『Abstract
The influence of the operational variables on the Anammox process
has been generally researched considering each variable separately.
However, the optimization of the process also requires the identification
of the more significant variables and their possible interactions.
Response surface models were successfully applied to evaluate
the performance of the Anammox process in a deammonification system
(i.e., one-stage biofilm Anammox process) taking into account
the combined effects caused by two sets of three variables. Specific
Anammox activity was measured by a manometric method and used
as the response variable. The obtained models pointed out that
the significant variables were the temperature, the value of pH,
and the ratio between the unionized species of the substrates
(free ammonia and free nitrous acid (FA/FNA). There were interactions
among them caused by chemical equilibriums. Total nitrogen concentration
and ammonium concentration were found to be not significant in
the tested range. According to the models, the optimum values
of temperature, pH, and free ammonia to free nitrous acid ratio
within the test ranges were, respectively, 30℃, 7.0, and 0.3.
Further research at higher temperatures and lower values of pH
and FA/FNA ratios would be necessary in order to find the absolute
optimum conditions for the process. The obtained model can be
also useful in order to develop control strategies that take into
account the significant variables and their optimum ranges. A
strategy to control deammonification reactors has been proposed,
according to the results of the modeling.
Keywords: Anammox; Activity; Deammonification; Optimization; Response
surface modeling』
1. Introduction
2. Materials and methods
2.1. Reactor and biomass
2.2. SAA tests
2.3. Statistic methods, experimental strategy, and computer data
analysis
2.3.1. First study
2.3.2. Second study
2.3.3. Computer data analysis
3. Results and discussion
3.1.First study: Effects of ammonium, pH, and temperature
3.2. Second study: Effects of total nitrogen, FA/FNA ratio, and
temperature
3.3. Discussion and application
4. Conclusions
Acknowledgements
References