scholarly journals Adsorption Study for Trifluralin on Iraqi ? –Alumina

2012 ◽  
Vol 9 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Adsorption Process ◽  
Kinetic Equations ◽  
Adsorption Study ◽  
Adsorption Capacities ◽  
Experimental Parameters ◽  
Freundlich Adsorption Isotherm ◽  
Equilibrium Adsorption Isotherm

Equilibrium adsorption isotherm for the removal of trifluralin from aqueous solutions using ? –alumina clay has been studied. The result shows that the isotherms were S3 according Giels classification. The effects of various experimental parameters such as contact time, adsorbent dosage, effect of pH and temperature of trifluralin on the adsorption capacities have been investigated. The adsorption isotherms were obtained by obeying freundlich adsorption isotherm with (R2 = 0.91249-0.8149). The thermodynamic parameters have been calculated by using the adsorption process at five different temperature, the values of ?H, ?G and ?S were (_1.0625) kj. mol-1, (7.628 - 7.831) kj.mol-1 and (_2.7966 - _2.9162) kg. k-1. mol-1 respectively. The kinetic study of adsorption process has been studied depending on three kinetic equations: 1- Allergen equation 2- Morris –weber eguation 3- Reichenberg eguation. In general, the result shows the isotherm were on ?- alumina according to Giels classification.? –alumina and thermodynamic

scholarly journals Adsorption Study for Chromium (VI) on Iraqi Bentonite

2010 ◽  
Vol 7 (1) ◽  
pp. 745-756
Author(s):  
Baghdad Science Journal
Keyword(s):  
Adsorption Isotherm ◽  
Adsorption Process ◽  
Kinetic Equations ◽  
Bentonite Clay ◽  
Sorption Process ◽  
Adsorption Study ◽  
Chromium Vi ◽  
Freundlich Adsorption Isotherm ◽  
Different Temperatures ◽  
The Subject

The subject of this research involves studying adsorption to remove hexavalent chromium Cr(VI) from aqueous solutions. Adsorption process on bentonite clay as adsorbent was used in the Cr(VI) concentration range (10-100) ppm at different temperatures (298, 303, 308 and 313)K, for different periods of time. The adsorption isotherms were obtained by obeying Langmuir and Freundlich adsorption isotherm with R2 (0.9921-0.9060) and (0.994-0.9998), respectively. The thermodynamic parameters were calculated by using the adsorption process at four different temperatures the values of ?H, ?G and ?S was [(+6.582 ? +6.547) kJ.mol-1, (-284.560 ? -343.070) kJ.mol-1 and (+0.977 ? +1.117) kJ.K-1.mol-1] respectively. This data indicates the spontaneous sorption process. The kinetic study of adsorption process was studied depending on three kinetic equations: 1- Lagergren equation 2- Morris-Weber equation 3- Reichenberg equation

scholarly journals Removal of Malachite Green from Single and Multi-Dye Aqueous Solutions by Acid-Treated Sawdust

2019 ◽  
Vol 35 (4) ◽  
pp. 1384-1391
Author(s):  
Abdur-Rahim Adebisi ◽  
Giwa Khadijat Ayanpeju ◽  
Abdulsalam Francois Wewers ◽  
Mary Adelaide Oladipo
Keyword(s):  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Malachite Green ◽  
Removal Efficiency ◽  
Contact Time ◽  
Adsorption Process ◽  
Parkia Biglobosa ◽  
Order Model ◽  
Experimental Conditions ◽  
Pseudo Second Order

The study investigates the effectiveness and mechanism of the adsorption of malachite green from single and mixed dyes aqueous solutions by an adsorbent prepared from acid-treated Parkia biglobosa sawdust. The adsorbent was characterized using different techniques, and the adsorption was conducted in single, binary, ternary and quaternary dye systems under different experimental conditions. Experimental results were subjected to different isotherm and kinetics models. The adsorption process was endothermic and thermodynamically feasible with the removal efficiency increasing with increase in adsorbent dosage, solution working pH, initial dye concentration and contact time. The rate of sorption of the dye was fast; it attained equilibrium within 180 minutes in both the single and mixed solute systems. Pseudo-second order model gives the best kinetics fit (R2 = 0.998). The adsorption isotherm in all solute systems have best fits for the Temkin model (R2 > 0.96).

