Adsorption of Ni(II) from Aqueous Solution by Sulfuric Acid and Thermally Treated Attapulgite

2014 ◽  
Vol 1073-1076 ◽  
pp. 90-94 ◽  
Author(s):  
Jun Ren ◽  
Xiao Wei Song ◽  
Dan Xu ◽  
Dong Dong Gou ◽  
Ling Tao
Keyword(s):  
Entropy Change ◽  
Enthalpy Change ◽  
Gibbs Free Energy Change ◽  
Temperature Dependent ◽  
Sorption Data ◽  
Initial Concentration ◽  
Pseudo Second Order ◽  
Modified Attapulgite ◽  
Equilibrium Adsorption Isotherm ◽  
Good Agreement

Adsorption of Ni (II) onto modified attapulgite was investigated with respect to temperature, initial concentration and contact time. The kinetics data related to the adsorption of nickel from aqueous solutions were in good agreement with the pseudo-second order equation in ranges of initial concentration of 20-200 mg/L, and temperature of 298-328K.The thermodynamic experiment results showed that the equilibrium adsorption isotherm was closely fitted with the Langmuir model. Enthalpy change (△H0), entropy change (△S0) and Gibbs free energy change (△G0) were calculated from the temperature dependent sorption data, and the results indicated that the sorption of Ni (II) on modified attapulgite was a spontaneous process, and the sorption was endothermic.

Adsorption Mechanism of Attapulgite for Cu(ΙΙ) in Aqueous Solution

2014 ◽  
Vol 1065-1069 ◽  
pp. 1867-1870
Author(s):  
Jun Ren ◽  
Ya Qiong Zhao ◽  
Dong Dong Gou ◽  
Ling Tao ◽  
Mei Wei Zhang
Keyword(s):  
Adsorption Mechanism ◽  
Entropy Change ◽  
Order Kinetic ◽  
Gibbs Free Energy Change ◽  
Temperature Dependent ◽  
Sorption Data ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Equilibrium Adsorption Isotherm

Adsorption of Cu(Ⅱ) onto natural attapulgite was investigated with respect to temperature, initial concentration and contact time. The adsorption process can be well described by the pseudo-second-order kinetic model, and the equilibrium adsorption isotherm was closely fitted with the Freundlich model. Enthalpy change(△H0), entropy change(△S0) and Gibbs free energy change(△G0) were calculated from the temperature dependent sorption data, and the results indicated that the sorption of Cu(Ⅱ) on attapulgite was a spontaneous process, and the sorption was endothermic.

Adsorption of Cr (VI) from Aqueous Solution by Purified Attapulgite

2014 ◽  
Vol 1051 ◽  
pp. 583-587
Author(s):  
Ling Tao ◽  
Xiao Wei Song ◽  
Jian Li Yuan ◽  
Jun Ren ◽  
Yan Zhuo Zhang
Keyword(s):  
Aqueous Solution ◽  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Order Equation ◽  
Langmuir Model ◽  
Initial Concentration ◽  
Pseudo Second Order ◽  
Equilibrium Adsorption Isotherm ◽  
Good Agreement

Adsorption of Cr6+ onto purified attapulgite was investigated with respect to temperature, initial concentration and contact time. The kinetics data related to the adsorption of chromium from aqueous solutions are in good agreement with the pseudo-second order equation in ranges of initial concentration of 20~200 mg/L, and temperature of 298~328K. The thermodynamic experiment results show that the equilibrium adsorption isotherm was closely fitted with the Langmuir model.

scholarly journals Removal of antibiotic Ciprofloxacin Hydrochloride from water by Kandira stone: Kinetic models and thermodynamic

2015 ◽  
Vol 17 (3) ◽  
pp. 498-507 ◽  
Keyword(s):  
Freundlich Isotherm ◽  
Entropy Change ◽  
Building Stone ◽  
Order Kinetic ◽  
Sorption Data ◽  
Ciprofloxacin Hydrochloride ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Rate Controlling Step ◽  
Cladding Material

