Removal of EDTA by UV-C/hydrogen peroxide.
Mineralization of a 5 mM EDTA solution at pH 3 was evaluated via TOC removal under UV-C irradiation in the presence of H2O2 at various conditions. The highest TOC removal (78%) was obtained using a 40:1 H2O2/EDTA molar ratio, after 540 min irradiation. However, a 20:1 ratio gave slightly lower results, being economically more attractive. Best results of TOC removal were obtained under pH controlled conditions. Addition of TiO2 (1 g l(-1)) was detrimental, even in the presence of H2O2, indicating that at this concentration, TiO2 inhibits the mineralization, probably by scattering or by screening of the light.
Baeza
C
C
Laboratorio de Recursos Renovables, Facultad de Ciencias Químicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
Rossner
A
A
Jardim
W F
WF
Litter
M I
MI
Mansilla
H D
HD
D002614:Chelating Agents / Q000737:chemistry / Q000302:isolation & purification*; D004492:Edetic Acid / Q000737:chemistry / Q000302:isolation & purification*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D016877:Oxidants / Q000737:chemistry*; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*
D002614:Chelating Agents; D007220:Industrial Waste; D016877:Oxidants; D004492:Edetic Acid; D006861:Hydrogen Peroxide