Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies
The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests...
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MDPI AG
2020-02-01
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| Series: | Geosciences |
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| Online Access: | https://www.mdpi.com/2076-3263/10/2/59 |
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| author | Liana Carolina Carvalho Rocha Lazaro Valentin Zuquette |
| author_facet | Liana Carolina Carvalho Rocha Lazaro Valentin Zuquette |
| author_sort | Liana Carolina Carvalho Rocha |
| collection | DOAJ |
| description | The purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests and a flushing process to evaluate the adsorption and desorption capacities of the zeolite. In the column experiments, the samples were subjected to eight successive cycles involving the percolation of a potassium aqueous solution (1500 mg/L) and a subsequent flushing process with water. Batch tests were conducted by mixing 20 g of zeolite with 100 mL of single-element aqueous solutions of K and Zn with concentrations of 200 mg/L. The results indicate that the zeolite rock is composed predominantly of clinoptilolite species and has a Si/Al ratio of 6.8, a high cationic exchange capacity (CEC) of 180 cmol<sub>c</sub>/kg and a high K<sup>+</sup> adsorption rate with a removal efficiency of 78%. The adsorption isotherms of the zeolite follow the Langmuir model and are well fit by a pseudo-second-order kinetic model showing a high correlation coefficient (r<sup>2</sup> > 0.999) for both K<sup>+</sup> and Zn<sup>2+</sup> cations. Additionally, the contaminant transport parameters for K<sup>+</sup> ions (R<sub>d</sub> = 24.9; D<sub>h</sub> = 1.32 × 10<sup>−2</sup> cm<sup>2</sup>/s and α = 1.42) reveal that the zeolite is resistant to the dispersion of ions in the barrier, indicating that the material has advantageous characteristics for use in a PRB. However, the flushing process of the material is not efficient, indicating that the appropriate use of the zeolite is in clean-up systems in which the adsorbent material can be exchanged after losing its efficiency as a reactive barrier. |
| first_indexed | 2024-12-21T04:02:15Z |
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| language | English |
| last_indexed | 2024-12-21T04:02:15Z |
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| series | Geosciences |
| spelling | doaj.art-0a93197875724690b43866cbc0d8a3882022-12-21T19:16:41ZengMDPI AGGeosciences2076-32632020-02-011025910.3390/geosciences10020059geosciences10020059Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column StudiesLiana Carolina Carvalho Rocha0Lazaro Valentin Zuquette1São Carlos School of Engineering, University of São Paulo, São Carlos, SP, 13566-590, BrazilSão Carlos School of Engineering, University of São Paulo, São Carlos, SP, 13566-590, BrazilThe purpose of this work is to evaluate the capacity of a natural zeolite to be used as a reactive material in a permeable reactive barrier (PRB) to remove inorganic contaminants from groundwater. To this aim, zeolite samples were subjected to characterization tests, column experiments, batch tests and a flushing process to evaluate the adsorption and desorption capacities of the zeolite. In the column experiments, the samples were subjected to eight successive cycles involving the percolation of a potassium aqueous solution (1500 mg/L) and a subsequent flushing process with water. Batch tests were conducted by mixing 20 g of zeolite with 100 mL of single-element aqueous solutions of K and Zn with concentrations of 200 mg/L. The results indicate that the zeolite rock is composed predominantly of clinoptilolite species and has a Si/Al ratio of 6.8, a high cationic exchange capacity (CEC) of 180 cmol<sub>c</sub>/kg and a high K<sup>+</sup> adsorption rate with a removal efficiency of 78%. The adsorption isotherms of the zeolite follow the Langmuir model and are well fit by a pseudo-second-order kinetic model showing a high correlation coefficient (r<sup>2</sup> > 0.999) for both K<sup>+</sup> and Zn<sup>2+</sup> cations. Additionally, the contaminant transport parameters for K<sup>+</sup> ions (R<sub>d</sub> = 24.9; D<sub>h</sub> = 1.32 × 10<sup>−2</sup> cm<sup>2</sup>/s and α = 1.42) reveal that the zeolite is resistant to the dispersion of ions in the barrier, indicating that the material has advantageous characteristics for use in a PRB. However, the flushing process of the material is not efficient, indicating that the appropriate use of the zeolite is in clean-up systems in which the adsorbent material can be exchanged after losing its efficiency as a reactive barrier.https://www.mdpi.com/2076-3263/10/2/59prbclinoptilolitelaboratorial testsadsorption isothermkinetic model |
| spellingShingle | Liana Carolina Carvalho Rocha Lazaro Valentin Zuquette Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies Geosciences prb clinoptilolite laboratorial tests adsorption isotherm kinetic model |
| title | Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies |
| title_full | Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies |
| title_fullStr | Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies |
| title_full_unstemmed | Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies |
| title_short | Evaluation of Zeolite as a Potential Reactive Medium in a Permeable Reactive Barrier (PRB): Batch and Column Studies |
| title_sort | evaluation of zeolite as a potential reactive medium in a permeable reactive barrier prb batch and column studies |
| topic | prb clinoptilolite laboratorial tests adsorption isotherm kinetic model |
| url | https://www.mdpi.com/2076-3263/10/2/59 |
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