|Oxidation processes belong to advanced water treatment technologies, which are usually utilised with an aim to enhance the removal of undesirable compounds by subsequent coagulation. Under suitable circumstances, oxidation may increase the removal of, e.g., natural organic compounds via the modification of their properties, or as a result of their complete degradation. On the contrary, unsuitably conducted oxidation prior to coagulation may decrease the removal of undesirable pollutants. Our research within this field is focused on the optimisation of oxidation conditions (the type and dose of an oxidant, reaction pH) in dependence on the character of the target compounds so as to maximise their removal efficiency. Additionally, we focus on the application of oxidation for the elimination of cyanobacterial toxins.