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Open AccessArticle

Production of the Hydroxyl Radical and Removal of Formaldehyde by Calcined Green Tuff Powder and Tile

1
College of Resources, Environment and Materials, Guangxi University, 100 Daxue Road, Nanning 530004, China
2
Graduate School of Engineering, the University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
3
Korea Institute of Geoscience and Mineral Resources (KIGAM), 92 Gwahang-no, Yuseong-gu, Daejeon 305-350, Korea
4
Doctoral Programs in Medical Sciences, The University of Tsukuba, Tsukuba city, Ibaraki 305-8575, Japan
5
Towada Green-tuff AgroScience Co., Ltd. Meguro-ku, Tokyo 152-0011, Japan
*
Author to whom correspondence should be addressed.
Sustainability 2019, 11(12), 3390; https://doi.org/10.3390/su11123390
Received: 10 May 2019 / Revised: 15 June 2019 / Accepted: 18 June 2019 / Published: 19 June 2019
Waste green tuff powder produced by cutting Towada stone has been utilized to eliminate formaldehyde related to greenhouse gases. The green tuff contains TiO2 on zeolite as observed by scanning electron microscope (SEM)t. The green tuff is a natural catalyst that can produce hydrogen peroxide with moisture and oxygen with light. The optimum temperature for calcination of the green tuff powder has been investigated in order to produce hydroxyl radicals from the decomposition of hydrogen peroxide using ultraviolet light (UV) and no light. The green tuff calcined at 800 °C showed a high decomposition rate of hydrogen peroxide with no UV light under high alkaline conditions when measured by using ESR. With UV light, the optimum temperature for calcination of green tuff powder in order to reduce the hydroxyl radical was also 800 °C. Next, the powder calcined at 800 °C was used to produce the tile by compression and heating, and then the formaldehyde adsorption rate was measured. The green tuff powder calcined at 800 °C showed a high adsorption rate, similar to that of the activated carbon. The tiles formed at 40 MPa and heated at 1100 °C were the strongest and also showed adsorption with respect to formaldehyde. The adsorbed formaldehyde on the green tuff tile and powder was possibility decomposed by the hydroxyl radical produced by photocatalysis. View Full-Text
Keywords: green tuff; towada stone; calcination; recycle; tile; hydrogen peroxide; radical; ESR; adsorption; formaldehyde; UV; photocatalysis green tuff; towada stone; calcination; recycle; tile; hydrogen peroxide; radical; ESR; adsorption; formaldehyde; UV; photocatalysis
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MDPI and ACS Style

Fujita, T.; Zhang, L.; Dodbiba, G.; Anh, J.-W.; Wei, Y.; Kurokawa, H.; Matsui, H.; Yamamoto, S.; Kawaguchi, H. Production of the Hydroxyl Radical and Removal of Formaldehyde by Calcined Green Tuff Powder and Tile. Sustainability 2019, 11, 3390.

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