Removal of carbon and nitrogen in wastewater from a poultry processing plant in a photobioreactor cultivated with the microalga Chlorella vulgaris

Abstract

This study evaluates the removal of COD and nitrogen from poultry wastewater in photobioreactors. Cell growth, the effect of light intensity (3200, 9800, and 12000 lux) and air flow (1.6, 3.2, and 4.8 L min⁻¹) as a source of CO₂ in bold basal medium and wastewater with different concentrations of COD were evaluated. The growth kinetics were modeled by using the Gompertz model and logistic model for both culture media. COD removals of up to 95% were achieved, and poultry wastewater was found to be a viable growing medium for Chlorella vulgaris. Finally, the wastewater met Mexican standards, and biomass was obtained with products valued as lipids (3.2 g lipid/100 g biomass) and proteins (342.94 mg L⁻¹). The culture was found to have a dilatory behavior, and the rheological models of Ostwald de Waele, Ostwald de Waele linealized and Herschel Bulkley were utilized, showing a laminar behavior.

Keywords:

• wastewater
• microalgae
• Chlorella vulgaris

Acknowledgments

We thank the soil analysis laboratory of the company Fertilizadores Tepeyac S. A. de C. V. for the support in carrying out the heavy metal analysis in its facilities, as well as the Centro de Investigaciones Biológicas del Noroeste, S. C. for their support in carrying out the arsenic analysis.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and/or its supplementary materials.