Modeling of supercritical fluid extraction of phenanthrene from clayey soil.

The supercritical fluid (SFC) extraction efficiency of phenanthrene from clayey soils was modeled. The model accounts for effective diffusion of the phenanthrene in the solid pores, axial dispersion in the fluid phase, and external mass transfer to the fluid phase from the particle surface. This model, involving partial differential equations, was solved using the finite difference.

Effect of supercritical fluid extraction parameters and clay properties on the efficiency of phenanthrene extraction.

Clay soils have specific properties that cause difficulty in the assessment and remediation of contaminated sites. Furthermore, polyaromatic hydrocarbons, when present in soil, are difficult to extract due to their nonpolar, high molecular weight characterization. In this study, the supercritical fluid (carbon dioxide) extraction (SFE) technique, with and without methanol modifier, was used for removal of PAHs (phenanthrene) from kaolinite, illite, and montmorillonite soils.

Changes in the rheological and colloidal properties of paper coating liquids with paper-yellowing inhibition additives.

This is an investigation of the effect of paper-yellowing inhibitors on the rheological, colloidal, and interfacial properties of paper-coating liquids and the associated changes in the liquid surface microstructure. In addition to rheological measurements, we measured the zeta potential and imaged the surface microstructure of coating liquids by transmission electron microscopy (TEM) using an advanced Pt/C replica technique. The zeta potential is related to the concentration of added inhibitors.