Catalytic treatment of synthetic dye wastewater: COD and color reduction

The current work aims at reduction of Reactive Red 74 from synthetic wastewater using catalytic thermolysis as a pre-treatment. Reduction is observed in terms of COD and color. Catalysts used in this study include CuSO4·5H2O, CuO, MgSO4·7H2O, FeCl3, CaCl2 and FeSO4·7H2O. Experiments were performed at various pH, temperature, time periods, catalyst loading, initial concentration of dye and catalyst variety. A removal of about 95% COD and 68% color of synthetic wastewater were achievable with CuSO4·5H2O loading of 4 g/L at 60 ± 2 °C for pH 11 and 100 mg/L of initial concentration of dye when the run lasts for 90 min. Chemical kinetics was found to follow first order. Initial pH value of wastewater showed a pronounced effect on precipitation process and so on the color. Copper contamination associated with treated wastewater can be fought by recycling this water with fresh Catalyst which in turn reduces the addition of new catalyst.