A Spherical Zwitterionic Cellulose Acetate/ Graphene Oxide Composite Adsorbent for Efficient Removal of Cu2+ and Cd2+ from Aqueous Solution

Abstract

A novel composite adsorbent was prepared by using cellulose acetate modified with zwitterion, for zwitterionic cellulose acetate (ZCA), then blended with graphene oxide (GO). The adsorbent was prepared by solgel method and used to remove Cu 2+ and Cd 2+ from aqueous solution. The morphologies, surface chemical structures, and crystallinity of the obtained adsorbents were characterized by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffractometer (XRD), respectively. N2 adsorptiondesorption measurements revealed that the surface area and pore volume were 45.3 m 2 g -1 and 0.249 cm 3 g -1 . For adsorption, effect of time, and pH, adsorbate concentration was investigated; different adsorption models were also evaluated. The results showed that the maximum adsorption capacity was 32.0 mg/g for Cu 2+ and 27.6 mg/g for Cd 2+ , observed at pH 5.5 and 298 K. Simultaneously, the adsorption isotherms were well-fitted to the Langmuir model, and kinetics study showed that the adsorption process was fitted well by the pseudo-second-order model. Further regeneration experiments revealed that the adsorption of ZCA/GO was about 90% of the initial saturation adsorption capacity after repeated use 5 times, indicating that they are promising absorbents for practical application in industry.

Removal of Antidiabetic Pharmaceutical (Metformin) Using Graphene Oxide Microcrystalline Cellulose (GOMCC): Insights to Process Optimization, Equilibrium, Kinetics, And Machine Learning

“…The D-band (antipairing (E2g) phonons) in the graphite was dramatically improved and lifted to 1288 cm –1 in the GO, demonstrating the decrease in the extent of the in-plane sp 2 vibrations due to complete oxidation and exfoliation . The Raman peaks found around 1098 cm –1 (D band) and 1118 cm –1 (G band) in the Raman spectra of GOMCC suggested that as the disorder of the GO sheets composited with lignocellulosic materials increased, so did the vibration of sp 2 carbons and antipairing photons. , The GO’s I D / I G ratio was close to 0.97, while the GOMCC’s was 1.09. The I D / I G ratio is increased while converting GO to GOMCC by compositing with cellulose due to the reduction in the sp 2 group size caused by removing oxygen groups .…”

“…17 The Raman peaks found around 1098 cm −1 (D band) and 1118 cm −1 (G band) in the Raman spectra of GOMCC suggested that as the disorder of the GO sheets composited with lignocellulosic materials increased, so did the vibration of sp 2 carbons and antipairing photons. 21,39 The GO's I D /I G ratio was close to 0.97, while the GOMCC's was 1.09. The I D /I G ratio is increased while converting GO to GOMCC by compositing with cellulose due to the reduction in the sp 2 group size caused by removing oxygen groups.…”