Influence of pH, Ionic Strength and Temperatureon Adsorption of Lead, Copper and Zinc in Natural Soil

2011 ◽  
Vol 255-260 ◽  
pp. 2810-2814
Author(s):  
Feng Jie Zhang ◽  
Xiao Xia Ou ◽  
Chun Qiu Ran ◽  
Yun Na Wu
Keyword(s):  
Ionic Strength ◽  
Adsorption Process ◽  
Langmuir Equation ◽  
Regression Coefficients ◽  
Natural Soil ◽  
Solution Ph ◽  
Enthalpy Changes ◽  
Freundlich Equation ◽  
Different Temperatures ◽  
Influence Of Ph

Sorption of Pb, Zn, Cu by natural soils was investigated under conditions of variable pH, ionic strength and temperature. The results obtained from adsorption isotherm indicated that these data can be better fitted with the Freundlich equation than with the Langmuir equation in terms of regression coefficients. The parameters in the adsorption process were influenced greatly by solution pH and ionic strength. The Freundlich parameter KF increased with increasing pH and decreasing ionic strength, but the Freundlich parameter n changed adversely. Thermodynamic parameters of the process were calculated from sorption studies performed at different temperatures, and enthalpy changes (△H°) and entropy changes (△S°) of adsorption were found as -20.70 kJ/mol and 34.76 J/mol.K for Pb(II), -7.762 kJ/mol and 1.139 J/mol.K for Cu(II), -20.60 kJ/mol and 51.93 J/mol.K for Zn(II) respectively, showing that adsorption of Pb2+, Cu2+, and Zn2+ on natural soil were exothermic and spontaneous at 5-45°C.

scholarly journals Adsorption of Tetracycline on the Bauxite and Modified Bauxite at Different Temperatures

2017 ◽  
Vol 30 (3) ◽  
pp. 150
Author(s):  
Israa M. Radhi ◽  
Yousif I. Mohammed ◽  
Takialdin A. Himdan ◽  
Dhefaf H. Badri
Keyword(s):  
Aqueous Solutions ◽  
Temperature Effect ◽  
Thermodynamic Functions ◽  
Adsorption Process ◽  
Equation Model ◽  
Langmuir Equation ◽  
Equilibrium Time ◽  
Freundlich Equation ◽  
Different Temperatures

  In this study, bauxite and modified bauxite /polymer, which were prepared as an adsorbent surfaces to adsorption of the tetracycline from aqueous solutions. A series of adsorption experiments were conducted to determine the equilibrium time and temperature effect on the adsorption process. The results showed that adsorption was agreed with the Freundlich equation model for the surface of the bauxite. As for the modified bauxite surface, the results were consistent with the Langmuir equation model. The values of the basic thermodynamic functions of the adsorption process were calculated, so the process of adsorption was founded   spontaneous and endothermi

scholarly journals New Insights into the Interaction between Graphene Oxide and Beta-Blockers

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1429
Author(s):  
Yuehua Deng ◽  
Yani Li ◽  
Wenjie Nie ◽  
Xiang Gao ◽  
Shentan Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Adsorption Process ◽  
Beta Blockers ◽  
Langmuir Equation ◽  
Synthetic Material ◽  
Magnetic Graphene Oxide ◽  
First Order ◽  
Freundlich Equation ◽  
Pseudo First Order ◽  
Nano Adsorbent

As a nano-adsorbent, magnetic graphene oxide (GO/Fe3O4) was synthesized to potentially adsorb propranolol (PRO) from water. The synthetic material was characterized by SEM, TEM, VSM, FTIR, XRD, zeta potential, and XPS. The environmental factors, such as pH, humic acid concentration, PRO concentration, and contact time, were investigated regarding their effect on the adsorption process. The kinetics data fitted the pseudo first-order and second-order kinetics equations. The Langmuir equation, the Freundlich equation, and the Sips equation were used to analyze the adsorption isotherms. Electrostatic attraction, hydrogen bonding, and the π–π interaction all contributed to the adsorption process of PRO onto GO/Fe3O4. The discovery of this study emphasized the feasibility of GO/Fe3O4 removal of PRO and expanded the scope of the application of GO.

