Enhanced Adsorption of Zn(II) onto Graphene Oxides Investigated Using Batch and Modeling Techniques

Nanomaterials

Chang Liu¹  Min Pan²  Xiaoming Huang²  Xinxin Lin²  Guangxue Wu³ 

[1] College of Environmental Science and Engineering, Anhui Normal University, Wuhu 241002, China;Fujian Engineering and Research Center of Rural Sewage Treatment and Water Safety, School of Environmental Science and Engineering, Xiamen University of Technology, Xiamen 361024, China;Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China;

关键词: graphene oxides;    surface complexation modeling;    adsorption;    Zn(II);   

DOI  :  10.3390/nano8100806

来源: DOAJ

【 摘 要 】

Graphene oxide (GO) was synthesized and employed as an adsorbent for Zn(II) removal from an aqueous solution. The adsorption isotherms showed that Zn(II) adsorption can be better described using the Freundlich model than the Langmuir model. The maximum adsorption capacity of Zn(II) on GO determined using the Langmuir model at pH 7.0 and 293 K was 208.33 mg/g. The calculation of thermodynamic parameters revealed that the process of Zn(II) adsorption on GO was chemisorptions, endothermic, and spontaneous. Kinetic studies indicated that the pseudo-second-order kinetic model showed a better simulation of Zn(II) adsorption than the pseudo-first-order kinetic model. On the basis of surface complexation modeling, the double layer model provided a satisfactory prediction of Zn(II) by inner-sphere surface complexes (for example, SOZn+ and SOZnOH species), indicating that the interaction mechanism between Zn(II) and GO was mainly inner-sphere complexation. In terms of reusability, GO could maintain 92.23% of its initial capability after six cycles. These findings indicated that GO was a promising candidate for the immobilization and preconcentration of Zn(II) from aqueous solutions.

【 授权许可】

Unknown