scholarly journals Boron Removal from Aqueous Solutions by Using a Novel Alginate-Based Sorbent: Comparison with Al2O3 Particles

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1509 ◽  
Author(s):  
Demey ◽  
Barron-Zambrano ◽  
Mhadhbi ◽  
Miloudi ◽  
Yang ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Alginate Beads ◽  
Rate Equations ◽  
Basic Medium ◽  
Boron Removal ◽  
Calcium Alginate Beads ◽  
Batch System ◽  
Maximum Sorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Boron removal was evaluated in the present work by using calcium alginate beads (CA) and a novel composite based on alginate–alumina (CAAl) as sorbents in a batch system. The effects of different parameters such as pH, temperature, contact time, and composition of alginate (at different concentrations of guluronic and mannuronic acids) on boron sorption were investigated. The results confirm that calcium alginate beads (CA) exhibited a better adsorption capacity in a slightly basic medium, and the composite alginate–alumina (CAAl) exhibited improved boron removal at neutral pH. Sorption isotherm studies were performed and the Langmuir isotherm model was found to fit the experimental data. The maximum sorption capacities were 4.5 mmol g−1 and 5.2 mmol g−1, using CA and CAAl, respectively. Thermodynamic parameters such as change in free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0) were also determined. The pseudo-first-order and pseudo-second-order rate equations (PFORE and PSORE, respectively) were tested to fit the kinetic data; the experimental results can be better described with PSORE. The regeneration of the loaded sorbents was demonstrated by using dilute HCl solution (distilled water at pH 3) as eluent for metal recovery.

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 Calcium Alginate Beads Doped with Nano-ZrO2 and Activated Carbon of Annona reticulate Plant as an Effective Adsorbent for Water Remediation of Chromium(VI)

2021 ◽  
Vol 33 (2) ◽  
pp. 281-290
Author(s):  
WONDWOSEN KEBEDE BIFTU ◽  
KUNTA RAVINDHRANATH
Keyword(s):  
Activated Carbon ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Water Remediation ◽  
Polluted Water ◽  
Isotherm Models ◽  
Kinetics Of Adsorption ◽  
Calcium Alginate Beads ◽  
Chromium Vi ◽  
Pseudo Second Order

An activated carbon produced from stems of Annona reticulate plant (SACAR) by conc. H2SO4 digestion, is observed to have strong affinity for toxic Cr(VI) ions. Its adsorptivity for Cr(VI) ions was enhanced by admixing it with ‘nano-ZrO2’ (Zr-SACAR)-synthesized adopting green methods. For ensuring easy filtration, the ‘active carbon + nanoparticle composite’ was immobilized in calcium alginate beads (Zr-SACAR-Ca). Optimum extraction conditions for these three adsorbents for the removal of Cr(VI) ions from water were investigated. The adsorption capacities were found to be 92.2 mg/g for SACAR; 109.83 mg/g for Zr-SACAR and 119.34 mg/g for Zr-SACAR-Ca. The sorption nature was characterized by XRD, FTIR, FESEM and EDX studies. The sorption mechanism was investigated using various isotherm models. Thermodynamic studies revealed the endothermic and spontaneous nature of sorption. The kinetics of adsorption was well defined by the pseudo-second-order model. The spent adsorbent are regenerated and reused until six cycles with marginal decrease in Cr-adsorptivity. The adsorbents developed are effectively applied in the treatment of polluted water samples collected from Ethiopia

scholarly journals Tannin-based biosorbent encapsulated into calcium alginate beads for Cr(VI) removal

2020 ◽  
Vol 81 (5) ◽  
pp. 936-948 ◽  
Author(s):  
Xubing Sun ◽  
Jiayong Zhang ◽  
Guowen Ding ◽  
Yaohui You
Keyword(s):  
Photoelectron Spectroscopy ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Formaldehyde Resin ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intra Particle Diffusion ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Low Toxicity

Abstract A composite biosorbent (AC-TFR) prepared by encapsulating tannin-formaldehyde resin (TFR) into calcium alginate (AC) beads was used to remove Cr(VI) from an aqueous solution. Various influencing factors, such as TFR dosage, pH, initial Cr(VI) concentration, contact time, temperature and presence of co-ions in the medium, were investigated. The structures and adsorption performances of the adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Compared with other AC-TFR adsorbents, AC-TFR-2 (mass ratio of AC:TFR = 1:1) showed an excellent adsorption capacity based on the efficiency of Cr(VI) removal. The kinetic data fitted to pseudo-second-order and intra-particle diffusion models suggested that the adsorption process was subject to a rate-controlling step. The equilibrium adsorption data fitted well to the Langmuir isotherm model, and the maximum adsorption capacities of AC-TFR-2 were 145.99, 167.22 and 174.52 mg/g at 288, 298, and 308 K, respectively. The thermodynamic parameters revealed that Cr(VI) removal by AC-TFR-2 was endothermic and spontaneous, and the process was chemical adsorption. The mechanism of Cr(VI) removal consisted first of reduction to Cr(III), which has a low toxicity, and then chelation onto AC-TFR-2 via ion exchange.

