Wastewater treatment is of absolute importance nowadays for the secured ecological and economic perspective of the future. In addition to the treatment itself, it is mandatory to improve the existing and devise new water treatments that don’t require large investments or additional environmental damage. An increasingly common method of wastewater treatment is advanced oxidation processes characterized by fast reaction rates, low environmental footprint, no new waste is produced, almost all organic compounds are treated, and no sludge formed as in biological or chemical processes. In this paper, heterogeneous photocatalysis, based on the shift of electrons from valence to conductive band with light absorption by semiconductors or photocatalysts, is taken as the basis. The most researched photocatalyst titanium dioxide (TiO2) is characterized by several beneficial properties such as availability, chemical and biological inertness and corrosion resistance that make it the most suitable for use. To increase the operation efficiency and to avoid difficulties in its implementation, it is desirable to attach the photocatalyst to a carrier. This immobilization, carried out by one of the described methods, creates physical or chemical bonds between the catalyst and the carrier, which prolongs the life of the catalyst ad allows a continuous process. Recently discovered as a potential carrier, characterized by availability and harmlessness, is perlite or volcanic glass. Attention has been paid to increasing the effectiveness of the procedure when using perlite as a carrier and to the factors influencing the process in which the TiO2/perlite composite was used. Given the activity of TiO2 in a narrow range of UV wavelengths, possible improvements of the mentioned have been investigated.