In recent years, due to the high consumption of drugs both for human needs and for their growing use, especially as regards antibiotics, in the diet of livestock, water pollution has reached very high levels and attracted widespread attention. Drugs have a stable chemical structure and are recalcitrant to many treatments, especially biological ones. Among the methods that have shown high efficiency are advanced oxidation processes (AOPs) which are, among other things, inexpensive and eco-friendly. AOPs are based on the production of reactive oxygen species (ROS) able to degrade organic pollutants in wastewater. The main problem related to the degradation of drugs is their partial oxidation to compounds that are often more harmful than their precursors. In this review, which is not intended to be exhaustive, we provide an overview of recent advances in the removal of organic drugs via advanced oxidation processes (AOPs). The salient points of each process, highlighting advantages and disadvantages, have been summarized. In particular, the use of AOPs such as UV, ozone, Fenton-based AOPs and heterogeneous photocatalysis in the removal of some of the most common drugs (tetracycline, ibuprofen, oxytetracycline, lincomycin) has been reported.

The depletion of fossil fuel requires the search for alternative renewable feedstock and environmentally friendly methods for the production of high value-added compounds and fuels. In this context, the efficient use of biomass has emerged as a significant research field as it represents an alternative green and renewable carbon source. Various technologies have been explored for this purpose and heterogeneous photocatalysis represents a valid alternative to the catalytic methods since it can be carried out under mild experimental conditions without the addition of harmful oxidizing agents. Different biomass components have been used as the starting materials, and many valuable chemicals have been obtained with different selectivity depending on some experimental conditions as, for instance, type of photocatalyst, solvent, and physico-chemical features of the catalysts. Moreover, by carrying out the reaction in de-aerated systems, in addition to high added value compounds, hydrogen can be obtained in the gaseous phase. In particular, photocatalytic conversion of lignocellulose, carbohydrates, 5-hydroxymethyl-2-furfural and glycerol (considering only the partial oxidation products) is reported.