vol.62-5 (2025/1/31)

Cleaning and modification equipment use ultraviolet rays and evaluation of modification using electron beam

This paper provides an overview of technologies, equipment and application that use ultraviolet rays (UV) and electron beam (EB) radiation to clean organic contaminants from surfaces and modify surface properties. UV radiation generates ozone and active oxygen, which effectively clean and modify surfaces. EB radiation, with its higher energy efficiency, allows for rapider process. This paper summarizes the principles of UV and EB cleaning and modification, as well as equipment and application examples.

Photo cleaning technology by Xe₂^* excimer lamp and its application

Ultraviolet light (UV light) has relatively high photon energy, and it has efficient productivity of reactive oxygen species and excited molecules. Therefore, UV light has become widespread as UV photo cleaner for production line of flat panel display and semiconductor. Xe₂^* excimer lamp (excimer lamp) and Low-pressure mercury lamp are commonly used for UV photo cleaner. Especially, excimer lamp generates reactive oxygen species more efficiently than Low-pressure mercury lamp, so excimer lamp is applied to production line in several fields. For instance, Li-ion batteries, perovskite solar cells and inactivation of endotoxin. In addition, excimer lamp can occur various photochemical reactions by its high photon energy. Excimer lamp is anticipated for additional applications.

UV technology and latest trends in water treatment

Water treatment technology is essential to produce drinking water and industrial water, and research into water recycling and wastewater treatment technologies is progressing toward the realization of a sustainable society. Among these, ultraviolet (UV) technology was developed to remove bacteria and organic matter in water and is still used today for efficient water purification. UV sterilization and UV oxidation processes use light with wavelengths of 254 nm and 185 nm to kill bacteria and oxidize organic matter. These technologies are being introduced into pure water production systems for pharmaceutical, food, electronic component and semiconductor manufacturing, and the water quality after UV oxidation treatment can be reduced to less than 1 μg/L in terms of total organic carbon (TOC). Each method has its own issues, and UV sterilization is not suitable for sterilizing the entire system, so effective sterilization can be achieved by combining multiple sterilization methods. Issues with UV oxidation treatment include the by-product hydrogen peroxide and the difficulty of efficiently oxidizing and decomposing persistent organic matter. Other issues include the use of Hg lamps, which is not good for environmental impact, and high running costs. To solve these issues, automatic light control systems and UV-LEDs are being developed. In recent years, there have also been efforts to break down PFAS, which have come under concern due to their bad effects on the environment and human body. We hope to establish technology that simultaneously reduces environmental impact and operating costs.

Development of air purifiers equipped with UV-C LED

This paper focuses on ultraviolet (UV) technology integrated into air purifiers, specifically discussing the utilization and effects of UV-C LEDs. In recent years, interest in removing airborne pathogens have increased significantly due to the COVID-19 pandemic, highlighting the importance of air purification technology. UV-C LEDs, emitting UV light at a wavelength of 265nm, are highly effective in inhibiting the growth of various microorganisms by acting on their DNA/RNA. This paper first explores the inactivation effects of UV light on microorganisms and viruses, next discusses the current state of the UV-C LED market, and finally presents specific development examples of air purifiers equipped with UV-C LEDs. Furthermore, considerations on the safety design of products are also included. Through this discussion, the potential power of UV-C LEDs in air-conditioning equipment and other applications, and how their technological advancements contribute to public health improvement, are examined.
As such, readers will gain a deeper understanding of the crucial role that UV-C LED technology will play in the future development of air purification technology and the benefits brought by its technological progress.

Decomposition of organic air pollutants in air using advanced oxidation processes

One of the advanced oxidation processes (AOP) is chemical treatment using ultraviolet (UV) light. Vacuum ultraviolet (VUV) can effectively decompose gaseous and particulate organic pollutants in air by photolysis or active species generated by photochemical reactions. However, high concentrations of ozone, water-soluble organic compounds including particulate matter, and water-insoluble organic compounds are generated as degradation products. In order to establish this method as an air purification technique, it is necessary to consider the complete decomposition (mineralization and detoxification) of these degradation products. Since active species are generated when ozone is decomposed, it is effective to use these active species to simultaneously decompose ozone and the degradation products. On the other hand, it is effective to temporarily trap water-soluble degradation products in water and then use an AOP such as UV₂₅₄/H₂O₂ to promote complete decomposition without generating ozone. In addition, by performing AOP in the presence of mist, it is possible to decompose organic pollutants while capturing the degradation products. Here, we provide an overview of our previous studies on the chemical treatment of organic pollutants in air using UV light.

Anti-virus, anti-bacteria and anti-allergy ability of photocatalysts

Many emerging and re-emerging infectious diseases have caused tremendous damage to lives, livelihoods, and the economy worldwide. Overcoming these infectious diseases is one of the greatest challenges of the 21st century. Allergic diseases are also major public health concern worldwide. Therefore, novel methods for treating infectious and allergic diseases are essential. Maintaining a clean-living environment is essential for disease prevention. Photocatalysts can degrade organic matter while being harmless to human health. Thus, they have attracted significant attention as potential antiviral and antimicrobial agents. In addition, photocatalyst inactivate not only virus and bacteria but the allergen. Therefore, photocatalyst is suitable tools for cleaning the environment. This review outlines the antiviral, antimicrobial, and anti-allergenic effects of photocatalysts. Especially, we have discussed the inactivation of SARS-CoV-2 in liquids and aerosols, elimination of Legionella pneumophila in liquids, decomposition of its endotoxin, decomposition of cat and dog allergens, and elimination of their allergenicity using photocatalysts based on our previous reports. Furthermore, we discuss future perspectives on how photocatalysts can purify living environments.

Relevant standards (GMP, HACCP)

In this lecture on BCR, we will introduce the relevant standards, namely, pharmaceutical GMP and food HACCP. In both cases, the main focus is on management standards.
Therefore, although it does not necessarily coincide with the BCR related standards, it shows the basic concept and rational and efficient operation to achieve and consistently maintain and guarantee the product quality that users desire, and to ensure the safety of products for human consumption.