Photo-oxidative degradation of Direct Yellow 12 using hydrogen peroxide

Abstract

<span style="font-size:12.0pt;line-height: 115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">The photo-oxidation process by combination of UV light and H₂O₂ generates hydroxyl radicals which are capable of oxidising many organic compounds which are refractory type and difficult to oxidize by conventional chemical treatment. In the present study, photo-oxidation of Direct Yellow 12 (DY 12) dye has been carried out in an annular type photoreactor using 8 Watt low pressure mercury lamp along with H₂O₂ as oxidant. Synthetic dye solutions of 50 mg/L concentration were used to carry out the experiments. Complete dye degradation and colour removal took place within 30 min with 85-95 % reduction in COD (Chemical Oxygen Demand) value. The process of degradation is dependent upon the <i>p</i>H of the solution.</span>