The efficiency of photochemical degradation of pollutants in water treatment facilities can be improved by optimizing various factors and implementing advanced techniques. Some of these factors and techniques include:1. Light source: The choice of light source is crucial for efficient photolysis. Using high-intensity light sources, such as UV lamps or LEDs, can enhance the photodegradation process. Additionally, optimizing the wavelength of light to match the absorption spectra of the target pollutants can improve the efficiency of the process.2. Photocatalysts: The use of photocatalysts, such as titanium dioxide TiO2 , can significantly enhance the photochemical degradation of pollutants. These photocatalysts generate reactive oxygen species ROS upon light irradiation, which can effectively break down pollutants. The photocatalyst's surface area, crystalline structure, and doping with other elements can be optimized to improve its performance.3. Advanced oxidation processes AOPs : Combining photocatalysis with other oxidation processes, such as ozonation or hydrogen peroxide addition, can lead to the formation of highly reactive hydroxyl radicals, which can further improve the degradation efficiency of pollutants.4. Reaction conditions: Factors such as pH, temperature, and pollutant concentration can affect the photolysis rate. Optimizing these conditions can enhance the degradation process. For example, adjusting the pH to match the pKa of the pollutant can improve its solubility and interaction with the photocatalyst.5. Reactor design: The design of the photoreactor can significantly impact the efficiency of the process. Factors such as light penetration, mixing, and mass transfer should be considered when designing a photoreactor. For example, using a thin-film reactor can improve light penetration and mass transfer, leading to enhanced photodegradation.6. Pre-treatment methods: Implementing pre-treatment methods, such as adsorption or coagulation, can help remove high molecular weight pollutants or suspended solids, which can interfere with the photochemical degradation process.In summary, improving the efficiency of photochemical degradation of pollutants in water treatment facilities can be achieved by optimizing the light source, photocatalyst, reaction conditions, and reactor design, as well as implementing advanced oxidation processes and pre-treatment methods.