零价铁/氧化石墨烯复合吸附剂对染料和重金属的吸附性能

针对目前酸性染料染色废水中染料和重金属Cr(Ⅵ)引起的严重环境污染问题,以零价铁(Fe⁰)/氧化石墨烯(GO)复合物作为吸附剂,以分别含有弱酸性蓝AS和Cr(Ⅵ)的水溶液模拟染色废水,探究Fe⁰与GO的质量比、溶液pH值及染料与Cr(Ⅵ)的初始质量浓度对吸附性能的影响,考察Fe⁰/GO吸附剂对酸性染料与Cr(Ⅵ)的吸附机制,研究其吸附热力学与动力学。结果表明:Fe⁰与GO吸附剂在质量比为4∶1时具有最佳吸附效果,弱酸性蓝AS染液初始质量浓度为75 mg/L,温度为30 ℃,pH值为4.0时,12 h后去除率为85.6%,最大吸附量达到85.6 mg/g;Cr(Ⅵ)溶液初始质量浓度为75 mg/L,温度为30 ℃,pH值为3.0时,12 h后去除率为95.8%,最大吸附量达到95.8 mg/g;Fe⁰/GO对2种污染物的吸附过程均符合Langmuir模型和准二级动力学模型。

Dye and heavy metal adsorption performance of zero-valent iron/graphene oxide blend absorbent

In order to combat the serious pollution caused by dyes and heavy metal Cr(Ⅵ) in acid dye, zero-valent iron (Fe⁰)/graphene oxide (GO) compound was used as an adsorbent. The aqueous solutions containing Weak Acid Blue AS dye and heavy metal Cr(Ⅵ), respectively, were employed to simulate dye wastewater. The effects of the mass ratio of Fe⁰ and GO, the pH value of solution, and the initial mass concentration of dye and Cr(Ⅵ) on the adsorption performance were analyzed. The adsorption mechanism of Fe⁰/GO blend adsorbent for acid dye and Cr(Ⅵ) was investigated, and the adsorption thermodynamics and kinetics were studied. The results show that Fe⁰/GO blend adsorbent has the best adsorption capacity when the weight ratio is 4∶1. When the initial concentration of dye wastewater is 75 mg/L at 30 ℃ and pH is 4.0, the removal percentage is 85.6% after 12 h, and the maximum adsorption capacity reaches 85.6 mg/g. When the initial concentration of Cr(Ⅵ) is 75 mg/L at 30 ℃ and pH is 3.0, the removal percentage reaches 95.8% after 12 h, and the maximum adsorption capacity reaches 95.8 mg/g. The adsorption processes to both acid dye and Cr(Ⅵ) were both in accordance with the Langmuir model and the pseudo-second-order kinetic model.