Kinetics of Obtaining Microalgal Biomass and Removal of Organic Contaminants in Photobioreactors Operated with Microalgae—Study Case: Treatment of Wastewater from a Poultry Slaughterhouse

Abstract

Increases in poultry industry production have resulted in the generation of more hazardous effluents with high nitrogen and chemical oxygen demand (COD) concentrations. It is necessary to develop more efficient technologies in terms of water purification without the need to increase the volumes of commonly used reactors. This work analyzed the addition of micronutrients (Mo, Zn, Cu, and Mn) for the cultivation of the microalgae Chlorella spp. and Spirulina maxima in poultry wastewater. The effects of micronutrients on the production of biomass and algal cells were also assessed. For the Chlorella species, removal efficiencies of up to 99.14% for COD and 99.33% for nitrogen were achieved; for the Spirulina strain, these efficiencies were 98% for COD and 99% for nitrogen. The modified Gompertz equation was used to analyze the kinetic parameters. For both microalgae, the R2 values were greater than 98%. The results indicated that the dose with the highest algal cell generation rate was dose 2 for Chlorella spp., at 4.35 days, and dose 1 for Spirulina maxima, at 6.26 days. Microalgae are biological alternatives suitable for wastewater treatment, and their pollutant removal efficiency can increase with the addition of micronutrients, which has additional benefits for the production of valuable biomasses for industrial applications.

Keywords

• <i>Chlorella</i> spp.
• supplemental micronutrients
• poultry wastewater
• <i>Spirulina maxima</i>