Jingjing Yang
TRITA LWR Degree Project
Table 8. Mathematical relationships Type of relationship Diffusion through cell membranes of ammonium and nitrite
Relationship Note Half-order reaction based on diffusion Suggested in Trela et al. combined with zero order reaction: Diffu- (2008); Trela et al., (2009). sion rate = k1 * (ammonium conc.)^0.5* (nitrite conc.)^0.5 Based on Anthonisen et al., Chemical equilibrium (1976) relationships of FA and FNA
(FA = free ammonia; FNA = free nitrous acid; T = temperature K)
Main metabolic reac- Monod function based on electron donator (ammonium) and electron acceptor tions (nitrite) Small effect on cell components for nitroCell synthesis gen removal, possible use for seeding, production of nitrate during cell synthesis Effect of pH-value Effect of temperature Effect of oxygen
Substrate inhibition
Other inhibitors
Typical approach, IAWQ- models
as
in
Modelling based on stoichiometry and seeding models
Combination of metabolic reactions and Used in Trela et al., (2009) chemical equilibrium (FA; FNA) Combination of metabolic reactions and Used in Trela et al., (2009) chemical equilibrium (FA; FNA) Probably reversible inhibition of Anam- Many studies available mox reaction but important in single stage deammonification as supply of nitrite as electron acceptor for anammox reaction Assumed to occur if accumulation of ammonium or nitrite occurring inside cells due to less metabolic rate than transport rate due to diffusion through membranes. Assumed to occur for low molecular substances especially in molecular form
Different substrate models are available based on enzyme kinetics
Different enzyme kinetic models based on competitive/uncompetitive inhibition programs, inhibitors thesis study to thesis works and hypothesis modeling were done in the master’s thesis study. Start up study A. Continuous reactor is better than batch reactor in start up process. Chemical compound or ions can easily be accumulated in the reactor and will cause inhibition effects when the amount of chemical compound or ions is increased up to a certain level.
anammox reaction. A more complex measurement cell may include other measurement devices such as oxygen meter, pH-meter, redox potential meter, dinitrogen oxide meter. The discontinuous measurement device may in the future be developed for continuous measurements for control and optimization purposes.
6 C ONCLUSIONS Studies on anammox start up, optimization of anammox process by SIMCA and MODDE 26