Photocatalytic discoloration kinetics of Reactive Black 5 (RB5), a vinylsulfone dye, has been studied spectrophotometrically by following the decrease in dye concentration with time at ambient conditions using a flow ...Photocatalytic discoloration kinetics of Reactive Black 5 (RB5), a vinylsulfone dye, has been studied spectrophotometrically by following the decrease in dye concentration with time at ambient conditions using a flow loop reactor. UV lump, Black Light Blue (BLB) emitting at maximum wavelength of 365 nm and Ahlstrom Research Service paper consistent of TiO2 P500 coated on non woven paper was used respectively as source of UV light and photocatalyst. At natural pH, the result shows that photolysis of RB5 and its adsorption in the presence of photocatalyst was negligible while the photocatalytic oxidation (PCO) permits 30.8% of RB5 degradation. The degradation of dye was studied under a variety of conditions such as volumetric flow rate, initial pH, photocatalyst reuse, and in the presence of electron acceptor such as sodium persulphate ((Na)2S2O8). The degradation rates were found to be strongly influenced by all the above parameters. The circulation flow rate of 108 L/h was the best. The rate constant calculated when the initial pH was varied shows that pH 3 was more favorable for RB5 removal. Peroxydisulphate ions have the strong effect on RB5 discoloration even in dark without and with photocatalyst. When UV light was used in the presence of photocatalyst, 50 min was enough for quasi-total removal of RB5 with (0.2 M).展开更多
文摘Photocatalytic discoloration kinetics of Reactive Black 5 (RB5), a vinylsulfone dye, has been studied spectrophotometrically by following the decrease in dye concentration with time at ambient conditions using a flow loop reactor. UV lump, Black Light Blue (BLB) emitting at maximum wavelength of 365 nm and Ahlstrom Research Service paper consistent of TiO2 P500 coated on non woven paper was used respectively as source of UV light and photocatalyst. At natural pH, the result shows that photolysis of RB5 and its adsorption in the presence of photocatalyst was negligible while the photocatalytic oxidation (PCO) permits 30.8% of RB5 degradation. The degradation of dye was studied under a variety of conditions such as volumetric flow rate, initial pH, photocatalyst reuse, and in the presence of electron acceptor such as sodium persulphate ((Na)2S2O8). The degradation rates were found to be strongly influenced by all the above parameters. The circulation flow rate of 108 L/h was the best. The rate constant calculated when the initial pH was varied shows that pH 3 was more favorable for RB5 removal. Peroxydisulphate ions have the strong effect on RB5 discoloration even in dark without and with photocatalyst. When UV light was used in the presence of photocatalyst, 50 min was enough for quasi-total removal of RB5 with (0.2 M).
