scholarly journals Efficient Sulfate Adsorption on Modified Adsorbents Prepared from Zea mays Stems

2021 ◽  
Vol 11 (4) ◽  
pp. 1596
Author(s):  
Candelaria Tejada-Tovar ◽  
Ángel Villabona-Ortíz ◽  
Angel Dario Gonzalez-Delgado ◽  
Adriana Herrera ◽  
Andrea Viera De la Voz
Keyword(s):  
Zea Mays ◽  
Adsorption Capacity ◽  
Thermodynamic Parameters ◽  
Adsorption Kinetics ◽  
Volume Ratio ◽  
Effect Of Temperature ◽  
Sulfate Adsorption ◽  
Modified Adsorbents ◽  
Adsorption Kinetics And Isotherm ◽  
Mass Volume

The effect of temperature on the sulfate adsorption capacity of adsorbents prepared from corn stalks (Zea mays) was evaluated. Two bioadsorbents were prepared from biomass: a biochar modified with H2SO4 with mass: volume ratio 1:1 (B 1:1), and cellulose modified with cetyl trimethyl ammonium chloride (CTAC). There were also determined thermodynamic parameters (ΔG°, ΔS° and ΔH°) and it was studied the adsorption kinetics and isotherm. At 25 °C was obtained the highest adsorption capacity of 16.4 and 7.4 mg/g with mass/volume ratio B 1:1 and modified corn (MC) respectively; it was observed an adverse effect of temperature increase on bioadsorbents’ performance. The thermodynamic parameters showed that the adsorption process is exothermic, not spontaneous, and it was given by chemisorption. Adsorption kinetics showed that equilibrium was reached at 420 min and that the pseudo-second-order model adjusted the experimental data with R2 > 0.98 and qe of 16.64 and 7.48 mg/g for B 1:1 as well as MC. The adsorption isotherm showed a good fit to Freundlich’s model when using B 1:1, whereas using MC as adsorbents the data was adjusted by Dubinin-Radushkevich’s model. Zea mays stems are an abundant agricultural residue and are a good source for the preparation of biochar type bioadsorbents as well as the extraction of cellulose, its use is recommended in the removal of sulfates in solution.

Insights into cationic methyl violet 6B dye–kaolinite interactions: kinetic, equilibrium and thermodynamic studies

Clay Minerals ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 85-95 ◽  
Author(s):  
İ. Sargin ◽  
N. Ünlü
Keyword(s):  
Experimental Data ◽  
Ionic Strength ◽  
Adsorption Capacity ◽  
Thermodynamic Parameters ◽  
Adsorption Kinetics ◽  
Adsorption Process ◽  
Methyl Violet ◽  
Order Type ◽  
Kinetic And Thermodynamic Parameters ◽  
Initial Ph

AbstractIn this study, adsorption and adsorption kinetics of methyl violet dye from aqueous solutions onto kaolinite were investigated. The effects of adsorbent dosage, pH, ionic strength, contact time, temperature and initial dye concentration were studied. Kinetic and thermodynamic parameters were determined using experimental data. Adsorption capacity decreased with increasing ionic strength. Changes in the initial pH of the dye solution in a range close to the dye's natural pH (i.e. ∼ pH 5.0) values affected adsorption capacity slightly, indicating that adsorption studies could be carried out at the dye's natural pH. The adsorption process followed the Freundlich-type adsorption isotherms and pseudo-second order type adsorption kinetics. However, an intraparticle diffusion process was found to have effects in adsorption processes. Thermodynamic parameters were calculated from the experimental data and enthalpy of the adsorption, ΔH0, was found to be –6.82 kJ mol–1, indicating physisorption nature of the adsorption. Other thermodynamic parameters, ΔS0 and DG0, were also calculated. Negative values of ΔG0 indicated that the adsorption process for methyl violet on kaolinite is spontaneous.

scholarly journals Effect of The Surfactant Loaded Amount Into The Bentonite on The Elimination of Two Anionic Dyes: Adsorption, Kinetics, and Isotherm Studies

2021 ◽  
Author(s):  
Brahim Guezzen ◽  
Mehdi Adjdir ◽  
Abdelkader Elaziouti ◽  
Mohamed Amine Didi
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Indigo Carmine ◽  
Exchange Capacity ◽  
Hexadecyltrimethylammonium Bromide ◽  
Anionic Dyes ◽  
Intra Particle Diffusion ◽  
Pseudo Second Order ◽  
Dyes Adsorption ◽  
Adsorption Kinetics And Isotherm

Abstract The present work focused on the preparation of hybrid-bentonite adsorbents by treating sodium bentonite (Na-B) with different amounts of hexadecyltrimethylammonium bromide (HDTMA+ Br-), corresponding to 50, 100 and 200% the value of the cation exchange capacity (CEC). The samples prepared, namely 50HDTMA-B, 100HDTMA and 200HDTMA-B, were characterized by different techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA ). The removal efficiency of two anionic dyes, namely. Congo Red (CR) and Indigo Carmine (IC), from aqueous solutions, was studied as a function of the amount of HDTMA, contact time, hybrid adsorbent and initial dye concentration. In addition, a kinetic study was conducted to fit the experimental data in order to compare the adsorption rate constants and the equilibrium sorption capacities of anionic dyes on the prepared materials. The results obtained indicated that the adsorption kinetics of clay samples could be best described by the pseudo-second-order model, and the adsorption capacity of the hybrid-Bentonite is affected by the amount of modifier used. Based on Weber-Morris intra-particle diffusion equation, it was found that the CR and IC dyes diffused faster as the cationic surfactant loading increased from 0 to 100% of the CEC value. The Langmuir isotherm exhibited the best fit, with an adsorption capacity equal to 292 and 289 mg g-1, for CR and IC dyes, respectively.