<div> <p>In this study, Kandira stone, extensively used as a cladding material for building stone has been examined for the removal of an antibiotic Ciprofloxacin hydrochloride (CIP) from its aqueous solution. Batch experiments were performed to investigate the adsorption kinetics, equilibrium and thermodynamics between the adsorbent surfaces and CIP. The sorption data follows Freundlich isotherm. A chemical adsorption was dominant. The adsorption behaviour of CIP onto Kandira stone followed the pseudo-second-order kinetic model, indicating that the adsorption process can be expressed with the chemisorption mechanism. The intraparticle diffusion process is a rate-controlling step. The adsorption thermodynamic parameters of the free energy change (∆G<sup>o</sup>), the isosteric enthalpy change (∆H<sup>o</sup>) and the entropy change (∆S<sup>o</sup>) were calculated. The negative ∆H<sup>o</sup> values indicated that sorption of CIP was the exothermic process. The positive value of ∆G<sup>o</sup> indicates non-spontaneous nature of CIP adsorption.&nbsp;</p> </div> <p>&nbsp;</p>

Removal of 4-nitrophenol from aqueous solution by adsorption onto activated carbon prepared from Acacia glauca sawdust

2015 ◽  
Vol 73 (4) ◽  
pp. 955-966 ◽  
Author(s):  
Prashant T. Dhorabe ◽  
Dilip H. Lataye ◽  
Ramakant S. Ingole
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Adsorption Process ◽  
Enthalpy Change ◽  
Optimum Dose ◽  
Batch Adsorption ◽  
Gibbs Free Energy Change ◽  
Pseudo Second Order ◽  
Percentage Removal ◽  
Maximum Removal

The present paper deals with a complete batch adsorption study of 4-nitrophenol (4NP) from aqueous solution onto activated carbon prepared from Acacia glauca sawdust (AGAC). The surface area of the adsorbent determined by methylene blue method is found to be 311.20 m2/g. The optimum dose of adsorbent was found to be 2 g/l with 4NP uptake of 25.93 mg/g. The equilibrium time was found to be 30 minutes with the percentage removal of 96.40 at the initial concentration of 50 ppm. The maximum removal of 98.94% was found to be at pH of 6. The equilibrium and kinetic study revealed that the Radke–Prausnitz isotherm and pseudo second order kinetics model fitted the respective data well. In the thermodynamic study, the negative value of Gibbs free energy change (−26.38 kJ/mol at 30°C) and enthalpy change (−6.12 kJ/mol) showed the spontaneous and exothermic nature of the adsorption process.

Adsorption performance of magnetic aminated lignin for the removal of Cu(II) and Cd(II)

TAPPI Journal ◽  
2019 ◽  
Vol 18 (01) ◽  
pp. 9-18
Author(s):  
Dafeng Zheng ◽  
Yingzhi Ma ◽  
Xueqing Qiu ◽  
Xuejun Pan
Keyword(s):  
Heavy Metals ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Adsorption Performance ◽  
Monolayer Adsorption ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order

The adsorption behavior of Cu(II) and Cd(II) onto a magnetic lignin-based nanomaterial (MLN) was investigated in detail. The results showed that the adsorption isotherm was better described by the Langmuir model, showing monolayer adsorption with a maximum adsorption capacity of 135.7 and 156.5 mg/g. The kinetics fit the pseudo-second-order model. The thermodynamics showed the enthalpy change of the adsorption for Cu(II) and Cd(II) was 24.12 and 36.49 kJ/mol, with entropy change of 85.12 and 130.3 J/mol·K, respectively; thus, the adsorption was endothermic and spontaneous in the range of 25°C–45°C. Additionally, the adsorbent was easy to regenerate. This study shows that MLN is a capable, sustainable absorbent for the removal of heavy metals.

