Fenton’s reagent augmented with TiO_2 for photocatalytic degradation of pulp and paper mill wastewater by plug flow baffle reactor under visible and sunlight irradiation

摘要

The efficiency of solar photocatalytic plug flow baffle reactor by using Fenton's reagent augmented with TiO2 (solar/Fe2+/TiO2/H2O2) process for the degradation and decolourisation of pulp and paper wastewater has been studied. For this study, a reactor has been designed with pyrexglass in the form of a pond divided with baffle plates. The experiment was performed by varying three significant independent variables such as flow rate in the range of 0-300 mL/min, liquid depth in the range of 2-6 cm and residence time in the range of 0-120 min. The standard response surface methodology (RSM) and central composite design were followed. The maximum COD and colour removal of 98% and 97% respectively was obtained at optimum conditions of flow rate = 75 mL/min, liquid depth = 5 cm and residence time = 75 min. Also, the effect of aeration and without aeration, addition of iron dosage and the kinetics was studied. It was observed that the sequential addition of iron is efficient than single addition and the kinetics followed the pseudo first order reaction with high correlation coefficients. The reaction rate constant for aeration was 2.33 times greater than the reaction without aeration.