scholarly journals Adsorption isotherm, kinetic and mechanism studies of 2-nitrophenol on sedimentary phosphate

2015 ◽  
Vol 4 (6) ◽  
pp. 289-296 ◽  
Author(s):  
Hind Yaacoubi ◽  
Zuo Songlin ◽  
Mustapha Mouflih ◽  
Mina Gourai ◽  
Said Sebti

Sedimentary phosphate (SP) was used as an adsorbent for the removal of 2-nitrophenol from aqueous solutions in an attempt to investigate (the feasibility of) its application (to) in wastewater purification.  The adsorbent was characterized by X-ray diffraction (XRD), IR spectroscopy, Fluorescence X and BET.  The results indicated that the SP (was) is francolite (Ca10 (PO4,CO3)6F2) and mesoporous. The effect of the adsorption time and the pH of the solution were studied. The pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to fit adsorption data in the kinetic studies. The equilibrium isotherms were determined using the Langmuir, Freundlich and Dubinin-Radushkevich models. The results show that the Dubinin-Radushkevich isotherm had better agreement with the 2-nitrophenol adsorption on SP with a correlation coefficient of 0.98, an equilibrium adsorption capacity of 633 mg. g-1 and a corresponding contact time of 2 h. The results imply that intraparticle diffusion could be summarized as the basic rate-controlling mechanisms during 2-nitrophenol adsorption on SP.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed S. Yahia ◽  
Ahmed S. Elzaref ◽  
Magdy B. Awad ◽  
Ahmed M. Tony ◽  
Ahmed S. Elfeky

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.


2019 ◽  
Vol 4 (4) ◽  
pp. 101
Author(s):  
Neza Rahayu Palapa ◽  
Bakri Rio Rahayu ◽  
Tarmizi Taher ◽  
Aldes Lesbani ◽  
Risfidian Mohadi

Zn/Al and Zn/Fe layered double hydroxides has successfully synthesized by co-precipitation methods with molar ration 3:1. The samples were characterized using X-Ray Diffraction, Fourier Transform Infrared Spectroscopy and Surface Area using BET method. In this study, Zn/Al and Zn/Fe layered double hydroxides were used to remove direct yellow dye in aqueous solution. The experiments were carried out time variations with the aim of observing the kinetic studies. The results showed that the adsorption of direct yellow onto Zn/Al and Zn/Fe layered double hydroxides based on co-efficient correlation kinetic models more fit using pseudo-second-order than pseudo-first-order.


2012 ◽  
Vol 65 (11) ◽  
pp. 2055-2060 ◽  
Author(s):  
Yihe Zhang ◽  
Wei Chen ◽  
Guocheng Lv ◽  
Fengzhu Lv ◽  
Paul K. Chu ◽  
...  

Several types of red mud-based porous materials (RMPM) and other raw minerals via different processes were prepared and characterized using X-ray diffraction (XRD) analyses and scanning electron microscope (SEM) observations. Using the polymer sponge method, a 72% apparent porosity could be reached compared with 64% by adding a pore-forming agent. These materials were tested for their adsorption of polyvinyl alcohol (PVA) from simulated textile wastewater. The best mass ratio of RMPM to PVA solution was 50:100 with a removal maximum of 25.8% after they were in contact for 50 min. The adsorption rate and kinetics could be better described by Lagergren's pseudo-second-order model in comparison with the pseudo-first-order model.


2012 ◽  
Vol 14 (4) ◽  
pp. 88-94 ◽  
Author(s):  
R.P. Suresh Jeyakumar ◽  
V. Chandrasekaran

Abstract In this work, the efficiency of Ulva fasciata sp. activated carbons (CCUC, SCUC and SSUC) and commercially activated carbon (CAC) were studied for the removal of Cu (II) ions from synthetic wastewater. Batch adsorption experiments were carried out as a function of pH, contact time, initial copper concentration and adsorbent dose. The percentage adsorption of copper by CCUC, SSUC, SCUC and CAC are 88.47%, 97.53%, 95.78% and 77.42% respectively. Adsorption data were fitted with the Langmuir, Freundlich and Temkin models. Two kinetic models pseudo first order and the pseudo second order were selected to interpret the adsorption data.


