scholarly journals Studies on the Adsorption Behaviour of Lutetium on Sand

1996 ◽  
Vol 13 (2) ◽  
pp. 127-135
Author(s):  
M.A. Rauf ◽  
M.J. Iqbal ◽  
I. Ellahi
Keyword(s):  
Metal Ions ◽  
Distribution Coefficient ◽  
Freundlich Isotherm ◽  
Adsorption Behaviour ◽  
Foreign Ions ◽  
Adsorption Data

The adsorption behaviour of lutetium on sand samples was investigated and the conditions for maximum adsorption optimized. The effects of foreign ions, both cations and anions, were also investigated. The distribution coefficient value, KD, was compared to those for other metal ions adsorbed under similar conditions. The adsorption data seem to provide a good fit to the Freundlich isotherm and to the Dubinin–Radushkevich (D–R) equation.

scholarly journals 1,2,3,4-Tetrahydropyrimidine Derivative for Selective and Fast Uptake of Cadmium Ions from Aqueous Solution

Environments ◽  
2019 ◽  
Vol 6 (6) ◽  
pp. 68
Author(s):  
Mohamed Ould M’hamed ◽  
Lotfi Khezami
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Kinetics ◽  
Heavy Metal Ions ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Solution Interface ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Thermodynamic Variables

The aim of this work was to evaluate the performance of a 1,2,3,4-tetrahydropyrimidine derivative as a powerful heterocyclic compound for the elimination of Cd(II) ions from aqueous solutions. The tetrahydropyrimidine derivative was prepared during 30 min of milling by planetary ball mill with a ball-to-powder mass ratio of 8:1 and a rotation speed of 750 rpm. Nuclear magnetic resonance (NMR) and infrared (IR) were used to identify the obtained tetrahydropyrimidine derivatives. Furthermore, batches of experiments were carried out to establish the adsorption equilibrium, kinetics, and thermodynamic variables of the tetrahydropyrimidine derivatives for toxic heavy Cd(II) ions. The adsorption data were simulated by applying the Langmuir manner, the Freundlich equation, the pseudo-first-order and pseudo-second-order equations. The adsorption procedure was discovered to be very influenced by PH. The removal of heavy metal ions reached a maximum value quickly within 6 min and the adsorption data better adjusted the Langmuir isotherm than that of the Freundlich isotherm. The maximum Cd(II) ions adsorption capacity was approximated to be 151.16 mg g−1 at 328 K and a pH of 6 to 7. It was found that the adsorption kinetics of Cd(II) ions obeyed pseudo-second-order adsorption kinetics. The examination of the thermodynamic variables of tetrahydropyrimidine derivative showed a spontaneous endothermic adsorption procedure. Otherwise, positive entropy values put forward a rise in the randomness at the solid-solution interface when heavy metal ions are adsorbed.

scholarly journals Adsorption of cadmium and copper onto natural clay: isotherm, kinetic and thermodynamic studies

2018 ◽  
Vol 20 (2) ◽  
pp. 198-207 ◽  
Keyword(s):  
Mass Transfer ◽  
Metal Ions ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Adsorption Rate ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Adsorption Data ◽  
Removal Of Heavy Metals ◽  
Heavy Metals Ions

Clay of the Middle Atlas Mountains region, Morocco, was used to investigate the removal of heavy metals ions (Cadmium and Copper) from aqueous solutions with respect to several experimental conditions including pH, contact time, initial solute concentrations, temperature and ionic strength. Kinetic study revealed that metal ions uptake was fast with 90% or more of the adsorption occurring within first 30 min of contact time. Adsorption rate increased with the increasing initial metal ions concentrations and the sorption rate was well fitted by the pseudo-second-order rate model. The data according to mass transfer and intraparticle diffusion models confirmed diffusion of solutes inside the clay particles as the rate-controlling step and more important for the adsorption rate than the external mass transfer. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherm models. Equilibrium and kinetic adsorption data showed that clay displays a high selectivity with an affinity order of Cd > Cu. Thermodynamic parameters including the Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) changes indicated that the present adsorption process was feasible and endothermic in the temperature range of 25–45 °C.

scholarly journals Adsorption Studies of Antimony on Manganese Dioxide Using Radiometric Techniques