Removal of Methyl Orange from Aqueous Solution by Adsorption onto a Hydrogel Composite

2018 ◽  
Vol 26 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Yaoji Tang ◽  
Rui Yang ◽  
Dong Ma ◽  
Bin Zhou ◽  
Linhui Zhu ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Acrylic Acid ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Initial Concentration ◽  
Hydrogel Composite ◽  
Ph Values ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Good Agreement

Poly(acrylic acid- co-2-acrylamide-2-methyl-1-propanesulfonic acid)/kaolin hydrogel composite was synthesised using acrylic acid (AA), 2-acrylamide-2-methyl-1-propanesulfonic acid (AMPS) and kaolin (KL) as main materials. The composite was characterised and used to remove methyl orange (MO) from aqueous solutions. Effect of adsorption conditions, including initial concentration of MO, contact time, pH values and ionic strength, on the adsorption capacities was studied. Maximal adsorption capacity was 506 mg/g as the initial concentration of MO was 1000 mg/L. It showed that the adsorption process was spontaneous, and the isotherms and kinetics were in good agreement with the Freundlich isotherm model and pseudo-second-order equation, respectively.

scholarly journals Chemical pretreatments of Trapa bispinosa's peel (TBP) biosorbent to enhance adsorption capacity for Pb(ll)

2019 ◽  
Vol 17 (1) ◽  
pp. 325-336
Author(s):  
Muhammad Nadeem Zafar ◽  
Muzna Saeed ◽  
Raziya Nadeem ◽  
Sajjad Hussain Sumrra ◽  
Syed Salman Shafqat ◽  
...  
Keyword(s):  
Kinetic Study ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Sorption Process ◽  
Ion Concentration ◽  
Sorption Data ◽  
Pseudo Second Order ◽  
Chemical Pretreatments ◽  
Order Rate Equation ◽  
Good Agreement

AbstractIn this study, Trapa bispinosa's peel (TBP) biomass is exploited as an effective, low cost and new adsorbent to remove Pb(II) from aqueous solution. TBP is pretreated and modified with HNO3, HClO4 and H2O2 to enhance the Pb(II) removal and it is perceived that chemical modifications enhance the adsorption capacity of TBP. The adsorption behavior of Pb(II) is studied under different conditions, including pH (3-6), TBP dose (0.050.8 g), stirring speed (100-200 rpm), initial Pb(II) ion concentration (25-400 mg L-1) and contact time (0-1440 min). Kinetic study reveals sorption is fast in first 15 to 30 min achieving equilibrium in 60 min with qmax (mg g-1) are 77.09, 105.40 and 123.82 for NT-TBP, NA-TBP and HCA-TBP respectively. The Langmuir model successfully defines the sorption data having higher R2 and good agreement between theoretical and experimental uptake capacity of Pb(II). The kinetic study exhibits that the pseudo-second order rate equation is better portrayed sorption process. TBP modified with HClO4 shows the highest metal uptake in comparison to HNO3, H2O2 modified TBP and native TBP.

Separation of static and dynamic thermodynamic parameters for the interaction between pyropheophorbide methyl ester and copper

2014 ◽  
Vol 18 (04) ◽  
pp. 297-304 ◽  
Author(s):  
Saleh Al-Omari
Keyword(s):  
Free Energy ◽  
Methyl Ester ◽  
Fluorescence Quenching ◽  
Thermodynamic Function ◽  
Binding Constant ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Gibbs Free Energy Change ◽  
Quenching Process ◽  
Different Temperatures

The interaction between pyropheophorbide methyl ester (PPME) and the ionic metal of copper ( Cu 2+) was investigated using fluorescence and UV-vis techniques. By analysis of the fluorescence spectra, it was observed that Cu 2+ has a strong ability to quench the intrinsic fluorescence of PPME through dynamic and static quenching process. The binding constants of Cu 2+ with PPME were determined at different temperatures depending on the results of fluorescence quenching. Based on the modified form of the Stern–Volmer equation, static binding constant (kS) and the dynamic binding constant (kD) of Cu 2+-PPME association were obtained at different temperatures. The static thermodynamic function of the enthalpy change (ΔHS), the dynamic thermodynamic function of the enthalpy change (ΔHD), the static thermodynamic function of the entropy change (ΔSS), and the dynamic thermodynamic function of the entropy change (ΔSD) for the binding interaction were determined according to the van't Hoff equation. The values of static Gibbs free energy change (ΔGS) and dynamic Gibbs free energy change (ΔGD) were determined to be negative indicating that the interaction process was a spontaneous. ΔHD and ΔSD values were positive indicating that the dynamic quenching process of Cu 2+-PPME interaction was driven mainly by hydrophobic forces. For the static binding quenching, ΔHS and ΔSS values were negative which indicated that hydrogen bond, electrostatic interaction, and van der Waals interaction were important driving forces for PPME- Cu 2+ association. Both static and dynamic fluorescence quenching were related to the distance between PPME and Cu 2+ indicating that the electron transfer process occurred.

