A new kinetic model to predict substrate inhibition and better efficiency in an airlift reactor on deammonification process

Abstract

A collection of kinetic models to explore the bacteria pathway inhibition by high-ammonia during deammonification process was fitted. The main goal was to determine the substrate concentration to operate the deammonification with efficiency, performance and low impact to ANAMMOX and ammonia-oxidizing bacteria (AOB) by substrate. A new mathematical model was created to describe the deammonification behavior, since the empirical theoretical models showed inconsistent parameters to describe the process. The proposed model showed significant prediction to the estimable parameters and according to it, until 550 mg NH₃-N L^-1 no inhibitions by ammonia and nitrite were observed. However, concentrations higher than this promote the decrease on specific bacterial activity and nitrite accumulation, since it was not quickly consumed by the bacteria. The proposed model can be applied to predict microorganism affinity and inhibition by substrate over a wide range of ammonia concentrations (<900 mgNH₃-N L^-1) in reactors treating high-ammonia concentration swine wastewater.

Keywords: ANAMMOX; Mainstream deammonification; Mathematic models; Nitrogen removal rate.