Given the fact that we live in a world that is developing extremely fast technologically and industrially, it is important that the environmental protection industry can keep up with this pace with innovative solutions to preserve the earth and all natural resources. We are becoming more and more victims of our own actions, and when it comes to pollution, it is precisely the pesticides used for pest control and food preservation that are one of the most important pollutants in the environment. Advanced oxidation processes are new solutions that allow to combat the harmful effects of the presence of pesticides in the environment, and photocatalytic decomposition can be particularly highlighted. When TiO2 is used in the process and the abundant UV radiation in the atmosphere is utilized, with additional optimizations it is possible to perform pollutant decomposition reactions with minimal formation of harmful byproducts. In the theoretical overview of this article, a little more is said about pesticides, especially imidacloprid, and about the legal regulations related to pesticides at the EU level. In addition, the process of photocatalysis with TiO2 as photocatalyst is presented in detail and an overview of photocatalytic reactor systems is given. UV radiation is mentioned and described in detail as an important component of the photocatalytic process, and the magnetic field is discussed as a possible tool in the photocatalytic process. In the experimental part, the intensification of the photocatalytic degradation of imidacloprid is carried out using a permanent magnet, and in this paper all the obtained results are listed, and a discussion based on the obtained data is presented. At the end, all aspects of the work are summarized in a brief and clear conclusion.