scholarly journals Study of impact of acids and comparison of adsorption efficiency of Pb(II) from carbon and its modified nano-nickel coated version

2019 ◽  
Vol 79 (12) ◽  
pp. 2337-2344
Author(s):  
Tayyaba Asim ◽  
Riaz Ahmed ◽  
Muhammad Shahid Ansari
Keyword(s):  
Active Sites ◽  
Lead Removal ◽  
Temperature Dependent ◽  
Acidic Media ◽  
Sorption Data ◽  
Acidic Solutions ◽  
Pseudo Second Order ◽  
Nano Nickel ◽  
Adsorption Rates ◽  
Coated Carbon

Abstract Acidic content in wastewaters poses greater difficulty in lead removal from most adsorbents as their removal efficiency significantly decreases in acidic media. Nano-nickel coated carbon (Ni/C), compared with uncoated carbon (C), has shown a much enhanced (almost 80% higher) tendency of Pb(II) removal from solutions having different acid concentrations. All of the characterization results show the creation of more active sites and functional groups on Ni/C. The pertinent kinetic models and thermodynamics of Pb(II) adsorption have demonstrated much improved efficiency by Ni/C. Various isotherms subjected to the sorption data revealed significant increase in the sorption capacities for Ni/C. The adsorption (evidently chemisorption) kinetics are best represented by a pseudo-second-order equation. The adsorption rates in acidic solutions were much higher for Ni/C. The temperature-dependent study enabled thermodynamic parameters to be worked out for C and Ni/C; for C the values are ΔH: 19.4 ± 0.5 kJ·mol−1, ΔS: 76.1 ± 2.1 J·mol−1·K−1, ΔG298: −0.37 ± 0.01 kJ·mol−1 while for Ni/C the values are ΔH: 30 ± 1 kJ·mol−1, ΔS: 114 ± 4 J·mol−1·K−1, ΔG298: −4.56 ± 0.02 kJ·mol−1. Both cases indicate endothermic, spontaneous and entropy-driven processes.

scholarly journals Sorption of melanoidin onto surfactant modified zeolite

2011 ◽  
Vol 17 (4) ◽  
pp. 385-395 ◽  
Author(s):  
Maurice Onyango ◽  
Jacob Kittinya ◽  
Nomcebo Hadebe ◽  
Vincent Ojijo ◽  
Aoyi Ochieng
Keyword(s):  
Sorption Kinetics ◽  
Wastewater Discharge ◽  
Solution Ph ◽  
Sorption Data ◽  
Initial Concentration ◽  
Modified Zeolite ◽  
Brown Colour ◽  
Distillery Wastewater ◽  
Pseudo Second Order ◽  
Adsorbent Dose

Melanoidin is responsible for the dark brown colour of distillery wastewater. Discharge of coloured wastewater has a major environmental impact on the biota of the receiving water body. Consequently, this study explores the removal of melanodin from aqueous solution. The equilibrium, kinetics and thermodynamics of melanoidin sorption are studied by varying initial solution pH, initial concentration, adsorbent dose and temperature. Kinetically, the melanoidin removal from solution by a surfactant modified zeolite is rapid and the amount adsorbed is dependent on pH, initial concentration, adsorbent dose and temperature. The equilibrium sorption data are fitted to the Freundlich and Langmuir models while the sorption, kinetics is described by the Ho pseudo-second order and Elovich models. The thermodynamic analysis indicates that the sorption is spontaneous and endothermic in nature. The FTIR spectra analyses show no new peaks or shift in peaks after sorption indicating that the melanoidin sorption may have occurred by a physical process. The results from desorption studies showed that melanoidin eluted back easily to the solution using distilled water which corroborates the physical sorption mechanism.

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