224-230The degradation of
commonly used textile dye reactive red 2 in an aqueous solution by means of
photocatalysis using ZnO in the form of slurry is studied. The influence of
initial concentration of the dye, pH of the reaction mixture. Catalyst loading,
the presence of oxygen, hydrogen peroxide, and potassium persulphate on the
degradation rate is observed. When concentration of the dye increases from 60
to 140 ppm, the rate constants vary between 0.055 and 0.019 min-1. The
disappearance of the dye follows approximately pseudo-first order kinetics. For
an irradiation time of 60 min, 86 per cent COD reduction is noted, whereas 100
per cent degradation observed at 300min of irradiation time. The oxidising
agents (oxygen, hydrogen peroxide and potassium persulphate) enhance the
degradation rate of the dye. Carbonate ions present in dye solution inhibit the
degradation rate of the dye. This method suggests the possible use of ZnO photocatalysed
degradation of textile dye present in wastewater