12 - Pilot-plant scaled water treatment technologies, standards for the removal of contaminants of emerging concern based on photocatalytic materials

Abstract

Environmental health also means clean, waste-free water, which is nowadays achieved in developed countries. However, with scientific progress in medicine/pharmacology and also in the field of cosmetics and plastic development as well as the appearance of novel pesticides, new resistant contaminants have emerged. These compounds can be removed via advanced oxidation processes, including heterogeneous photocatalysis. There are different kinds of reactor designs that were developed for the solar-driven degradation of organic pollutants, including these new threats, the so-called contaminants of emerging concern. Hydrodynamic, illumination, and mass-transfer aspects were the driving parameters that defined the geometry and functioning modality of the reactors. In some cases, mathematical modeling was also applied to further enhance the properties of the reactors. The success rate, however, is not well reflected in the literature as several issues, such as the slow removal of DOC, the fate of the semiconductor nanoparticles (effects on environment), and scaling up, have been raised. Despite this, promising results are still emerging, and standardization procedures have been elaborated (they were also included in 2016 in the Best Available Techniques (BAT) Reference Document for Common Wastewater and Waste Gas Treatment/Management Systems in the Chemical Sector). Nevertheless, while photocatalysis is considered mainly in photodegradation procedures, new approaches, including standardization, have also been started for photocatalytic synthesis.