ABACO: A New Model of Microalgae-Bacteria Consortia for Biological Treatment of Wastewaters

Abstract

Microalgae-bacteria consortia have been proposed as alternatives to conventional biological processes to treat different types of wastewaters, including animal slurry. In this work, a microalgae-bacteria consortia (ABACO) model for wastewater treatment is proposed, it being calibrated and validated using pig slurry. The model includes the most relevant features of microalgae, such as light dependence, endogenous respiration, and growth and nutrient consumption as a function of nutrient availability (especially inorganic carbon), in addition to the already reported features of heterotrophic and nitrifying bacteria. The interrelation between the different populations is also included in the model, in addition to the simultaneous release and consumption of the most relevant compounds, such as oxygen and carbon dioxide. The implementation of the model has been performed in MATLAB software; the calibration of model parameters was carried out using genetic algorithms. The ABACO model allows one to simulate the dynamics of different components in the system, and the relative proportions of microalgae, heterotrophic bacteria, and nitrifying bacteria. The percentage of each microbial population obtained with the model was confirmed by respirometric techniques. The proposed model is a powerful tool for the development of microalgae-related wastewater treatment processes, both to maximize the production of microalgal biomass and to optimize the wastewater treatment capacity.

Production of Scenedesmus almeriensis Using Pilot-Scale Raceway Reactors Located inside a Greenhouse

“…Moreover, because of the strong impact of environmental conditions on the performance of microalgae, the above-mentioned study developed one model for each season. This is a simple model to predict biomass productivity based only on operational conditions, other aspects related to the biology of microalgae and environmental conditions would better predict biomass productivity [35,36]. In the present study, the difference between the predicted and experimental values was lower than 5% in spring and 8% in summer, suggesting the validity of the model.…”

Year-long evaluation of microalgae production in wastewater using pilot-scale raceway photobioreactors: Assessment of biomass productivity and nutrient recovery capacity

“…The current study will also discuss the effect of environmental conditions namely temperature and solar radiation on the performance of the system. A secondary aim of the manuscript was to validate the ABACO model, a robust tool that can be used to predict biomass productivity as a function of environmental (solar radiation, temperature, pH, and dissolved oxygen concentration) and biological parameters (microalga growth rate, nutrient saturation coefficients, and nutrient inhibition coefficients, among others) [28]. The validation of models using data generated using large reactors located outdoors is of key importance as this allows to predict the suitability of models for predicting industrial processes.…”

An Interactive Tool for Simulation of Biological Models Into the Wastewater Treatment With Microalgae

“…Finally, ABACO model was calibrated and validated in the laboratory photobioreactors using pig slurry as a nutrient source, demonstrating the validity of the developed model (Sánchez-Zurano et al, 2021b).…”

“…As a result, and through oxygen production, it is possible to obtain models to predict the biomass productivity in these complex systems. -Zurano et al (2021a) developed a dynamic model considering several important environmental parameters (light intensity, temperature, pH, and dissolved oxygen) on microalgae and bacteria growth (Sánchez Zurano et al, 2021b). The model equations were built using experimental data related to the influence of the environmental parameters on the photosynthesis rate and the respiration rate of microalgaebacteria consortium, distinguishing between microalgae activity, heterotrophic activity, and nitrifying activity and by considering the methodology proposed by (Sánchez-Zurano et al, 2020a).…”