scholarly journals Sorption of Ammonium Ions onto Natural and Modified Egyptian Kaolinites: Kinetic and Equilibrium Studies

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ola I. El-Shafey ◽  
Nady A. Fathy ◽  
Thoria A. El-Nabarawy
Keyword(s):  
Surface Acidity ◽  
Chemical Properties ◽  
Intraparticle Diffusion ◽  
Solution Ph ◽  
Equilibrium Studies ◽  
Sorption Data ◽  
Thermally Activated ◽  
Physical Sorption ◽  
Pseudo Second Order ◽  
Physical And Chemical

Thermally activated, acid-activated, and acid-leached of thermally activated kaolinites were prepared from the Egyptian ore. The physical and chemical properties were studied using N2 sorption at −196°C, FTIR, SEM, and the total surface acidity. The sorption of NH4+ ions on the investigated sorbents was controlled with the solution pH, sorbent dosage, and initial concentration of NH4+ solution. Kinetic and equilibrium NH4+ sorption at 30°C were employed. Four kinetic models were applied to the kinetic sorption data; pseudo-second-order, Elovich, and intraparticle diffusion models fitted well the kinetic data whereas pseudo-first-order model was less applicable. Elovich parameters refer to physical sorption type of NH4+ on nonuniform sites and the intraparticle diffusion controls the sorption of NH4+ by kaolinites to a small extent. The equilibrium sorption data followed Langmuir and D-R models; the negative value of ΔG indicates a spontaneous sorption and the mean sorption energy obtained shows also physical sorption. The sorption capacities of nonactivated and activated Egyptian kaolinites towards NH4+ sorption (10.87–45.45 mg·g−1) were good sorbents as compared with those uptaken by other clays reported in the literature and proved to be more active besides being less expensive and highly available.

scholarly journals Facile Synthesis of Cross-linked Hyperbranched Polyamidoamines Dendrimers for Efficient Hg(Ⅱ) Removal From Water

2021 ◽  
Vol 9 ◽  
Author(s):  
Xue Geng ◽  
Rongjun Qu ◽  
Xiangyu Kong ◽  
Shengnan Geng ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Metal Ion ◽  
Large Scale ◽  
Chemical Properties ◽  
Diglycidyl Ether ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Solution Ph ◽  
Pseudo Second Order ◽  
Physical And Chemical

Dendrimers as commonly used metal ions adsorption materials have the advantages of good adsorption performance and high reuse rate, but the high cost limits its extensive use. Compared with dendrimers, hyperbranched dendrimers have similar physical and chemical properties and are more economical. Therefore, hyperbranched dendrimers are more suitable for industrial large-scale adsorption. The hyperbranched polyamidoamine (HPAMAM) gels were prepared by cross-linking hyperbranched polyamidoamine (HPAMAM-ECH-x and HPAMAM-EGDE-x) with different amounts of epichlorohydrin (ECH) and ethylene glycol diglycidyl ether (EGDE), respectively. The as-synthesized adsorbents were characterized by FT-IR, SEM and XPS. The prepared adsorbents were used to adsorb Hg(Ⅱ) in aqueous solution, and the effects of solution pH, contact time, temperature and initial concentration of metal ion on the adsorption capacity were investigated. The effect of solution pH indicated that the optimum condition to Hg(Ⅱ) removing was at pH 5.0. The adsorption kinetic curves of the two kinds of materials were in accordance with the pseudo-second-order model. For the HPAMAM-ECH samples, the adsorption thermodynamic curves fitted the Langmuir model, while for the HPAMAM-EGDE samples, both Langmuir and Freundlich equations fitted well. The maximum adsorption capacity of HPAMAM-ECH-3 obtained from Langmuir model toward Hg(Ⅱ) was 3.36 mmol/g at pH 5.0 and 35°C.

scholarly journals Adsorption Characteristics and Mechanism of Bisphenol A by Magnetic Biochar

2020 ◽  
Vol 17 (3) ◽  
pp. 1075 ◽  
Author(s):  
Jinpeng Wang ◽  
Ming Zhang
Keyword(s):  
Bisphenol A ◽  
Exothermic Reaction ◽  
Chemical Properties ◽  
Solution Ph ◽  
Acceptor Interaction ◽  
Endocrine Disrupting Chemical ◽  
Magnetic Biochar ◽  
Grapefruit Peel ◽  
Initial Adsorption ◽  
Physical And Chemical