scholarly journals Effect of Temperature on the Corrosion Inhibition of Trans-4-Hydroxy-4′-Stilbazole on Mild Steel in HCl Solution

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Ayssar Nahlé ◽  
Ideisan I. Abu-Abdoun ◽  
Ibrahim Abdel-Rahman
Keyword(s):  
Weight Loss ◽  
Double Bond ◽  
Adsorption Isotherm ◽  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Thermodynamic Parameters ◽  
The Other ◽  
Effect Of Temperature ◽  
Temkin Adsorption Isotherm ◽  
Hcl Solution

The inhibition and the effect of temperature and concentration of trans-4-hydroxy-4′-stilbazole on the corrosion of mild steel in 1 M HCl solution was investigated by weight loss experiments at temperatures ranging from 303 to 343 K. The studied inhibitor concentrations were between  M and  M. The percentage inhibition increased with the increase of the concentration of the inhibitor. The percentage inhibition reached about 94% at the concentration of  M and 303 K. On the other hand, the percentage inhibition decreased with the increase of temperature. Using the Temkin adsorption isotherm, the thermodynamic parameters for the adsorption of this inhibitor on the metal surface were calculated. Trans-4-hydroxy-4′-stilbazole was found to be a potential corrosion inhibitor since it contained not only nitrogen and oxygen, but also phenyl and pyridine rings that are joined together with a double bond (–C=C–) in conjugation with these rings.

scholarly journals Adsorption Characteristics of Phosphate Ions by Pristine, CaCl2 and FeCl3-Activated Biochars Originated from Tangerine Peels

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 32 ◽  
Author(s):  
Changgil Son ◽  
Wonyeol An ◽  
Geonhee Lee ◽  
Inho Jeong ◽  
Yong-Gu Lee ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Chemical Activation ◽  
Isotherm Models ◽  
Order Model ◽  
Phosphate Ions ◽  
Adsorption Capacities ◽  
Adsorption Isotherm Models ◽  
Endothermic Reactions ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm

This study has evaluated the removal efficiencies of phosphate ions (PO43−) using pristine (TB) and chemical-activated tangerine peel biochars. The adsorption kinetics and isotherm presented that the enhanced physicochemical properties of TB surface through the chemical activation with CaCl2 (CTB) and FeCl3 (FTB) were helpful in the adsorption capacities of PO43− (equilibrium adsorption capacity: FTB (1.655 mg g−1) > CTB (0.354 mg g−1) > TB (0.104 mg g−1)). The adsorption kinetics results revealed that PO43− removal by TB, CTB, and FTB was well fitted with the pseudo-second-order model (R2 = 0.999) than the pseudo-first-order model (R2 ≥ 0.929). The adsorption isotherm models showed that the Freundlich equation was suitable for PO43− removal by TB (R2 = 0.975) and CTB (R2 = 0.955). In contrast, the Langmuir equation was proper for PO43− removal by FTB (R2 = 0.987). The PO43− removal efficiency of CTB and FTB decreased with the ionic strength increased due to the compression of the electrical double layer on the CTB and FTB surfaces. Besides, the PO43− adsorptions by TB, CTB, and FTB were spontaneous endothermic reactions. These findings demonstrated FTB was the most promising method for removing PO43− in waters.

scholarly journals Optimization of cadmium(II) adsorption onto modified and unmodified lignocellulosics (rice husk and egussi peeling)

2015 ◽  
Vol 5 (1) ◽  
pp. 45
Author(s):  
Tchuifon Tchuifon Donald Raoul ◽  
Nche George Ndifor-Angwafor ◽  
Ngakou Sadeu Christian ◽  
Kamgaing Théophile ◽  
Ngomo Horace Manga ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Rice Husk ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Batch Technique ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorbed Quantity ◽  
Minimal Mass ◽  
Modified Adsorbents

<p>The present study is based on the adsorption of cadmium (II) ions on rice husk and egussi peeling, unmodified and modified with nitric acid in aqueous solution, using batch technique. It was carried out as a function of contact time, dosage, pH and initial concentration. The equilibrium time was achieved within 25 minutes for unmodified rice husk (Glu NT) and 20 minutes for unmodified egussi peeling (Cuc NT) with an adsorbed quantity of 13.18 mg/g. In the case of modified materials, we obtained 15 minutes for modified rice husk (Glu HNO3) and 10 minutes for modified egussi peeling (Cuc HNO3) with an adsorbed quantity of 18.77 mg/g. The maximum biosorption occurred at pH 5.5 for all biosorbents. The adsorbent mass for maximum adsorption was 0.4 g giving an adsorption capacity of 62.02 % for unmodified adsorbents. In the case of modified adsorbents, the minimal mass at which maximum adsorption occurred was 0.4 g giving an adsorption capacity of 98.33 % and 0.6 g giving an adsorption capacity of 98.33 % for modified rice husk and egussi peeling respectively. The adsorbent/adsorbate equilibrium was well described by the pseudo-second order kinetic model and by Langmuir’s and Freundlich adsorption model. This models showed that the adsorption of cadmium (II) is a chemisorption process.</p>

scholarly journals Harnessing of Newly Tailored Poly (Acrylonitrile)-Starch Nanoparticle Graft Copolymer for Copper Ion Removal via Oximation Reaction

2021 ◽  
Author(s):  
khaled Mostafa ◽  
H. Ameen ◽  
A. Ebessy ◽  
A. El-Sanabary
Keyword(s):  
Experimental Data ◽  
Adsorption Capacity ◽  
Graft Copolymer ◽  
Adsorption Kinetics ◽  
Copper Ions ◽  
Copper Ion ◽  
Second Order ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order

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.

Sign in / Sign up

Export Citation Format

Share Document