UV-induced decolourization of acid alizarine violet N by homogeneous advanced oxidation processes

The decolourization of an azo dye acid alizarine violet N by photoactivated hydrogen peroxide and sodium periodate (UV/H2O2 and UV/IO4−) has been studied in a small scale batch photoreactor. The wavelength of the UV source used was 254 nm. The treatment was carried out under different concentrations of peroxide (34–272 mg l−1) and periodate (5.35–32.1 mg l-1). The results obtained showed that increasing the concentration of peroxide or periodate resulted in a higher decolourization rate of the dye. The disappearance of the dye followed first-order kinetics. Reaction rate orders with respect to the oxidant species were 0.93 and 1.6 for respectively, peroxide and periodate. Kinetic parameters of the photodegradation process such as apparent rate constant (kapp), half life time (t1/2) and initial reaction rate (Rinitial) were calculated.