Investigation of the effect of different parameters on the oxidation of reactive black 5 by CaO2

In this study, the removal of Reactive Black 5 (RB5) was studied by using calcium peroxide (CaO2), which is an environmentally friendly and strong chemical oxidizer, under different conditions (pH, CaO2 doses and anion doses). The characterization of CaO2 synthesized under laboratory conditions was revealed by Scanning Electron Microscopy (SEM), X-ray Spectroscopy (EDX), X-ray Diffraction Diffractometry (XRD) and Fourier Transmission Infrared Spectroscopy (FTIR) analyzes. For the effect of 9 different pH (4-12) and 5 different CaO2 doses (0.1-0.9 g) to determine the appropriate pH in the removal of 100 mg/L RB5 experimental studies have been carried out. In the removal of RB5 with CaO2, the optimum CaO2 dose was determined as 0.5 g at pH 10. In the oxidation of 0.5 g CaO2 and 100 mg/L RB5, 91.12% removal efficiency was obtained after 120 minutes at pH 10. In these conditions, the effects of the presence of different anions (Cl-, CO32-, HCO3-, PO43-, SO42-, NO3-, NO2-) at 10 different concentrations (100-1000 mg/L) on RB5 removal were investigated and RB5 removal efficiencies were calculated as 67.7%, 67.7%, 55.5%, 14.4%, 59.7%, 87.12% and 78.7%, respectively, at the 1000 mg/L anion doses. It was revealed that Cl-, CO32-, HCO3-, PO43-, SO42- anions affected the removal negatively, but NO3- and NO2- had no significant effect. The effect of different parameters on RB5 oxidation with CaO2 was confirmed by Multiple Linear Regression (CLR) Method. The R2 regression coefficient obtained from the graph of the RB5 removal efficiency according to the CLR model was found to be 0.9189.