A comparative study of quantum yield and electrical energy per order (E(Eo)) for advanced oxidative decolourisation of reactive azo dyes by UV light.
This paper evaluates the quantum yield and electrical energy per order (E(Eo)) efficiency of Reactive Orange 4 (RO4) and Reactive Yellow 14 (RY14) azo dyes by three advanced oxidation processes (AOPs). Both dyes were completely decolourised by all these processes. The relative decolourisation efficiencies of these processes were in the following order: Fe(2+)/H(2)O(2)/UV>UV/TiO(2)>UV/H(2)O(2). The low efficiency of UV/H(2)O(2) process is mainly due to low UV absorption by hydrogen peroxide at the 365nm. The figure of merit E(Eo) values showed that UV/H(2)O(2) process consumes more electrical energy than the other two processes. The electrical energy consumption is in the following order: UV/H(2)O(2)>UV/TiO(2)>Fe(2+)/H(2)O(2)/UV. At low initial dye concentration higher quantum yield was observed in UV/TiO(2) process, whereas in photo-Fenton process higher quantum yield was observed at high initial dye concentration. The structure of dye molecule also influences the quantum yield and E(Eo) value.
Muruganandham
M
M
Department of Chemistry, Annamalai University, Annamalai Nagar, India.
Selvam
K
K
Swaminathan
M
M
D001391:Azo Compounds / Q000737:chemistry* / Q000528:radiation effects*; D003116:Color; D004396:Coloring Agents / Q000737:chemistry* / Q000528:radiation effects*; D004560:Electricity; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D010084:Oxidation-Reduction; D011720:Pyrazoles / Q000737:chemistry* / Q000528:radiation effects*; D013463:Sulfuric Acid Esters / Q000737:chemistry* / Q000528:radiation effects*; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects; D018508:Water Purification
D001391:Azo Compounds; D004396:Coloring Agents; D011720:Pyrazoles; D013463:Sulfuric Acid Esters; D014874:Water Pollutants, Chemical; C514309:reactive yellow 14; C109260:reactive orange; C009495:titanium dioxide; D006861:Hydrogen Peroxide; D014025:Titanium; D007501:Iron