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

PLoS One. 2017 Oct 30;12(10):e0187166. doi: 10.1371/journal.pone.0187166. eCollection 2017.

Abstract

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.

MeSH terms

  • Adsorption
  • Chromium / isolation & purification*
  • Ethylenediamines / chemistry*
  • Ferrosoferric Oxide / chemistry*
  • Graphite / chemistry*
  • Hydrogen-Ion Concentration
  • Microscopy, Electron, Transmission
  • Thermodynamics

Substances

  • Ethylenediamines
  • Chromium
  • chromium hexavalent ion
  • Graphite
  • Ferrosoferric Oxide

Grants and funding

This study was financially supported by the National Natural Science Foundation of China (Grant No. 5160820 to Xinjiang Hu), the Project funded by China Postdoctoral Science Foundation (Grant No. 2017M610513 Xinjiang Hu), the Research Foundation of Education Department of Hunan Province, China (Grant No. 17K105 to Xinjiang Hu), the Natural Science Foundation of Guangdong Province (grant numbers 2016A030310246 and 2016A030310456 to Xinjiang Hu), the Science and Technology Planning Project of Hunan Province (grant numbers 2016TP2007 and 2016TP1014 to Yunlin Zhao), and the Scientific Research Staring Foundation for the attracted talent of Central South University of Forestry and Technology (grant number 2016YJ001 to Xinjiang Hu). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.