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| Characteristics and mechanism of cadmium adsorption by Solidago canadensis-derived biochar |
| Received:October 15, 2018 |
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| KeyWord:Solidago canadensis;biochar;cadmium;adsorption |
| Author Name | Affiliation | E-mail | | TANG Jia-wen | Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China | | | CHEN Jin-huan | Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China | | | WANG Kai-nan | Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China | | | ZHANG Qiu-zhuo | Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai 200241, China
Institute of Eco-Chongming(IEC), Shanghai 200062, China | qzhzhang@des.ecnu.edu.cn |
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| Abstract: |
| Solidago canadensis (Canadian goldenrod) is a herbaceous worldwide invasive plant, which spreads rapidly and poses a serious threat to ecological environments in China. In order to improve the management of this highly problematic alien invasive species and enhance resource utilization efficiency, Solidago canadensis-derived biochar was prepared in the present study. The basic properties of biochar produced at various pyrolysis temperatures were investigated. The optimum conditions for cadmium adsorption by biochar in aqueous solution were studied systematically through batch adsorption experiments. In addition, the adsorption mechanism was explored. The results showed that the SCBC450, which was the Solidago canadensis-derived biochar pyrolyzed at 450℃ by stem-leaf mixture as the raw material, out-performed the other prepared biochar. Three factors were selected for orthogonal experiments, and their influence on the adsorption of Cd2+ by biochar were as follows:initial concentration of adsorbate > pH > temperature. The highest adsorption efficiency Cd2+ could achieve was (95.6±0.38)% when the initial concentration of adsorbate was 50 mg·L-1 at 35℃ with pH 6. Under these optimal conditions, the adsorption process was better fitted using Langmuir isotherm and pseudo second-order model, which demonstrated that chemical adsorption dominated. The maximum theoretical adsorption capacity could reach 107.03 mg·g-1. The analysis of biochar by XPS, FTIR, and SEM-EDS analyses showed that ion exchange, complexation, precipitation, and physical adsorption were the main mechanisms of Cd2+ adsorption by SCBC450. Therefore, the study showed that Solidago canadensis-derived biochar has a great potential for cadmium adsorption in water treatment. |
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