Method for detecting ozone in water by UV-1100 ultraviolet spectrophotometer - Master's thesis - Dissertation

Application Method of Ultraviolet Spectrophotometer for Detecting Ozone in Water

Keywords: aesthetic instrument, UV-visible spectrophotometer, ozone detection, analytical method, UV-1100, UV-1300 Ozone (O₃) was first recognized by people in the 1840s. Composed of three oxygen atoms, it has a high oxidation potential, making it an effective oxidizer capable of degrading impurities and killing bacteria, viruses, and other pathogens. For example, it can eliminate up to 98% of certain aquatic organisms like beetle larvae and rotifers. The use of ozone for sterilization dates back to 1886 in France, and by 1906, the Nice Water Plant in France became the first large-scale facility using ozone treatment. This marked the beginning of modern ozonation in water treatment. Since the 1980s, many developed countries have adopted ozone treatment on a large scale, including Canada’s Montreal plant, which treated 2.3 million tons of water daily. In China, some water plants, such as those in Beijing and Kunming, started using ozone around the same time. However, compared to global standards, China's adoption of ozone technology remains limited due to high costs and energy consumption. Despite this, bottled water companies in China have widely embraced ozone treatment because of its ability to meet strict quality standards and ensure safety. One of the key advantages of ozone is that it doesn’t produce harmful byproducts like chlorine does. Excess ozone quickly decomposes, making it a safer option for disinfection. However, improper application—such as using low-quality generators or insufficient contact time—can lead to ineffective results and even health risks. To achieve effective ozone sterilization, two main factors must be considered: the concentration of dissolved ozone and the contact time between ozone and water. Research by Professor Ma Yilun showed that the rate of bacterial inactivation depends on both the ozone concentration and the duration of exposure. This relationship is described by a kinetic equation involving parameters like temperature, pressure, and flow rate. In practice, the design of the contact device plays a crucial role. Common methods include bubble columns, venturi injectors, and mechanical mixers. Each has its own advantages and limitations, but all aim to maximize ozone absorption and ensure proper mixing. Measuring ozone concentration is also essential for monitoring effectiveness. Methods such as iodometric titration, ultraviolet absorption, and electrochemical analysis are commonly used. Among these, the DPD colorimetric method is popular due to its simplicity and accuracy, especially for on-site testing. Overall, ozone is a powerful tool for water treatment, but its success depends on proper implementation, accurate measurement, and consistent maintenance. As technology advances, its use is expected to grow, particularly in industries where water purity is critical. Keywords: aesthetic instrument, UV-visible spectrophotometer, ozone detection, analytical method, UV-1100, UV-1300