Ethylenediamine grafted to graphene oxide@Fe3O4 for chromium(VI) decontamination: Performance, modelling, and fractional factorial design

by Xinjiang Hu, Jiawen Xu, Cuiyu Wu, Jianbin Deng, Wenwei Liao, Yuxiang Ling, Yuanxiu Yang, Yina Zhao, Yunlin Zhao, Xi Hu, Hui Wang, Yunguo Liu

A method for grafting ethylenediamine to a magnetic graphene oxide composite (EDA-GO@Fe₃O₄) was developed for Cr(VI) decontamination. The physicochemical properties of EDA-GO@Fe₃O₄ were characterized using HRTEM, EDS, FT-IR, TG-DSC, and XPS. The effects of pH, sorbent dose, foreign anions, time, Cr(VI) concentration, and temperature on decontamination process were studied. The solution pH can largely affect the decontamination process. The pseudo-second-order model is suitable for being applied to fit the adsorption processes of Cr(VI) with GO@Fe₃O₄ and EDA-GO@Fe₃O₄. The intra-particle diffusion is not the rate-controlling step. Isotherm experimental data can be described using the Freundlich model. The effects of multiple factors on the Cr(VI) decontamination was investigated by a 2⁵⁻¹ fractional factorial design (FFD). The adsorption process can significantly be affected by the main effects of A (pH), B (Cr(VI) concentration), and E (Adsorbent dose). The combined factors of AB (pH × Cr(VI) concentration), AE (pH × Adsorbent dose), and BC (Cr(VI) concentration × Temperature) had larger effects than other factors on Cr(VI) removal. These results indicated that EDA-GO@Fe₃O₄ is a potential and suitable candidate for treatment of heavy metal wastewater.

from ! Medicine by Alexandros G. Sfakianakis via als.fakia on Inoreader http://ift.tt/2gNX1JS
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