Treatment Technologies for Wastewater Reuse: Fate of Contaminants of Emerging Concern

The presence of thousands of microcontaminants in wastewaters and their potential risks has drawn a large attention of the scientific community during the last years. The presence of these contaminants is especially controversial when wastewater is considered for reuse because a large number of microcontaminants are frequently not totally removed by conventional wastewater treatment processes. As a contribution to the knowledge in this field, this chapter focuses on the application of four well-known and widely used technologies to the elimination of microcontaminants. Membranes, activated carbon, ozonation, and advanced oxidation processes (AOPs) are deeply reviewed to assess their efficiency and safety in the elimination of these contaminants from wastewater effluents. A brief description of each technology is presented together with a review of their real application, mostly in wastewater treatment plants (WWTPs). A deep analysis of the found data allows to conclude that the four presented alternatives can be useful for microcontaminant mitigation although none of them seem to be a universal barrier for microcontaminants when used separately. In addition, each technology presents drawbacks which demand further research to be overcome. Depending on the final use of reclaimed water, the treatment may require the combination of several of the studied technologies although that results in an economic impact which cannot be neglected.