Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> Waste
The adsorption properties of <i>Aloe vera</i> (<i>Aloe barbadensis Miller</i>) for the uptake of Methylene Blue (MB) from water were investigated after pre-treating the material with water–ethanol solutions at different ethanol concentrations: 0% <i>v</i>/<i>...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-08-01
|
| Series: | Materials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1996-1944/15/16/5566 |
| _version_ | 1797409185908916224 |
|---|---|
| author | Leone Mazzeo Irene Bavasso Melissa Spallieri Maria Paola Bracciale Vincenzo Piemonte Luca Di Palma |
| author_facet | Leone Mazzeo Irene Bavasso Melissa Spallieri Maria Paola Bracciale Vincenzo Piemonte Luca Di Palma |
| author_sort | Leone Mazzeo |
| collection | DOAJ |
| description | The adsorption properties of <i>Aloe vera</i> (<i>Aloe barbadensis Miller</i>) for the uptake of Methylene Blue (MB) from water were investigated after pre-treating the material with water–ethanol solutions at different ethanol concentrations: 0% <i>v</i>/<i>v</i> (AV0), 25% <i>v</i>/<i>v</i> (AV25), and 50% <i>v</i>/<i>v</i> (AV50). The pre-treated materials were characterized as follows: the pHZC was evaluated to be 6, 5.7, and 7.2 for AV0, AV25, and AV50, respectively; from BET-BJH analysis the mesoporous nature of the material and an increase from 108.2 (AV0) to 331.7 (AV50) m<sup>2</sup>/kg of its solid surface area was observed; TG analysis revealed a significat increase in volatile compounds from the untreated (5.4%) to the treated materials (8.9%, 10.3%, and 11.3% for AV0, AV25, and AV50, respectively). Adsorption batch tests were then performed to investigate the equilibrium, the kinetics, and the thermodynamics of the process. Results suggested that the Langmuir model was in agreement with the experimental results, and values for q<sub>max</sub> of 199 mg/g, 311 mg/g, and 346 mg/g were calculated for AV0, AV25, and AV50, respectively. The kinetic results were used to develop a mathematical model to estimate the effective diffusion coefficient for each type of Aloe adopted. Effective diffusion coefficients of 5.43·10<sup>−7</sup> cm<sup>2</sup>/min, 3.89·10<sup>−7</sup> cm<sup>2</sup>/min, and 5.78·10<sup>−7</sup> cm<sup>2</sup>/min were calculated for AV0, AV25, and AV50, respectively. It was found that pre-treatment, on the one hand, enhances the adsorption capacity of the material and on the other, reduces its affinity toward MB uptake. |
| first_indexed | 2024-03-09T04:09:41Z |
| format | Article |
| id | doaj.art-7459dac0fe14471681d31255220193bc |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-09T04:09:41Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-7459dac0fe14471681d31255220193bc2023-12-03T14:01:19ZengMDPI AGMaterials1996-19442022-08-011516556610.3390/ma15165566Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> WasteLeone Mazzeo0Irene Bavasso1Melissa Spallieri2Maria Paola Bracciale3Vincenzo Piemonte4Luca Di Palma5Department of Chemical Engineering Materials & Environment, Sapienza University of Rome, Via Eudossiana, 18, 00184 Rome, ItalyDepartment of Chemical Engineering Materials & Environment, Sapienza University of Rome, Via Eudossiana, 18, 00184 Rome, ItalyDepartment of Chemical Engineering Materials & Environment, Sapienza University of Rome, Via Eudossiana, 18, 00184 Rome, ItalyDepartment of Chemical Engineering Materials & Environment, Sapienza University of Rome, Via Eudossiana, 18, 00184 Rome, ItalyDepartment of Engineering, University Campus Biomedico of Rome, Via Alvaro del Portillo, 21, 00128 Rome, ItalyDepartment of Chemical Engineering Materials & Environment, Sapienza University of Rome, Via Eudossiana, 18, 00184 Rome, ItalyThe adsorption properties of <i>Aloe vera</i> (<i>Aloe barbadensis Miller</i>) for the uptake of Methylene Blue (MB) from water were investigated after pre-treating the material with water–ethanol solutions at different ethanol concentrations: 0% <i>v</i>/<i>v</i> (AV0), 25% <i>v</i>/<i>v</i> (AV25), and 50% <i>v</i>/<i>v</i> (AV50). The pre-treated materials were characterized as follows: the pHZC was evaluated to be 6, 5.7, and 7.2 for AV0, AV25, and AV50, respectively; from BET-BJH analysis the mesoporous nature of the material and an increase from 108.2 (AV0) to 331.7 (AV50) m<sup>2</sup>/kg of its solid surface area was observed; TG analysis revealed a significat increase in volatile compounds from the untreated (5.4%) to the treated materials (8.9%, 10.3%, and 11.3% for AV0, AV25, and AV50, respectively). Adsorption batch tests were then performed to investigate the equilibrium, the kinetics, and the thermodynamics of the process. Results suggested that the Langmuir model was in agreement with the experimental results, and values for q<sub>max</sub> of 199 mg/g, 311 mg/g, and 346 mg/g were calculated for AV0, AV25, and AV50, respectively. The kinetic results were used to develop a mathematical model to estimate the effective diffusion coefficient for each type of Aloe adopted. Effective diffusion coefficients of 5.43·10<sup>−7</sup> cm<sup>2</sup>/min, 3.89·10<sup>−7</sup> cm<sup>2</sup>/min, and 5.78·10<sup>−7</sup> cm<sup>2</sup>/min were calculated for AV0, AV25, and AV50, respectively. It was found that pre-treatment, on the one hand, enhances the adsorption capacity of the material and on the other, reduces its affinity toward MB uptake.https://www.mdpi.com/1996-1944/15/16/5566<i>Aloe vera</i>adsorptionextractionmethylene bluemass transfer |
| spellingShingle | Leone Mazzeo Irene Bavasso Melissa Spallieri Maria Paola Bracciale Vincenzo Piemonte Luca Di Palma Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> Waste Materials <i>Aloe vera</i> adsorption extraction methylene blue mass transfer |
| title | Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> Waste |
| title_full | Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> Waste |
| title_fullStr | Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> Waste |
| title_full_unstemmed | Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> Waste |
| title_short | Effect of Water–Ethanol Extraction as Pre-Treatment on the Adsorption Properties of <i>Aloe vera</i> Waste |
| title_sort | effect of water ethanol extraction as pre treatment on the adsorption properties of i aloe vera i waste |
| topic | <i>Aloe vera</i> adsorption extraction methylene blue mass transfer |
| url | https://www.mdpi.com/1996-1944/15/16/5566 |
| work_keys_str_mv | AT leonemazzeo effectofwaterethanolextractionaspretreatmentontheadsorptionpropertiesofialoeveraiwaste AT irenebavasso effectofwaterethanolextractionaspretreatmentontheadsorptionpropertiesofialoeveraiwaste AT melissaspallieri effectofwaterethanolextractionaspretreatmentontheadsorptionpropertiesofialoeveraiwaste AT mariapaolabracciale effectofwaterethanolextractionaspretreatmentontheadsorptionpropertiesofialoeveraiwaste AT vincenzopiemonte effectofwaterethanolextractionaspretreatmentontheadsorptionpropertiesofialoeveraiwaste AT lucadipalma effectofwaterethanolextractionaspretreatmentontheadsorptionpropertiesofialoeveraiwaste |