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| Adsorption of As(Ⅴ) from Aqueous Solution by Lanthanum Oxide-loaded Biochar:Process and Mechanisms |
| Received:June 05, 2015 |
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| KeyWord:lanthanum;biochar;As(Ⅴ);adsorption |
| Author Name | Affiliation | E-mail | | FENG Yan-fang | Institute of Resources and Environment, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture, Jiangsu Academy of Agriculture Sciences, Nanjing 210014, China
Institute of Soil Science, State Key Laboratory of Soil and Sustainable Agriculture, Chinese Academy of Sciences, Nanjing 210008, China | | | XUE Li-hong | Institute of Resources and Environment, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture, Jiangsu Academy of Agriculture Sciences, Nanjing 210014, China | | | YANG Bei | Institute of Resources and Environment, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture, Jiangsu Academy of Agriculture Sciences, Nanjing 210014, China | | | LIU Yang | Institute of Soil Science, State Key Laboratory of Soil and Sustainable Agriculture, Chinese Academy of Sciences, Nanjing 210008, China
Institute of Agricultural Economics and Information, Jiangsu Academy of Agriculture Sciences, Nanjing 210014, China | | | DUAN Jing-jing | Institute of Resources and Environment, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture, Jiangsu Academy of Agriculture Sciences, Nanjing 210014, China | | | HE Shi-ying | Institute of Resources and Environment, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture, Jiangsu Academy of Agriculture Sciences, Nanjing 210014, China | | | YANG Lin-zhang | Institute of Resources and Environment, Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture, Jiangsu Academy of Agriculture Sciences, Nanjing 210014, China
Institute of Soil Science, State Key Laboratory of Soil and Sustainable Agriculture, Chinese Academy of Sciences, Nanjing 210008, China | Lzyang@issas.ac.cn |
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| Abstract: |
| In this study, a lanthanum(La)-loaded biochar was prepared by impregnating, loading, and carbonizing La oxide nanoparticles with biochar derived from corn stalk and was used to study its removal of As(Ⅴ) from aqueous solutions. The prepared La-biochar was characterized by scanning electron microscopy(SEM) and X-ray photoelectron spectra(XPS). The effects on As(Ⅴ) adsorption by various factors, including adsorbent rate, contact time, solution pH, and initial As(Ⅴ) concentrations, were investigated. The removal efficiency of As(Ⅴ) increased with increasing La-biochar rates. The maximum adsorption was attained when the adsorbent rate was 2.0 g·L-1. However, the removal efficiency decreased as the solution pH increased. The adsorption isotherm of As(Ⅴ) on La-biochar was well described by Langmuir adsorption model and Freundlich adsorption isotherm, with better fitting by Langmuir model. The maximum adsorption capacity estimated by the Langmuir model was 38.02 mg·g-1, which was higher than the previous reported adsorption amount for biochars. This La-biochar adsorbed As(Ⅴ) very fast, with the adsorption being equilibrated within 60~90 min. The kinetics of As(Ⅴ) adsorption followed the pseudo-second-order kinetic model. Moreover, intraparticle diffusion model showed that diffusion was present between particles during adsorption process. The dominant adsorption mechanism might be complicated ion exchange. The results indicate La-biochar would be a promising adsorbent that can be utilized in purifying As(Ⅴ)-contaminated water. |
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