Avaliação de um reator de lodo ativado aplicado à nitrificação utilizando ensaios cinéticos

Abstract

In this work, an activated sludge lab-scale reactor used for nitrification was monitored by specific activity kinetic assays. The nitrification biomass activity was carried out by respirometric methods in order to characterize the inoculum and the reactor sludge after two different operation conditions: during the feeding of the reactor with synthetic autotrophic medium, and after feeding it with effluent from an UASB reactor used for denitrification. The efficiency of nitrification reached 90% in both operation conditions. Results obtained by the kinetic activity assays were better adjusted by the kinetic model of Andrews, which includes the inhibition constant by the substrate (Ki), than the Monod model. However, an increase was observed in the inhibition constant (Ki) of the sludge after the operation of the reactor as compared with the inoculum. This effect demonstrates an adaptation of the biomass to the new nitrification conditions (loading rate).