Anionic surfactant degradation by UV-H2O2 advanced oxidation process and optimization of process parameters

This work deals with the degradation of widely used anionic surfactant, sodium dodecyl sulfate (SDS) by UV-H2O2 advanced oxidation process (UV-H2O AOP) and the use of a statistical tool, central composite design (CCD) based response surface methodology (RSM), and to investigate the effects of essential process parameters such as peroxide dose, initial target pollutant concentration, pH and nitrate concentration on SDS degradation individually and interactively. Experimental results indicated that an increase in surfactant and nitrate concentrations adversely affects the degradation rate. Higher peroxide dose and pH showed an increasing trend in the fluence-based rate constant up to a maximum, followed by a decrease in degradation rate upon a further increase in either factor's concentration. The maximum fluence-based rate constant (0.0059 cm(2)/ mJ) was obtained under the numerical optimization of initial surfactant concentration 100 mg/L, pH 7, and nitrate concentration 0.25 mM and peroxide dose 1 mol H2O2/mol of SDS.