膨胀石墨负载氧化锌吸附废水中的Cr(Ⅵ)

Adsorption of Cr(Ⅵ) in Wastewater by Expanded Graphite Supported Zinc Oxide

采用化学氧化法将氧化锌负载在膨胀石墨表面,制备了膨胀石墨氧化锌复合材料。以废水中的Cr(VI)为去除对象,采用静态吸附法,研究了Cr(VI)在膨胀石墨氧化锌表面的吸附行为,探讨了Cr(VI)初始浓度、溶液pH等因素对吸附效果的影响;并从吸附热力学和动力学角度讨论了吸附机理。结果表明,吸附量可达99.46 mg/g,吸附焓变为11.64 kJ/mol;拟二级动力学模型和Langmuir等温方程式能较好的拟合吸附过程,证明Cr(VI)主要以单分子层形式被吸附于吸附剂表面且整个吸附过程放热反应占主导地位。

Expanded graphite zinc oxide composites were prepared by chemical oxidation of zinc oxide on the surface of expanded graphite.The Cr(VI)in wastewater as the removal object,the adsorption behavior of Cr(VI) on the surface of expanded graphite zinc oxide was studied by static adsorption method. The adsorption effect of Cr(VI) initial concentration and solution p H on the adsorption effect was investigated. The adsorption mechanism was discussed from the perspective of adsorption thermodynamics and kinetics. The results showed that the adsorption capacity could reach 99.46 mg/g and the adsorption enthalpy changed to 11.64 kJ/mol. The pseudo second-order kinetic model and the Langmuir isotherm equation could better fit the adsorption process, which proved that Cr(VI) was mainly adsorbed on the surface of adsorbent with monolayer, and the exothermic reaction dominated the entire adsorption process.