Employing UV/H2O2 process for degradation of 2,4-Diaminotoluene in synthetic wastewater

Background & Aims of the Study: Toluene-2, 4-diamine (TDA) is a famous carcinogenic aromatic amine that is mostly employed as an intermediate in the production of dyes and toluene diisocyanate. In this study, degradation and mineralization of TDA were investigated by UV/H2O2 process. Materials & Methods: This study is an experimental investigation on a laboratory scale. The study performed on synthetic wastewater that holds TDA. The influence of different operating variables such as the initial dosage of H2O2 and TDA, additive salts and pH was investigated. The optimization of variables was done by one factor at a time method. Results: The results specify that the degradation efficiency relies on the H2O2 and TDA concentrations, so that reduces as the initial concentrations of TDA are improved, but, it enhances with increasing the extent of H2O2 until an optimum value and then decreases to some extent. The reaction rate significantly reduced with an increase in initial pH value in alkaline solution, which means hydroxide ions could inhibit the degradation of TDA. The removal time was increased with an increase in the initial concentration of TDA. The optimal conditions were obtained at pH of 7, initial concentration of pollutant and hydrogen peroxide at  M and  M, respectively. At optimum condition, the removal of TDA and Chemical Oxygen Demand (COD) was 97.6 and 43.5%, respectively. Conclusions: The results of this work show that separate UV radiation and H2O2 oxidation process can hardly degrade TDA from contaminated water and the UV/H2O2 process can be employed for complete degradation of TDA. The removal of TDA in UV/H2O2 process follows the pseudo-first order kinetics and the first order rate constants ( 35.7 ) and half-life of reaction (    were determined.