scholarly journals Sorption of Pb(II) from Aqueous Solutions by Acid-Modified Clinoptilolite-Rich Tuffs with Different Si/Al Ratios

2019 ◽  
Vol 9 (12) ◽  
pp. 2415 ◽  
Author(s):  
Mohamed Abatal ◽  
Atl V. Córdova Quiroz ◽  
María T. Olguín ◽  
América R. Vázquez-Olmos ◽  
Joel Vargas ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Batch Studies ◽  
X Ray ◽  
Pseudo Second Order ◽  
Modified Clinoptilolite ◽  
Adsorbent Dose

The removal of Pb(II) from aqueous solutions by acid-modified clinoptilolite-rich tuff was investigated in this work. Clinoptilolite-rich tuff samples were treated using H2SO4 at different concentrations. Prior to and following acid treatment, the samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Fourier-transform infrared spectroscopy (FTIR). The pH of the point of zero charge (pHPZC) was also determined as part of this characterization. Batch studies were studied to investigate Pb(II) removal as a function of contact time, initial Pb(II) concentration, adsorbent dosage, and solution pH. The results of the XRD and SEM techniques showed that clinoptilolite is the main mineral of the non- and acid-treated natural zeolite samples. However, EDS analysis indicated that the Si/Al ratio increases as the exchangeable ions decrease with increasing acid concentrations. The optimum conditions for Pb(II) removal for samples with 4.37 ≤ Si/Al ≤ 7.9 were found to be as follows: Contact time of 60–360 min, pH: 6–8, and adsorbent dose of 6 mg g−1; whereas for acid-modified clinoptilolite-rich tuffs with 9.01 ≤ Si/Al ≤ 9.52, these conditions were as follows: Contact time of 1440 min, pH: 8–10, and adsorbent dose of 10 mg g−1. The experimental data were analyzed by kinetic and isotherms models. The results showed that the sorption of Pb(II) on samples with Si/Al ratios of 4.37, 5.31, and 7.91 were in agreement with the pseudo-second order and Langmuir isotherm with qm = 48.54, 37.04, and 14.99 mg g−1, respectively, while the kinetic data and isotherm for samples with 9.01 ≤ Si/Al ≤ 9.52 were found to fit the pseudo-first order and Freundlich model.

scholarly journals The Removal of Uranium and Thorium from Their Aqueous Solutions by 8-Hydroxyquinoline Immobilized Bentonite

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.

scholarly journals Magnetic Fe3O4 Nanoparticle Biochar Derived from Pomelo Peel for Reactive Red 21 Adsorption from Aqueous Solution

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Van Hao Nguyen ◽  
Huu Tap Van ◽  
Van Quang Nguyen ◽  
Xuan Van Dam ◽  
L. P. Hoang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Bet Surface Area ◽  
Solution Temperature ◽  
Solution Ph ◽  
Experimental Conditions ◽  
X Ray ◽  
Pomelo Peel ◽  
Pseudo Second Order ◽  
Adsorbent Dose

In this study, Fe3O4 nanoparticle-loaded biochar derived from the pomelo peel (FO-PPB) was synthesized and applied as an affordable material for the adsorption of Reactive Red 21 (RR21) in an aqueous solution. The characteristics of FO-PPB were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), Raman spectra, Fourier transform infrared spectra (FTIR), and Brunauer–Emmett–Teller (BET) surface area. The adsorption process of FO-PPB with RR21 was evaluated through batch experiments to examine various parameters including solution pH, contact time, adsorbent dose, initial RR21 concentration, and solution temperature. Results show that FO-PPB produced by the impregnation ratio between iron (Fe) and pomelo peel biochar (PPB) of 5 : 1 (w/w) had the best adsorption performance. The adsorption capacities of PPB and FO-PPB at optimum experimental conditions (solution pH 3, contact time of 60 min, solution temperature of 40°C, initial RR21 concentration of 300 mg/L, and adsorbent dose of 2 g/L) were 18.59 and 26.25 mg/g, respectively. The adsorption isotherms of RR21 on PPB and FO5-PPB were described well by Langmuir and Sips models with high R2 values of 0.9826 and 0.9854 for FO5-PPB and 0.9701 and 0.9903 for PPB, respectively. The obtained data also well matched the pseudo-first-order and pseudo-second-order models with R2 values ≥ 0.96. Chemisorption through sharing or electronic exchange was determined as the main adsorption mechanism.

