Wastewater Treatment Approaches for the Removal of Antidepressant Residues

Abstract

Pharmaceuticals are a major class of contaminants of emerging concern for wastewaters and natural waters alike. Among pharmaceuticals, antidepressants are the most rapidly increasing subclass, as more and more people are dealing with depression in their fast-paced and challenging everyday lives. As psychotropic medications, residual antidepressants in water must be carefully monitored and maintained below levels, where human health may be endangered. Moreover, aquatic life forms were shown to be seriously affected when such pollutants entered their natural habitat, in terms of locomotory, reproductive functions, or social behavior. Therefore, modern wastewater treatment plant technologies should incorporate solutions for removing antidepressant residues. This chapter summarizes recent efforts toward this goal and covers a wide range of proposed treatment approaches. Firstly, adsorptive methods are presented, whether based on classic, yet effective adsorbents like activated carbon or silicates, or modern alternatives such as ion-exchange resins or molecularly imprinted polymers. Secondly, extractive methods are considered, although currently impractical due to lack of both cheap and environmentally-benign solvents. Thirdly, advanced oxidation processes are surveyed, including ozone treatment, ultraviolet, gamma radiation, and electrochemical options, some of which, alone or in combination, may yield complete mineralization of antidepressant toxicants. Lastly, biological treatment with microorganisms is discussed, which may be highly specific, but usually does not enable a complete mineralization.