Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) Adsorbents
Banana peel waste is abundant and can be utilized as a low-cost adsorbent for removing toxic Cr (VI) from wastewater. The acid modification of banana peels significantly enhances their adsorption capacity for Cr (VI). An adsorbent was prepared by treating banana peel powder with 50% H<sub>2<...
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| Format: | Article |
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MDPI AG
2024-02-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/29/5/990 |
| _version_ | 1797264134345064448 |
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| author | Zhouyang Huang Robyn Campbell Chirangano Mangwandi |
| author_facet | Zhouyang Huang Robyn Campbell Chirangano Mangwandi |
| author_sort | Zhouyang Huang |
| collection | DOAJ |
| description | Banana peel waste is abundant and can be utilized as a low-cost adsorbent for removing toxic Cr (VI) from wastewater. The acid modification of banana peels significantly enhances their adsorption capacity for Cr (VI). An adsorbent was prepared by treating banana peel powder with 50% H<sub>2</sub>SO<sub>4</sub> at 50 °C for 24 h. The acid treatment increased the surface area of the adsorbent from 0.0363 to 0.0507 m<sup>2</sup>/g. The optimum adsorbent dose was found to be 1 g/L for the complete removal of Cr (VI) from 100 ppm solutions. The adsorption capacity was 161 mg/g based on the Langmuir isotherm model. The adsorption kinetics followed a pseudo-second order model. Increasing the temperature from 20 to 50 °C increased the initial adsorption rate but had a minor effect on the equilibrium adsorption capacity. Thermodynamics studies showed that the process was spontaneous and endothermic. The activation energy was estimated as 24.5 kJ/mol, indicating physisorption. FTIR analyses before and after adsorption showed the involvement of hydroxyl, carbonyl and carboxyl groups in binding the Cr (VI). The Cr (VI) was reduced to Cr (III), which then bound to functional groups on the adsorbent. Desorption under acidic conditions could recover 36% of the adsorbed Cr as Cr (III). No desorption occurred at a neutral pH, indicating irreversible adsorption. Overall, acid-modified banana peel is an efficient, low-cost and eco-friendly adsorbent for removing toxic Cr (VI) from wastewater. |
| first_indexed | 2024-04-25T00:24:04Z |
| format | Article |
| id | doaj.art-1a226cfdd4a84a84ae818c6af0a85c80 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-04-25T00:24:04Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-1a226cfdd4a84a84ae818c6af0a85c802024-03-12T16:50:39ZengMDPI AGMolecules1420-30492024-02-0129599010.3390/molecules29050990Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) AdsorbentsZhouyang Huang0Robyn Campbell1Chirangano Mangwandi2School of Chemistry and Chemical Engineering, Queen’s University Belfast, David Kier Building, Stranmillis Road, Belfast BT95AG, Northern Ireland, UKSchool of Chemistry and Chemical Engineering, Queen’s University Belfast, David Kier Building, Stranmillis Road, Belfast BT95AG, Northern Ireland, UKSchool of Chemistry and Chemical Engineering, Queen’s University Belfast, David Kier Building, Stranmillis Road, Belfast BT95AG, Northern Ireland, UKBanana peel waste is abundant and can be utilized as a low-cost adsorbent for removing toxic Cr (VI) from wastewater. The acid modification of banana peels significantly enhances their adsorption capacity for Cr (VI). An adsorbent was prepared by treating banana peel powder with 50% H<sub>2</sub>SO<sub>4</sub> at 50 °C for 24 h. The acid treatment increased the surface area of the adsorbent from 0.0363 to 0.0507 m<sup>2</sup>/g. The optimum adsorbent dose was found to be 1 g/L for the complete removal of Cr (VI) from 100 ppm solutions. The adsorption capacity was 161 mg/g based on the Langmuir isotherm model. The adsorption kinetics followed a pseudo-second order model. Increasing the temperature from 20 to 50 °C increased the initial adsorption rate but had a minor effect on the equilibrium adsorption capacity. Thermodynamics studies showed that the process was spontaneous and endothermic. The activation energy was estimated as 24.5 kJ/mol, indicating physisorption. FTIR analyses before and after adsorption showed the involvement of hydroxyl, carbonyl and carboxyl groups in binding the Cr (VI). The Cr (VI) was reduced to Cr (III), which then bound to functional groups on the adsorbent. Desorption under acidic conditions could recover 36% of the adsorbed Cr as Cr (III). No desorption occurred at a neutral pH, indicating irreversible adsorption. Overall, acid-modified banana peel is an efficient, low-cost and eco-friendly adsorbent for removing toxic Cr (VI) from wastewater.https://www.mdpi.com/1420-3049/29/5/990banana peelchromiumdesorptionwastewaterreductionsulfuric acid |
| spellingShingle | Zhouyang Huang Robyn Campbell Chirangano Mangwandi Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) Adsorbents Molecules banana peel chromium desorption wastewater reduction sulfuric acid |
| title | Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) Adsorbents |
| title_full | Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) Adsorbents |
| title_fullStr | Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) Adsorbents |
| title_full_unstemmed | Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) Adsorbents |
| title_short | Kinetics and Thermodynamics Study on Removal of Cr(VI) from Aqueous Solutions Using Acid-Modified Banana Peel (ABP) Adsorbents |
| title_sort | kinetics and thermodynamics study on removal of cr vi from aqueous solutions using acid modified banana peel abp adsorbents |
| topic | banana peel chromium desorption wastewater reduction sulfuric acid |
| url | https://www.mdpi.com/1420-3049/29/5/990 |
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