The increased use of antiparasitics for veterinary and other medical purposes, and the widespread use of pesticides in agriculture, lead to the continuous and uncontrolled release of xenobiotics into the environment. Although they and their degradation and transformation products are found in traces in the environment, they can cause a long-term high concentration of these pollutants and thus have a harmful effect on the environment. Sooner or later, these compounds end up in the water environment and waste water through washing or runoff. Numerous studies show that the removal of many xenobiotics in conventional waste water treatment devices is often incomplete and therefore pollution of natural waterways occurs. It is known that disinfectants also remove organic pollutants, therefore the aim of this work is to evaluate the influence of the presence of sodium hypochlorite as a disinfectant on the removal of xenobiotics in wastewater after batch biodegradation as a conventional and often applied method. The biodegradation process was carried out in three aerated batch reactors with different contents. The first reactor contained activated sludge and a working solution of xenobiotics with a mass concentration of 10 mg L^-1. As control reactors, the second reactor contained only activated sludge, while the third reactor contained only the working solution of the tested xenobiotic of the same concentration. In addition to testing the physico-chemical parameters of biodegradation, the concentration was monitored at sampling intervals. After the biodegradation process, the xenobiotic solutions are subjected to the photolysis process as a form of tertiary wastewater treatment. Photolysis was carried out in four quartz vessels with different contents. During the photolysis process, the influence of the presence of sodium hypochlorite on the removal of xenobiotics was examined, with a comparative performance of xenobiotic removal with hydrogen peroxide as a very effective method. The results showed a different percentage of removal of the six tested xenobiotics. Newly formed degradation and/or transformation products were detected by high performance liquid chromatography. Also, the toxicity of the investigated solutions of xenobiotics was evaluated using the bioluminescent method of determining acute toxicity by the bacterium Vibrio fischeri.