scholarly journals Thermodynamic, Kinetic, and Equilibrium Parameters for the Removal of Lead and Cadmium from Aqueous Solutions with Calcium Alginate Beads

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ruth Alfaro-Cuevas-Villanueva ◽  
Aura Roxana Hidalgo-Vázquez ◽  
Consuelo de Jesús Cortés Penagos ◽  
Raúl Cortés-Martínez
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Second Order ◽  
Order Kinetic ◽  
Calcium Alginate Beads ◽  
Kinetic And Thermodynamic Parameters ◽  
Lead And Cadmium ◽  
Cadmium And Lead

The sorption of cadmium (Cd) and lead (Pb) by calcium alginate beads (CAB) from aqueous solutions in batch systems was investigated. The kinetic and thermodynamic parameters, as well as the sorption capacities of CAB in each system at different temperatures, were evaluated. The rate of sorption for both metals was rapid in the first 10 minutes and reached a maximum in 50 minutes. Sorption kinetic data were fitted to Lagergren, pseudo-second-order and Elovich models and it was found that the second-order kinetic model describes these data for the two metals; comparing kinetic parameters for Cd and Pb sorption a higher kinetic rate (K2) for Pb was observed, indicating that the interaction between lead cations and alginate beads was faster than for cadmium. Similarly, isotherm data were fitted to different models reported in literature and it was found that the Langmuir-Freundlich (L-F) and Dubinin-Radushkevich (D-R) models describe the isotherms in all cases. CAB sorption capacity for cadmium was 27.4 mg/g and 150.4 mg/g for lead, at 25°C. Sorption capacities of Cd and Pb increase as temperature rises. According to the thermodynamic parameters, the cadmium and lead adsorption process was spontaneous and endothermic. It was also found that pH has an important effect on the adsorption of these metals by CAB, as more were removed at pH values between 6 and 7.

scholarly journals Adsorption of Cu (II) and Ni (II) Ions from Solution onto Calcium Alginate Beads

2020 ◽  
Vol 24 (2) ◽  
pp. 329-333
Author(s):  
D.O. Jalija ◽  
A . Uzairu
Keyword(s):  
Contact Time ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Second Order ◽  
Ion Concentration ◽  
Order Kinetic ◽  
Calcium Alginate Beads ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order

The objective of this study was to investigate the biosorption of Cu (II) and Ni (II) ions from aqueous solution by calcium alginate beads. The effects of solution pH, contact time and initial metal ion concentration were evaluated. The results showed that maximum Cu (II) removal (93.10%) occurred at pH of 9.0, contact time of 120 minutes and initial ion concentration of 10 mg/L while that of Ni (II) was 94.6%, which was achieved at pH of 8.0, contact time of 120 minutes and initial ion concentration of 10 mg/L. The equilibrium data fitted well to the Langmuir Isotherm indicating that the process is a monolayer adsorption. The coefficients of determination, R2, values for the Langmuir Isotherm were 0.9799 and 0.9822 respectively for Cu (II) and Ni (II) ions. The values of the maximum biosorption capacity, Qo, were 10.79 and 6.25 mgg-1 respectively. The kinetic data also revealed that the sorption process could best be described by the pseudo – second order kinetic model. The R2 values for the pseudo – second order kinetic plots for Cu (II) and Ni (II) were 0.9988 and 0.9969 respectively. These values were higher than those for the pseudo – first order plots. The values of the biosorption capacity qe obtained from the pseudo – second order plots were very close to the experimental values of qe indicating that the biosorption process follows the second order kinetics. This study has therefore shown that calcium alginate beads can be used for the removal of Cu (II) and Ni (II) ions from wastewaters. Keywords: Keywords: Adsorption, Calcium alginate, Isotherm, Langmuir, Pseudo- first order, Pseudo-second order

scholarly journals Removing of Hexavalent Chromium from Aqueous Solutions Using Dried Yogurt, and Studying Isotherm, Kinetic and Thermodynamic Parameters

2019 ◽  
Vol 16 (3) ◽  
pp. 0603
Author(s):  
Sultan Et al.
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Hexavalent Chromium ◽  
Treatment Time ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Order Kinetic ◽  
Kinetic And Thermodynamic Parameters ◽  
Pseudo Second Order ◽  
Adsorbent Treatment

