Degradation of Alizarin Yellow R Using Ultraviolet/Hydrogen Peroxide (UV/H202) Advanced Oxidation Process

The homogeneous advanced oxidation process of Ultraviolet (UV) radiation in
presence of Hydrogen Peroxide (H2O2) was utilized to degrade Alizarin Yellow R,
one of the most used azo dyes in the textile industry. The UV/H2O2 oxidation
process is a feasible and efficient alternative for wastewater treatment from
recalcitrant compounds such as azo dyes. In this study, the effects ofinitial hydrogen
peroxide concentration, imtial dye concentration, initial pH and temperature were
examined to determine the optimum operating conditions that give the maximum rate
of degradation. Complete decolourization was achieved in the relatively short time of
60-80 minutes of irradiation. The degradation efficiency increased with increasing
initial concentration of H2O2 up to an optimum value. Faster decolourization was
achieved at medium acidic and neutral pH environment ranging from p 5-7 and at
high temperature. The degradation reaction was found to follow the first order
kinetics with respect to the dye concentration. The Box-Behnken response surface
methodology (RSM) was utilized for mathematical modelling for degradation rate
and used to optimize the operating condition of this degradation process. The
optimum operating conditions were imtial H2O2 concentration of0.25M, initial pH of
4.59 and temperature of 50°C. Under such conditions, the proposed model of Box-
Behnken fitted very well with the experimental data with R =0.989. In general, the
result indicates that the UV/H2O2 technology proved to have good potential for
removing dyestuff from wastewater but further treatment might be necessary to
achieve complete mineralization ofthe organic intermediates.