Mechanism of Petroleum Hydrocarbon Contaminated Groundwater Remediated by Scoria

Abstract

Scoria which is a kind of natural light bone material was selected as the reaction media of permeable reactive barrier (PRB) in this study. The aim is to investigate the scoria’s adsorption kinetics, adsorption isothermal model and reaction mechanism during the process of its purification to petroleum hydrocarbon contaminated groundwater. Parallel batch tests showed that the removal efficiency of TPH (total petroleum hydrocarbons) was 87.91% when the experiment time to 90 min. The adsorption of scoria to TPH was well fitted by the pseudo-second order kinetic equation and Langmuir isotherm, with the kinetic formula t/Qt=2.3082t+20.692 and the isothermal equation 1/Qe=6.5644/Ce+0.0007, respectively. It was also shown that the apparent maximum adsorption capacity of scoria was 1.7g/g. Analysis results from SEM, IR, XRD and other methods indicated that scoria’s composition and its material structure were closely related to the remediation mechanism of petroleum hydrocarbon contaminated groundwater. However, it was not only physical adsorption but also chemical adsorption happened during scoria’s adsorption process. The results could provide a reliable reaction medium for PRB technology which used in petroleum hydrocarbon contaminated groundwater remediation.