Non-aqueous phase liquid behavior in the subsurface: Transportation, source zone characterization and remediation

Contaminant behaviour in soils and fractured rock is very complex, not least because of the heterogeneity of the subsurface environment. For non-aqueous phase liquids (NAPLs), a liquid density contrast and interfacial tension between the contaminant and interstitial fluid adds to the complexity of behaviour, increasing the difficulty of predicting NAPL behaviour in the subsurface. This paper outlines the need for physical model tests that can improve fundamental understanding of NAPL behaviour in the subsurface, enhance risk assessments of NAPL contaminated sites, reduce uncertainty associated with NAPL source remediation and improve current technologies for NAPL plume remediation. Four case histories are presented to illustrate physical modelling approaches that have addressed problems associated with NAPL transport, remediation and source zone characterization. © 2006 Taylor & Francis Group, London.

Studies on the phase behavior of lyotropic liquid crystal in DAD/C4OH/n-C8H18/D2O system

The lytropic liquid crystals in dodecanic acid diethanolamine (DAD)/n-butanol (C4OH)/octane (n-C8H18)/deuteron (D2O) system were studied to determine the phase regions and were investigated by H-2-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods. The results indicate that the lamellar, hexagonal and cubic liquid crystals all exist in the above system. Keeping the weight ratio of DAD and C4OH constant,the microphase structure, H-2 quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.