Applicability of the Arrhenius model for ammonia oxidizing bacteria subjected to temperature time gradients

Autor: Giulio Munz, Alberto Mannucci, Claudio Lubello, Gualtiero Mori, Jan A. Oleszkiewicz
Rok vydání: 2014
Předmět:
Zdroj: Frontiers of Environmental Science & Engineering. 9:988-994
ISSN: 2095-221X
2095-2201
Popis: The aim of this work is to identify the range of applicability of Arrhenius type temperature dependence for Ammonia Oxidizing Bacteria (AOB) subjected to temperature time gradients through continuous titrimetric tests. An innovative online differential titrimetric technique was used to continuously monitor the maximum biologic ammonia oxidation rate of the biomass selected in a pilot scale membrane bioreactor, as a function of temperature time gradients. The monitoring technique is based on the measurement of alkalinity and hydrogen peroxide consumption rates in two parallel reactors operated in nonlimiting substrate conditions for AOB; both reactors were continuously fed with mixed liquor and in one of them AOB were inhibited with allylthiourea. The effects of temperature decrease rates in the range 1 to 4°C·h−1 were evaluated by controlling the titrimetric reactor in the temperature range 10°C-20°C. The dependence of growth kinetics on temperature time gradients and the range of applicability of Arrhenius model for temperature dependency of AOB growth kinetics were assessed. The Arrhenius model was found to be accurate only with temperature gradients lower than 2°C·h−1. The estimated Arrhenius coefficients (θ) were shown to increase from 1.07 to 1.6 when the temperature decrease rate reached 4°C·h−1.
Databáze: OpenAIRE
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