Sorption of vanadium (V) onto natural soil colloids under various solution pH and ionic strength conditions

Chemosphere ◽  
2017 ◽  
Vol 169 ◽  
pp. 609-617 ◽  
Author(s):  
Xiuhua Luo ◽  
Lin Yu ◽  
Changzhao Wang ◽  
Xianqiang Yin ◽  
Ahmed Mosa ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Natural Soil ◽  
Solution Ph ◽  
Soil Colloids

scholarly journals Adsorption of Chelerythrine from Toddalia asiatica (L.) Lam. by ZSM-5

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Yunlong Liu ◽  
Jie Guo ◽  
Zhuobing Xiao ◽  
Dazhao Peng ◽  
Ke Song
Keyword(s):  
Adsorption Process ◽  
Inorganic Materials ◽  
Maximum Adsorption Capacity ◽  
Separation And Purification ◽  
Active Components ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Isotherm Adsorption ◽  
Different Temperatures ◽  
Toddalia Asiatica

Separation and purification of active components from biomass by inorganic materials during the pretreatment process of hydrothermal conversion are studied in this work. The batch experiment results show that an initial solution pH of 6 favors chelerythrine adsorption, and the optimum adsorbent dosage is 2.0 g. The adsorption mechanism of ZSM-5 for chelerythrine is investigated by adsorption kinetics, isotherm adsorption models, and thermodynamics analysis. The results show that the kinetics data fit the pseudo-second-order model well (R2 = 0.9991), and the intraparticle diffusion model has 3 diffusion stages, preliminarily indicating that chemisorption plays a major role in the adsorption process, and the sorption mechanism includes intraparticle, external, and boundary diffusion. The adsorption isotherms agree well with the Langmuir model, indicating the occurrence of monolayer molecular adsorption during the adsorption process. Meanwhile, the maximum adsorption capacity is 2.327, 2.072, and 1.877 mg/g at different temperatures (288 K, 298 K, and 308 K), respectively. The thermodynamic data demonstrate that the adsorption process is exothermic and spontaneous in nature. These observed results clearly confirm that ZSM-5 has potential superior properties for the enrichment and purification of alkaloids during the pretreatment of biomass.

scholarly journals Release of soil phosphorus during runoff as affected by ionic strength and temperature

1996 ◽  
Vol 5 (2) ◽  
pp. 193-202 ◽  
Author(s):  
Markku Yli-Halla ◽  
Helinä Hartikainen
Keyword(s):  
Ionic Strength ◽  
Soil Phosphorus ◽  
Langmuir Equation ◽  
Runoff Water ◽  
P Release ◽  
Release Capacity ◽  
Different Temperatures ◽  
Dissolved Reactive Phosphorus ◽  
Labile P ◽  
Reactive Phosphorus

Dissolved reactive phosphorus (DRP) from two cultivated clay soil samples (Vertic Cambisols) was extracted under conditions simulating the variation in the properties of surface runoff water in the field. DRP was extracted at three temperatures (5, 15 and 25°C), and at different ionic strengths by using deionized water and CaCl2 solutions (0.00005-0.005 M) as extractants. The solution-to-soil ratio varied from 50 to 2000 1 kg-1. Sorption to and desorption from the soils were studied at different temperatures and ionic strengths by determining quantity-intensity (Q/I) plots at the solution-to-soil ratio of 50 l kg-1, and the results were fitted to a modified Langmuir equation: Q = QmaxI/(1/K + I)-Q0 where Q is P sorbed or desorbed, Qmax = maximum P sorption, I = P concentration in the equilibrium solution, K = sorption/desorption equilibrium constant, and Q0 = instantly labile P. The desorption of DRP was depressed by increases in the CaCl2 concentration of the extractant and promoted by widening of the solution-to-soil ratio. At the solution-to-soil ratio of 50 l kg-1, the increase in the temperature from 5 to 25°C raised the DRP release to water from 12.6 to 20.7 mg kg-1 in the Aurajoki soil and from 1.8 to 3.4 mg kg-1 in the Jokioinen soil. In the Aurajoki soil, the constant Q0 of the Langmuir equation responded to the changes of ionic strength and temperature in the same way as did DRP extracted at wide solution-to-soil ratios. However, the P release capacity of both soils was underestimated by the constant Q0.

scholarly journals Synthesis and Characterization of Novel Uracil-Modified Chitosan as a Promising Adsorbent for Efficient Removal of Congo Red Dye

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 271
Author(s):  
Nouf F. Al-Harby ◽  
Ebtehal F. Albahly ◽  
Nadia A. Mohamed
Keyword(s):  
Congo Red ◽  
Adsorption Process ◽  
Ph Value ◽  
Dye Adsorption ◽  
Amino Groups ◽  
Step Method ◽  
Solution Ph ◽  
Intraparticle Diffusion Model ◽  
Modified Chitosan ◽  
Different Temperatures