In this paper, biochar (BC) was prepared from discarded grapefruit peel and modified to prepare magnetic biochar (MBC). Physical and chemical properties of BC and MBC were characterized, and the results showed that the type of iron oxide loaded by MBC was γ-Fe2O3. Compared with BC, MBC has a larger specific surface area and pore volume, with more oxygen-containing functional groups on the surface. BC and MBC were used to adsorb and remove endocrine-disrupting chemical (EDC) bisphenol A (BPA) from simulated wastewater. The results showed that the adsorption kinetics and adsorption isotherm of BPA adsorption by BC and MBC were mainly in accordance with the pseudo-second-order kinetics model and the Langmuir model. This indicates that the adsorption of BPA on BC and MBC is mainly a chemically controlled monolayer adsorption. Adsorption thermodynamics show that BC and MBC adsorption of BPA is a spontaneous exothermic reaction, and lowering the temperature is conducive to the adsorption reaction. The effect of solution pH on the adsorption of BPA by both was significant. The optimum pH for BC and MBC to absorb BPA was 6 and 3, respectively. The concentration of Na+ in the range of 0–0.10 mol·L−1 can promote the adsorption of BPA to MBC. MBC loaded with γ-Fe2O3 not only has excellent magnetic separation ability, but can also reach about 80% of the initial adsorption capacity after four cycles of adsorption. By analyzing the adsorption mechanism, it was found that the H-bond and the π–π electron donor–acceptor interaction (EDA) were the main forces for BC and MBC to adsorb BPA.

scholarly journals Efficient adsorption of Hg(II) from aqueous solution by N, S co-doped MnFe2O4@C magnetic nanoparticles

2020 ◽  
Vol 81 (6) ◽  
pp. 1273-1282 ◽  
Author(s):  
Hangdao Qin ◽  
Hao Cheng ◽  
Chenggui Long ◽  
Xiaogang Wu ◽  
Yanhong Chen ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Chemical Properties ◽  
Point Of Zero Charge ◽  
Simple Method ◽  
Transmission Electron ◽  
Pseudo Second Order ◽  
Enhanced Adsorption ◽  
Adsorption Desorption ◽  
Physical And Chemical ◽  
Co Doped

Abstract N, S co-doped MnFe2O4@C magnetic nanoparticles were successfully synthesized by a simple method involving the preparation of MnFe2O4 nanoparticles and subsequent pyrolysis treatment. The physical and chemical properties of MnFe2O4, MnFe2O4@C and MnFe2O4@C–NS nanoparticles were characterized by X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), N2 adsorption–desorption and the pH at the point of zero charge. Their performances in the adsorption of Hg(II) from water were investigated. The adsorption process followed pseudo-second-order kinetics and the experimental data of equilibrium isotherms fitted well with the Langmuir model. MnFe2O4@C–NS showed the highest adsorption capacity of 108.56 mg/g, increasing more than 1.7 times compared to MnFe2O4. The enhanced adsorption performance was attributed to the larger specific surface area as well as the complexation of N and S ligands on the surface. The thermodynamic parameters of ΔH°, ΔS° and ΔG° at 30 °C were −24.39 kJ/mol, −0.046 kJ/mol K and −10.45 kJ/mol, respectively, which indicated that the adsorption of Hg(II) on MnFe2O4@C–NS was exothermic and spontaneous in nature. Moreover, MnFe2O4@C–NS showed superior selectivity towards Hg(II) compared with other metal ions generally present in mercury-containing industrial wastewater.

Removal of Strontium Ions from Aqueous Solution by Sunflower Straw

2013 ◽  
Vol 726-731 ◽  
pp. 1922-1925 ◽  
Author(s):  
Lian Ai ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Si Zhao Zhang
Keyword(s):  
Aqueous Solution ◽  
Batch Adsorption ◽  
Order Model ◽  
Solution Ph ◽  
Sorption Data ◽  
Freundlich Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Sunflower Straw ◽  
Langmuir And Freundlich Models

The sorptive potential of sunflower straw (≤125 μm) for Sr2+ from aqueous solution was evaluated. Batch adsorption experiments were carried out as a function of solution pH, adsorbent dosage, Sr2+ concentration and contact time. FT-IR spectra and SEM of sunflower straw were employed to explore the functional groups available for the binding of Sr2+ and morphology of the adsorbent. Maximum uptake capacity of sunflower straw was 17.48 mg/g occurred at around pH 3-7. The adsorption equilibrium can be achieved within 5 min and kinetic data were fitted well to pseudo-second-order model. The Langmuir and Freundlich models were applied to describe isotherm sorption data. The Langmuir model gave an acceptable fit than Freundlich model.