1994 ◽  
Vol 11 (1) ◽  
pp. 41-50 ◽  
Author(s):  
M.A. Rauf ◽  
M. Ikram ◽  
S.M. Hasany ◽  
S.M. Najam-ud-Din
Keyword(s):  
Metal Ions ◽  
Manganese Dioxide ◽  
Langmuir Equation ◽  
Adsorption Behaviour ◽  
Optimum Conditions ◽  
Equilibrium Time ◽  
Adsorption Studies ◽  
Foreign Ions ◽  
Sorption Energy ◽  
The Mean

The efficiency of manganese dioxide as an adsorbent for the removal of antimony has been examined using radiometric techniques. The optimum conditions for maximum adsorption were investigated. The influence of equilibrium time, the nature and composition of the electrolytes, shaking time and the effect of foreign ions and other metal ions on the adsorption behaviour of antimony was also studied. On the basis of these data, TeIV can be easily removed from antimony using manganese dioxide as an adsorbent. The adsorption was also found to obey the Langmuir equation, the mean sorption energy of Sb on MnO2 being 11.7 kJ/mol.

scholarly journals A Comparative Study of Copper and Zinc Ion Adsorption on to Activated and Non-activated Date-pits

2002 ◽  
Vol 20 (4) ◽  
pp. 319-335 ◽  
Author(s):  
Fawzi Banat ◽  
Sameer Al-Asheh ◽  
Deaa Al-Rousan
Keyword(s):  
Metal Ions ◽  
Activated Carbons ◽  
Ph Value ◽  
Freundlich Isotherm ◽  
Zinc Ion ◽  
Ion Adsorption ◽  
Chemical Pretreatment ◽  
Adsorption Capacities ◽  
Adsorption Data ◽  
Date Pits

Date-pits (an agricultural by-product available commercially) were utilized, with and without activation, as an adsorbent for the removal of Zn2+ and Cu2+ ions from aqueous solutions. Activated carbons were prepared from date-pits by carbon dioxide activation at 700°C. The effects of contact time, pH, temperature and the adsorbent concentration on the removal of Zn2+ and Cu2+ ions were studied. The Freundlich isotherm model described the equilibrium adsorption data. Non-activated date-pits exhibited higher Zn2+ and Cu2+ ion uptake than activated date-pits. The uptake of Cu2+ ions by both activated and non-activated date-pits was higher than the uptake of Zn2+ ions. The uptake of both metal ions increased on increasing the pH value of the system from 3.5 to 5.0 as well as on decreasing the temperature from 50°C to 25°C. Adsorption capacities for the non-activated date-pits towards Cu2+ and Zn2+ ions as high as 0.15 mmol/g and 0.09 mmol/g, respectively, were observed. This study demonstrated that date-pits without any physical or chemical pretreatment could be used as an effective adsorbent for the treatment of waters containing heavy metal ions such as Zn2+ and Cu2+.

Spatial Distribution of Heavy Metal Ions in Glass Forming Melts: Spectroscopic and Physical-Chemical Study

2008 ◽  
Vol 39-40 ◽  
pp. 41-44 ◽  
Author(s):  
A. Anan’ev ◽  
L. Maksimov
Keyword(s):  
Heavy Metal ◽  
Spatial Distribution ◽  
Metal Ions ◽  
Distribution Coefficient ◽  
Heavy Metal Ions ◽  
Brillouin Scattering ◽  
Chemical Study ◽  
Sodium Borate ◽  
Glass Host ◽  
Glass Forming

Spatial distribution of heavy metal ions (HMI) in inorganic glass forming melts was studied by measuring HMI distribution coefficient between two unmixable melts: sodium-borate glass forming melt and non-glass forming molten sodium sulfate. Combining the data on glass host composition dependence of HMI distribution coefficient with the data of Rayleigh and Mandel’shtam-Brillouin scattering (RMBS) spectroscopy of glasses doped with HMI and undoped ones made it possible to evidence the segregation of HMI into alkali-enriched inhomogeneities of glass hosts and offer the approach to choosing compositions of glass host in which HMI segregation will be minimized.

scholarly journals Analysis of Cr(III) ions adsorption on the surface of algae: implications for the removal of heavy metal ions from water

2021 ◽  
Vol 4 (10(112)) ◽  
pp. 14-23
Author(s):  
Zhadra Tattibayeva ◽  
Sagdat Tazhibayeva ◽  
Wojciech Kujawski ◽  
Bolatkhan Zayadan ◽  
Kuanyshbek Мusabekov ◽  
...  
Keyword(s):  
Cell Surface ◽  
Metal Ions ◽  
Functional Groups ◽  
Ζ Potential ◽  
Adsorption Data ◽  
Abnormal Increase ◽  
Ph Range ◽  
Langmuir And Freundlich Models ◽  
Phosphate Groups ◽  
Comprehensive Study