     In this study, Yogurt was dried and milled, then shaked with distilled water to remove the soluble materials, then again dried and milled. Batch experiments were carried out to remove hexavalent chromium from aqueous solutions. Different parameters were optimized such as amount of adsorbent, treatment time, pH and concentration of adsorbate. The concentrations of Cr6+ in solutions are determined by UV-Visible spectrophotometer.  Maximum percentage removal of Cr6+ was 82% at pH 2. Two equilibrium adsorption isotherms mechanisms are tested Langmuir and Freundlich, the results showed that the isotherm obeyed to Freundlich isotherm. Kinetic models were applied to the adsorption of Cr6+ ions on the adsorbents, pseudo-first-order, the pseudo second-order respectively. Results showed that pseudo second-order kinetic model was applicable to the experimental data well. The thermodynamic parameters such as ΔGº, ΔHº and ΔSº were calculated. ∆H°, ∆S° and ΔGº for this study were negative indicating that the process is exothermic, while negative values of ΔGº indicate spontaneous process.

Adsorption of Ni(II) by a thermo-sensitive colloid: methylcellulose/calcium alginate beads

2019 ◽  
Vol 68 (7) ◽  
pp. 495-508
Author(s):  
Zhongmin Li ◽  
Wanwan Wu ◽  
Wenyan Jiang ◽  
Guangtao Wei ◽  
Yunshang Li ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Adsorption Process ◽  
Alginate Beads ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Isothermal Adsorption ◽  
Calcium Alginate Beads ◽  
Lower Temperature ◽  
Kinetics And Isotherms

Abstract The adsorption of Ni(II) by a thermo-sensitive adsorbent of methylcellulose/calcium alginate beads (CAMCBs) was studied using batch adsorption tests to determine the adsorption process and properties, the effects of adsorbent dosage, initial concentration, adsorption time and temperature. The adsorption process was further investigated using kinetics, isotherms and thermodynamic methods. The kinetics and isotherms studies showed the adsorption of Ni(II) on CAMCBs was fitted by the pseudo-second-order kinetic model and Langmuir isothermal adsorption model, respectively. The thermodynamic parameters indicated that the adsorption process was spontaneous and exothermic at lower temperature, and the entropy of the adsorption process was negative. In the study of regeneration, it was confirmed that under the temperature of 60 °C, the desorption agent of CaCl2 with concentration of 3 g·L−1 was more conducive to the desorption of Ni(II) from CAMCBs. Both adsorption capacity and mechanical strength of the used CAMCBs could be basically recovered to the level of fresh CAMCBs after desorption. The prepared CAMCBs had a good property of adsorption of Ni(II) and an excellent regeneration performance.

scholarly journals Analysis of removal of cadmium by action of immobilized Chlorella sp. micro-algae in alginate beads

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 54 ◽  
Author(s):  
Christian Valdez ◽  
Yomaira Perengüez ◽  
Bence Mátyás ◽  
María Fernanda Guevara
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Atomic Absorption ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Cadmium Removal ◽  
Initial Concentration ◽  
Calcium Alginate Beads ◽  
Chlorella Sp ◽  
Metabolic Systems

Cadmium (Cd) is a metal that can negatively interfere with the metabolic systems of living beings. The objective of this work was to evaluate the capacity for cadmium removal in aqueous solutions by immobilized Chlorella sp. in calcium alginate beads. Beads without Chlorella sp. were used as a control. All the treatments were established in triplicate for 80 min, at four concentrations of cadmium (0, 20, 100 and 200 ppm), taking samples of aqueous solution every 10 min, to be read using atomic absorption equipment. The study determined that the treatment of alginate beads with immobilized Chlorella sp. removed 59.67% of cadmium at an initial concentration of 20 ppm, this being the best removal result.

Synthesis of phosphate-embedded calcium alginate beads for Pb(II) and Cd(II) sorption and immobilization in aqueous solutions

2016 ◽  
Vol 26 (8) ◽  
pp. 2230-2237 ◽  
Author(s):  
Yun-yan WANG ◽  
Wen-bin YAO ◽  
Qing-wei WANG ◽  
Zhi-hui YANG ◽  
Li-fen LIANG ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Calcium Alginate Beads
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