Rapid adsorption of industrial cationic dye pollutant using base-activated rice straw biochar: performance, isotherm, kinetic and thermodynamic evaluation
Abstract This work intends to effectively remove methylene blue (MB) dye from wastewater using an agricultural waste-derived sorbent made from pyrolyzing rice straw to generate biochar. This is done while keeping the sustainability idea in mind and tackling the crises arising from environmental cont...
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| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Springer
2025-01-01
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| Series: | Discover Sustainability |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/s43621-025-00835-4 |
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| Summary: | Abstract This work intends to effectively remove methylene blue (MB) dye from wastewater using an agricultural waste-derived sorbent made from pyrolyzing rice straw to generate biochar. This is done while keeping the sustainability idea in mind and tackling the crises arising from environmental contamination with dyes. The physicochemical scrutinization of the non-activated and the base-activated biochar materials showed that the materials have promising textural properties and surface functionalization, leading to high and fast capability to retrieve MB from aqueous solutions in alkaline conditions. The adsorption equilibrium for all the biochar was reached within a time span of 15 min, but 90 percent of the dye removed at equilibrium was already eliminated in less than 5 min. The behaviour of the equilibrium adsorption for the biochar materials was thoroughly assessed using Langmuir and Freundlich adsorption isotherms. Interestingly, the adsorption process for the base-activated biochar follows both Langmuir and Freundlich isotherms at higher pH. The base-activated biochar exhibited a maximum adsorption capacity of 129.87 mg/g at alkaline pH. The adsorption data analysis with various kinetic models revealed that the adsorption process follows a pseudo-second-order kinetics for all the biochar materials. The Gibbs free energy and activation energy studies clearly revealed the adsorption of MB on biochar to be spontaneous and physiosorption in nature. The adsorption mechanism of the fast and efficient removal of MB by the base-activated biochar involves electrostatic interactions, hydrogen bonding, n-π and π-π interactions. Overall, the base-activated biochar with higher and faster adsorption capacity in alkaline conditions is a promising low-cost bioadsorbent with a simple production process for the removal of cationic dyes from aqueous environments and practical dyeing wastewater purification. |
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| ISSN: | 2662-9984 |