THE USE OF THE EXFOLIATED GRAPHITE FOR THE REMOVAL OF THE AQUEOUS NAPHTHENIC ACIDS

摘要

NAs are the primary toxic compounds in the Oil SandrnProcess-affected Waters (OSPW) (MacKinnon andrnRetallack 1981). They are water soluble hydrocarbons atrnhigh pH values and responsible for the acidic content ofrnbitumen. NAs removal using the exfoliated graphite (EG)rnis a promising remediation tool, especially that a reportedrn(130g/g) of hydrocarbons are effectively removed fromrnwater using the EG. The purpose of the current research isrnto study the removal efficiency of the NAs using differentrnsamples of EG. Those EG samples were prepared atrndifferent exfoliation temperatures and then characterizedrnusing the Scanning Electron Microscopy (SEM) and XrayrnDiffraction (XRD). The isotherm experiments tookrnplace to assess the adsorption capacity of the EGs and thernquantifications of aqueous NAs were obtained by the FTIRrnspectroscopy before and after the adsorption (Jivraj etrnal., 1995). However the lower expansion volume andrnsurface area of the EG sample fabricated at 500 ℃ (EG-rn500) than that of the EG-800, higher removal efficiencyrnwas observed for EG-500. The pH values of solutionsrnwere measured before and after adsorption and lower pHrnwas detected for the sample contained EG-500. Samplesrnwere investigated using the electron dispersivernspectroscopy (EDS) and the results showed that the EG-rn500 contained higher residual sulphur. This acidic contentrndecreases the solubility of the NAs and facilitates thernadsorption for the EG-500. Accordingly a pH buffer wasrnused in the following experiments and the results showedrnhigher removal efficiency for EG-800. The maximumrnremoval efficiency reached was almost 70% of the totalrnNAs in solutions.