## 2 Methods of Eliminating Hormones and Pharmaceuticals
### Chemical Methods
#### 2.2.4 Photocatalysis Without and with Activated Carbon  
For photocatalysis with carbon, the reduction in micropollutant concentrations depends on the exposure time. Table 7 shows the removal rate of hormones in deionised water and the actual effluent for E2, EE2, and BPA as a function of the irradiation times of 10 min and 60 min. The greatest reduction in concentration with photocatalysis was observed for E2. Differences in the decomposition efficiency of micropollutants may be related to their physicochemical properties. However, the higher decomposition rate of the tested micropollutants for the model effluent is due to the presence of chemicals in the effluent that enable so-called sensitised photocatalysis to take place. After 60 min of the process, the complete decomposition of E2 occurred, and the EE2 removal rate exceeded 95% [61]. In photocatalysis, the rate of decomposition of the reactions of the micropollutants mentioned above is greater for the model effluent. The values range from about 0.1 min\({}^{-1}\) for BPA to more than 0.08 min\({}^{-1}\) for E2. In the case of the deionised water solution, the reaction rate constants for hormone oxidation (E2 and EE2) are approximately six times higher compared to the value of this parameter determined for BPA [21; 68; 70]. According to the literature [21; 68; 70], photocatalysis with activated carbon was carried out for BPA. It was shown that the performance of the photocatalysis process conducted in the presence of 1 mg/dm\({}^{3}\) of activated carbon was comparable to photocatalysis conducted with TiO\({}_{2}\) alone. The process of single adsorption of bisphenol A on the activated carbon surface in the presence of 1 mg/dm3 of activated carbon had a low efficiency. After the process was carried out for 60 min, the concentration of bisphenol A only decreased by about 16%. In contrast, when the researchers used a dose of activated carbon that was five times higher (5 mg/dm\({}^{3}\)), about 50% of the compound was removed after 20 min of exposure, and after 60 min, about 64% was removed. A total of 10 min of exposure allowed 70% BPA decomposition for the actual drain and 40% for the model drain. Furthermore, for the model drain, a degradation rate of 65% was achieved after 60 min of exposure, while after this time for the actual drain, approximately 90% of bisphenol A was removed. Photocatalytic wastewater treatment processes, especially using semiconductors such as TiO\({}_{2}\) activated by UV or visible light, represent one of the most promising methods for the elimination of hormones and pharmaceuticals. The mechanism of action is based on the generation of reactive oxygen species, mainly hydroxyl radicals, which efficiently oxidise organic pollutants. As indicated in the work of [31] photocatalysis can lead to the efficient degradation of substances such as E2, EE2, diclofenac, and carbamazepine, even reaching more than 90% efficiency under laboratory conditions with the right choice of pH, catalyst dose, and radiation exposure time [31]. However, the effectiveness of this method may be limited by the presence of other substances in the actual wastewater that compete for active sites on the photocatalyst surface and by the possibility of forming toxic intermediates. Additionally, research conducted by a group of researchers [126], although focusing on plasma properties, can be used to understand the energetics and kinetics of pollutant decomposition in advanced hybrid systems based on plasma-assisted photocatalysis [126]. Photodegradation in the context of the elimination of hormones and pharmaceuticals from wastewater represents an important process based on the ability of light (mainly UV radiation) to initiate chemical reactions, leading to the degradation of complex organic pollutants. Under natural conditions (solar photolysis) or assisted by an artificial UV source, photodegradation can contribute to the removal of substances such as EE2, diclofenac, ibuprofen, or carbamazepine. The mechanism is based on the absorption of light energy by