Publication Date:
2008-09-04
Description:
Our main purpose was to study the disinfection of a secondary wastewater anaerobic effluent by a combined photolytic-photocatalytic continuous reactor using solar irradiation. This reactor had a rectangular section and included back-and-forth-flow internal channels. It comprised two compartments: the first one (6.4l) corresponded to photolytic disinfection with a 1h residence time and the second one (12.8l) corresponded to photocatalytic disinfection with a 2h residence time. The photocatalyst used was Degussa P-25 TiO2 fixed on an ordinary tile. By use of this reactor between 9:00h and 16:00h with a water flow rate of 3.4lh−1, the total coliform concentration diminished by four orders of magnitude, reaching values lower than 102MPN (most probable number)/100ml, which are below the regulation. Even if photolysis was important, this single process did not permit one to obtain an outlet coliform concentration below 103MPN∕100ml; however, it helped to improve the photocatalytic performance. A decrease in chemical oxygen demand (COD) was also observed in the photocatalytic compartment, illustrating an oxidation of organic pollutants. In parallel, batch experiments were carried out to get information about the residence times, the photocatalytic performance of TiO2 fixed on an ordinary tile, and the photolytic effect. The results suggest that this low cost and easy to operate treatment system could be a promising alternative to usual systems for the decrease in COD and the disinfection of domestic wastewaters.
Print ISSN:
0199-6231
Electronic ISSN:
1528-8986
Topics:
Energy, Environment Protection, Nuclear Power Engineering
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