Study of Refractory COD Removal from Pharmaceutical Wastewater

This study investigates the treatment of pharmaceutical wastewater containing recalcitrant, non-biodegradable compounds that are inadequately addressed by conventional treatment methods. The objectives include improving wastewater biodegradability and comparing the efficacy of various advanced treatment approaches. Untreated wastewater samples were collected from a pharmaceutical intermediate manufacturing unit. Initial characterization, including pH measurement and acute toxicity assessment, was conducted. Primary treatment involved neutralization, coagulation, flocculation, and settling. Advanced oxidation processes (AOPs) such as H₂O₂, TiO₂/H₂O₂, Fe²⁺/H₂O₂ (Fenton), HCO₃⁻, and Fe²⁺/H₂O₂/O₃ (Fentozone) were applied.Post-treatment analyses revealed varied improvements in biodegradability (BOD/COD ratio). The Fentozone process emerged as the most effective, achieving a BOD/COD improvement of 0.43 after 60 minutes. Comparative results showed moderate improvements with TiO₂/H₂O₂ (0.32) and Fe²⁺/H₂O₂ (0.30), while H₂O₂ alone achieved a marginal improvement of 0.26. No improvement was observed with HCO₃⁻treatment.In conclusion, the Fentozone process proves to be a promising technology.