Ethylenediamine-Functionalized Graphene Oxide Nanosheets for Modifying Chitosan/Polyvinyl Alcohol Membrane Adsorbents for RB19 Removal from Wastewater

Abstract

Graphene oxide (GO) was covalently functionalized with ethylenediamine (ED-GO) and characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, and field emission scanning electron microscopy techniques. Afterward, ED-GO-embedded chitosan/polyvinyl alcohol membrane adsorbents (CP/ED-GO) were fabricated by incorporating different amounts (0−1 wt %) of ED-GO, and the resultant membrane adsorbents were applied for the adsorption of reactive blue 19 dye (RB19) from water. According to the batch adsorption results, the adsorbent containing 0.25 wt % ED-GO possessed the best performance in RB19 removal. Adsorption of RB19 dye onto the CP/ED-GO-0.25 wt % membrane was also optimized using the response surface methodology. The solution pH, initial dye concentration, and adsorbent mass were selected as independent variables. The dye removal of 95% was achieved under the optimized conditions, close to the experimentally measured value, indicating the reliability of the optimization. Isothermal adsorption experiments revealed that RB19 dye adsorption onto CP, CP/ED-GO-0.25 wt %, and CP/GO-0.25 wt % could be well described by the Freundlich isotherm model. The adsorption kinetic of RB19 dye using CP, CP/ED-GO-0.25 wt %, and CP/GO-0.25 wt % membrane adsorbents followed the pseudo-second-order kinetic pattern. The adsorption capacity values of 333.33 1 , 303.03, and 256.41 mg g −1 were obtained for CP/ED-GO-0.25 wt %, CP, and CP/GO membrane adsorbents, respectively. In summary, the CP/ED-GO-0.25 wt % membrane was found to be a promising adsorbent for wastewater decoloring.

Diethylenetriamine-functionalized reduced graphene oxide having more amino groups for methylene blue removal

“…The products or composites possessed excellent properties. These compounds might include 1-aminopropyl-3methylimidazolium chloride, 7 1,4-phenylenediamine or 2,3,5,6-tetramethyl-1,4-phenylenediamine, 8,9 amino-modied MXene (3-trimethoxysilylpropan-1-amine modied MXene), 10 ethylenediamine, [11][12][13] 4,4 ′ -diaminodiphenylmethane, 14 and amino acids (e.g., alanine, tyrosine, and cysteine). 15 The epoxide of GO can also react with an amino group that is also attached directly or indirectly to the graphene sheet.…”