Treatability of biodiesel wastewaters by using KMnO4 and KMnO4/O3 processes and kinetic analysis

This study aims to investigate the treatability of ECBD by KMnO4 and KMnO4/O-3 processes. The ECBD removal efficiencies of both KMnO4/O-3 and KMnO4 methods were compared, and the COD and MeOH removal efficiencies with the KMnO4/O-3 process gave better results than the KMnO4 process. For the ECBD removal efficiencies, the experimental parameters including pH, KMnO4 dose, O-3 dose and reaction time were optimized by changing the one parameter at a time. As a result of 6 h of KMnO4 oxidation, 91.74% of COD and 95.93% of MeOH removal was achieved under the optimum conditions. However, the COD and MeOH removal efficiencies have been obtained under optimum conditions for KMnO4/O-3 as 97.79% and 98.30%, respectively. The second order kinetic model has been found to be the most suitable model for both processes and the R-2 has been found as 0.999 and 0.999 for KMnO4 and KMnO4/O-3, respectively. The reaction k have been also calculated as 6 x 10(-5) L center dot mg(-1)center dot min(-1) and 1.63 x 10(-4) L center dot mg(-1)center dot min(-1) for COD and MeOH in KMnO4 oxidation, respectively. Furthermore, the k have been also calculated as 6 x 10(-5) L center dot mg(-1)center dot min(-1) and 1.6 x 10(-4) L center dot mg(-1)center dot min(-1) for COD and MeOH in KMnO4/O-3 oxidation, respectively.