Novel Uracil-modified chitosan (UCs) adsorbent has successfully been synthesized through a four-step method during which the amino groups of chitosan have been protected, then epoxy nuclei have been incorporated, afterwards the latter have been opened using 6-amino-1,3-dimethyl uracil, and finally the amino groups have been regained via removing the protection. Its structure was checked using FTIR, XRD and SEM techniques. The adsorption capacity of UCs for anionic Congo Red (CR) dye was studied under various conditions. It decreased significantly with increasing the solution pH value and dye concentration, while increased with increasing temperature. The adsorption of UCs for CR dye at different temperatures, solution pH and dye concentrations fitted to the kinetic model of pseudo-second order and Elovich model. The intraparticle diffusion model showed that the adsorption process involves multi-step process. The isotherm of CR dye adsorption by UCs conforms to the Langmuir isotherm model indicating the monolayer nature of adsorption. The maximum monolayer coverage capacity, qmax, was 434.78 mg g−1. Studying the thermodynamic showed that the adsorption of CR dye onto UCs was endothermic as illustrated from the positive value of enthalpy (21.37 kJ mol−1). According to the values of ΔG°, the adsorption process was spontaneous at all selected temperatures. The value of ΔS° showed an increase in randomness for the adsorption of CR dye by UCs. The value of activation energy was 18.40 kJ mol−1.

Influence of pH and ionic strength on the thermal gelation behaviour of pea protein

2021 ◽  
pp. 106903
Author(s):  
Caren Tanger ◽  
Michaela Müller ◽  
David Andlinger ◽  
Ulrich Kulozik
Keyword(s):  
Ionic Strength ◽  
Pea Protein ◽  
Thermal Gelation ◽  
Influence Of Ph

scholarly journals Synthesis of Polymer-Based Magnetic Nanocomposite for Multi-Pollutants Removal from Water

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1742
Author(s):  
Fatimah Mohammed Alzahrani ◽  
Norah Salem Alsaiari ◽  
Khadijah Mohammedsaleh Katubi ◽  
Abdelfattah Amari ◽  
Faouzi Ben Rebah ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Magnetic Composite ◽  
Sample Treatment ◽  
Water Type ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Vibration Sample Magnetometer ◽  
Pollutants Removal ◽  
Co Precipitation ◽  
Red Dye

A magnetic polymer-based nanocomposite was fabricated by the modification of an Fe3O4/SiO2 magnetic composite with polypyrrole (PPy) via co-precipitation polymerization to form PPy/Fe3O4/SiO2 for the removal of Congo red dye (CR) and hexavalent chromium Cr(VI) ions from water. The nanocomposite was characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), vibration sample magnetometer, and thermogravimetric analysis (TGA). The results confirm the successful fabrication of the nanocomposite in the size of nanometers. The effect of different conditions such as the contact time, adsorbent dosage, solution pH, and initial concentration on the adsorption process was investigated. The adsorption isotherm suggested monolayer adsorption of both contaminants over the PPy/Fe3O4/SiO2 nanocomposite following a Langmuir isotherm, with maximum adsorption of 361 and 298 mg.g−1 for CR dye and Cr(VI), respectively. Furthermore, the effect of water type on the adsorption process was examined, indicating the applicability of the PPy/Fe3O4/SiO2 nanocomposite for real sample treatment. Interestingly, the reusability of the nanocomposite for the removal of the studied contaminants was investigated with good results even after six successive cycles. All results make this nanocomposite a promising material for water treatment.

Inerte Amminkomplexe als mehrwertige Kationsäuren in wäßriger Lösung / Inert Ammine Complexes as Multivalent Cationic Acids in Aqueous Solution

1980 ◽  
Vol 35 (9) ◽  
pp. 1096-1103 ◽  
Author(s):  
Matthias Kretschmer ◽  
Lutwin Labouvie ◽  
Karl-W. Quirin ◽  
Helmut Wiehn ◽  
Ludwig Heck
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Spectrophotometric Method ◽  
Complex Cation ◽  
Aqua Ligand ◽  
Second Step ◽  
Acidity Constants ◽  
Ammine Complexes ◽  
Temperature Variations ◽  
Enthalpy Changes

Acidity constants of ammine complexes of tetravalent platinum in aqueous solutions have been determined by a spectrophotometric method at very low ionic strengths and extrapolated to zero ionic strength. Temperature variations of pK-values (25 °C and 50 °C) yield thermodynamic parameters for two successive deprotonation steps of hexaammineplatinum(IV), pentaamminechloroplatinum(IV), and tris(ethylenediamine)pla- tinum(IV) complexes and for the deprotonation of pentaammineaquacobalt(III) ion.The enthalpy changes for the first and second steps are similar and range from 50 to 75 kJ/mole while for the aqua ligand of Co(III) 33 kJ/mole are found. The very large dif­ference in the entropy changes (about 70 to 80 J/K mole for the first step and -10 to + 20 J/K mole for the second step) is interpreted by a model of solvation change. The primary hydration sphere of strongly oriented and immobilized water dipoles around the highly charged complex cation is transformed to a hydrogen-bonded solvation sheath when the electric field of the complex is weakened upon release of the first proton.

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