Enhancing adsorptive removal of sulfate by metal layered double hydroxide functionalized Quartz-Albitophire iron ore waste: preparation, characterization and properties

Horoz

et al. 2020

Environ Sci Pollut Res

In recent years, volatile organic compounds (VOCs) have become a group of major pollutants that endanger human health and the ecological environment. The main purpose of this study was to investigate the gas-phase adsorption processes of benzene and toluene, which are important VOCs, on the activated carbon (AC) produced from Elaeagnus angustifolia seeds by physical activation method. In this context, the central composite design (CCD) approach-based response surface methodology (RSM) was applied to examine and optimize the effects of process parameters on the adsorption of benzene and toluene by AC adsorbent. The characterization of the produced AC was performed by the Brunauer-Emmett-Teller surface area, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. The optimum process parameters were achieved (adsorption time of 74.98 min, initial benzene concentration of 16.68 ppm, and temperature of 26.97°C, and adsorption time of 73.26 min, initial toluene concentration of 18.46 ppm and temperature of 29.80°C) for benzene and toluene, respectively. The maximum adsorption capacities of benzene and toluene on AC were determined to be 437.36 and 512.03 mg/g, respectively, under optimum parameters. The adsorption process kinetics and equilibrium isotherms were also evaluated. Besides, AC reusability studies were performed five times for the gas-phase adsorption and desorption of benzene and toluene. After five cycles, it was observed that the benzene and toluene adsorption capacity of the AC decreased slightly by 8.10% and 7.42%, respectively. The results revealed that the produced AC could be utilized successfully for the removal of benzene and toluene in the gas-phase adsorption systems because of its high surface area, high adsorption capacity, and high reusability performance. Furthermore, the adsorption processes of benzene and toluene were investigated, both sole components and in a Highlights • Activated carbon (AC) was successfully produced, characterized, and used for the gas-phase adsorption of benzene and toluene. • The optimization of the process parameters for the maximum adsorption capacity of benzene and toluene by AC was performed by employing RSM. • Kinetic and isothermal parameters were determined for the gas-phase adsorption of benzene and toluene on AC. • The reusability study of AC was carried out for adsorption-desorption of benzene and toluene. • The maximum adsorption capacities of benzene and toluene on AC were determined to be 437.36 and 512.03 mg/g, respectively, under optimum parameters. • The adsorption behaviors of benzene and toluene against AC were quite different when they were in the competition and without competition.

Section: Equilibrium and Kinetic Models Fittingmentioning

confidence: 66%

High-performance gas-phase adsorption of benzene and toluene on activated carbon: response surface optimization, reusability, equilibrium, kinetic, and competitive adsorption studies

Baytar

Horoz

et al. 2020

Environ Sci Pollut Res

“…However, in the situation indicating 8 kJ mol -1 < E <16 kJ/mol and E >16 kJ mol -1 , adsorption occurs by ion exchange and diffusion, respectively. 29 In the study, the estimated qmax from the Langmuir model was 237.192 mg g -1 , KL was 0.281 l mg -1 . The R 2 value was 0.999, indicating the equilibrium isotherm data of benzene in the vapor-phase adsorption process by the Fe3O4@SiO2 better fitted to the D-R model.…”

Section: Isotherm Studiesmentioning

confidence: 79%

Silica-coated magnetic Fe3O4 nanoparticles as efficient nano-adsorbents for the improvement of the vapor-phase adsorption of benzene

Ece

Kutluay

International Journal of Chemistry and Technology

2021

This study focused on the preparation of silica-coated Fe3O4 (Fe3O4@SiO2) for the improvement of the vapor-phase adsorption of benzene. The Fe3O4@SiO2 was prepared via the co-precipitation method, while its characterization was carried out using FT-IR, SEM and BET surface area analyses. The experimental parameters were evaluated for the vapor-phase adsorption of benzene using response surface methodology (RSM). The Fe3O4@SiO2 adsorbed 197.50 mg g -1 of the vaporphase benzene under the following optimum conditions: 39.93 min residence time, 13.57 mg l -1 initial benzene concentration and 26.87°C temperature. The vapor-phase adsorption mechanism of benzene on the Fe3O4@SiO2 was clarified by investigating the isotherms including Dubinin-Radushkevich (D-R), Freundlich and Langmuir, and the experimenatal data were well fitted to the D-R model. The vapor-phase adsorption kinetics of benzene on the Fe3O4@SiO2 was clarified by investigating the kinetics such as pseudo first-order (PFO) model and pseudo second-order (PSO) model, and the experimantal results obeyed the PSO model. This study demonstrated the application potential of magnetic Fe3O4@SiO2 as promising low-cost nano-adsorbent.

“…In this study, the adsorption isotherm models (Langmuir, Freundlich, and D–R) for each VOC of the synthesized Fe 3 O 4 /AC@SiO 2 @1,4-DAAQ magnetic nanoparticles at various initial VOC concentrations of 5, 10, 15, 20, 25, 30, and 40 ppm under optimum operating parameters (Figure S2) were studied to investigate the relationship between the nanoadsorbent and adsorbates. − Langmuir adsorption isotherm models for the monolayer coating of adsorption surfaces. It assumes that adsorption takes place on a structurally homogeneous adsorbent and that all adsorption zones are the same in terms of energy.…”

Section: Resultsmentioning

confidence: 99%

Development of Novel Fe₃O₄/AC@SiO₂@1,4-DAAQ Magnetic Nanoparticles with Outstanding VOC Removal Capacity: Characterization, Optimization, Reusability, Kinetics, and Equilibrium Studies

Ece

Kutluay

et al. 2020

Ind. Eng. Chem. Res.

The adsorption of pollutants to the surface of adsorbents plays a critical role in the effectiveness of adsorption technology for air purification applications. Herein, novel magnetic nanoparticles functionalized with 1,4diaminoanthraquinone (1,4-DAAQ), namely, Fe 3 O 4 /activated carbon (AC)@SiO 2 @ 1,4-DAAQ, were innovatively synthesized via co-precipitation and sol−gel techniques. After that, these nanoparticles were used for high-efficiency removal of volatile organic compounds (VOCs) (i.e., benzene and toluene). The synthesized nanoparticles were characterized by various techniques such as Fourier transform IR spectroscopy, thermogravimetric analysis/differential thermal analysis, scanning electron microscopy, and Brunauer−Emmett−Teller analysis. The dynamic adsorption process of VOCs was optimized based on operating parameters. The adsorption experiments revealed that Fe 3 O 4 /AC@SiO 2 @1,4-DAAQ showed exceptional performance for the removal of VOCs. It was observed that for benzene, Fe