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 lead from aqueous solutions by low cost and waste biosorbents (lemon, bean and artichoke shells)

2020 ◽  
Vol 81 (1) ◽  
pp. 159-169
Author(s):  
Feyza Ergüvenerler ◽  
Şerif Targan ◽  
Vedia Nüket Tirtom
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Low Cost ◽  
Standard Free Energy ◽  
Freundlich Isotherm ◽  
Standard Entropy ◽  
X Ray ◽  
Adsorption Capacities ◽  
Influence Of Ph ◽  
Scanning Electron

Abstract Simple, fast, effective, low cost and waste biosorbents, lemon, bean and artichoke shells, were used to remove lead (II) ions from aqueous solution. The influence of pH, contact time, temperature and lead (II) concentration of the removal process was investigated. The sufficient contact time was deemed 10 minutes for bean and artichoke shells and 60 minutes for lemon shells for Pb(II) ions. The thermodynamic parameters, such as standard free energy (ΔG), standard enthalpy (ΔH), and standard entropy (ΔS) of the adsorption process were calculated as −5.6786, −5.5758, −3.1488 kJmol−1 for ΔG, −7.2791, −20.285, −9.5561 kJ mol−1 for ΔH, −0.00545, −0.05017, −0.02185 kJ mol−1 K−1 for ΔS, respectively, for lemon, artichoke and bean shells. Maximum adsorption capacities of lead (II) were observed as 61.30 mg g−1, 88.5 mg g−1 and 62.81 mg g−1, respectively, for lemon, bean and artichoke shells according to the Freundlich isotherm model at 20 °C. Scanning electron microscope (SEM) and energy-dispersive X-ray detector (EDX) were used to characterize the surface morphology of the adsorbents. Consequently, Pb(II) removal using lemon, bean and artichoke shells would be an effective method for the economic treatment of wastewater.

Adsorption of Copper Ions from Wastewater by Carboxymethylcellulose Sulfate

2011 ◽  
Vol 393-395 ◽  
pp. 1098-1101 ◽  
Author(s):  
Yan Yu ◽  
Feng Yuan Huang
Keyword(s):  
Contact Time ◽  
Copper Concentration ◽  
Adsorption Process ◽  
Ph Value ◽  
Copper Ions ◽  
Adsorption Capacities ◽  
Monolayer Adsorption ◽  
Optimum Ph ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model

In the present paper, the ability of carboxymethylcellulose sulfate (CMC-S) for Cu(II) removal was studied. The influence of factors, such as the pH value, the initial copper concentrations, and the contact time, were investigated in detail. Atomic absorption spectrophotometer was applied to determined the concentration of Cu(II). The results showed that the adsorption process was strongly dependent on the pH value and the initial copper concentration. The optimum pH value was in the range of 6-7. The theoretical adsorption capacities for Cu(II) was 127.7 mg/g. The equilibrium data was well fitted to the Langmuir isotherm model at 25°C, which can be explained as a monolayer adsorption.

scholarly journals Microstructural and Equilibrium Adsorption Study of the System of Waste Foundry Molding Sand/Cu (II) Ions

2016 ◽  
Vol 61 (4) ◽  
pp. 1805-1812
Author(s):  
A. Strkalj ◽  
Z. Glavas ◽  
L. Slokar
Keyword(s):  
Experimental Data ◽  
Adsorption Process ◽  
Order Kinetic ◽  
Molding Sand ◽  
Adsorption Study ◽  
Eds Analysis ◽  
Adsorption Capacities ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Casting Production

Abstract This paper deals with the waste foundry molding sand which originally comes from the casting production. Adsorption of Cu (II) ions on the waste foundry molding sand was studied. Experimental data were processed using adsorption isotherms. Obtained results show that the experimental data are best described by the Langmuir isotherm. The following adsorption capacities are obtained: 7.153 mg/g to 293 K, 8.403 mg/g at 333 K and 9.208 mg/g at 343 K. The kinetics and thermodynamics of the process were analysed. The obtained results indicate that the adsorption process takes place according to the pseudo second order kinetic model with the following constants: 0.438 g/mg min at 293 K, 0.550 g/mg min at 333 K and 1.872 g/mg min at 343 K. The following values of ΔG° were obtained: − 95.49 J/mol at 293 K, − 736.99 J/mol at 333 K and − 1183.46 J/mol at 343 K. The value of ΔH° is − 4.16 kJ/mol and the value of ΔS° is 15.17 J/molK. These results were confirmed by microscopic examinations. The results indicate that the adsorption process of Cu (II) ions on waste foundry molding sand is possible. Results of microscopic examinations show the homogeneity of the surface, which is proof of the chemisorption. Cu (II) ions on the surface of the waste foundry molding sand were detected after adsorption by EDS analysis, which proves the existence of the adsorption process.

