Degradation of microcystin-LR toxin by Fenton and Photo-Fenton processes.
This study reports a laboratory investigation of the degradation of microcystin-LR using Fenton (Fe2+ + H2O2) and Photo-Fenton processes. The effect of hydrogen peroxide concentration on the Fenton reaction rate was investigated at constant Fe2+ concentrations. It was observed that at low concentrations of hydrogen peroxide (0.25-0.5 mM), the extent of microcystin-LR degradation was low, even after prolonged reaction time (up to 600 min). Higher H2O2 concentrations (2.5-5 mM) resulted in higher degradation rates that yielded microcystin-LR degradation as high as 60% in approximately 180 min. However, the highest degradation efficiency of the toxin was achieved during the Photo-Fenton process in which UV radiation was involved. In the Photo-Fenton process, the removal efficiency of microcystin-LR reached 84% in the first 25 min and 100% in approximately 35-40 min of irradiation. These results are encouraging for the application of efficient UV-based advanced oxidation technologies for toxin removal from drinking water sources.
Bandala
Erick R
ER
Instituto Mexicano de Tecnología del Agua, Paseo Cuauhnáhuac 8532, Jiutepec, Morelos 62550, México. ebandala@tlaloc.imta.mx
Martínez
Dolores
D
Martínez
Evaristo
E
Dionysiou
Dionysios D
DD
D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000737:chemistry*; D005618:Fresh Water; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008387:Marine Toxins; D008800:Mexico; D052998:Microcystins; D010456:Peptides, Cyclic / Q000737:chemistry*; D010777:Photochemistry; D013997:Time Factors; D014466:Ultraviolet Rays; D018508:Water Purification / Q000379:methods*
C045076:Fenton's reagent; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; D006861:Hydrogen Peroxide; D007501:Iron; C057862:cyanoginosin LR