Photoassisted electrochemical degradation of organic pollutants on a DSA type oxide electrode: process test for a phenol synthetic solution and its application for the E1 bleach Kraft mill effluent.
In this paper, the performance of a photoassisted electrolysis process, for the degradation of organic pollutants, is investigated. Results obtained in this work have shown that the thermally prepared anode of titanium, coated with 70TiO2/30RuO2, exhibits photoactivity and may be used for the treatment of effluents. A synthetic phenol aqueous solution and a real paper mill industry effluent were treated. Kinetic analysis showed a synergetic effect of electrolysis and photocatalysis and degradation rates are an order of magnitude greater than the sum of the results reached by using both processes individually. Using a 125 W mercury bulb and 20 mA cm-2, the phenol concentration decayed 85% in 90 min and 70% reduction of TOC was obtained. In the application of the treatment process for the degradation of the E1 bleach Kraft mill effluent, total phenols were practically eliminated in a short period of processing time, and color, usually resistant to biological treatment, was reduced to 10% from its initial value measured in terms of absorbance. Reductions of AOX, COD, and BOD by 25%, 30%, and 35%, respectively, were also observed.
Pelegrini
R T
RT
Faculdade de Engenharia Mecânica, Universidade Estadual de Campinas, Caixa Postal 6122-13083-970, Campinas, SP, Brazil.
Freire
R S
RS
Duran
N
N
Bertazzoli
R
R
D002384:Catalysis; D004202:Disinfectants / Q000737:chemistry*; D004566:Electrodes; D004572:Electrolysis; D007221:Industry; D007700:Kinetics; D009930:Organic Chemicals; D010209:Paper; D019800:Phenol / Q000737:chemistry*; D010777:Photochemistry; D014025:Titanium; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis*
D004202:Disinfectants; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D019800:Phenol; D014025:Titanium