scholarly journals Biosorption of Lead and Cadmium Ions on the Green Parts of Daucus Carota

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Martin MUCHA
Keyword(s):  
Daucus Carota ◽  
Contact Time ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Infrared Spectrometry ◽  
Adsorptive Removal ◽  
Ph Values ◽  
Lead And Cadmium ◽  
Adsorption Capacities ◽  
Stems And Leaves

This study deals with utilization of milled stems and leaves of carrot (Daucus carota) for the adsorptive removal of Pb(II) and Cd(II)from the aqueous solution. Carrot was bought in the local grocery, it was dried at the laboratory temperature and milled. Preparedmaterial was analysed by the infrared spectrometry which confirms good structural homogeneity of the sample. Kinetic measurementswere performed for estimation of adsorption equilibrium time. Equilibrium of Pb(II) adsorption was established after 6 hours of contact time, equilibrium of Cd(II) adsorption was established after 24 hours of contact time. The isotherms’ measurements were realizedwith the contact time 24 hours for the estimation of adsorption capacities of the studied sorbent. Adsorption capacities were around47 mg/g for Cd(II) and 154 mg/g for Pb(II). Changes of pH values of the sorption solutions were negligible but some amount of Ca(II),Mg(II), K(I) and Na(I) ions was released to the solution during adsorption process. Daucus carota stems and leaves exhibit good sorption capacities and they could be utilized for adsorptive removal of Pb(II) and Cd(II) ions from the aqueous solutions.

scholarly journals Polyaniline Modified with Cobalt-Hexacyanoferrate (PmCH) as an Adsorbent for Removal of Heavy Metals from Aqueous Solutions

2018 ◽  
Vol 51 ◽  
pp. 03004
Author(s):  
Nima Moazezi ◽  
Mohammad Ali Moosavian
Keyword(s):  
Heavy Metals ◽  
Ionic Strength ◽  
Aqueous Solutions ◽  
Metal Ions ◽  
Contact Time ◽  
Ion Concentration ◽  
Adsorption Capacities ◽  
Cobalt Hexacyanoferrate ◽  
Optimum Ph ◽  
Removal Of Heavy Metals

In this study, polyaniline modified with cobalt-hexacyanoferrate (PmCH) composite was synthesized and characterized for removal of Rb+, Cd2+, Zn2+, Pb2+, and Ni2+ by FTIR and XRD. The effect of pH, adsorbent dosage, ionic strength, contact time, initial ion concentration, and temperature were studied. The competition adsorption experiments between metal ions were investigated. Batch desorption was also conducted to evaluate the reusability of PmCH. The maximum adsorption capacities were 96.15, 27.17, 17.85, 19.15, and 4.76 mg g-1 of Rb+, Cd2+, Zn2+, Pb2+, and Ni2+, respectively. The optimum pH was determined at natural pH of each solution.

Synthesis of carboxylated chitosan and its adsorption properties for cadmium (II), lead (II) and copper (II) from aqueous solutions

2009 ◽  
Vol 60 (2) ◽  
pp. 467-474 ◽  
Author(s):  
K. L. Lv ◽  
Y. L. Du ◽  
C. M. Wang
Keyword(s):  
Aqueous Solutions ◽  
Ph Value ◽  
Order Model ◽  
Adsorption Capacities ◽  
Kinetic Rates ◽  
Experimental Parameters ◽  
Exothermic Process ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Equilibrium Data

Carboxylated chitosan (CKCTS) was prepared for the removal of Cd(II), Pb(II), and Cu(II) from aqueous solutions. The effects of experimental parameters such as pH value, initial concentration, contact time and temperature on the adsorption were studied. From the results we can see that the adsorption capacities of Cd(II), Pb(II), and Cu(II) increase with increasing pH of the solution. The kinetic rates were best fitted to the pseudo-second-order model. The adsorption equilibrium data were fitted well with the Langmuir isotherm, which revealed that the maximum adsorption capacities for monolayer saturation of Cd(II), Pb(II), and Cu(II) were 0.555, 0.733 and 0.827 mmol/g, respectively. The adsorption was an exothermic process.

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