Microalgae: a cheap tool for wastewater abatement and biomass recovery

ABSTRACT Environmental control is essential for a steady economic upswing and advancement. The application of microorganism for the removal of pollutants from environment provide cheaper substitutes to the traditional treatment methods. The selection of easily culturable and effective microorganism that could do the treatment is a major challenge. Microalgae present a viable, eco-friendly and economical agent of wastewater treatment and production of value-added substances such as biofuel, carotenoids and polyunsaturated fatty acids, pharmaceuticals and dyeing agents. In this article, we reviewed and presented the use of microalgae for the removal of several kinds of pollutants, the mechanisms employed for the degradation and their diversity in wastewater. The removal of pollutants such as nitrogen, phosphate, heavy metal, chemical oxygen demand, biological oxygen demand and dye by different strains as well as the mechanism involved were identified and discussed. Cultivation of microalgae in the large-scale void of bloom, mechanism of stress tolerance and the potential value-added substances to be produced while decontaminating the environment concomitantly were also highlighted. The article also highlighted the fate of organic pollutants in the application of microalgae biomass. This review demonstrated the use of microalgae for wastewater treatment to be a win-win strategy that has dual role of pollutants removal and multiple product formations. Such benefits can be enhancing via integrating multiple methods of treatments and microalgae engineering. GRAPHICAL ABSTRACT