The presence of pharmaceuticals in the environment has raised an emerging interest due to the fact that they pose negative environmental impact and health hazards related to long-term toxicity effects.
Its removal from wastewater and from important drinking water sources is a big challenge to be faced by wastewater treatment plants (WWTPs) and environmental engineers due to the low concentration that is usually present in the water in addition to its high diversity (chemical structure, mode of action, Kow). Pharmaceuticals end up into the influent of WWTPs mainly through the sewage system that transports excreted faeces and urine from households but they do not have yet maximum discharge guidelines and standards.
Conventional treatments used nowadays in WWTPs are not able to totally remove pharmaceuticals from wastewater and therefore it is necessary to seek for alternative advanced technologies such as oxidation with chlorine dioxide (ClO2). ClO2 needs to be manufactured at the point of use and it is a highly selective oxidant for several functional groups that are usually present in the chemical structure of pharmaceuticals. The capital cost for a ClO2 generator is lower than other oxidative technologies such as ozone and therefore it could be a good option for small scale WWTPs.
Author: Alcalá Borao, Raquel