Removal of Mn(II) from Aqueous Solution Using Saponified Garlic Peel

2014 ◽  
Vol 694 ◽  
pp. 382-386 ◽  
Author(s):  
Bo Liang ◽  
Wan He Zhao ◽  
Kai Huang ◽  
Hong Min Zhu
Keyword(s):  
Metal Ion ◽  
Chemical Properties ◽  
Correlation Coefficients ◽  
Ion Concentration ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Physical And Chemical ◽  
Garlic Peel

The removal of Mn (II) ion by saponified garlic peel (S-GP) was investigated using batch adsorption. SEM and FT-IR were employed to investigate the physical and chemical properties of S-GP. The adsorption was evaluated as a function of initial metal ion concentration, contact time and temperature. The maximum adsorption capacity for Mn (II) was 0.51 mol/kg, and the adsorption process followed the Langmuir model. Pseudo-second-order models fitted the experimental data well and kinetic parameters, rate constants, equilibrium sorption capacity and related correlation coefficients at various temperatures were calculated and discussed. A possible adsorption mechanism based on a cation exchange was proposed for the adsorption of Mn (II).

scholarly journals A Comprehensive Characterization of Different Fractions of Corn Stover and Their Relationships to Multipollutant Sorption Characteristics

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Dan Peng ◽  
Fan Ouyang ◽  
Min Deng ◽  
Lei Nie ◽  
Sifang Kong
Keyword(s):  
Adsorption Capacity ◽  
Corn Stover ◽  
Organic Pollutants ◽  
Lignin Content ◽  
Chemical Properties ◽  
Cellulose Content ◽  
Adsorption Effect ◽  
Adsorption Processes ◽  
Pseudo Second Order ◽  
Physical And Chemical

Corn stover (CS) is mainly composed of three parts: pith (CSP), rind (CSR), and leaf (CSL). These parts have different lignocellulosic constituents and structural properties. Herein, biosorbents derived from individual corn stover constituents were prepared in an effort to determine the significance of each constituent for multipollutant removal. In this study, SEM, BET, XRD, FTIR, XPS, fibre composition, and contact angle measurements were used to characterize and analyse the physical and chemical properties of the three components of CS and to study their adsorption effects, adsorption isotherms, and kinetics. The lignocellulosic compositions of CSP and CSR were similar, the cellulose content in CSP and CSR was significantly higher than that in CSL, and the hemicellulose content of CSL was much higher than those of CSP and CSR. The minimum lignin content was found in CSP, and the maximum lignin content was found in CSR. The results show that each component had a certain adsorption effect on typical organic pollutants (antibiotics, oils, and dyes). CSP had the strongest oil adsorption capacity, CSR was more suitable for adsorbing antibiotics, and CSL had outstanding adsorption capacity for dye. The pseudo-second-order model and the Langmuir adsorption isotherm model could describe the adsorption processes well, and they consisted of monolayer adsorption accompanied by chemical adsorption reactions. The focus of this study was to provide references for selecting effective adsorbent precursors to remove organic pollutants from wastewater.

Adsorption of Cr6+ and Pb2+ on soy sauce residue biochar from aqueous solution

BioResources ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. 4653-4669 ◽  
Author(s):  
Xiaoxun Xu ◽  
Chenying Zhou ◽  
Shirong Zhang ◽  
Zhang Cheng ◽  
Zhanbiao Yang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Pyrolysis Temperature ◽  
Chemical Properties ◽  
Soy Sauce ◽  
Order Kinetic ◽  
Metals Removal ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Pyrolysis Of Biomass ◽  
Physical And Chemical

