nitrate Cin,i mgN L−1 Chosen 
Initial concentrations C0,i Cin,i mgO2 L−1 Chosen 
Biomass concentration in the biofilm 
 Ammonia oxidizers, AOB CF,XAOB 50 (base case) 50 or 35 (with NOB) g L−1 Typical value, Wanner et al. (2006)  
 Nitrite oxidizers, NOB CF,XNOB 0 (base case) 15 (with NOB) g L−1 Picioreanu et al. (1997)  
Concentration total redox mediators CT,Med 0.01 mol kg−1 Ni et al. (2014)  
Biofilm thickness LF 100 (base case) 2, 50, 100 (varied) μm Typical values 
Liquid flow rate Q 11 mL min−1 Chosen 
Liquid volume in the reactor VB Chosen 
Biofilm surface area AF 0.5 m2 Chosen 
Gas volume VG 3.5 Chosen 
Gas flow rate QG L min−1 Chosen 
Gas-liquid mass transfer coeff. kLa 100 h−1 Chosen 
Henry gas-liquid coefficient N2O (25 °C) HN2O 0.611 mol mol−1 CRC Handbook (2014)  
ParameterSymbolValueUnitsSource
Concentrations in influent 
 Oxygen Cin,O2 from 0.001 to 5 (varied) mg L−1 Typical range 
 Ammonia Cin,NH3 80 mgN L−1 Chosen 
 Hydroxylamine, nitrous oxide, nitric oxide, nitrite, nitrate Cin,i mgN L−1 Chosen 
Initial concentrations C0,i Cin,i mgO2 L−1 Chosen 
Biomass concentration in the biofilm 
 Ammonia oxidizers, AOB CF,XAOB 50 (base case) 50 or 35 (with NOB) g L−1 Typical value, Wanner et al. (2006)  
 Nitrite oxidizers, NOB CF,XNOB 0 (base case) 15 (with NOB) g L−1 Picioreanu et al. (1997)  
Concentration total redox mediators CT,Med 0.01 mol kg−1 Ni et al. (2014)  
Biofilm thickness LF 100 (base case) 2, 50, 100 (varied) μm Typical values 
Liquid flow rate Q 11 mL min−1 Chosen 
Liquid volume in the reactor VB Chosen 
Biofilm surface area AF 0.5 m2 Chosen 
Gas volume VG 3.5 Chosen 
Gas flow rate QG L min−1 Chosen 
Gas-liquid mass transfer coeff. kLa 100 h−1 Chosen 
Henry gas-liquid coefficient N2O (25 °C) HN2O 0.611 mol mol−1 CRC Handbook (2014)  

Close Modal

or Create an Account

Close Modal
Close Modal