2020 ◽  
Vol 168 ◽  
pp. 00026
Author(s):  
Liliia Frolova ◽  
Mykola Kharytonov ◽  
Iryna Klimkina ◽  
Oleksandr Kovrov ◽  
Andrii Koveria

Plasma method is used to synthesize manganese ferrite. The basic properties of ferrite are determined by IR spectroscopy, UV spectroscopy, X-ray phase analysis, vibration magnetometry. The paper shows that the use of magnetically controlled sorbent allows to purify waste waters from chromium (III). The process of adsorption of chromium cations (III) is investigated. The kinetics of the process is studied. To describe the equilibrium isotherms, the experimental data are analysed by the models of Langmuir, Freundlich isotherms. Pseudo-first order, pseudo-second-order, and Weber-Morris are used to elucidate the kinetic parameters and mechanism of the adsorption process. It has been established that the removal of Cr (III) cations is described by the pseudo-second order of the Langmuir reaction and mechanism.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 218 ◽  
Author(s):  
Alfred Mensah ◽  
Pengfei Lv ◽  
Christopher Narh ◽  
Jieyu Huang ◽  
Di Wang ◽  
...  

In this study, a novel green adsorbent material prepared by the esterification of bacterial cellulose (BC) and graphene oxide (GO), richly containing hydroxyl, alkyl, and carboxylate groups was characterised by FTIR (Fourier Transform infrared spectroscopy), XRD (X-ray diffraction), SEM (Scanning electron microscopy) and TGA (Thermo-graphimetric analysis). The specific surface area (SSA) and pore size distribution (PSD) analysis of materials were also analysed. Batch experiments–adsorption studies confirmed the material to have a very high Pb2+ removal efficiency of over 90% at pH 6–8. Kinetic studies showed that the uptake of metal ions was rapid with equilibrium attained after 30 min and fitted well with the pseudo-second-order rate model (PSO). Isotherm results with a maximum adsorption capacity (Qmax) of 303.03 mg/g were well described by Langmuir’s model compared to Freundlich. Desorption and re-adsorption experiments realised that both adsorbent and adsorbates could be over 90–95% efficiently recovered and reused using 0.1 M HNO3 and 0.1 M HCl.


2019 ◽  
Vol 25 (5) ◽  
pp. 742-752 ◽  
Author(s):  
Nidhi Yadav ◽  
Dhruv Narayan Maddheshiaya ◽  
Shalu Rawat ◽  
Jiwan Singh

In this study, waste cauliflower leaves were used for adsorbent preparation. The waste cauliflower leaves were converted into activated carbon by pyrolysis at two different temperatures 250˚C and 500˚C with magnetic property. The prepared adsorbents were denoted as CAC-250 and CAC-500 and characterized by the use of scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The adsorbents were applied for the removal of phenol and PNP from their aqueous solutions. The adsorption of phenol was found very less by the application CAC-250, whereas by the application of CAC-500 the adsorption of both phenol and PNP was enhanced. The maximum adsorption of phenol was found 99% and that of PNP was found ~100% using CAC-500, with initial adsorbate concentration 5 mg/L at 25˚C. The adsorption data was analysed with Langmuir, Freundlich and Temkin isotherm models and different kinetic models that are pseudo first order, pseudo second order, Elovich, intraparticle and pore diffusion model.


2019 ◽  
Vol 4 (12) ◽  
pp. 78-85
Author(s):  
Aboiyaa A. Ekine ◽  
Patience N. Ikenyiri ◽  
O. Hezekiah-Braye

