scholarly journals A High-Efficiency Approach for the Synthesis of N235-Impregnated Resins and the Application in Enhanced Adsorption and Separation of Vanadium(V)

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 358 ◽  
Author(s):  
Bo Chen ◽  
Shenxu Bao ◽  
Yimin Zhang ◽  
Ruwei Zheng
Keyword(s):  
Chemical Reaction ◽  
High Efficiency ◽  
Order Kinetic ◽  
Equilibrium Time ◽  
Rate Limiting Step ◽  
Reaction Constant ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Enhanced Adsorption ◽  
Rate Limiting

Trialkylamine (N235)-tributyl phosphate (TBP) impregnated resins (N-TIRs) were prepared, so as to evaluate the effects of the addition of TBP on the preparation and adsorption performance of N235-impregnated resins (NIRs). The results show that TBP can obviously increase the impregnation ratio and shorten the impregnation equilibrium time of the N-TIRs when compared to that of the NIRs (57.73% versus 36.95% and 5 min versus 240 min). It is confirmed that TBP can interact with N235 during the impregnation process, which shorten the adsorption equilibrium time and increases the adsorption capacity of the N-TIRs for V(V) when compared to that of the NIRs (6 h versus 10 h and 50.95 mg·g−1 versus 46.73 mg·g−1). The kinetics fitting results demonstrate that the adsorption of V(V) onto N-TIRs and NIRs all conform to pseudo-second order kinetic model and chemical reaction is the rate-limiting step of the whole adsorption process. In the meanwhile, the reaction constant (Ks) implies that the chemical reaction rate of V(V) with the impregnated extractants in N-TIRs is faster than that in NIRs. The N-TIRs present higher stability and selectivity than NIRs. This study manifests that the addition of a secondary reagent may be a potential and novel technique on the preparation of SIRs and the enhancement of adsorption and separation for ions.

scholarly journals Evaluation of Pb (II) Removal from Water Using Sodium Alginate/Hydroxypropyl Cellulose Beads

2020 ◽  
Vol 148 ◽  
pp. 02002 ◽  
Author(s):  
Rodel Guerrero ◽  
Catherine Acibar ◽  
Christine Marie Alarde ◽  
Jane Maslog ◽  
Christine Joy Pacilan
Keyword(s):  
Adsorption Capacity ◽  
Sodium Alginate ◽  
Contact Time ◽  
Hydroxypropyl Cellulose ◽  
Order Kinetic ◽  
Hydrogel Beads ◽  
Rate Limiting Step ◽  
Pseudo Second Order ◽  
Rate Limiting ◽  
Adsorption Kinetic Model

This study examined the removal of Pb2+ ions from aqueous solution with two different lead concentrations using a hydrogel-forming polymer based on hydroxypropyl cellulose (HPC) and sodium alginate (SA). The feasibility of the adsorption behavior of SA/HPC beads has been investigated with three varying ratios of 50:50, 75:25 and 100:0 under a stir condition. The adsorption experiments were done to determine the effects of contact time, lead concentration and SA-HPC ratio to the adsorption capacity of SA-HPC hydrogel beads. The results showed that the ratio 75:25 showed higher adsorption capacity compared to 100:0 and 50:50. It showcased 47.72 mg/g adsorption capacity and 95.45% adsorption percentage after three hours of contact time. The adsorption kinetic model indicated that the adsorption of Pb2+ ions onto the beads followed a pseudo-second order kinetic equation. This means that the adsorption mechanism shows a chemisorption process and its sole rate-limiting step is intraparticle diffusion.

scholarly journals Enhanced Adsorption of Orange II Using Cationic Surfactant Modified Biochar Pyrolyzed from Cornstalk

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xiao Mi ◽  
Guoting Li ◽  
Weiyong Zhu ◽  
Lili Liu
Keyword(s):  
Adsorption Process ◽  
Orange Ii ◽  
Order Kinetic ◽  
Nonlinear Simulation ◽  
Modified Biochar ◽  
Order Kinetic Model ◽  
Alkaline Conditions ◽  
Pseudo Second Order ◽  
Acidic Conditions ◽  
Enhanced Adsorption

