磁性蚕砂基活性炭的制备及其在吸附方面的应用
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摘要
以掺杂了纳米Fe3O4的蚕砂为前体材料,经碳化和NaOH活化制备磁性蚕砂基活性炭。磁性的蚕砂基活性炭对亚甲基蓝具有599.6mg/g饱和吸附量。振动样品磁强计测定磁性蚕砂基活性炭的饱和磁化强度是16.77 emu/g,具有良好的磁分离性能。从热力学和动力学的角度,以磁性蚕砂基活性炭为吸附剂,以亚甲基蓝溶液为吸附质,研究了磁性蚕砂基活性炭对吸附质的吸附行为。磁性蚕砂基活性炭对亚甲基蓝的吸附遵循伪二级模型。磁性蚕砂基活性炭对亚甲基蓝的吸附遵循Langmuir等温线模型这意味着吸附限于染料分子在磁性蚕砂基活性炭表面上均匀单层覆盖。
Magnetic silkworms' feces-based activated carbons were obtained by chemical activation method from silkworms' feces that were fixed with the Fe3 O4 nanoparticles. Magnetic silkworms' feces-based activated carbons exhibited 16.77 emu/g saturation magnetization(Ms) and 599.6 mg/g maximum adsorption capacity toward Methylene Blue at pH=8. Based on the R2 values, Langmuir isotherm model yielded better fit with better R2 value compared to the Freundlich isotherm model. This implied that adsorption was limited to monolayer coverage of dye molecule on the homogenous surface of magnetic silkworms' feces-based activated carbons. The adsorption of methylene blue onto magnetic silkworms' feces-based activated carbons follows the pseudo-second order model, which indicates that the adsorption process was dominated by chemisorption.
Magnetic silkworms' feces-based activated carbons were obtained by chemical activation method from silkworms' feces that were fixed with the Fe3 O4 nanoparticles. Magnetic silkworms' feces-based activated carbons exhibited 16.77 emu/g saturation magnetization(Ms) and 599.6 mg/g maximum adsorption capacity toward Methylene Blue at pH=8. Based on the R2 values, Langmuir isotherm model yielded better fit with better R2 value compared to the Freundlich isotherm model. This implied that adsorption was limited to monolayer coverage of dye molecule on the homogenous surface of magnetic silkworms' feces-based activated carbons. The adsorption of methylene blue onto magnetic silkworms' feces-based activated carbons follows the pseudo-second order model, which indicates that the adsorption process was dominated by chemisorption.
引文
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[2]Elshafei G M S,Elsherbiny I M A,Darwish A S,et al.Silkworms’feces-based activated carbons as cheap adsorbents for removal of cadmium and methylene blue from aqueous solutions[J].Chemical Engineering Research&Design,2014,92(3):461-470.