scholarly journals Superhigh Adsorption of Cadmium(II) Ions onto Surface Modified Nano Zerovalent Iron Composite (CNS-nZVI): Characterization, Adsorption Kinetics and Isotherm Studies

2021 ◽  
Vol 15 (4) ◽  
pp. 457-464
Author(s):  
Prabu Deivasigamani ◽  
◽  
Senthil Kumar Ponnusamy ◽  
Sathish Sundararaman ◽  
Suresh A ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Kinetics ◽  
Freundlich Isotherm ◽  
Zerovalent Iron ◽  
Nanoscale Zerovalent Iron ◽  
Cashew Nut ◽  
Pseudo Second Order ◽  
Cashew Nut Shell ◽  
Surface Modified ◽  
Adsorption Kinetics And Isotherm

The efficiency of surface modified nanoscale zerovalent iron (nZVI) composite by cashew nut shell (CNS) was tested for the removal of cadmium ions from the aqueous solutions. 2 g/l CNS-nZVI was efficient for 98% removal. The adsorption capacity was 35.58 mg/g. The Freundlich isotherm (R2 = 0.9769) and the pseudo-second order adsorption kinetics data fitted well. This proved CNS-nZVI has a high removal efficiency for Cd(II) from aqueous solutions.

Adsorption of Methylene Blue on Modified Bentonite

2013 ◽  
Vol 726-731 ◽  
pp. 2380-2383
Author(s):  
Li Xia Li ◽  
Xin Dong Zhai
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Adsorption Kinetics ◽  
Freundlich Isotherm ◽  
Batch Process ◽  
Experimental Results ◽  
Order Model ◽  
Modified Bentonite ◽  
Equilibrium Data ◽  
Pseudo Second Order

Modified bentonite was used as adsorbent for the methylene blue adsorption in a batch process. Experimental results show that the adsorption kinetics is well described by pseudo-second-order model and the equilibrium data was better represented by the Freundlich isotherm model. The results revealed that the modified bentonite has the potential to be used as a good adsorbent for the removal of methylene blue from aqueous solutions.

scholarly journals Cashew nut shell (Anarcadium accidentale L) charcoal as bioadsorbent to remove Cu2+ and Cr3+

2021 ◽  
Vol 10 (2) ◽  
pp. e0510212238
Author(s):  
Karine Fonseca Soares de Oliveira ◽  
Joemil Oliveira de Deus Junior ◽  
Talita Lorena da Silva do Nascimento ◽  
Raoni Batista dos Anjos ◽  
Dulce Maria de Araújo Melo ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Low Cost ◽  
Chemical Properties ◽  
Industrial Effluents ◽  
Second Order ◽  
Point Of Zero Charge ◽  
Cashew Nut ◽  
Pseudo Second Order ◽  
Cashew Nut Shell ◽  
Removal Of Metal Ions

Lignocellulosic materials have been used as bioadsorbents for contaminants removal from industrial effluents due to their physical-chemical properties, renewable source, low-cost and efficiency that make them competitive to commercial activated carbon. The objective of this work is to develop an efficient and low cost bioadsorbent reusing the cashew nut shell (Anarcadium accidentale L), CNS, for the removal of metal ions (Cu2+ and Cr3+). The CNS was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), the point of zero charge (pHpzc) and the Boehm titration. The kinetics and adsorption equilibrium experiments were carried out in a monoelementary system, in batch runs at room temperature. The adsorption kinetics was evaluated by the mathematical models of pseudo first-order, pseudo second-order and intraparticle diffusion, while the adsorption isotherm was adjusted according to the Langmuir, Freundlich and Redlich-Peterson models. The removal percentage was 91% (Cu2+) and 96% (Cr3+) and adsorption kinetics was better adjusted to the pseudo second-order model, suggesting the predominance of chemisorption. The fit of the Langmuir isotherm was better for the experimental data of Cu2+ and Cr3+ ions, indicating adsorption in monolayers. It is concluded that the bioabsorbent produced from the cashew nut shell has a high potential for the removal of metals, in addition to being an abundant product in nature, is renewable and biodegradable and its reuse contributes to the reduction of environmental pollution, the production of waste and improves the local circular economy through the valorization of the byproduct.

scholarly journals Adsorption Characteristics of Phosphate Ions by Pristine, CaCl2 and FeCl3-Activated Biochars Originated from Tangerine Peels

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 32 ◽  
Author(s):  
Changgil Son ◽  
Wonyeol An ◽  
Geonhee Lee ◽  
Inho Jeong ◽  
Yong-Gu Lee ◽  
...  
Keyword(s):  
Adsorption Kinetics ◽  
Chemical Activation ◽  
Isotherm Models ◽  
Order Model ◽  
Phosphate Ions ◽  
Adsorption Capacities ◽  
Adsorption Isotherm Models ◽  
Endothermic Reactions ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm

This study has evaluated the removal efficiencies of phosphate ions (PO43−) using pristine (TB) and chemical-activated tangerine peel biochars. The adsorption kinetics and isotherm presented that the enhanced physicochemical properties of TB surface through the chemical activation with CaCl2 (CTB) and FeCl3 (FTB) were helpful in the adsorption capacities of PO43− (equilibrium adsorption capacity: FTB (1.655 mg g−1) > CTB (0.354 mg g−1) > TB (0.104 mg g−1)). The adsorption kinetics results revealed that PO43− removal by TB, CTB, and FTB was well fitted with the pseudo-second-order model (R2 = 0.999) than the pseudo-first-order model (R2 ≥ 0.929). The adsorption isotherm models showed that the Freundlich equation was suitable for PO43− removal by TB (R2 = 0.975) and CTB (R2 = 0.955). In contrast, the Langmuir equation was proper for PO43− removal by FTB (R2 = 0.987). The PO43− removal efficiency of CTB and FTB decreased with the ionic strength increased due to the compression of the electrical double layer on the CTB and FTB surfaces. Besides, the PO43− adsorptions by TB, CTB, and FTB were spontaneous endothermic reactions. These findings demonstrated FTB was the most promising method for removing PO43− in waters.

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.

Mathematical Modelling for Copper and Lead Adsorption on Coffee Grounds

2017 ◽  
Author(s):  
Jurgita Seniūnaitė ◽  
Rasa Vaiškūnaitė ◽  
Kristina Bazienė
Keyword(s):  
Heavy Metals ◽  
Mathematical Modelling ◽  
Adsorption Kinetics ◽  
Adsorption Process ◽  
Freundlich Isotherm ◽  
Sorption Process ◽  
Second Order ◽  
Order Kinetic ◽  
Coffee Grounds ◽  
Pseudo Second Order

Research studies on the adsorption kinetics are conducted in order to determine the absorption time of heavy metals on coffee grounds from liquid. The models of adsorption kinetics and adsorption diffusion are based on mathe-matical models (Cho et al. 2005). The adsorption kinetics can provide information on the mechanisms occurring be-tween adsorbates and adsorbents and give an understanding of the adsorption process. In the mathematical modelling of processes, Lagergren’s pseudo-first- and pseudo-second-order kinetics and the intra-particle diffusion models are usually applied. The mathematical modelling has shown that the kinetics of the adsorption process of heavy metals (copper (Cu) and lead (Pb)) is more appropriately described by the Lagergren’s pseudo-second-order kinetic model. The kinetic constants (k2Cu = 0.117; k2Pb = 0,037 min−1) and the sorption process speed (k2qeCu = 0.0058–0.4975; k2qePb = 0.021–0.1661 mg/g per min) were calculated. After completing the mathematical modelling it was calculated that the Langmuir isotherm better reflects the sorption processes of copper (Cu) (R2 = 0.950), whilst the Freundlich isotherm – the sorption processes of lead (Pb) (R2 = 0.925). The difference between the mathematically modelled and experimen-tally obtained sorption capacities for removal of heavy metals on coffee grounds from aqueous solutions is 0.059–0.164 mg/l for copper and 0.004–0.285 mg/l for lead. Residual concentrations of metals in a solution showed difference of 1.01 and 0.96 mg/l, respectively.

scholarly journals The Removal of Uranium and Thorium from Their Aqueous Solutions by 8-Hydroxyquinoline Immobilized Bentonite

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 626 ◽  
Author(s):  
Salah ◽  
Gaber ◽  
Kandil
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Langmuir Isotherm ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

The sorption of uranium and thorium from their aqueous solutions by using 8-hydroxyquinoline modified Na-bentonite (HQ-bentonite) was investigated by the batch technique. Na-bentonite and HQ-bentonite were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. Factors that influence the sorption of uranium and thorium onto HQ-bentonite such as solution pH, contact time, initial metal ions concentration, HQ-bentonite mass, and temperature were tested. Sorption experiments were expressed by Freundlich and Langmuir isotherms and the sorption results demonstrated that the sorption of uranium and thorium onto HQ-bentonite correlated better with the Langmuir isotherm than the Freundlich isotherm. Kinetics studies showed that the sorption followed the pseudo-second-order kinetic model. Thermodynamic parameters such as ΔH°, ΔS°, and ΔG° indicated that the sorption of uranium and thorium onto HQ-bentonite was endothermic, feasible, spontaneous, and physical in nature. The maximum adsorption capacities of HQ-bentonite were calculated from the Langmuir isotherm at 303 K and were found to be 63.90 and 65.44 for U(VI) and Th(IV) metal ions, respectively.

scholarly journals Synthesis of Nanoscale Zerovalent Iron (nZVI) Supported on Biochar for Chromium Remediation from Aqueous Solution and Soil