scholarly journals Adsorption Study for the Removal of Nitrate from Water Using Local Clay

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
A. Battas ◽  
A. El Gaidoumi ◽  
A. Ksakas ◽  
A. Kherbeche
Keyword(s):  
Solution Concentration ◽  
Optimal Conditions ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Local Clay ◽  
Initial Concentration ◽  
X Ray ◽  
Rate Of Reaction ◽  
Pseudo Second Order ◽  
Adsorbent Dose

Our research aimed at the removal of nitrate ions through adsorption by local clay. A series of batch experiments were conducted to examine the effects of contact time, adsorbent characteristics, initial concentration of nitrate, pH of the solution, concentration, and granulometry of adsorbent. Adsorption isotherms studies indicated that local clay satisfies Freundlich’s model. The rate of reaction follows pseudo-second-order kinetics. Local clay successfully adsorbs nitrates at pH acid. The adsorption capacity under optimal conditions was found to be 5.1 mg/g. The adsorption yield increases with adsorbent dose and decrease with initial concentration of nitrate. The local clay was characterized by the X-ray fluorescence method (XRF), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), scanning electronics microscopy (SEM), and measurement of specific surface area (BET). The results of the study indicated that local clay is useful materials for the removal of nitrates from aqueous solutions which can be used in water treatment without any chemical modification.

Biosorption of Zn(II) from Aqueous Solution by Amusium pleuronectes Shell

2016 ◽  
Vol 675-676 ◽  
pp. 7-10
Author(s):  
K. Chantarasunthon ◽  
Kanyakorn Teanchai ◽  
Wichian Siriprom
Keyword(s):  
Aqueous Solution ◽  
Experimental Investigation ◽  
Contact Time ◽  
Physical Adsorption ◽  
Absorption Capacity ◽  
X Ray Diffraction ◽  
Batch Method ◽  
Solution Ph ◽  
X Ray ◽  
High Level

In this study, the experimental investigation and assessment the absorption capacity for Zn ion with Amusium Pleuronectes shell. The investigations were carried out by batch method and variables of the batch experiment include solution pH, Contact time, were determind. The mechanism of bisorption is chemisorption or/and physical adsorption was confirmed by X-ray Diffraction (XRD) and Energy Dispersive X-ray Fluorescence (EDXRF). The results showed that the Amusium Pleuronectes shell has a high level of absorption capacity for Zn (II) ions. Another that result of mechanism of biosorption suggests and confirm with the result of XRD and EDXRF.

scholarly journals Hen feather a bio-waste material for adsorptive removal of methyl red dye from aqueous solutions

2021 ◽  
Author(s):  
Samina Zaman ◽  
Md. Nayeem Mehrab ◽  
Md. Shahnul Islam ◽  
Gopal Chandra Ghosh ◽  
Tapos Kumar Chakraborty
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Methyl Red ◽  
Experimental Conditions ◽  
Potential Applicability ◽  
Pseudo Second Order ◽  
Red Dye ◽  
Adsorbent Dose

Abstract This study investigates the potential applicability of hen feather (HF) to remove methyl red (MR) dye from aqueous solution with the variation of experimental conditions: contact time (1–180 min), pH (4–8), initial dye concentration (5–50 mg/L) and adsorbent dose (3–25 g/L). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) evaluate the surface morphology and chemistry of HF, respectively. The maximum removal of MR by HF was 92% when the optimum conditions were initial MR dye concentration 05 mg/L, pH 4.0, adsorbent dose 07.0 g/L and 90.0 min equilibrium contact time. Langmuir isotherm (R2 = 0.98) was more suited than Freundlich isotherm (R2 = 0.96) for experimental data, and the highest monolayer adsorption capacity was 6.02 mg/g. The kinetics adsorption data fitted well to pseudo-second-order model (R2 = 0.999) and more than one process were involved during the adsorption mechanism but film diffusion was the potential rate-controlling step. The findings of the study show that HF is a very effective and low-cost adsorbent for removing MR dye from aqueous solutions.