For purposeful control of the adsorption process, a comprehensive study of the properties of the original cells and the effect of metal ions on them is necessary. In this regard, the features of the adsorption of Cr(III) ions on the cell surface of Spirulina platensis algae were studied. FTIR spectroscopy revealed that the main functional groups responsible for the binding of Cr(III) ions are carboxyl, hydroxyl, amino, and phosphate groups on the surface of algae. The adsorption data were processed using the Langmuir and Freundlich models. It is shown that the maximum adsorption of Cr(III) ions on the surface of algae cells is 31.25 mg/g. The Freundlich constant 1/n is 0.65. The study of the effect of the concentration of Cr(III) ions on the Zeta-potential of algae cells revealed an abnormal increase in the negative value of the ζ – potential at 10–5 mol/L, caused by the release of an additional amount of anionic functional groups to the surface. A further increase in the concentration of Cr(III) ions in the algae suspension leads to a decrease in the ζ – potential and recharge of the surface at C>10–2 mol/L. It was found that the adsorption of Cr(III) ions also affects the morphology of the cell surface. If before contact with Cr(III) ions, the surface of algae cells is represented as a uniform green grid, after adsorption of Cr(III) ions, the surface becomes green-brown, with swollen spirals. The study of the effect of pH on the adsorption and desorption processes shows an increase in the desorption of Cr(III) ions from the surface of algae during acidification of the medium. The adsorption reaches a maximum value in the pH range of 6–7. In the region of optimal Cr(III)/biosorbent ion ratios, the recovery rate of Cr(III) reaches 98.5–99.3 %.

scholarly journals Sythesis of Nano Zerovalent Iron Supported Sawdust (NZVI/SD) and Its Application for Removal of Arsenic (III) from Aqueous Solution

2020 ◽  
pp. 1-12
Author(s):  
Tasrina R. Choudhury ◽  
Snahasish Bhowmik ◽  
M. S. Rahman ◽  
Mithun R. Nath ◽  
F. N. Jahan ◽  
...  
Keyword(s):  
Ph Value ◽  
Ferrous Sulphate ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Zerovalent Iron ◽  
Isotherm Model ◽  
Order Kinetic ◽  
Adsorption Sites ◽  
Adsorption Data ◽  
Pseudo Second Order

Sawdust supported nano-zerovalent (NZVI/SD) iron was synthesized by treating sawdust with ferrous sulphate followed by reduction with NaBH4. The NZVI/SD was characterized by SEM, XRD, FTIR and Chemical method. Adsorption of As (III) by NZVI/SD was investigated and the maximum uptake of As (III) was found at pH value of 7.74 and equilibrium time of 3 hrs. The adsorption isotherm modelling revealed that the equilibrium adsorption data were better fitted with the Langmuir isotherm model compared with the Freundlich Isotherm model. This study revealed that the maximum As (III) ions adsorption capacity was found to be 12.66 mg/g for using NZVI/SD adsorbent. However, the kinetics data were tested by pseudo-first-order and pseudo-second-order kinetic models; and it was observed that the adsorption data could be well fitted with pseudo-second-order kinetics for As (III) adsorption onto NZVI/SD depending on both adsorbate concentration and adsorption sites. The result of this study suggested that NZVI/SD could be developed as a prominent environment-friendly adsorbent for the removal of As (III) ions from aqueous systems.

scholarly journals Biosorption of Pb2+ and Cd2+ from Simulated Wastewater Using Melina (Gmelina arborea) Tree Leaves Powder

2018 ◽  
pp. 1-12
Author(s):  
N. O. Ilelaboye ◽  
A. A. Oderinde
Keyword(s):  
Metal Ions ◽  
Waste Treatment ◽  
Anthropogenic Activities ◽  
Freundlich Isotherm ◽  
Solution Concentration ◽  
Isotherm Models ◽  
Operational Parameters ◽  
Solution Ph ◽  
Separation Parameter ◽  
Optimum Solution

