scholarly journals Investigation into the Adsorption of Methylene Blue and Methyl Orange by UiO-66-NO2 Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hien Thi Dinh ◽  
Nam Trung Tran ◽  
Dai Xuan Trinh

In this work, the adsorptive removal of methylene blue and methyl orange by UiO-66-NO2 nanoparticles was studied. The influence of pH on the adsorption capacity was assessed. The kinetics of the adsorption process were investigated and compared with pseudo-first-order, pseudo-second-order, Elovich, and intraparticle models. The kinetics of the adsorption fits moderately with the pseudo-first-order, but perfectly fits with pseudo-second-order models, and has a very good fit with the Elovich and intraparticle models. The adsorption isotherms were measured and compared with the Langmuir and Freundlich models. The adsorption capacity of methyl orange (MO) on UiO-66-NO2 nanoparticles (142.9 mg/g) was over three times higher than that of methylene blue (MB) on the nanoparticles (41.7 mg/g). The discrepancy between these capacities was attributed to the presence of the -NO2 functional group, which caused a strong negative mesomeric effect in the metal-organic framework structure.

2021 ◽  
Author(s):  
khaled Mostafa ◽  
H. Ameen ◽  
A. Ebessy ◽  
A. El-Sanabary

Abstract Our recently tailored and fully characterized poly (AN)-starch nanoparticle graft copolymer having 60.1 G.Y. % was used as a starting substrate for copper ions removal from waste water effluent after chemical modification with hydroxyl amine via oximation reaction. This was done to change the abundant nitrile groups in the above copolymer into amidoxime one and the resultant poly (amidoxime) resin was used as adsorbent for copper ions. The resin was characterized qualitatively via rapid vanadium ion test and instrumentally by FT-IR spectra and SEM morphological analysis to confirm the presence of amidoxime groups. The adsorption capacity of the resin was done using the batch technique, whereas the residual copper ions content in the filtrate before and after adsorption was measured using atomic adsorption spectrometry. It was found that the maximum adsorption capacity of poly (amidoxime) resin was 115.2 mg/g at pH 7, 400ppm copper ions concentration and 0.25 g adsorbent at room temperature. The adsorption, kinetics and isothermal study of the process is scrutinized using different variables, such as pH, contact time, copper ion concentration and adsorbent dosage. Different kinetics models comprising the pseudo-first-order and pseudo-second-order have been applied to the experimental data to envisage the adsorption kinetics. It was found from kinetic study that pseudo-second-order rate equation was better than pseudo-first-order supporting the formation of chemisorption process. While, in case of isothermal study, the examination of calculated correlation coefficient (R2) values showed that the Langmuir model provide the best fit to experimental data than Freundlich one.


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.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jhonatan R. Guarín ◽  
Juan Carlos Moreno-Pirajan ◽  
Liliana Giraldo

Currently, there is a great pollution of water by the dyes; due to this, several studies have been carried out to remove these compounds. However, the total elimination of these pollutants from the aquatic effluents has represented a great challenge for the scientific community, for which it is necessary to carry out investigations that allow the purification of water. In this work, we studied the bioadsorption of methylene blue on the surface of the biomass obtained from the algae D. antarctica. This material was characterized by SEM and FTIR. To the data obtained in the biosorption experiments, different models of biosorption and kinetics were applied, finding that the best fit to the obtained data is given by applying the pseudo-second-order models and the Toth model, respectively. It was also determined that the maximum adsorption capacity of MB on the surface of the biomass is 702.9 mg/g, which shows that this material has great properties as a bioadsorbent.


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.


2020 ◽  
Vol 24 (2) ◽  
pp. 329-333
Author(s):  
D.O. Jalija ◽  
A . Uzairu

The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters. Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order


2013 ◽  
Vol 803 ◽  
pp. 157-160
Author(s):  
Zhen Zhen Kong ◽  
Dong Mei Jia ◽  
Su Wen Cui

The composite weakly basic resin (D301Fe) was prepared and examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption kinetics of glyphosate from aqueous solution onto composite weakly basic resin (D301Fe) were investigated under different conditions. The experimental data was analyzed using various adsorption kinetic models like pseudo-first order, the pseudo-second order, the Elovich and the parabolic diffusion models to determine the best-fit equation for the adsorption of glyphosate onto D301Fe. The results show that the pseudo-second order equation fitted the experimental data well and its adsorption was chemisorption-controlled.


2015 ◽  
Vol 1125 ◽  
pp. 281-285
Author(s):  
Siti Aishah Muhmed ◽  
Mohd Ghazali Mohd Nawawi

Crosslinked Sago Starch (CSS) was prepared by crosslinking native starch with Sodium Trimetaphosphate. As a biodegradable adsorbent, CSS was used to remove methylene blue (MB) from the aqueous solution based on its characterization, including the granule morphology, crystalline nature and molecular structure. The adsorption capacity of CSS was evaluated as a function of pH, adsorbent dosage, initial concentration and time. It was favorable for adsorption under condition of neutral and at high initial concentration. The adsorption capacity trend was decreased with increasing the adsorbent dosage. The equilibrium isotherms were conducted using Langmuir, Freundlich and Tempkin model. It has been demonstrated that the better agreement was Langmuir isotherm with correlation coefficient of 0.99, equilibrium adsorption capacity of 3.75 mg g-1, chi-square test, χ2 of 0.03% and corresponding contact time of 4 hours. The pseudo-first-order, pseudo-second-order and intra-particle diffusion were used to fit adsorption data in the kinetic studies. And results showed that the adsorption kinetics was more accurately described by the pseudo-second-order model with correlation coefficient, R2 of 0.99 and standard deviation, SSE of 0.12%. The obtained results suggest that CSS could be promising candidates as an adsorbent for dye removal.


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.


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