Thermodynamics and Kinetic Studies for the Adsorption Process of Methyl Orange by Magnetic Activated Carbons (original) (raw)
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Dye is one of the dangerous contaminants because it can interfere with the health of living things and the environment. This research aims to study the comparison of adsorption capacity between activated carbon and its magnetic composite on methylene blue and eriochrome black T, as azo dyes, an organic compound contains a functional group of –N=N-, that are hardly to be degraded in the environment. The activated carbon used in this study was obtained commercially while the composite material was synthesized using activated carbon which was carried by iron species from a solution of Fe2+ and Fe3+ salts. The variables studied in this research were contact periodic time and dye concentration. The adsorption process was evaluated using a kinetics and isotherm model. Furthermore, the characterization of the two adsorbents was conducted using Fourier-transform Infrared (FTIR) spectrometer. The results of FTIR characterization show a functional group that indicates of the proper of magneti...
Journal of Hazardous Materials, 2009
The combination of magnetic nanoparticles with other adsorbents not only does not affect their magnetic properties, but also leads to the formation of adsorbents that improve the refining process. The aim of this study was synthesis of magnetic activated carbon by Fe 3 O 4 and investigation of its efficiency in adsorption of Lead from aqueous solutions. Magnetic adsorbent prepared by the method of sequestration and physical characteristics and structure of synthesized absorbent were determined by XRD and TEM. To remove the Lead from aqueous solutions, the Box-Behnken design (BBD) of response surface methodology (RSM) was employed for optimizing all parameters affecting the adsorption process. The studied parameters were pH (5-9), temperature (25-45 ⁰C) and the amount of adsorbent (0.5-2 g). 15 experimental runs were calculated by using BBD. The optimal condition for removal of Lead by synthesis of magnetic activated carbon by Fe 3 O 4 nanoparticles was pH=7, 450 ⁰C temperature and 2 g of adsorbent. Kinetic studies of the adsorption process specified the efficiency of the pseudo second-order kinetic model and showed the optimal time was 15 min, respectively. The maximum percentage of Lead removed after 90 min was 86.87%. The adsorption isotherm was well-fitted to Longmire model. The study showed that magnetic activated carbon has a high potential for Lead removal. Therefore, it is believed that magnetized active carbon by keeping its physical and surface properties could be a suitable method to solve some related problems including separation and filtration.
Journal of Water and Wastewater, 2021
Dyes are one of the most important industrial environmental pollutants, and therefore their removal from industrial wastewater is very important. The malachite green is a very toxic dye for the environment and humans, therefore an economical and high-efficiency method to remove this dye from water solutions is necessary. In this study, the removal of malachite green was investigated using a economical and effective adsorbent, in which activated carbon from date kernel was used. Activated carbon from date kernel was modified by Fe3O4 magnetic nanoparticles and calcium oxide. The properties and characteristics of these adsorbents were investigated using FTIR, VSM, TGA, XRD and SEM analyzes. Parameters affecting the adsorption process such as pH, adsorbent dosage, contact time and initial concentration of malachite green were optimized. Equilibrium and kinetic study of adsorption process was performed using common models. The results showed optimal conditions for adsorption of malachite green using the adsorbent are: initial concentration equal to 10 mg/l, pH=7, contact time equal to 20 minutes, adsorbent dose for AC, AC/Fe3O4 and AC/Fe3O4/CaO equal to 3, 3 and 2 g/l, respectively. The Freundlich model also has a higher ability to describe process equilibrium behavior and the pseudo-second-order kinetics model has a good ability to express reaction kinetics. The Langmuir adsorption capacity of malachite green by the AC, AC/Fe3O4 and AC/Fe3O4/CaO was determined to be 50.9 mg/g, 85.7 mg/g and 107.4 mg/g respectively. The desorption and reuse ability of AC/Fe3O4/CaO was investigated up to 8 steps, which showed that the adsorbent has the ability to be reused several times in the adsorption process. The results showed that modification of activated carbon with magnetic Fe3O4 nanoparticles and calcium oxide increases its adsorption efficiency and makes it a suitable adsorbent for commercialization.
Applied Water Science
Textile industries use large amounts of water and chemicals for finishing and dying processes. The chemical structures of dyes vary enormously, and some have complicated aromatic structures that resist degradation in conventional wastewater treatment processes because of their stability to sunlight, oxidizing agents, and microorganisms. The objective of this research is to compare the adsorption efficiency of two types of magnetic activated carbons derived from Banana peel and Salvia seed for the removal of basic blue 41 dye. The faculty of the produced activated carbons to remove basic blue 41 dye from aqueous solutions via batch adsorption has been examined under several operating conditions such as pH, adsorbent dose, initial adsorbate concentration and contact time. The cheap, non-toxic produced activated carbons (AC) were characterized by scanning electron microscope and Brunauer-Emmett-Teller analyses. The best conditions of dye adsorption with BPAC@ Fe3O4 equal to pH = 9, AC ...
