Adsorption Performance of Methyl Violet via α-Fe2O3@Porous Hollow Carbonaceous Microspheres and Its Effective Regeneration through a Fenton-Like Reaction

Abstract

α-Fe 2 O 3 @porous hollow carbonaceous microspheres (α-Fe 2 O 3 @PHCMs) were prepared through a combination of hydrothermal and calcination method. The novel α-Fe 2 O 3 @PHCMs integrated the adsorptive and catalytic performances and served as an inexpensive adsorbent to rapidly remove cationic dye (methyl violet (MV)) from aqueous solution. Equilibrium studies indicated that the dye molecules obeyed Langmuir type of adsorption with the calculated maximum adsorption capacity of 539.8 mg¨g´1 at 313.15 K. Kinetic data were better described by pseudo-second-order model and the thermodynamic studies illustrated that MV adsorption onto the composite was spontaneous, endothermic and occurred by physisorption. The Fenton-like process was found to be effective for the regeneration of the spent α-Fe 2 O 3 @PHCMs. The regeneration efficiency, as high as 88.0%, was still maintained after three consecutive adsorption-regeneration cycles. FTIR and XRD characterizations of the composite before and after adsorption-regeneration treatment showed that the Fenton-like process did not cause serious damage to the structure of composites.

Single step modification of micrometer‐sized polystyrene particles by electromagnetic polyaniline and sorption of chromium(VI) metal ions from water

“…Whereas the theoretical q e value (1.2 mg g −1 ) estimated from the pseudo‐first‐order kinetic model [Figure (a)] is much less than the experimental value (3.0 mg g −1 ). This strongly suggests that the adsorption of Cr(VI) on the PS/PANi–Fe 3 O 4 composite particles followed pseudo‐second‐order rate process and the adsorption process was controlled by chemisorptions …”

“…In order to understand the mechanism and rate controlling steps involved in the adsorption process, pseudo‐first‐order and pseudo‐second‐order kinetic models were used to test the experimental data obtained from the time‐dependent adsorption study at 298 K (Figure ). The pseudo‐first‐order kinetic model is expressed by the following Lagergren rate equation where q t (mg g −1 ) is the amount of Cr(VI) adsorbed on the surface of the PS/PANi–Fe 3 O 4 composite particles at any time t , k 1 (min −1 ) is equilibrium rate constant of the pseudo‐first‐order adsorption.…”

Green one‐pot preparation of α‐Fe2O3@carboxyl‐functionalized yeast composite with high adsorption and catalysis properties for removal of methylene blue

“…The Langmuir isotherm model on account of monolayer adsorptions can be given as where q e (mg/g) and C e (mg/L) are the equilibrium adsorption capacity and the equilibrium concentration, q m (mg/g) is the maximum monolayer adsorption capacity at equilibrium condition, and K L (L/mg) is the Langmuir adsorption constant. To determine whether the adsorption of MB is favorable, an equilibrium parameter R L is investigated on the basis of Langmuir isotherm and could be described as where K L (L/mg) is the above‐mentioned Langmuir adsorption constant and C 0 (mg/L) is the initial MB concentration, respectively. The value of parameter R L reveals the nature of the adsorption process of α‐F@CFYC, which is favorable (0 < R L < 1) or unfavorable ( R L > 1).…”

Removal of Metanil Yellow by Batch Biosorption from Aqueous Phase on Egg Membrane: Equilibrium and Isotherm Studies

“…Different methods have been developed to remove synthetic dyes from wastewater in order to reduce their impact on the environment. The methods include floatation, electro-coagulation, ozonation, photo-catalytic degradation, chemical oxidation, precipitation, filtration and adsorption [3,13]. Adsorption is superior to the other mentioned methods due its low cost, flexibility, simplicity of design, ease of operation and insensitivity to toxic pollutants [13].…”