scholarly journals Adsorption of hexavalent chromium ions from aqueous solutions using nano-chitin: kinetic, isotherms and thermodynamic studies

2021 ◽  
Vol 16 (2) ◽  
pp. 436-451
Author(s):  
Meghdad Sheikhi ◽  
Hassan Rezaei
Keyword(s):  
Aqueous Solutions ◽  
Correlation Coefficient ◽  
Hexavalent Chromium ◽  
Contact Time ◽  
New Technology ◽  
Kinetic Studies ◽  
Chromium Vi ◽  
Effects Of Ph ◽  
Pseudo Second Order ◽  
Adsorbent Dose

Abstract Treatment of the industrial wastewater before discharging into aquatic ecosystems using a new technology such as nanotechnology seems necessary. There are different methods for the removal of the heavy metals in the wastewater. In this study, nano-chitin was purchased from the Nano-Novin Polymer Company and used as an adsorbent for the removal of chromium (VI) ions from aqueous solution in a batch system. The effects of pH, temperature, contact time, concentration, and adsorbent dose were investigated. According to the results, the optimum conditions of adsorption occurred at pH = 6, temperature = 25 °C, 60 minutes contact time, and 0.6 g·L−1 adsorbent dose. Investigation of equilibrium isotherms showed that the isotherm fitted the Freundlich model with a correlation coefficient of R2 = 0.9689. The pseudo second-order model with the larger correlation coefficient had a greater fitness against experimental data in the kinetic studies. Thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy were calculated, which indicated spontaneous, endothermic, and random processes, respectively. Given the good results of this project, nano-chitin can be suggested as a novel adsorbent which is highly capable of adsorbing hexavalent chromium from aqueous solutions.

scholarly journals Comparison of Rhodotorula sp. and Bacillus megaterium in the removal of cadmium ions from liquid effluents

2018 ◽  
Vol 7 (1) ◽  
pp. 74-88 ◽  
Author(s):  
Mihaela Roşca ◽  
Raluca-Maria Hlihor ◽  
Petronela Cozma ◽  
Elena Niculina Drăgoi ◽  
Mariana Diaconu ◽  
...  
Keyword(s):  
Bacillus Megaterium ◽  
Contact Time ◽  
Point Of Zero Charge ◽  
Operating Parameters ◽  
Order Kinetic ◽  
Cadmium Ions ◽  
X Ray ◽  
Freundlich Isotherms ◽  
Accuracy And Precision ◽  
Pseudo Second Order

AbstractThis study compares the capacity ofRhodotorulasp. andBacillus megateriumfor Cd(II) removal considering the influence of operating parameters (pH, biosorbent dosage, contact time, temperature, initial metal concentration in solution). The highest Cd(II) uptake of 14.2 mg/g byRhodotorulasp. was exhibited at 30°C, when working at pH 6 and with 5 g/l biosorbent dosage, after 48 h of contact time. In these conditions, a removal efficiency of 85% was obtained. Similar outcomes were obtained forB. megaterium(15.1 mg/g, 90%) at 35°C, pH 4 and 3 g/l biosorbent dosage, considered as the optimum set of parameters, equilibrium being achieved for a contact time of 20 min. The possible interaction mechanisms between the biosorbents and Cd(II) were evaluated through point of zero charge (pHpzc), Fourier transform infrared (FTIR), spectroscopy and scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDX). Data were modeled using pseudo-first and pseudo-second order kinetic models and Langmuir and Freundlich isotherms models. Further studies considered a modeling approach based on linear regression with Durbin-Watson statistics, while the accuracy and precision of experiments were evaluated by ANOVA.

scholarly journals Kinetic and Thermodynamic Study of Adsorption of Copper (II) Ion on Moroccan Clay

2019 ◽  
Vol 9 (2) ◽  
pp. 102-115
Author(s):  
Hanane Essebaai ◽  
Ilham Ismi ◽  
Ahmed Lebkiri ◽  
Said Marzak ◽  
El Housseine Rifi
Keyword(s):  
Contact Time ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increase With Increase ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Kinetic And Thermodynamic Study