Thermal conversion of pineapple crown leaf waste to magnetized activated carbon for dye removal
Bioresource Technology, 2019
Pineapple crown leaf was successfully converted to the magnetized activated carbon (MAC) as an attractive solution to overcome separation problems. The activated carbon (AC) was produced by an innovative method combining KOH activation and microwave heating while the magnetization process was prepared by a co-precipitation method. In this sense, the activation stage was studied at different impregnation ratio. The resulted magnetic adsorbent was further tested its feasibility for methyl violet dye removal. The result shows that MAC consists of both micropores and mesopores with more oxygen-containing functional groups, indicating it can be used to remove dye from contaminated water. The increase of impregnation ratio led to an increase in the MAC porosity and a decrease in the magnetic property. The adsorption behavior of methyl violet dye onto MAC was well described by the Redlich-Peterson isotherm model.
This paper presents the feasibility for the removal of methyl orange (MO) dye from aqueous solution using an activated carbon prepared from Prosopis julifl ora bark. Batch adsorption experiments were carried out as a function of pH, contact time, adsorbate concentration, adsorbent dosage and temperature. The commonly applicable isotherms namely Freundlich and Langmuir equations are used for the prediction of isotherm parameters. A comparison of linear least-square method and a trial-and-error non-linear method are examined in Freundlich and Langmuir (Four forms) isotherms. The nature of adsorption isotherm feasibility was evaluated with dimensionless separation factors (R L ). The dynamics of adsorption process was analyzed with Lagergren's Pseudo-fi rst order and Pseudo-second order kinetic equations. Thermodynamic parameters like the change in enthalpy (∆H o ), change in entropy (∆S o ) and change in Gibbs free energy (∆G o ) were evaluated and ΔG o shows a negative value whereas ΔH o shows the positive value indicating that the adsorption process was spontaneous and endothermic in nature. The functional group characterization of the adsorbent was done using Fourier transform infrared spectroscopy (FTIR). The thermal stability of activated carbon was analyzed using Thermo gravimetric analysis (TGA) and Differential thermal analysis (DTA).
DESALINATION AND WATER TREATMENT
In the present study, activated carbon (AC) was prepared from jackfruit leaves (JFL) using phosphoric acid as activating agent. The prepared AC was characterized by Fourier-transform infrared spectroscopy, nitrogen adsorption-desorption analyses and scanning electron microscopy. The adsorptive performance of the prepared activated was investigated by the adsorption of anionic dye methyl orange (MO) from aqueous solutions. The batch adsorption experiments were carried by varying operation parameters such as pH, adsorbent dosage, initial concentration of dye and contact time. The adsorption capacity was increased with increasing concentration of dye. The equilibrium adsorption data were well fitted to Langmuir isotherm model and maximum adsorption capacity was obtained to be 833 mg/g. The adsorption followed the pseudo-second-order kinetic model. Thermodynamic study suggested the endothermic nature of MO adsorption onto prepared activated carbon. Considering high dye adsorption capacity, AC prepared from jackfruit leaves can be used as a promising low-cost adsorbent for the removal of organic dyes from aqueous solution.
Brilliant blue FCF dye adsorption using magnetic activated carbon from Sapelli wood sawdust
Environmental Science and Pollution Research, 2023
Sapelli wood sawdust-derived magnetic activated carbon (SWSMAC) was produced by single-step pyrolysis using KOH and NiCl 2 as activating and magnetization agents. SWSMAC was characterized by several techniques (SEM/EDS, N 2 adsorption/ desorption isotherms, FTIR, XRD, VSM, and pH PZC) and applied in the brilliant blue FCF dye adsorption from an aqueous medium. The obtained SWSMAC was a mesoporous material and showed good textural properties. Metallic nanostructured Ni particles were observed. Also, SWSMAC exhibited ferromagnetic properties. In the adsorption experiments, adequate conditions were an adsorbent dosage of 0.75 g L −1 and a solution pH of 4. The adsorption was fast, and the pseudo-secondorder demonstrated greater suitability to the kinetic data. The Sips model fitted the equilibrium data well, and the maximum adsorption capacity predicted by this model was 105.88 mg g −1 (at 55 °C). The thermodynamic study revealed that the adsorption was spontaneous, favorable, and endothermic. Besides, the mechanistic elucidation suggested that electrostatic interactions, hydrogen bonding, π-π interactions, and n-π interactions were involved in the brilliant blue FCF dye adsorption onto SWSMAC. In summary, an advanced adsorbent material was developed from waste by single-step pyrolysis, and this material effectively adsorbs brilliant blue FCF dye.