Photodegradation of Organic Compounds in Tap Water using High Reactive Titanium Dioxide

• Published in: Journal of Environmental Chemistry Vol. 15; no. 4; pp. 847 - 853
• Main Authors: ISHIKAWA, Seiichi, MATSUOKA, Yasushi, HASHIMOTO, Akio, HANADA, Yoshifumi, SHINOHARA, Ryota, KADOKAMI, Kiwao, TANIZAKI, Teiji
• Format: Journal Article
• Language: English
• Published: Japan Society for Environmental Chemistry 2005
• Subjects: formaldehyde; THM; TiO2; TOX; UV irradiation
• ISSN: 0917-2408; 1882-5818
• DOI: 10.5985/jec.15.847

Nano-structured TiO2, which is developed as one of high reactive type photocatalyst was employed to remove organic compounds, for trihalomethane (THM), total organic halogenate (TOX), total organic carbon (TOC) and formaldehyde in tap water. Especially, chloroform, main substance of THM, and TOC which is huge molecular compounds passed tap water treatment process from raw water, are known to be not degradable easily by advanced oxidation process (AOP), for example ozonation. In this report, photodegradtion experiment, using nano-structured TiO2, chlorofom and TOC could be degradated immediately. The reaction rate of TiO2photodegradation of chloroform in tap water was 1/3 compared to that quantified by same experiment in Mili-Q water. Because it is considered that radical scavenger, for example CO2-3, disturb the reaction. TOX substances which are generated by chlorination of tap water treatment process, were removed by UV irradiation and TiO2photodegradation, easily. Some reports said that the concentration of formaldehyde increase on the process of TiO2photodegradation for tap water and raw water. But in our experiment, the concentration of formaldehyde did not change, and increased from 7 ng/mlto 30 ng/mlwith 3h on the only UV irradiation experiment.