This Research investigated the adsorption capacity of locally prepared adsorbents from Egg shells for the removal of fluoride ion in well water. It evaluated the performance of these adsorbents calcinated at 3000C and modified with 1.0M HNO3 (trioxonitrate (v)) acid. Batch adsorber was used to allow for interaction between adsorbent (grounded Egg shells) with water containing fluoride ion. The batch experiment was performed with particle size of 2.12 contact time (60, 120, 180, 240, 300min), mass dosage (5g, 10g, 15g, 20g) and temperature (250C, 300C, 400C, 500C). The modified adsorbent was characterized to determine the physiochemical properties of grounded Egg shells (GE). Also the chemical composition of the modified adsorbent was analyzed to determine the percentage of calcium element required for the uptake of the fluoride ions in water for calcium as 39.68% for grounded Egg shells (GE). Percentage adsorption increased with increase in contact time, mass dosage and temperature for the adsorbent. The adsorption capacity was also determined which also increased with increase in contact time, temperature but decreased with increase in mass dosage at constant time of 60minutes. The pseudo first-order, pseudo second order and intraparticle diffusion kinetic models were fitted into the experimental results. The results obtained indicated that the pseudo first order and intraparticle diffusion models for the grounded Egg shells (GE) reasonably described the adsorption process very well whereas the pseudo second order model was not suitable for a calcinations temperature of 3000C and particle size of 2.12m. The adsorption isotherms were obtained from equilibrium experiment Performed at temperature of 25, 35, 45 and 550C. The result showed that Langmuir and Freundlich isotherm fitted perfectly the experimental data. However, the negative values of Gibb’s free energy indicated that adsorption was favourable and the positive enthalpy change H0 revealed that adsorption process was endothermic while the positive value of the entropy change signified increased randomness with adsorption.


2021 ◽  
Vol 22 (4) ◽  
pp. 11-17
Author(s):  
Haider Abbas ◽  
Ammar S. Abbas

In recent years, it has been evident that searching for alternative methods with low-price and eco-friendly features that produce high-quality adsorbents is in high demand. In the present work, Rice husk from Iraqi rice named (Amber) had been used as the primary source to produce rice husk ash (RHA) for the removal of the antibiotic metronidazole (Flagyl) from water. After optimum drying of rice husk, rice husk ash (RHA) was obtained at 600 °C using an electric oven. RHA has been investigated for properties using X-ray diffraction (XRD), porosity, and surface area (SA). The experimental work adsorption data were optimized to evaluate Langmuir and Freundlich constants. The thermodynamic parameters likely a change in Gipp's energy (ΔG), enthalpy (ΔH), and entropy (ΔS). The impacts of increasing temperature on adsorption capacity were investigated, and the results indicate that the pseudo-second-order kinetics model could be presented the dynamic adsorption data that it has. The resultant values for the heat of adsorption and the free energy indicated that adsorption of Flagyl is preferred at low temperatures.


2020 ◽  
Vol 1 (1) ◽  
pp. 11717
Author(s):  
Lívia Katia Dos Santos Lima ◽  
Antônio Vilas Boas Quintiliano Júnior ◽  
André Henrique Zeferino ◽  
Ana Paula Duarte

The textile industry stands out for generating effluents with high levels of dyes, which have a high polluting potential. Among these dyes, the Remazol Brilliant Blue R azo dye, is one of the most used for dyeing wool and cotton, being released in excess on these effluents. Intended for the carcinogenic and mutagenic potential of this type of dyes, several researches are developed in search of economical technologies for their removal. An adsorption is a viable technique, since several materials can be used for this purpose. Bovine bone activated carbon, as it is a residue from the livestock industry that is easily obtained, has been studied as an adsorbent material in the removal of dyes. Therefore, the objective of this project was to evaluate the performance of the adsorption kinetics of the Remazol Brilliant Blue R dye from the effluents using bovine bone activated carbon. The experiments were carried out in batches, with solutions concentrations of 20, 50 and 100 ppm, and the mathematical models of pseudo-first order, pseudo-second order and intraparticle diffusion were adjusted to the experimental data. For concentrations of 20 and 50 ppm, the model that best fits was the pseudo-first order, while for the concentration of 100 ppm the pseudo-second order model obtained the best result with R2 of 0.992. The intraparticle diffusion model showed that the higher the concentration of the dye in solution, the greater the thickness of the boundary layer and that the intraparticle diffusion does not control the adsorption process in any of the study criteria.


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