Rapid photocatalytic gold recovery from industrial cyanide-based gold plating wastewater via TiO<inf>2</inf>/WO<inf>3</inf> nanocomposites: Role of mixed hole scavengers and operating conditions
7
Issued Date
2023-10-01
Resource Type
eISSN
22133437
Scopus ID
2-s2.0-85166661853
Journal Title
Journal of Environmental Chemical Engineering
Volume
11
Issue
5
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of Environmental Chemical Engineering Vol.11 No.5 (2023)
Suggested Citation
Hunsom M., Kunthakudee N., Ramakul P., Serivalsatit K., Sangkhanak S., Wongyongnoi P., Pruksathorn K. Rapid photocatalytic gold recovery from industrial cyanide-based gold plating wastewater via TiO<inf>2</inf>/WO<inf>3</inf> nanocomposites: Role of mixed hole scavengers and operating conditions. Journal of Environmental Chemical Engineering Vol.11 No.5 (2023). doi:10.1016/j.jece.2023.110534 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/88305
Title
Rapid photocatalytic gold recovery from industrial cyanide-based gold plating wastewater via TiO<inf>2</inf>/WO<inf>3</inf> nanocomposites: Role of mixed hole scavengers and operating conditions
Other Contributor(s)
Abstract
A rapid photocatalytic gold recovery from the industrial cyanide-based gold plating wastewater was carried out via TiO2/WO3 nanocomposites synthesized by hydrothermal method. Effects of different weight ratios of TiO2 and WO3 in nanocomposites, types of hole scavenger (Na2S2O3, C2H5OH, Na2S2O3/C2H5OH), concentrations of Na2S2O3 (0–100 mM) and photocatalyst loading (1–4 g/L) were examined. The preliminary results demonstrated that the employed wet chemical process induced a well formation of TiO2/WO3 nanocomposites with better textural properties as well as a more negative band position than the pristine WO3. The presence of mixed hole scavengers of Na2S2O3 and C2H5OH played a crucial role on the photocatalytic gold recovery from the cyanide-based gold plating wastewater. A more stable form of gold cyanide ([Au(CN)2]-) was altered to a less stable form ([Au(S2O3)2]3-) by the addition of Na2S2O3. At the end, approximately 85.9 % and 98.2 % of gold were respectively recovered within 180 and 300 min via the T6/WO3 nanocomposite in the presence of 10 mM Na2S2O3 and 20 vol% C2H5OH at photocatalyst loading of 2 g/L and light intensity of 3.20 mW/cm2. The photocatalytic gold recovery was significantly improved via the 1st reused T6/WO3 nanocomposite, in which 99.9 % of gold was recovered within 180 min. The obtained results can pave the way for the design of novel TiO2/WO3 nanocomposites for gold recovery as well as the strategy of waste management for the practical operation.