## 2 Methods of Eliminating Hormones and Pharmaceuticals
### Chemical Methods
#### 2.2.3 Photolysis  
[PERSON]. [68] observed in her study that in the photolysis process, the concentration of bisphenol A decreases with an increasing irradiation time for water, with the greatest reduction in the concentration of this compound occurring at the initial irradiation time. The greatest removal of bisphenol A occurs at an irradiation time of 30 min for the actual tide (Table 6). This is due to the fact that chemicals that show effects  
Figure 8: Effect of pH on elimination of bisphenol A; authors’ own elaboration based on [68]. similar to photosensisers may be present in effluent after biological treatment. These compounds have the ability to absorb the energy of electromagnetic radiation and transfer it to other substances involved in photochemical reactions [68]. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Type of Wastewater** & **Name of Association** & **Process Parameter—Exposure Time** & **Degree of Reduction** \\ \hline deionised water & BPA & 0–10 min & 60\% \\ \hline model drains & BPA & 0–10 min & 85\% \\ \cline{3-4}  & BPA & 20 min & 64\% \\ \hline  & BPA & 20 min & 95\% \\ \cline{3-4} actual drain & BPA & 30 min & 98\% \\ \cline{3-4}  & E2 & 5 min & 94\% \\ \cline{3-4}  & EE2 & 20 min & 93\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Degree of micropollutant reduction depending on exposure time; authors’ own elaboration based on [68; 70]. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Type of Wastewater** & **Process Parameters** & **Degree of Reduction** \\ \hline  & Ozone dose—1 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & 0.4\% \\  & pH—7 & \\ \cline{3-4}  & deionised water & Ozone dose—5 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & 0.7\% \\  & pH—7 & \\ \cline{3-4}  & Ozone dose—10 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & \textgreater{}90\% \\  & pH—7 & \\ \hline  & Exposure time—20 min & 75\% \\ \cline{3-4}  & Ozone dose—1 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & 8\% \\  & pH—7 & \\ \cline{3-4}  & Ozone dose—5 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & 5\% \\  & pH—7 & \\ \cline{3-4}  & Ozone dose—10 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & 30\% \\  & pH—7 & \\ \hline  & Ozone dose—1 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & 15\% \\  & pH—7 & \\ \cline{3-4}  & actual drain & Ozone dose—5 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & 43\% \\  & pH–7 & \\ \cline{3-4}  & Ozone dose—10 mg\(\cdot\)dm\({}^{-3}\) & \\  & Response time—1 min & \textgreater{}90\% \\  & pH—7 & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Degree of reduction in BPA depending on ozone dose, pH, and reaction time; authors’ own elaboration based on [68; 70]. Table 6 shows the degree of removal of E2, EE2, and BPA as a function of exposure times of 5 min and 20 min in the real drain. The first two hormones achieved a very high degree of reduction in the initial exposure time, while bisphenol A needed about 20 min of exposure to achieve a similar result. The different structural and physicochemical properties of the compounds mentioned above directly affect their stability and reactivity in aqueous solutions [70]. The ozonation process combined with photolysis allows for a higher degree of BPA removal to be achieved than that observed when a single photolysis process is carried out for deionised water and actual effluent. In most of the studies presented in the literature on the application of advanced oxidation processes, a higher efficiency of the combined UV/O\({}_{3}\) process was demonstrated compared to single processes, that is, ozonisation or photolysis [96; 122; 123]. The efficiency of the process is determined by a number of factors, such as, e.g., the reaction, solution composition, or physicochemical properties of the reactant itself [68]. The decomposition rate of both E2 and EE2 in deionised water solution did not increase when ozone was added to the reactor.