Increased anthropogenic activities have led to serious environmental problems due to pollution caused by toxic materials such as heavy metals whose levels are rising in the environment. The inefficiency and high cost of conventional methods of waste treatment have prompted the investigation of environmentally friendly and cheaper methods of treatment using natural products. In this study, G. arborea leaves powder was investigated with a view of using it as cheap material for the biosorption of Pb2+ and Cd2+   from wastewater. The effects of operational parameters like pH, biosorbent dose [g/L], initial metal ions concentration [mg/L], contact time [minutes] and stirring speed [rpm] on the biosorption efficiency [%] were determined. The optimum solution pH for Pb2+ and Cd2+adsorption was 5.0 and peak adsorption of 91.33% and 82.53% for Pb2+ and Cd2+, respectively. 5 g/L Melina leaves were enough to achieve peak removal of both metal ions. The removal of the metal ions was comparatively quick, and stability was achieved after 30 minutes. The optimum stirring speed was 250 rpm for both metal ions. The uptake efficiency of the biosorbent was determined by Langmuir and Freundlich isotherm models. The value of Langmuir isotherm separation parameter [RL] of Pb2+ ion [0.0446 - 0.78125] and Cd2+ [0.1005- 0.9482] were within range of 0 -1 indicating favorable biosorption for both metal ions. The degree of non-linearity [n] values between Pb2+ [12.79] and Cd2+ [11.79] solution concentration and biosorption in Freundlich equation were greater than 1, indicating physical biosorption of Pb2+ and Cd2+ on to G. arborea leaves. G. arborea can serve as efficient biosorbent not only for Pb2+ and Cd2+ ions but also for other heavy metal ions in a wastewater stream

scholarly journals Adsorption Behaviors of Oxytetracycline onto Sediment in the Weihe River, Shaanxi, China

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Dong-Hui Cheng ◽  
Sheng-Ke Yang ◽  
Yue Zhao ◽  
Jing Chen
Keyword(s):  
Freundlich Isotherm ◽  
Entropy Change ◽  
Impact Factors ◽  
Isotherm Models ◽  
Solution Ph ◽  
Adsorption Behaviors ◽  
Adsorption Data ◽  
Negative Effect ◽  
Weihe River ◽  
The Impact

Adsorption behaviors of oxytetracycline onto sediment in the Weihe River were described. The impact factors in the processes of adsorption, such as contact time, solution pH, temperature, and ionic strength, were determined by experiments. The experimental results were analyzed by kinetic and isotherm models. The adsorption kinetics was found to follow a pseudo-first-order model. The equilibrium adsorption data fitted well with the Langmuir and Freundlich isotherm models. However, the Langmuir isotherm was more suitable to describe the adsorption. Thermodynamics parameters such as Gibbs-free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were calculated. Results showed that the adsorption was feasible, spontaneous, entropy increasing, and endothermic in nature, which reached equilibrium in about 24 hours. The adsorption capacity did not cause obvious change at solution pH 4.0–7.0, and both decreased in solution pH 7.0–10.0 and 4.0–2.0. The presence of electrolytes such as NaCl in aqueous solution had a significant negative effect on the adsorption. The mechanisms controlling the adsorption were supposed to be chemisorption.

scholarly journals Synthesis of acid treated carbonized mandarin peel for purification of copper

2020 ◽  
Vol 15 (2) ◽  
pp. 460-471
Author(s):  
T. Unugul ◽  
F. U. Nigiz
Keyword(s):  
Contact Time ◽  
Freundlich Isotherm ◽  
Kinetic Studies ◽  
Adsorption Kinetic ◽  
Adsorption Behaviour ◽  
Solution Ph ◽  
Copper Adsorption ◽  
Adsorbent Dosage ◽  
Mandarin Peel ◽  
Pseudo Second Order

Abstract In this study; acid treated carbonized mandarin peel (CMP) adsorbent was prepared and the adsorption behaviour of the adsorbent for copper removal was investigated. In the adsorption studies the effects of initial metal concentration, solution pH, adsorbent dosage and contact time on the removal were investigated. As a result; the highest removal of 100% was achieved when the copper concentration in water was 5 mg/L and the adsorbent dosage was 3.75 g/L at a solution pH of 7. Isotherm studies were also done and the appropriate isotherm was obtained as the Freundlich isotherm. According to the kinetic studies, the copper adsorption onto CMP adsorbent was adopted to the pseudo-second-order adsorption kinetic. After HCl regeneration, the adsorbent maintained 94% of its activity.

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