Scholars' Mine
Missouri S&T
Research Repository
Curtis Laws Wilson Library
400 W. 14th Street
Rolla, MO 65409-0060
scholarsmine@mst.edu
| Title: | Reverse osmosis properties of bentonite/glass bead mixtures at low compaction pressures |
| Author (s): | Saindon, Rosanna Whitworth, Mike |
| Department/Lab Affiliations: | Geological Sciences & Engineering |
| Keywords: | engineered barriers hyperfiltration |
| Subject Terms: | Bentonite. Clay. Reverse osmosis. |
| Issue Date: | 2006 |
| Publisher: | Elsevier |
| Citation: | Saindon, Rosanna and T.M. Whitworth. “Reverse osmosis properties of bentonite/glass bead mixtures at low compaction pressures.” Applied Clay Science, vol. 31, no. 1-2, pp. 90-95, 2006. |
| Abstract: | It is well-known that clays and shales can be membrane-functioning. When a hydraulic head difference exists across a membrane-functioning barrier, a portion of the solute is rejected from solution passing through the membrane. Many engineering structures such as landfill liners, mixed soil augered barriers, and retention pond liners consist of soil-clay mixes, which may have clay contents as low as 12%. Some shallow geologic environments may also contain similar clay/soil mixes. No previous testing has been performed to investigate hydraulic-head-induced solute rejection in such mixed soils. Therefore, we performed six experiments using five different mixes of Na-bentonite and glass beads (100%, 50%, 25%, 12%, and 0% clay) to determine if any of these mixes exhibited membrane properties and to determine what effect clay content had upon the membrane properties. All the mixtures were compacted to 690 kPa and the compacted soil samples were 0.56–1.40 mm thick. An approximately 35 ppm Cl− solution and a hydraulic head of approximately 90 kPa were used for all experiments. Experimental data shows that these simulated clay–sand mixtures do exhibit measurable membrane properties with as low as 12% clay by weight under these conditions. Calculated reflection coefficient values ranged from a low of 0.07 for 12% Na-bentonite to a high of 0.26 for 100% clay. Solute rejection ranged from 12.6% for 12% clay to a high of more than 40% for the 50% and 100% clay samples. The glass beads represent fine-grained sand and were shown to have no membrane properties. |
| Type: | Article - Journal text |
| In Title: | Applied Clay Science |
| Copyright Notice: | This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. Pre-print: author can archive with restrictions;Restriction: This does not include Cell Press; Post-print: author can archive; FULL COPYRIGHT INFORMATION: |
| Publisher URL: | |
| Link to this page: |
| title | Reverse osmosis properties of bentonite/glass bead mixtures at low compaction pressures |
| contributor.author | Saindon, Rosanna |
| contributor.author | Whitworth, Mike |
| contributor.deptlab | Geological Sciences & Engineering |
| contributor.sponsor | USDA |
| subject | engineered barriers |
| subject | hyperfiltration |
| subject.LCSH | Bentonite. |
| subject.LCSH | Clay. |
| subject.LCSH | Reverse osmosis. |
| date.issued | 2006 |
| publisher | Elsevier |
| identifier.citation | Saindon, Rosanna and T.M. Whitworth. “Reverse osmosis properties of bentonite/glass bead mixtures at low compaction pressures.” Applied Clay Science, vol. 31, no. 1-2, pp. 90-95, 2006. |
| identifier.pub.URI | |
| description.abstract | It is well-known that clays and shales can be membrane-functioning. When a hydraulic head difference exists across a membrane-functioning barrier, a portion of the solute is rejected from solution passing through the membrane. Many engineering structures such as landfill liners, mixed soil augered barriers, and retention pond liners consist of soil-clay mixes, which may have clay contents as low as 12%. Some shallow geologic environments may also contain similar clay/soil mixes. No previous testing has been performed to investigate hydraulic-head-induced solute rejection in such mixed soils. Therefore, we performed six experiments using five different mixes of Na-bentonite and glass beads (100%, 50%, 25%, 12%, and 0% clay) to determine if any of these mixes exhibited membrane properties and to determine what effect clay content had upon the membrane properties. All the mixtures were compacted to 690 kPa and the compacted soil samples were 0.56–1.40 mm thick. An approximately 35 ppm Cl− solution and a hydraulic head of approximately 90 kPa were used for all experiments. Experimental data shows that these simulated clay–sand mixtures do exhibit measurable membrane properties with as low as 12% clay by weight under these conditions. Calculated reflection coefficient values ranged from a low of 0.07 for 12% Na-bentonite to a high of 0.26 for 100% clay. Solute rejection ranged from 12.6% for 12% clay to a high of more than 40% for the 50% and 100% clay samples. The glass beads represent fine-grained sand and were shown to have no membrane properties. |
| type | Article - Journal |
| type.DCMIType | text |
| type.status | Postprint |
| rights | This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. |
| rights | Pre-print: author can archive with restrictions;Restriction: This does not include Cell Press; Post-print: author can archive; |
| rights.URI | |
| relation.isPartOf | Applied Clay Science |
| date.available | 2008-07-30T14:23:14Z |
| identifier.persist.URI |