Photobiotreatment model (PhBT): a kinetic model for microalgae biomass growth and nutrient removal in wastewater

Abstract

This article proposes a kinetic model for wastewater photobiotreatment with microalgae (the PhBT model). The PhBT model for nutrient uptake, coupled with the Verhulst growth model, is a simple and useful tool to describe batch experiments of nutrient removal by microalgae. The model has been validated with experiments of Chlorella vulgaris (C. vulgaris) grown in wastewater and different synthetic media. The model provided information about nitrogen and phosphorus limitation and their luxury uptake during the test. Productivity observed in synthetic medium (0.17 g SS L−1 d−1) was similar to that obtained in nutrient enriched wastewater (0.15 g SS L−1 d−1). Biomass productivity of this alga in wastewater and the efficient nutrient removal suggested that C. vulgaris could be cultured in wastewater for biomass production while nutrients are reduced from this stream.