RES³T - Rossendorf Expert System for Surface and Sorption Thermodynamics

This part of the RES³T interface allows users to easily extract specific data sets, e.g., all records relevant for the combination of a specific mineral and a specific SCM. They can also choose to show all sorption data available for a ligand / ion, all published surface area or protolysis data of a mineral. Once a data set has been generated based on queries and is shown on the screen, it can also be exported into CSV spreadsheets for further processing.

To obtain more information on the given output, the users can click on any associated hyperlink to find more detailed information for a specific database record / datum. The maximum amount of records displayed per screen is limited to 20. In case a larger data set was retrieved, the user can go forward by pressing the number of subsequent pages displayed on the right lower corner.

The literature reference code used in many places is a mnemonic abbreviation consisting of the first letter of the first up to five authors, the last two digits of the year of publication, and if necessary a small Latin character (a-z) for further distinguishing otherwise identical codes.

Data for a selected mineral

As compulsory first step, a mineral must be selected using a dropdown menu. If this is done, the buttons below will guide the user to detailed information on the selected mineral. Keep in mind that some minerals are quite close to each other in their surface complexation behaviour, so if you do not find appropriate data for, e.g., quartz you can also look under amorphous silica.

In case one wants to get the data not only for one mineral and/or one ligand it is advised to use the query forms presented under "Data Assembly & Formatting".

Specific Surface Area

Pressing the “Query” button in the line labelled "Specific Surface Area" will list all data records containing specific surface areas for the selected mineral. The columns are (from left to right): "Specific Surface Area in m²/g", "Reported Grain Size in µm", and "Literature Reference", sorted by the area size and the reference code.

Site Density & Protolysis:

Pressing the "Query" button in the line labelled "Surface Protolysis / Sites" will list all data records containing surface binding site densities and site protolysis constants for the selected mineral. The columns are (from left to right): "Site Type", "Site Density in nm²", "PZC" (Point of zero charge), "pK₁" (1^st protolysis constant), "pK₂" (2_nd protolysis constant), "C1" ((1^st Capacitance parameter), "SCM Type", and "Reference", sorted by the SCM type and the literature reference code.

All site density values presented are already converted from the original unit into nm⁻². If one is interested in the originally published value, a click on the references hyperlink will lead to the respective detailed data record.

Clicking on the pK-values or site densities hyperlink shows all information available for this specific data record. This includes a conversion to the reference state of infinite dilution (ionic strength correction information).

As clearly pointed out by Kulik (2006), the establishment of standard and reference states for surface complexation data is essential for a proper thermodynamic handling of such reactions. Therefore a respective normalization procedure has been integrated into RES³T, allowing a comparison of the various SCM parameters for given combinations of SCM subtype and mineral. Following Kulik and setting the reference site density to 2.31 nm⁻², the protolysis constants are normalized. These normalized values are shown accordingly in the columns labeled with "pK_1/2 (normalized)", next to the original value corresponding to the experimental site density (normalization information).

Surface Complex Formation - for a selected SCM

After choosing a Surface Complexation Model from the dropdown menu, the respective button generates a list of all data records containing surface complex formation constants for the selected combination of SCM and mineral. The columns are (from left to right): "1^st Ligand", " Equation", "log K", and "Reference", sorted by ligand formula and reaction equation. Clicking on the log K-values or site densities hyperlink shows all information available for this specific data record. As for the "Surface Protolysis / Sites" form, the columns for log K correspond to the experimental value, the one converted to infinite dilution, and the one normalized to a site density of 2.31 nm⁻² (normalization information).

Surface Complex Formation - for a selected ligand

After choosing a sorbing ligand from the dropdown menu, the respective button triggers a search for all data records containing surface complex formation constants for the selected combination of ligand and mineral. The columns of the result list are (from left to right): "SCM", "Equation", "log K", and "Reference", sorted by SCM type and reference code. Clicking on the log K-values or site densities hyperlink shows all information available or this specific data record. As for the "Surface Protolysis / Sites" form, the columns for log K correspond to the experimental value, the one converted to infinite dilution, and the one normalized to a site density of 2.31 nm⁻² (normalization information).

Surface Complex Formation - all data records

This button will list surface complex formation constants for the selected mineral, covering all relevant ligands simultaneously. The columns are (from left to right): "SCM", "1^st Ligand", "Equation", "log K", and "Reference", sorted by SCM type, ligand formula, and literature reference code. Clicking on the log K-values or site densities hyperlink shows all information available for this specific data record. As for the "Surface Protolysis / Sites" form, the columns for log K correspond to the experimental value, the one converted to infinite dilution, and the one normalized to a site density of 2.31 nm⁻²(normalization information).

Publications

This button helps to search for literature references, contrary to all the other search buttons above it is always activated and does not require the input of a mineral. The query field can contain either part of the name of an author, part of the references title or part of a (mnemonic) literature reference code. An asterisk (*) can be used as wildcard for the search string. The columns of the result list are (from left to right): "Reference", "Authors, "Title" (below the authors), and "Year", sorted by the literature reference code.

Hyperlinks below each of the search results allows to check for parameter sets stemming from the same source, namely records for specific surface areas, for site densities & protolysis constants, or for surface complexation constants. The 4^th button on these lines allows to format bibliographic citations in a style form specific for certain journals important in the field of sorption.