TREATMENT OF PHARMACEUTICAL WASTEWATER BY COAGULATIONAND FENTON PROCESSES

Abstract

Pharmaceutical wastewater contains highly stable aromatic compounds which are poorly degradable at normal condition and highly toxic for the environment. For the treatment of toxic wastewater there are numerous techniques available like Advance Oxidation Process (AOPs), Coagulation, Electrochemical processes, Adsorption, Catalytic degradation etc. Due to high toxicity of these compounds, biological treatment methods are not successful for treatment of this kind of wastewater causes poor growth of bacteria in the toxic environment. In the present work, actual pharmaceutical industry wastewater was treated by coagulation and Fenton processes. During coagulation and Fenton treatments, effect of various parameters such as coagulant dosage, pH, H2O2 dosage, Fe2+ dosage and time was studied on COD removal efficiency. During coagulation, Aluminum Sulphate and Ferric Chloride were used as coagulants and approximately 63. 87% and 58.17% of COD removals were observed respectively at optimum operating conditions (i.e aluminum sulphate dosage- 1200 mg/L pH- 7 and ferric chloride dosage- 900 mg/L pH- 9). In Fenton treatment, maximum COD removal was observed 67.32% at optimum conditions pH 3 and Fe+2/H2O2 ratio 1:11. Integration of process was also studied and it was found that coagulation using Aluminum Sulphate coagulant followed by Fenton gives higher COD removal. In both treatment processes, second order kinetic model was found to best fit the experimental data.