2019 ◽  
Vol 16 (22) ◽  
pp. 4430 ◽  
Author(s):  
Haixia Wang ◽  
Mingliang Zhang ◽  
Hongyi Li
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Zero Valent Iron ◽  
Zerovalent Iron ◽  
X Ray ◽  
Nanoscale Zerovalent Iron ◽  
Before And After ◽  
Pseudo Second Order ◽  
Xrd Patterns ◽  
Co Precipitation

Maize straw biochar-supported nanoscale zero-valent iron composite (MSB-nZVI) was prepared for efficient chromium (Cr) removal through alleviating the aggregation of zero-valent iron particles. The removal mechanism of MSB-nZVI was investigated by scanning electron microscopy with energy dispersive X-ray (SEM-EDX), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS). Cr(VI) removal from aqueous solution by MSB-nZVI was greatly affected by pH and initial concentration. The removal efficiency of Cr(VI) decreased with increasing pH, and the removal kinetics followed the pseudo-second-order model. XRD patterns of MSB-nZVI before and after reaction showed that reduction and precipitation/co-precipitation (FeCr2O4, Fe3O4, Fe2O3) occurred with the conversion of Cr(VI) to Cr(III) and Fe(0) to Fe(II)/Fe(III). The produced precipitation/co-precipitation could be deposited on the MSB surface rather than being only coated on the surface of nZVI particles, which can alleviate passivation of nZVI. For remediation of Cr(VI)-contaminated saline–alkali soil (pH 8.6–9.0, Cr 341 mg/kg), the released amount of Cr(VI) was 70.7 mg/kg, while it sharply decreased to 0.6–1.7 mg/kg at pH 4.0–8.0, indicating that the saline–alkali environment inhibited the remediation efficiency. These results show that MSB-nZVI can be used as an effective material for Cr(VI) removal from aqueous solution and contaminated soil.

Adsorption of Phosphorus by Lithium Silica Fume

2013 ◽  
Vol 368-370 ◽  
pp. 692-696
Author(s):  
Wei Lan Lin ◽  
Jin Chuan Gu ◽  
Yu Heng Wang ◽  
Wen Yuan Wang
Keyword(s):  
Silica Fume ◽  
Adsorption Kinetics ◽  
Removal Rate ◽  
Freundlich Isotherm ◽  
Good Method ◽  
Order Equation ◽  
Isotherm Equation ◽  
Dosage Effects ◽  
Adsorption Capacities ◽  
Pseudo Second Order

adsorption is a good method to remove phosphorus. In the experiment, lithium silica fume is used as the adsorption material, adsorption isotherms ,kinetics and dosage effects were examined. It shows that the adsorption kinetics data are consistent with the pseudo-second-order equation and the adsorption is easy to happen. Freundlich isotherm equation is fit for description of the adsorption. The maximum adsorption capacities on lithium silica fume is 1.166 mg/g. When dosage get to 12 g/l and the concentration of phosphorus solution is 2 mg/l, the removal rate reach to 95% at 308k.

Adsorption kinetics and isotherm of vanadium with melamine

2017 ◽  
Vol 75 (10) ◽  
pp. 2316-2321 ◽  
Author(s):  
Hao Peng ◽  
Zuohua Liu ◽  
Changyuan Tao
Keyword(s):  
Adsorption Kinetics ◽  
Impact Factors ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Initial Ph ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorption Kinetics And Isotherm ◽  
Langmuir And Freundlich Models

Melamine, possessing three free amino groups and three aromatic nitrogen atoms in its molecule, has great potential as an adsorbent for metal ions. We investigated three impact factors of the adsorption process: the initial pH of the vanadium solution, contact time and reaction temperature. The adsorption kinetics could be accurately described by the pseudo-second-order kinetic model. Langmuir and Freundlich models fitted well with the experimental equilibrium data, and the maximal adsorption capacity was found to be 1,428.57 mg vanadium/g melamine, and the Freundlich model showed the adsorption is privilege type.

scholarly journals Utilization of agricultural and industrial wastes for metal removal from aqueous solutions

2011 ◽  
Vol 13 (1) ◽  
pp. 20-22 ◽  
Author(s):  
Marta Biegańska ◽  
Ryszard Cierpiszewski
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Kinetics ◽  
Metal Removal ◽  
Order Equation ◽  
Industrial Wastes ◽  
Cadmium Removal ◽  
Cadmium Ions ◽  
Ph Values ◽  
Freundlich Equation ◽  
Pseudo Second Order

Utilization of agricultural and industrial wastes for metal removal from aqueous solutions In this study a possibility of obtaining sorbents from basketry wastes has been investigated. Therefore, adsorption of cadmium ions on wicker bark of Salix americana has been studied. The obtained experimental results were described by the Freundlich equation and adsorption kinetics by the pseudo-second order equation. The effect of pH on cadmium ions adsorption by S. americana was also investigated. It has been found that for the pH values ranging from 2 to 7 cadmium removal from the solution was held at almost constant level.

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