Adsorptive removal of congo red dye from aqueous solutions using Mo-doped CoFe₂O₄magnetic nanoparticles

Abstract

Purpose The main purpose of this paper is to investigate the adsorption properties of CoFe1.9Mo0.1O4 magnetic nanoparticles (CFMo MNPs) using, anionic dye “congo red (CR)” as a model of water pollutants. Design/methodology/approach The magnetic nano-adsorbent was synthesized via sol-gel process. Different techniques including; Fourier transform infrared spectroscopy, point of zero charge, scanning electron microscope and X-ray powder diffraction were used to characterize the prepared adsorbent. Adsorption experiments were conducted in batch mode under various conditions (contact time, shaking speed, initial dye concentration, initial solution pH, solution temperature and adsorbent amount) to investigate the adsorption capability of CFMo MNPs for CR. Findings The results showed that, CFMo MNPs could successfully remove more than 90% of CR dye within 20 min. Adsorption kinetics and isotherms were better described using pseudo-second-order (PSO) and Langmuir models, respectively. The maximum adsorbed amount (qmax) of CR dye was 135.14 mg/g. The adsorption process was found to be endothermic and spontaneous in nature as demonstrated by the thermodynamics ( ΔGo, ΔHoand ΔSo). Practical implications This study provided a good example of using an easily separated magnetic nano-adsorbent for fast removal of a very toxic organic pollutant, congo red, from the aquatic environment Originality/value The employment of Mo-doped cobalt ferrite for the first time for removing hazardous anionic dyes such as congo red from their aqueous solutions.

Biosorption of Congo Red Dye from Aqueous Solution Using Adsorbent Prepared from Vangueria infausta Fruit Pericarp

“…However, when the temperature was increased beyond 328 K, the adsorption efficiency was reduced. These results corroborate those reported by Amar et al who utilized Mg-doped CoFe 2 O 4 nanoparticles to remove CR dye from aqueous solutions [9].…”

“…Furthermore, the intraparticle diffusion model was employed to better understand the underlying adsorption mechanism and the rate-determining step. From Equation (9), the intraparticle diffusion model suggests that if by plotting q t versus t 0:5 yields a linear graph passing through the origin, then intraparticle diffusion is the only rate-limiting step of the adsorption process. Figure 13(c) shows that the plot of q t versus t 0:5 is not linear over the whole range of time and did not pass through the origin.…”

“…Compared to other conventional methods, adsorption is preferred for dye removal due to its inexpensiveness, adsorbent versatility, simplicity, less sludge production, and high efficiency [9]. Various adsorbents such as chitosan, zeolites, clays, polymeric resins, and activated carbon materials have been reportedly employed for dye removal from aqueous solutions.…”

Efficient augmentation of superparamagnetic ferrite with alum sludge as a sustainable nanoadsorbent matrix for promoting dye removal: preparation, characterization and application

“…This demonstrates that the proposed adsorption process may be described by the pseudo-second-order q e q e model. Given that the experimental adsorption data ts the pseudo-second-order model well, it can be concluded that the characteristics of the adsorbent and adsorbate materials in uence the adsorption mechanism [39]. The pseudo-second-order model is based on the hypothesis that rate-determining step may be chemical sorption or chemisorption involving electron sharing or exchange between prepared adsorbents and two proposed adsorbates, i.e.…”

Synthesis, characterization of Lanthanum (III) / Terephthalate metal-organic framework, and potential use for Removal of anionic and cationic exchange contaminants

“…Separate 1 ml from the suspension adsorbent solution after every 10 minutes and centrifuge for 5 minutes, measure the absorbance using UV spectrophotometer at wavelength 496 nm for CR and 664nm for MB. Used the following equation to estimate the removal percentage (%) [19,24].…”