## 1 Introduction  
Environmental pollution is a ubiquitous problem that humanity has been dealing with for many years. When considering the impact of various factors on the environment, more and more attention is paid to pharmaceuticals. These are biologically active compounds used to treat and prevent diseases, alleviate of symptoms, etc., in human and veterinary medicine [1, 2]. The modernization of technology and science has led to the promotion of quality of life through the increased production of medicines whose consumption is increasing every day [3]. Since information about their fate is still limited and there are no environmental laws, they can reach different sources in the environment and undergo processes, such as sorption, photolysis, hydrolysis or even biodegradation. These processes can often produce transformation or degradation products that are more toxic than the parent compound. The fact that they are still present in the environment at low concentrations is not reassuring due to their unknown long-term effects on the aquatic and terrestrial world [1; 4]. In addition to commonly studied classes of pharmaceuticals such as antibiotics [5; 6; 7; 8; 9], anticancer drugs are also a frequent research topic due to the increasing incidence of this disease and the potential carcinogenic, mutagenic, and teratogenic effects on the environment. They usually enter the environment as partially metabolized compounds via urine and feces discharged into municipal wastewater and hospitals [10; 11]. Examples of such anticancer drugs include imatinib and crizotinib, tyrosine kinase inhibitors used to treat leukemia and lung cancer, respectively. Imatinib has been found in wastewater treatment plant (WWTP) effluent at concentrations ranging from 54 to 180 ng/L and is characterized as a highly persistent compound in water that does not degrade [12; 13]. A similar fate is expected for crizotinib given the BIOWIN values calculated using the EPI Suite program (BIOWIN 3 = 1.0010, BIOWIN 5 = \(-\)0.4293, BIOWIN 7 = \(-\)0.3096). Moreover, these calculated modules predict the resistance of CRZ to biodegradation, aerobic and anaerobic, in terms of BIOWIN values of less than 0.5 [13]. Therefore, these two pharmaceuticals, along with other anticancer drugs, are not expected to be removed by conventional water treatment methods [14; 15]. The development of advanced oxidation processes, as more efficient methods for the water treatment, is often the focus of many studies when pharmaceuticals are compounds of interest [11; 16]. One such method for removing pharmaceuticals and other organic compounds from water is photocatalysis, which uses a catalyst that is excited by some type of radiation to form highly oxidative radicals (e.g., OH) that react with the pollutant to degrade ultimately into CO\({}_{2}\) and water [17]. However, for a photocatalytic reaction to occur at all, sorption of the drug on active sites on the surface/pores of the photocatalyst is a necessary step [18]. The most commonly used photocatalyst is TiO\({}_{2}\) due to its easy availability, low cost, non-toxicity, stability, and photochemical efficiency. It can be in the suspended form in water or immobilized on a solid support, which is also a more effective method because the immobilized catalyst can be much more easily removed from water after purification and its reuse is possible, which reduces processing costs [19; 20]. Due to all advantages provided by pure TiO\({}_{2}\), there are UV light limitations which are trying to be solved for many years by producing different composites with carbonaceous materials. One of these interesting support materials is carbon nanotubes (CNTs), which have been introduced as adsorbent and whose molecular structure allows greater surface area and more \(\pi\)-\(\pi\) interactions with aromatic organic pollutants. CNTs showed good suitability for sorption removal of some antibiotics, such as limomycin, sulfamethoxazole, and sulfapyridine [6; 21].