EFFECT OF FENTON PROCESS (H2O2 / FE2+) ON REMOVAL OF LINEAR ALKYLBENZENE SULFONATE (LAS) USING CENTERAL COMPOSITE DESIGN AND RESPONSE SURFACE METHODOLOGY

This study investigates the degradation of Linear Alkylbenzene Sulfonate (LAS) in aqueous solution using Fenton's process in a batch reactor (at pH = 3 and 25°C). Experiments were carried out to survey the effects of the amounts of ferrous sulfate (FeSO4.7H2O) and hydrogen peroxide (H2O2) on the LAS and COD removal. Central composite design and response surface methods were used to optimize the Fenton oxidation process through examination of three independent operating variables namely oxidant dose (H2O2), catalyst dose (Fe+2) and reaction time., hydrogen peroxide dose ranging from 150 to 750 mg /L and Fe+2 concentration in the range of 10 -130 mg /L were selected to be examined at different reaction times between 20 and 80 minutes. Models were developed and results shows that the oxidation capacities of H2O2 /Fe+2 were highly dependent on the concentration of H2O2 and Fe+2. Satisfactory decay rates of LAS to lock up biodegradable concentration level were obtained, and in the case for oxidation of 200 mg /L LAS, the optimum values were achieved at 600 and 130 mg/L for H2O2 and Fe+2, respectively.