Development of new technologies for wastewater treatment

Alcohol is used to remove impurities from the surface of semiconductors or electronics during the manufacturing process, and wastewater containing alcohol is treated using reverse osmosis, ozone and biological decomposition. Although this method can reduce the alcohol concentration in wastewater, it is not effective in completely decomposing the alcohol in wastewater with low alcohol concentration. This is because alcohol is miscible with water, and physical methods cannot be used to completely separate alcohol from alcohol, and chemical or biological treatment is extremely inefficient. For this reason, wastewater with low alcohol concentration is mainly treated by diluting it with a large amount of clean water before discharge.

Korea Institute of Science and Technology (KIST, Director Seok-Jin Yoon) announced that Dr. Sang Hoon Kim and Dr. Gun-hee Moon of the Center for Extreme Materials Research has developed a photocatalyst that can completely decompose trace amounts of alcohol in water in a short period of time by adding a very small amount of copper to iron oxide, which is used as a catalyst in advanced oxidation processes.

The research team employed the Fenton oxidation method, which uses an oxidant and a catalyst in an advanced oxidation process for water treatment. In other advanced oxidation process (AOP) studies, alcohols are commonly used as reagents to verify the generation of free radicals during Fenton oxidation, which are the targets for removal from semiconductor wastewater in this study.

This water treatment technology is expected to significantly reduce the cost and water input of semiconductor wastewater treatment. In the past, in order to reduce the 10 ppm alcohol concentration in wastewater to below 1 ppm, dilution of the wastewater required a volume of clean water 10 times larger than the wastewater being treated.

If the photocatalyst developed by KIST is used for water treatment, water resources can be saved. The research team applied the photocatalyst to wastewater from a semiconductor factory to demonstrate that levels of alcohol breakdown similar to those observed in the laboratory can be achieved in industrial practice.

“If large-scale semiconductor production lines are established, we expect the demand for semiconductor wastewater treatment to grow rapidly,” said Dr. gold. “Our findings will provide a solution to efficiently treat semiconductor wastewater using fewer resources and at a lower cost,” he added.

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Established in 1966, KIST is the first government-funded research institution in South Korea to establish a technology-based national development strategy to disseminate various industrial technologies to promote the development of major industries. KIST is now elevating the status of Korean technology by pursuing world-leading innovative R&D. For more information, visit KIST’s website: https://eng.kist.re.kr/

The research was funded by the Korea Materials Research Center (Minister Jong-Ho Lee) of the Ministry of Science and ICT, the Environmental Technology Development Program of the Ministry of Environment of Korea, and the Foundation Program of the Korea Institute of Science and Technology. Relevant research papers were published in the Journal of Chemical Engineering, a well-known academic journal in the field of chemical engineering and the environment.