Highly efficient low-cost adsorbent was applied for copper (II) ions uptake from aqueous solution. Characteristics of natural adsorbent were established using scanning X-ray diffraction (XRD), X-ray fluorescence, electron microscope (SEM) and Fourier Transform Infra-Red (FTIR). Various physicochemical parameters such as contact time, initial copper(II) ions concentration, adsorbent dosage, pH of copper (II) ions solution and temperature were investigated. The result showed that the adsorption of copper (II) ions by natural clay was favorable at pH=5,5. The adsorption was found to increase with increase in initial copper (II) ions concentration, and contact time. Equilibrium adsorption data were fitted using three isotherms and kinetic data tested with four kinetic models. Freundlich isotherm best described the adsorption of copper (II) ions onto utilised clay, the maximum monolayer adsorption capacity (qmax) was 8 mg/g. Pseudo-second-order model best described the kinetics of the adsorption process. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were determined. It was found that copper (II) ions adsorption was spontaneous (ΔG°<0) and endothermic (ΔH°>0).

scholarly journals Mass-transfer processes in the adsorption of crystal violet by activated carbon derived from pomegranate peels: Kinetics and thermodynamic studies

2020 ◽  
Vol 15 ◽  
pp. 155892502091984
Author(s):  
Moussa Abbas ◽  
Zahia Harrache ◽  
Mohamed Trari
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Crystal Violet ◽  
Agitation Speed ◽  
Second Order ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Solution Ph ◽  
Pseudo Second Order ◽  
Adsorbent Dose

This study investigates the potential use of activated carbon, prepared from pomegranate peels, as an adsorbent activated using H3PO4 and its ability to remove crystal violet from an aqueous solution. The adsorbent was characterized by the Brunauer–Emmett–Teller method (specific surface area: 51.0674 m2 g−1) and point of zero charge (pHPZC = 5.2). However, some examined factors were found to have significant impacts on the adsorption capacity of activated carbon derived from pomegranate peels such as the initial dye concentration (5–15 mg L−1), solution pH (2–14), adsorbent dose (1–8 g L−1), agitation speed (100–700 r/min), and temperature (298–338 K). The best adsorption capacity was found at pH 11 with an adsorbent dose of 1 g L−1, an agitation speed at 400 r/min, and a contact time of 45 min. The adsorption mechanism of crystal violet onto activated carbon derived from pomegranate peels was studied using the pseudo-first-order, pseudo-second-order, Elovich, and Webber–Morris diffusion models. The adsorption kinetics were found to rather follow a pseudo-second order kinetic model with a determination coefficient ( R2) of 0.999. The equilibrium adsorption data for crystal violet adsorbed onto activated carbon derived from pomegranate peels were analyzed by the Langmuir, Freundlich, Elovich, and Temkin models. The results indicate that the Langmuir model provides the best correlation with qmax capacities of 23.26 and 76.92 mg g−1 at 27°C and 32°C, respectively. The adsorption isotherms at different temperatures have been used for the determination of thermodynamic parameters like the free energy, enthalpy, and entropy to predict the nature of adsorption process. The negative values Δ G0 (−5.221 to −1.571 kJ mol−1) and Δ H0 (−86.141 kJ mol−1) indicate that the overall adsorption is spontaneous and exothermic with a physisorption process. The adsorbent derived from pomegranate peels was found to be very effective and suitable for the removal of reactive dyes from aqueous solutions, due to its availability, low-cost preparation, and good adsorption capacity.

Adsorption of 2,4,6-trichlorophenol on bentonite modified with benzyldimethyltetradecylammonium chloride

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Infrared Spectroscopy ◽  
Contact Time ◽  
Removal Rate ◽  
Organic Pollutant ◽  
Freundlich Isotherm ◽  
Solution Concentration ◽  
Isotherm Models ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pseudo Second Order

The objective of this study is to evaluate the performance and capacities of the bentonite of Maghnia, modified with benzyldimethyltetradecylammonium chloride, to remove the organic pollutant 2,4,6-Trichlorophenol (TCP). The modified sample was studied by X-ray diffraction (XRD) technique, infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) methods. The best removal rate (99.52%) was obtained at 19°C, pH 4, solution concentration of 50 mg/L, stirring speed of 180 rpm and contact time of 60 min. The results were well fitted by both Langmuir and Freundlich isotherm models and the pseudo-second-order is the best model to describe the process.

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