Microalgae for Biodiesel Production and Pharmaceutical Removal from Water

Summary

During the past 20 years, the presence of pharmaceutical active compounds in water bodies has been gaining increasing attention, and nowadays there is broad acknowledgement that they should be considered an emerging environmental problem. The existing scientific literature clearly points out that pharmaceuticals enter the environment and provoke adverse effects. The main source of these compounds is wastewater, since, after intake, the pharmaceutical compounds are absorbed, metabolized, and finally excreted into the sewerage system. Although wastewater is normally collected and delivered to treatment plants, it has been demonstrated that the regular treatments applied in such facilities are not completely effective for removal of a variety of pharmaceuticals, which are subsequently introduced into the environment. Microalgae can play a relevant role in remediation of wastewater. In addition to their well-known capacity to remove organic carbon, nutrients, and even heavy metals from water, microalgae have recently been revealed to have significant potential to remove pharmaceutical compounds from polluted effluents. Microalgae offer a further benefit to close the mass-to-energy loop, since their content of carbohydrates and oils allows them to be considered as a potential feedstock for the production of biofuels. In this chapter, the authors review the potential of microalgae to remove contaminants of emerging concern from water, paying special attention to pharmaceutical compounds. The immobilization techniques that can be used to facilitate the harvesting process and valorization of the biomass for the production of biodiesel are also assessed.