Method for treating hexavalent chromium-containing aqueous solution
US9802841B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 2014 |
| Grant date | Oct 31, 2017 |
| Priority date | — |
| Expiry date | Jun 15, 2035 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/37
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Provided is a method for treating a hexavalent chromium-containing aqueous solution by water treatment employing a titanium dioxide photocatalyst that is excellent in both photocatalytic activity and solid-liquid separation performance. The method according to the present disclosure includes the steps of: adding catalyst particles to the aqueous solution; reducing hexavalent chromium by irradiating the aqueous solution with light having a wavelength of 200 nanometers or more and 400 nanometers or less while stirring the catalyst particles in the aqueous solution; and stopping the stirring and separating the catalyst particles from the aqueous solution by sedimentation. Each catalyst particle is composed only of a titanium dioxide particle and a zeolite particle, the titanium dioxide particle is adsorbed on the outer surface of the zeolite particle, the zeolite particle has a silica/alumina molar ratio of 10 or more, and the catalyst particles are contained in the aqueous solution at a concentration of 0.4 grams/liter or more and 16 grams/liter or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.