热解炭去除污水中Cr(Ⅵ)（英文）

Removal of Cr(Ⅵ) from aqueous solution by pyrolytic charcoals

以胡桃壳在450℃裂解得到生物质炭BC450,以胡桃壳与20%沥青砂在450℃裂解得到BCTS20,与商业活性炭(CAC)进行对比研究去除污水中Cr(Ⅵ)的能力。与BC450相比,BCTS20具有更丰富的表面官能团。在适当条件下,BC450、BCTS20、CAC对Cr(Ⅵ)的去除率分别为80.47%、90.01%、95.69%。采用Langmuir、Freundlich、D-R模型研究吸附等温线,其中Langmuir模型最佳。BC450、BCTS20、CAC的最大Langmuir吸附容量分别为36.55、49.76、51.94 mg/g。这些炭材料对Cr(Ⅵ)的吸附可能归因于由离子交换、静电作用与螯合作用引起的化学过程。

Bio-chars produced by the pyrolysis of walnut shells at 450 ℃（BC450） and theco-pyrolysis of walnut shells and20 wt%tar sand（BCTS20） at the same temperature,were investigated as potential adsorbents for the removal of Cr（Ⅵ） ions from aqueous solutions using batch experiments.The BCTS20 has more abundant surface functional groups than BC450.The Cr（Ⅵ） removal percentages under optimal conditions were 80.47 and 95.69%for BC450 and BCTS20,respectively.Langmuir,Freundlich and D-R models were used to fit the adsorption isotherms and the Langmuir model described the adsorption isotherms best.The adsorption of Cr（Ⅵ） was by a chemical process dominated by ion-exchange,electrostatic attraction and chelation.The maximum Langmuir adsorption capacities were 36.55 and 49.76 mg per g of BC450 and BCTS20,respectively.The maximum Langmuir adsorption capacity of BCTS20 is comparable to that of some reported commercial activated carbons.