Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution
Natural limonite, which contains mainly nano-sized iron and manganese oxides, is widely distributed worldwide. This study investigated the kinetics, thermodynamics, and the effects of pH, ion strength, and anions on the adsorption of Sb(III) via limonites sampled from Xinqiao and Yeshan (Tongling, C...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-11-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/13/12/1494 |
| _version_ | 1797380017527717888 |
|---|---|
| author | Haicui Luo Yuefei Zhou Yan Chen Qiaoqin Xie Tianhu Chen |
| author_facet | Haicui Luo Yuefei Zhou Yan Chen Qiaoqin Xie Tianhu Chen |
| author_sort | Haicui Luo |
| collection | DOAJ |
| description | Natural limonite, which contains mainly nano-sized iron and manganese oxides, is widely distributed worldwide. This study investigated the kinetics, thermodynamics, and the effects of pH, ion strength, and anions on the adsorption of Sb(III) via limonites sampled from Xinqiao and Yeshan (Tongling, China). Results show that adsorption equilibrium is achieved after 24 h for all experiments. Under initial Sb(III) = 200 mg/L, pH = 3.0, and temperature = 25 °C, Sb adsorption quantities for X1 (Mn-free limonite from Xinqiao), X2 (Mn-containing limonite from Xinqiao), Y1 (Mn-free limonite from Yeshan), and Y2 (Mn-containing limonite from Yeshan) are 10.92, 12.97, 27.12, and 89.34 mg/g, respectively. Manganese oxides in limonites promote Sb removal through oxidizing Sb(III) to Sb(V). The adsorption processes for all four limonites are fitted with a pseudo-second-order model. All adsorptions except for X1 fit with the Freundlich model; for X1, the Langmuir adsorption model is better. All adsorptions are spontaneous reactions (ΔG < 0). All adsorptions except for Y1 (ΔH < 0, exothermic reaction) are endothermic reactions (ΔH > 0). Antimony adsorption is independent of solution pH for Mn-free limonites but is negatively related to solution pH for Mn-containing limonites. Generally, ion strength has a weak positive effect on Sb adsorption. The effects of anions on Sb adsorption are grouped into three types: weak negative (NO<sub>3</sub><sup>−</sup> and SO<sub>4</sub><sup>2−</sup>), negative (CO<sub>3</sub><sup>2−</sup>, SiO<sub>4</sub><sup>4−</sup>, and PO<sub>4</sub><sup>3−</sup>), and equivocal (humic acid). This study indicates that due to a much higher surface area, Yeshan (124.8 m<sup>2</sup>/g for X1 and 171.7 m<sup>2</sup>/g for X2) rather than Xinqiao (13.7 m<sup>2</sup>/g for Y1 and 12.8 m<sup>2</sup>/g for Y2) limonites are better materials for Sb(III) removal in an aqueous solution. The key factors for the better use of limonite as an Sb(III) treatment material include temperature, pH, ion strength, and Mn content. |
| first_indexed | 2024-03-08T20:31:22Z |
| format | Article |
| id | doaj.art-dd782ee953ad4aabab497e441d9febe3 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-08T20:31:22Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-dd782ee953ad4aabab497e441d9febe32023-12-22T14:26:32ZengMDPI AGMinerals2075-163X2023-11-011312149410.3390/min13121494Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous SolutionHaicui Luo0Yuefei Zhou1Yan Chen2Qiaoqin Xie3Tianhu Chen4Key Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, ChinaKey Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, ChinaChina Jikan Research Institute of Engineering Investigations and Design Co., Ltd., Xi’an 710043, ChinaKey Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, ChinaKey Laboratory of Nanominerals and Pollution Control of Anhui Higher Education Institutes, School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, ChinaNatural limonite, which contains mainly nano-sized iron and manganese oxides, is widely distributed worldwide. This study investigated the kinetics, thermodynamics, and the effects of pH, ion strength, and anions on the adsorption of Sb(III) via limonites sampled from Xinqiao and Yeshan (Tongling, China). Results show that adsorption equilibrium is achieved after 24 h for all experiments. Under initial Sb(III) = 200 mg/L, pH = 3.0, and temperature = 25 °C, Sb adsorption quantities for X1 (Mn-free limonite from Xinqiao), X2 (Mn-containing limonite from Xinqiao), Y1 (Mn-free limonite from Yeshan), and Y2 (Mn-containing limonite from Yeshan) are 10.92, 12.97, 27.12, and 89.34 mg/g, respectively. Manganese oxides in limonites promote Sb removal through oxidizing Sb(III) to Sb(V). The adsorption processes for all four limonites are fitted with a pseudo-second-order model. All adsorptions except for X1 fit with the Freundlich model; for X1, the Langmuir adsorption model is better. All adsorptions are spontaneous reactions (ΔG < 0). All adsorptions except for Y1 (ΔH < 0, exothermic reaction) are endothermic reactions (ΔH > 0). Antimony adsorption is independent of solution pH for Mn-free limonites but is negatively related to solution pH for Mn-containing limonites. Generally, ion strength has a weak positive effect on Sb adsorption. The effects of anions on Sb adsorption are grouped into three types: weak negative (NO<sub>3</sub><sup>−</sup> and SO<sub>4</sub><sup>2−</sup>), negative (CO<sub>3</sub><sup>2−</sup>, SiO<sub>4</sub><sup>4−</sup>, and PO<sub>4</sub><sup>3−</sup>), and equivocal (humic acid). This study indicates that due to a much higher surface area, Yeshan (124.8 m<sup>2</sup>/g for X1 and 171.7 m<sup>2</sup>/g for X2) rather than Xinqiao (13.7 m<sup>2</sup>/g for Y1 and 12.8 m<sup>2</sup>/g for Y2) limonites are better materials for Sb(III) removal in an aqueous solution. The key factors for the better use of limonite as an Sb(III) treatment material include temperature, pH, ion strength, and Mn content.https://www.mdpi.com/2075-163X/13/12/1494limoniteantimony(III)iron oxidemanganese oxideadsorptionoxidation |
| spellingShingle | Haicui Luo Yuefei Zhou Yan Chen Qiaoqin Xie Tianhu Chen Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution Minerals limonite antimony(III) iron oxide manganese oxide adsorption oxidation |
| title | Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution |
| title_full | Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution |
| title_fullStr | Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution |
| title_full_unstemmed | Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution |
| title_short | Limonite as a Natural Adsorbent for the Removal of Antimony(III) from an Aqueous Solution |
| title_sort | limonite as a natural adsorbent for the removal of antimony iii from an aqueous solution |
| topic | limonite antimony(III) iron oxide manganese oxide adsorption oxidation |
| url | https://www.mdpi.com/2075-163X/13/12/1494 |
| work_keys_str_mv | AT haicuiluo limoniteasanaturaladsorbentfortheremovalofantimonyiiifromanaqueoussolution AT yuefeizhou limoniteasanaturaladsorbentfortheremovalofantimonyiiifromanaqueoussolution AT yanchen limoniteasanaturaladsorbentfortheremovalofantimonyiiifromanaqueoussolution AT qiaoqinxie limoniteasanaturaladsorbentfortheremovalofantimonyiiifromanaqueoussolution AT tianhuchen limoniteasanaturaladsorbentfortheremovalofantimonyiiifromanaqueoussolution |