A Green Solution for Waste: Microalgal Bioremediation for Wastewater Treatment in Food and Agro-Food Industries

Food processing and agro-food industries generate wastewater rich in organic matter, heavy metals, and surplus nutrients, such as nitrogen and phosphorus. When this effluent enters rivers or lakes without proper treatment, it decreases the dissolved oxygen (DO) level of the water bodies, while parameters such as chemical oxygen demand (COD) and biochemical oxygen demand (BOD) increase, endangering fish and other aquatic life. Microalgae offer an efficient solution for this problem. They absorb heavy metals, feed on excess nutrients, and break down organic pollutants as they grow. Algal biomass can later be used for various purposes, such as producing bioactive compounds in pharmaceuticals, animal feed, or converted into biofuels. This chapter highlights key microalgal strains that excel at cleaning up the effluents of food processing and agro-food industries. It also examines the factors influencing the efficiency of bioremediation and the challenges associated with scaling up the technology. Microalgal bioremediation simultaneously treats wastewater and converts waste into a valuable biomass, advancing both circular economy goals and environmental sustainability.