Insights into the technology utilized to cultivate microalgae in dairy effluents

Abstract

The population increase has brought a number of consequences, such as greater demands for food, fossil fuels, and freshwater. The cultivation of microalgae appears to be an alternative source of food and energy because the biomass of microalgae can yield several products with applications in the fields of bioenergy, agriculture, and human and animal food. However, growing microalgae requires high concentrations of nutrients and water, making it an expensive process for large-scale production. The use of some effluents as culture media for microalgae has become a promising solution to reduce process costs and to obtain effluent treatment. The organic residues present in dairy effluent are considered harmful to the environment due to the high chemical and biochemical oxygen demand. Another problem is the high concentrations of nitrogen and phosphorus. However, these two nutrients are among the main nutrients used to grow microalgae. The ability of microalgae to effectively absorb nutrients from dairy effluent and the concomitant generation of value-added products make this effluent a potential medium for biomass production at a reduced cost. Therefore, this review aims to present recent advances in microalgae biotechnology for the treatment of dairy effluents. In addition, the review contributes to the existing literature by expanding knowledge about replacing drinking water and synthetic nutrients with dairy effluents in the cultivation of microalgae. This review shows the efficiency of the treatment of this effluent by microalgae and the possible applications of microalgae biomass cultivated in dairy effluents.