scholarly journals Extraction of Phosphate from Polluted Waters Using Calcium Alginate Beads Doped with Active Carbon Derived fromA. asperaPlant as Adsorbent

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Ravulapalli Sujitha ◽  
Kunta Ravindhranath
Keyword(s):  
Active Carbon ◽  
Calcium Alginate ◽  
Alginate Beads ◽  
Polluted Water ◽  
Sorption Mechanism ◽  
Order Model ◽  
Calcium Alginate Beads ◽  
Morphological Studies ◽  
Pseudo Second Order ◽  
Polluted Waters

An adsorbent prepared by entrapping active carbon derived from the stems ofAchyranthes asperaplant in the calcium alginate beads (CABAA) has been investigated for its adsorption nature towards the removal of phosphate by varying various physicochemical parameters. Surface morphological studies are made using FTIR, XRD, FESEM, and EDX. The sorption mechanism is analyzed using Freundlich, Langmuir, Dubinin-Radushkevich, and Temkin adsorption isotherms. The adsorption kinetics is found to follow the pseudo-second-order model. Thermodynamic parameters are analyzed and found that the adsorption is endothermic and nonspontaneous in nature. The maximum amount of phosphate adsorbed onto CABAA is found to be 133.3 mg/g of active carbon and, furthermore, the adsorbent is highly selective. The methodology developed is successfully applied to polluted water samples.

scholarly journals The Enzymatic Decolorization of Textile Dyes by the Immobilized Polyphenol Oxidase from Quince Leaves

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gulnur Arabaci ◽  
Ayse Usluoglu
Keyword(s):  
Polyphenol Oxidase ◽  
Calcium Alginate ◽  
Enzyme Stability ◽  
Industrial Effluent ◽  
Alginate Beads ◽  
Textile Dyes ◽  
Kinetic Properties ◽  
Synthetic Dyes ◽  
Cydonia Oblonga ◽  
Calcium Alginate Beads

Water pollution due to release of industrial wastewater has already become a serious problem in almost every industry using dyes to color its products. In this work, polyphenol oxidase enzyme from quince (Cydonia Oblonga) leaves immobilized on calcium alginate beads was used for the successful and effective decolorization of textile industrial effluent. Polyphenol oxidase (PPO) enzyme was extracted from quince (Cydonia Oblonga) leaves and immobilized on calcium alginate beads. The kinetic properties of free and immobilized PPO were determined. Quince leaf PPO enzyme stability was increased after immobilization. The immobilized and free enzymes were employed for the decolorization of textile dyes. The dye solutions were prepared in the concentration of 100 mg/L in distilled water and incubated with free and immobilized quince (Cydonia Oblonga) leaf PPO for one hour. The percent decolorization was calculated by taking untreated dye solution. Immobilized PPO was significantly more effective in decolorizing the dyes as compared to free enzyme. Our results showed that the immobilized quince leaf PPO enzyme could be efficiently used for the removal of synthetic dyes from industrial effluents.

scholarly journals Improving the Stability of Astaxanthin by Microencapsulation in Calcium Alginate Beads

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0153685 ◽  
Author(s):  
Shen-Fu Lin ◽  
Ying-Chen Chen ◽  
Ray-Neng Chen ◽  
Ling-Chun Chen ◽  
Hsiu-O Ho ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Alginate Beads ◽  
Calcium Alginate Beads ◽  
The Stability

scholarly journals Husk of Agarwood Fruit-Based Hydrogel Beads for Adsorption of Cationic and Anionic Dyes in Aqueous Solutions

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1437
Author(s):  
Chih Ming Ma ◽  
Bo-Yuan Yang ◽  
Gui-Bing Hong
Keyword(s):  
Aqueous Solutions ◽  
Selective Adsorption ◽  
Order Model ◽  
Anionic Dyes ◽  
Adsorption Selectivity ◽  
Hydrogel Beads ◽  
Batch System ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Hydrogel beads based on the husk of agarwood fruit (HAF)/sodium alginate (SA), and based on the HAF/chitosan (CS) were developed for the removal of the dyes, crystal violet (CV) and reactive blue 4 (RB4), in aqueous solutions, respectively. The effects of the initial pH (2–10) of the dye solution, the adsorbent dosage (0.5–3.5 g/L), and contact time (0–540 min) were investigated in a batch system. The dynamic adsorption behavior of CV and RB4 can be represented well by the pseudo-second-order model and pseudo-first-order model, respectively. In addition, the adsorption isotherm data can be explained by the Langmuir isotherm model. Both hydrogel beads have acceptable adsorption selectivity and reusability for the study of selective adsorption and regeneration. Based on the effectiveness, selectivity, and reusability of these hydrogel beads, they can be treated as potential adsorbents for the removal of dyes in aqueous solutions.

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