Claims
- 1. In a method for the photocatalytic treatment with titanium dioxide of aqueous mixtures of pollutants, wherein said mixtures are subjected to irradiation while circulating within a reactor formed by a hollow space of thickness of not more than 5 cm, the inner wall of said jacket being the outer wall of a lamp emitting radiation having a wavelength less than 400 nm, the improvement comprises:
- that the titanium dioxide is in the form of microspheres having a diameter of from 0.1 mm to 5.0 mm and that said microspheres are retained within said jacket and stirred by the flow of said mixtures, said microspheres prepared by
- (a) preparing an alcoholic solution of an organometallic compound of titanium;
- (b) optionally thickening said solution by the addition of an organic polymer;
- (c) subdividing the solution into droplets which are solidified into gel particles by contact with an alkaline solution in an anhydrous environment, or in an environment with a controlled water content;
- (d) drying and/or calcining the gel particles to form said microspheres.
- 2. The method of claim 1, in which said lamp emits at least a fraction of its radiation at a wavelength within the range of 320 to 380 nm.
- 3. The method of claim 1, in which said lamp is a high-pressure mercury vapor or high-pressure xenon vapor arc lamp.
- 4. The method of claim 1 in which air or oxygen is injected into the aqueous mixture of pollutants.
Priority Claims (2)
Number |
Date |
Country |
Kind |
20446 A/89 |
May 1989 |
ITX |
|
21038 A/89 |
Jun 1989 |
ITX |
|
Parent Case Info
This application is a continuation of application Ser. No. 07/807,758, filed on Dec. 17, 1991, now abandoned, which is a continuation of application Ser. No. 07/521,357 filed on May 8, 1990 now abandoned.
US Referenced Citations (15)
Foreign Referenced Citations (4)
Number |
Date |
Country |
PH7074 |
Jul 1987 |
AUX |
0306301 |
Mar 1989 |
EPX |
3245811 |
Jun 1983 |
DEX |
60-61094 |
Apr 1985 |
JPX |
Non-Patent Literature Citations (2)
Entry |
Water Research, vol. 20, No. 5, pp. 569-578, May, 1986, R. W. Matthews, "Photo-Oxidation of Organic Material In Aqueous Suspensions of Titanium Dioxide". |
Patent Abstracts of Japan, vol. 12, No. 258 (C-513), Jul. 20, 1988, & JP-A-63042793, M. Hosokawa, et al., "Method For Cleaning Fluid By Utilizing Titanium Oxide", Feb. 23, 1988. |
Continuations (2)
|
Number |
Date |
Country |
Parent |
807758 |
Dec 1991 |
|
Parent |
521357 |
May 1990 |
|