Preparation Of Amino Modified Magnetic Graphene Oxide Composite As Novel Absorbent And Its Adsorption Properties

Discharged heavy metal ions and dye seviously threaten the water environmental quality. Introducing adsorbants into the polluted water body, polluants can be isolated fast through adsorption process in this article. Adsorbents therefore have been comprehensively applied for water purification.In this work, GO was modified by triethylene tetramine?TETA? through isothermal stirring method on the surface then loaded with magnetic nanoparticles of cobalt ferrite by hydrothermal method, which resulted in synthesizing a novel composite adsorbent Magnetic Triethylene Tetramine Graphene Oxide?MTGO?. The characterization of MTGO by FTIR and XPS indicated that the chemical bonding between GO and TETA increase the adsorption sites. SEM, TEM and XRD results showed that MTGO presented lamellar structure with smooth surface and wrinkled edge. In addition magnetic nanoparticles of cobalt ferrite had been successfully introduced in MTGO which is thus endowed with the magnetic property, taking on a uniform dispersion.The component?TETA,Co Fe₂O₄ and GO? ratio of MTGO when reaching the highest adsorption capacity along with magnetic separation effect had also been obtained. Adopting the optimal component ratio, MTGO showed superior performance comparing with GO for the static adsorption of heavy metal ions? Cr??? and Cu???? as well as ionic dye?tartrazine?TY? and methylene blue?MB??, meanwhile can be recycled for several times.For Cr??? when pH was 2.0, the initial concentration of 200 mg·g-1 and the adsorption time was 2 h. After 5 times of adsorption, the adsorption amount was stable at 134.56 mg·g-1; Cationic Cu??? adsorption performances with the same adsorbent were studied. The results showed that the adsorption of Cu??? reached equilibrium when pH was 4.0, the initial concentration of 100 mg·g-1 and the adsorption time was 2 h. After 3 times of adsorption, the adsorption amount was stable at 201.46 mg·g-1. The adsorption process of Cr??? and Cu??? conforms to the pseudo-second-order model and Langmuir adsorption isotherm model. The results of Langmuir adsorption isotherm revealed that the saturated adsorption capacities of Cr??? and Cu??? were 183.82 mg·g-1 and 245.09 mg·g-1, respectively. The adsorption mechanism was speculated according to the XPS results: MTGO adsorbs Cr??? mainly through electrostatic attraction, additionally, the adsorption of Cu??? by MTGO mainly proceed through chelation.For TY, when pH was 1.0, the adsorption reached equilibrium when the initial concentration was 200 mg·g-1 and the adsorption time was 2.5 h; for MB, when pH was 12.0, the adsorption of MB reached equilibrium when the initial concentration was 200 mg·g-1 and the adsorption time was 5 h. After 5 times of adsorption, the adsorption amount of TY and MB was stable at 157.23 mg·g-1 and 167.22 mg·g-1, respectively. The adsorption process of TY and MB conformed to the pseudo-second-order model and Langmuir adsorption isotherm model. The results of Langmuir adsorption isotherm revealed that the saturated adsorption capacities of TY and MB are 157.23 mg·g-1 and 167.22 mg·g-1, respectively.