Efficient Removal Of Pharmaceutical Contaminants By Aluminium Sulphate Insights On Diclofenac And Ph Influence
Auteurs : Bacha Naima . Achour Samia .
Résumé
The widespread presence of pharmaceutical residues, particularly non-steroidal anti-inflammatory drugs (NSAIDs) like diclofenac, in aquatic environments poses significant risks to both ecosystems and human health. This study aimed to evaluate the effectiveness of coagulation-flocculation using aluminium sulfate for the removal of diclofenac from distilled water under different pH conditions. Experimental procedures involved jar-test coagulation-flocculation trials at pH levels of 4, 7, and 9, with varying initial diclofenac concentrations and coagulant dosages. Diclofenac removal efficiency was analyzed using UV-visible spectrophotometry. The results indicated that pH and coagulant dosage significantly influenced the removal efficiency. The highest removal efficiency (64.44%) was achieved at near-neutral pH (pH 7) with a coagulant dosage of 150 mg/L for a diclofenac concentration of 15 mg/L. At acidic (pH 4) and alkaline (pH 9) conditions, the removal efficiencies were lower, reaching up to 60.74% and 31.49%, respectively, for higher diclofenac concentrations. Reaction mechanisms varied with pH due to changes in aluminum speciation and diclofenac interactions, with strong complexation and ligand exchange observed at near-neutral pH.A stoichiometric relationship was identified between the initial diclofenac concentration and the optimal coagulant dosage, with variations based on pH. This study highlights the importance of pH optimization in coagulation processes and provides valuable insights for improving water treatment strategies to mitigate pharmaceutical contamination.
Mots clés
Pharmaceuticals ; Diclofenac ; coagulation-flocculation ; aluminiumsulphate ; pH optimization ; stoichiometry
