Use of Fenton’s Reagent for Pollutants Removal in Pharmaceutical Effluent

Abstract

Effluent from a pharmaceutical factory producing a single chemical product was treated on a bench scale with advance oxidation process (H2O2 & Fe2+). The effluent was as a result of the factory treatment of the pharmaceutical wastewater by UASB (up flow anaerobic sludge bed) and a SBR (sequencing batch reactor) process. The chromatechemical oxygen demand (CODcr) range of the discharged effluent was between 8000-10,000mg/L with some residual recalcitrant compounds. The residual recalcitrant compounds which were measured by gas chromatography mass spectrometry (GC-MS) mainly consisted of alcohols, phenols and nitrogenous and sulfur compounds. The experimental variables studied include dosages of Fe2+, H2O2 and mixing speed. The result showed that the oxidation by Fenton’s reagent was best when concentration of iron (II) sulfate and hydrogen peroxide were [Fe2+]=1.093mmol/L; [H2O2] = 2.5mmol/L at pH = 3.0 for 30min at 80rpm; followed by conditioning with lime (1%) to pH = 8.0 where coagulation by iron hydroxide took place over 20min. Under these optimal operating conditions, the maximum removal efficiency for CODcr, Color and the aromatic compounds were 56%, 95% and 90% respectively.