Evaluation and optimization of Fenton pretreatment integrated with granulated activated carbon (GAC) filtration for carbamazepine removal from complex wastewater of pharmaceutical industry

The bulk manufacturing of carbamazepine (CBZ) by pharmaceutical manufacturing industries leads to generation of huge amount of wastewater containing this recalcitrant compound. This necessitates the application of advanced oxidation processes (AOPs) as a pretreatment strategy for the treatment of such complex industrial wastewaters. Therefore, in the present study, effect of Fenton treatment was investigated for removal of CBZ from real wastewater containing higher CBZ concentrations. The preliminary studies were conducted to assess the significant factors in Fenton treatment and pH, Fenton dose and time were found to be statistically significant parameters affecting the Fenton process. Based on these results, further experimental trials were designed statistically using Central Composite Design in MINITAB 16 software. The process conditions were optimized using Response Surface Optimizer Tool in MINITAB 16 and pH = 3.5 and H2O2 concentration of 8.5 g/L was obtained as optimum condition leading to 49.39 ± 0.93% CBZ removal from pharmaceutical wastewater containing higher CBZ concentrations. The detoxification of Fenton-treated wastewater through granulated activated carbon (GAC) column resulted in an overall CBZ removal of 99.51 ± 0.02%. The detoxification was further corroborated through seed germination test which demonstrated a potential reduction in toxicity post-detoxification using GACs.