Degradation of high concentrations of PCE solubilized in SDS and biosurfactant with Fe/Ni bi-metallic particles

Abstract

A method to rapidly solubilize and degrade perchloroethylene (PCE) was investigated. Enhancing the water solubility of PCE (100mg/L in water) with an anionic (sodium dodecyl sulfate (SDS)) and a biosurfactant (UH-biosurfactant) were investigated at room temperature in continuously stirred batch reactors. The solubility of PCE in the surfactant solutions increased linearly with increase in surfactant concentrations up to 10g/L. Of the two surfactants studied, biosurfactant solubilized more PCE per gram of surfactant. To degrade solubilized PCE, bi-metallic iron–nickel (Fe–Ni) particles were used in continuously stirred batch reactors. The bi-metallic particles were synthesized using the solution method and the particles were characterized using the SEM, EDS and XRD. The PCE solubilized in the range of 500mg/L (five times the water solubility) in both surfactant solutions were degraded at various rates by 200g/L of bi-metallic Fe–Ni particles. PCE solubilized in the UH-biosurfactant was totally degraded in less than 3h, which is the highest concentration of PCE degraded in the shortest time compared to the chemical and biological methods used in the past. End products in the solution after the PCE degradation were analyzed to determine the by products and the chloride concentration to ensure complete degradation of PCE. While the degradation kinetics of PCE solubilized in water and SDS solution were linear, PCE solubilized in the UH-biosurfactant was of a higher order.