Biochar produced by the pyrolysis of biomass can be used to counter water pollution from heavy metals. The purpose of this work was to develop a biosorbent based on soy sauce residue (SSR) for the removal of Cr6+ and Pb2+. The SSR biochar (SBC) from oxygen-limited pyrolysis under the temperatures of 300 to 700 °C were obtained, and their adsorption capability was evaluated. After determining the optimum pyrolysis temperature, the effects of initial pH values, contact times, and initial metal concentrations on the Cr6+ and Pb2+ adsorption by SBC prepared at 600 °C (SBC600) were investigated. With the increase of pyrolysis temperature, the physical and chemical properties of SBC developed in a direction favorable to heavy metal adsorption. The SBC600 reached the adsorption equilibrium at the time of 2 (Cr6+) and 24 h (Pb2+), and the maximum adsorption amounts of Cr6+ and Pb2+ were 25.80 and 135.3 mg/g, respectively. The adsorption kinetics followed the pseudo-second-order kinetic equation, and the adsorption isotherms was best described by the Langmuir isotherms. The SBC was an adsorbent with certain potential for heavy metals removal in wastewater.

Removal of Cr(VI) from Aqueous Solutions Using PVA/SA Blend Films

2013 ◽  
Vol 781-784 ◽  
pp. 2142-2145
Author(s):  
Wen Juan Fan ◽  
Hong Xiang Ge ◽  
Yu Pang ◽  
Hui Chang
Keyword(s):  
Polyvinyl Alcohol ◽  
Sodium Alginate ◽  
Crosslinking Agent ◽  
Chemical Properties ◽  
Solution Ph ◽  
Hydrogen Bond Interaction ◽  
Blend Films ◽  
Molecular Force ◽  
Physical And Chemical ◽  
And Chemical Properties

The different ratios (PVA and SA) of PVA/SA blend films with cross-linking structure are successfully prepared by coagulating the mixture of sodium alginate (SA) and polyvinyl alcohol (PVA) in aqueous solution, then by treating with crosslinking agent CaCl2solution. The Surface morphology and flexibility of PVA/SA blend films were studied. The results indicate there is some strong interaction and good compatibility between sodium alginate and polyvinyl alcohol molecular. The physical and chemical properties of the PSA-80(PVA:SA=4:1) blend films are obviously improved owing to a molecular force and hydrogen bond interaction. The effects of parameters of the blend film was investigated in relation to its adsorption capability for low concentration ions Cr (VI) including such as SA content of the PVA/SA film, contact time, solution pH and temperature of solution. The results indicate that the maximum adsorption rate is 95.86% at the temperature 50°C under optimized pH 4 for 60min by PSA-80 films.

Experimental Investigation on Adsorptive Removal of Phenolic Compounds from Aqueous Solution by Cr-Bentonite

2010 ◽  
Vol 160-162 ◽  
pp. 163-170
Author(s):  
Hong Zheng ◽  
Yang Wang ◽  
Peng Liang ◽  
Hong Bin Qi
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Phenolic Compounds ◽  
Intraparticle Diffusion ◽  
Second Order ◽  
Synthetic Wastewater ◽  
Order Kinetic ◽  
Sorption Data ◽  
Adsorptive Removal ◽  
Pseudo Second Order

The ability of Cr-bentonite prepared using synthetic wastewater containing chromium was investigated for adsorptive removal of 4-aminophenol and 4-chlorophenol from aqueous solution in a batch system at 25 °C. The physic-chemical parameters including pH value of solution and contact time were studied. The experimental data were analyzed by the Langmuir, Freundlich and Temkin models of sorption. The equilibrium sorption data for 4-aminophenol and 4-chlorophenol were well fitted to Langmuir adsorption isotherm and the monolayer sorption capacity was found to be 26.53 and 23.81 mg/g at 25 °C, respectively. The sorption energy calculated from Dubinin-Redushkevich (D-R) isotherm are 8.31 and 8.20 kJ/mol for the uptake of 4-aminophenol and 4-chlorophenol respectively which indicates that both the sorption processes are chemical in nature. The kinetic data were analyzed using pseudo-first order, pseudo-second order kinetic equation and intraparticle diffusion model. The experimental data fit very well the pseudo-second order kinetic model. Intraparticle diffusion affects 4-aminophenol and 4-chlorophenol uptake. Sorption studies carried out using industrial wastewater samples containing phenolic compounds show that there is significant potential for Cr-bentonite as an adsorbent material for phenollic compounds removal from aqueous solutions.

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