Jump to main content
Jump to site search

Issue 25, 2018
Previous Article Next Article

Adsorption of organic ligands on low surface charge clay minerals: the composition in the aqueous interface region

Author affiliations

Abstract

An understanding of the mechanisms that control the adsorption of organic molecules on clay minerals is of interest in several branches of science and industry. Oil production using low salinity injection fluids can increase yields by as much as 40% over standard injection with seawater or formation water. The mechanism responsible for the low salinity response is still debated, but one hypothesis is a change in pore surface wettability. Organic contamination in soil and drinking water aquifers is a challenge for municipal water suppliers and for agriculture. A better understanding is needed for how mineral species, solution composition and pH affect the desorption of low molecular weight organic ligands from clay minerals and consequently their wettability. We used X-ray photoelectron spectroscopy under cryogenic conditions to investigate the in situ composition in the mineral–solution interface region in a series of experiments with a range of pH and ion concentrations. We demonstrate that both chlorite and kaolinite release organic molecules under conditions relevant for low salinity water flooding. This release increases with a higher solution pH but is only slightly affected by the character of the organic ligand. This is consistent with the observation that low salinity enhanced oil recovery correlates with the presence of chlorite and kaolinite. Our results indicate that the pore surface charge and salinity of formation water and injection fluids are key parameters in determining the low salinity response. In general, our results imply that clay mineral surface charge influences the composition in the interface through an affinity for organic molecules.

Graphical abstract: Adsorption of organic ligands on low surface charge clay minerals: the composition in the aqueous interface region

Back to tab navigation

Supplementary files

Publication details

The article was received on 21 Feb 2018, accepted on 24 May 2018 and first published on 24 May 2018


Article type: Paper
DOI: 10.1039/C8CP01189C
Citation: Phys. Chem. Chem. Phys., 2018,20, 17226-17233
  •   Request permissions

    Adsorption of organic ligands on low surface charge clay minerals: the composition in the aqueous interface region

    S. Jelavić, S. L. S. Stipp and N. Bovet, Phys. Chem. Chem. Phys., 2018, 20, 17226
    DOI: 10.1039/C8CP01189C

Search articles by author

Spotlight

Advertisements