Sorption properties of light hydrocarbon-contaminated clay under defined conditions

Abstract

Risk assessments and remediation plans of hydrocarbon-contaminated sites usually have been managed based on total petroleum hydrocarbon (TPH) content. Gasoline is one of the most mobile pollution agents, which consist mainly of light hydrocarbons. Measuring of TPH does not give enough information about the individual compounds. Another problem is using solvents such as nhexane for extraction. In some cases we would like to know about the hydrocarbon-adsorption properties of contaminated samples. The article describes a laboratory model for hydrocarbon contamination modeling, and measuring hydrocarbon sorption properties. For modeling the authors have chosen gasoline type hydrocarbon, homogeneous sand and clay samples from the Kiscell Clay Formation. Results of the modeling indicate that the referenced ATD-GC/MS method can be a very effective tool in the risk assessment of hydrocarbon-contaminated areas.

Sorption of light hydrocarbons on clays from the Oligocene Kiscell Clay Formation, Hungary

“…Further information on the mineralogy of the clays is given by, for example, Báldi (1998) and Kalmár et al (2003). The cation exchange capacity (CEC-value) of the sample, measured using Mehlich's method, is 33.16 meq/100 g (Tóth, Knapp 2007).…”

“…The detailed composition of the sorbed hydrocarbons was monitored by ATD-GC/MS (automatic thermodesorption-gas chromatograph/mass spectrometer). Details of the applied GC-FID and ATD-GC/MS methods are published elsewhere (Tóth, Török 2006;Tóth, Knapp 2007). In brief, the ATD-GC/MS analyses were performed with a Gerstel TDS A2 autosampling system, a Gerstel TDS 3 heating system, and a CIS 4 (Cooled Injection System) with an Agilent 6890N Gas Chromatograph interfaced to an Agilent 5973 Mass Selective Detector.…”