磁性氧化石墨烯和磁性竹炭对Cr(Ⅵ)的吸附

Adsorption of Cr(Ⅵ) on Magnetic Graphene Oxide and Magnetic Bamboo Charcoal

制备了两种磁性碳基材料——磁性氧化石墨烯(MGO)和磁性竹炭(MBC),并将其用于模拟含Cr(Ⅵ)废水的吸附。采用SEM,BET,FTIR技术对吸附剂进行了表征。表征结果显示:MBC具有与MGO相似的薄片层结构,且MBC的BET比表面积更大(为32.872 6 m2/g),可为Cr(Ⅵ)提供大量的吸附位点。实验结果表明:向100 m L废水中加入20.0 mg吸附剂,在废水p H为1.0、吸附温度为30℃、初始Cr(Ⅵ)质量浓度为10.0 mg/L的条件下,MGO和MBC的平衡吸附时间分别为50,70 min,平衡吸附量分别为37.7,49.7 mg/g,吸附平衡时的Cr(Ⅵ)去除率分别为75.4%和99.4%;两种磁性材料对Cr(Ⅵ)的吸附均很好地符合Langmuir等温吸附模型;在酸性介质中,MGO和MBC的表面基团与HCr2O7-和Cr2O72-之间有氢键作用。

Magnetic graphene oxide （MGO） and magnetic bamboo charcoal （MBC） were prepared, and used in adsorption of Cr（Ⅵ） from the simulated wastewater. The two kinds of adsorbents were characterized by SEM, BET and FTIR. The results show that： They have similar tiny-sheet structures but MBC has a larger BET specific surface area （32.872 6 m^2/g）, it can provide more adsorption sites to Cr（Ⅵ）. The experimental results show that Under the conditions of adding MGO 20.0 g or MBC 20.0 g into 100 mL of wastewater with pH 1.0 and Cr（Ⅵ） mass concentration 10.0 mg/L, and adsorption temperature 30 ℃, the adsorption equilibrium times are 50 min and 70 min, the adsorption capacities are 37.7 mg/g and 49.7 mg/g, the Cr（Ⅵ） removal rates are 75.4% and 99.4% respectively; The adsorptions of Cr（Ⅵ） on MGO and MBC both accord with Langmuir isotherm equation; In acidic medium, the surface groups of MOO and MBC are linked with HCrEO7^- and Cr2O7^2- via hydrogen bonding interaction.