Methylene Blue Adsorption from Aqueous Solution by Magnetic Cellulose/Graphene Oxide Composite: Equilibrium, Kinetics, and Thermodynamics

Abstract

In the present study, magnetic cellulose/graphene oxide composite (MCGO) was prepared as a novel adsorbent to dispose of dye wastewater. The morphology and chemical structure of the MCGO composite were characterized by the Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), and scanning electronic microscope (SEM). The adsorption of methylene blue (MB) onto MCGO was studied in relation to initial concentration of MB, contact time, adsorbent dose, and pH value of solution. Adsorption kinetics and the equilibrium adsorption isotherm were fitted by a pseudo-secondorder kinetic model and Langmuir isotherm, respectively. The thermodynamic parameters indicated that the adsorption was spontaneous, favorable, and exothermic in nature. Furthermore, MCGO was very stable and can easily be recycled. The adsorption efficiency of MCGO was still over 89% after recycling for five times.

Removal of methylene blue from water by cellulose/graphene oxide fibres

“…As the table shows, the MB adsorption capacity of CGO fibre is higher than carbon nanotube, [12] graphene, [13] magnetic CGO, [24] magnetic chitosan/graphene oxide, [33] and graphene oxide/calcium alginate. [23] Furthermore, the Langmuir isotherm model can be described by a separation factor, which is defined by the following equation [34]: where k L is the Langmuir constant (L/mg) and C 0 is the initial dye concentration (mg/L).…”

“…The decrease of the adsorption capacity under acidic condition may be attributed to the electrostatic repulsion between the positively charged surface of CGO fibres and MB cations. [24] As the pH increases, the carboxyl and hydroxyl groups of the CGO fibres are deprotonated to form ÀCOO -and ÀO -groups, which leads to an electrostatic attraction between the negatively charged surface of the CGO fibres and the MB cations, thus, leading to an increase in the adsorption capacity.…”

“…Shi et al [24] produced a magnetic cellulose/graphene oxide (CGO) composite for the adsorption of MB. However, the adsorption capacity (70 mg/g) is much lower than other common adsorbents; this may be attributed to the occupation of adsorption sites by magnetic Fe 3 O 4 nanoparticles.…”

Hybrid Monolith of Graphene/TEMPO-Oxidized Cellulose Nanofiber as Mechanically Robust, Highly Functional, and Recyclable Adsorbent of Methylene Blue Dye

“…However, higher content of CNFs showed little improvement in dye adsorption capacity and specific surface area, which could be explained as follows: higher incorporation of CNFs leads to aggregation into pore orifice thus reducing the full surface area coverage of hybrid monolith for dye molecules. Based on Table S4, candidate hybrid adsorbent showed notable adsorption performance compared with other reported work such as high cost carbon nanotube (CNT) [13], graphene/CNT monolith [33], MWCNT aerogel [51], graphene by toxic hydrazine [27], graphene/luffa sponge [12], thiourea assisted graphene sponge [31], polydopamine microspheres [23], polyaniline hydrogel [26], magnetic particle based graphene composite [9,19,[34][35][36][37][38], graphene coated biochar [40], and graphene oxide/calcium alginate [14]; for more comparison see Table S4.…”

Bionanocomposites for Magnetic Removal of Water Pollutants

“…On the other hand, the chitosan coating prevented particle agglomeration and also provided free amine groups for coordination to aqueous heavy metal ions. Magnetite cellulose/graphene oxide composites were prepared using a co-precipitation method [81]. By loading cellulose with Fe 3 O 4 NPs and GO, a rough texture at the surface of the matrix was achieved, which improved the sorption capacity of the composite in the magnetic removal of an azo dye.…”