As dissolution of raw biomass is serious when used as an adsorbent, the cheap biochar pyrolyzed from biomass might be a good matrix. Raw cornstalk biochar was intentionally modified by cetyltrimethylammonium bromide (CTAB) to prepare the composite adsorbent designed for the removal of negatively charged pollutants. After modification, the removal efficiency for anionic dye Orange II (ORII) increased from 46.9% of the virgin cornstalk biochar to 99.7% of the CTAB-modified cornstalk biochar. The uptake of ORII proved to be favorable under acidic conditions but unfavorable under alkaline conditions. By nonlinear simulation, the Elovich model was the best to describe the adsorption kinetics. For linear simulation of the kinetic data, the pseudo-second-order kinetic model fitted the experimental points better than the pseudo-first-order model. Kinetic analysis indicated that the ORII adsorption process on the CTAB-modified cornstalk biochar might be chemical adsorption accompanied by ion exchange. At 298 K, the maximal adsorption capacity of the modified biochar is 26.9 mg/g by the Langmuir model. The adsorption of ORII increased with a rise in the reaction temperature. The enthalpy and entropy of the adsorption process are calculated to be 38.45 KJ mol−1and 185.0 J mol−1 K−1, respectively. The negative values ofΔG0at 288, 298, and 308 K were −14.92, −16.50, and −18.62 KJ mol−1, respectively. The above thermodynamic analysis demonstrates that the adsorption process was endothermic and spontaneous.

scholarly journals Novel Hydroxyapatite Beads for the Adsorption of Radionuclides from Decommissioned Nuclear Power Plant Sites

2021 ◽  
Vol 11 (4) ◽  
pp. 1746
Author(s):  
Thi Nhung Tran ◽  
Junho Kim ◽  
Joo-Sung Park ◽  
Youngkun Chung ◽  
Jaemun Han ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Polyvinyl Butyral ◽  
Order Kinetic ◽  
Practical Applications ◽  
Adsorption Mechanisms ◽  
Rate Limiting Step ◽  
Aqueous Environments ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Although a powdered form of hydroxyapatite (p-HdA) has been studied for the adsorption of heavy metals that contaminate the restoration sites of decommissioned nuclear power plants, most of the studies are limited in the laboratory due to the head loss and post-separation in practical applications. Herein, we fabricated a porous bead form of HdA (b-HdA) as a novel adsorbent for removing radionuclides from aqueous environments via a facile synthesis by mixing the p-HdA precursor and polyvinyl butyral (PVB) as a binder and added a sintering process for the final production of a porous structure. The spherical b-HdA with an approximate diameter of 2.0 mm was successfully fabricated. The effectiveness of the b-HdA at removing Co(II) was investigated via the adsorption equilibrium at various experimental temperatures. The b-HdA exhibited the adsorption capacity for Co(II) ions with a maximum of 7.73 and 11.35 mg/g at 293 K and 313 K, respectively. The experimental kinetic data were well described using a pseudo-second-order kinetic model, and the adsorption mechanisms of Co(II) onto the b-HdA were revealed to be a chemisorption process with intraparticle diffusion being the rate-limiting step. In addition, the competitive adsorption onto the b-HdA with the order of U(VI) > Co(II) > Ni(II) > Sr(II) > Cs(I) was also observed in the multi-radionuclides system. Considering the advantages of the size, applicability to the continuous-flow column, and the easy separation from treated water, the b-HdA can be an excellent absorbent with high potential for practical applications for removing radionuclides.

Experimental and Modeling Studies of Sorption of Tetracycline onto Zeolite in the Presence of Copper(II)

2012 ◽  
Vol 512-515 ◽  
pp. 2355-2360 ◽  
Author(s):  
Hong Huang ◽  
Yan Li Zou ◽  
Ya Nan Li
Keyword(s):  
Removal Rate ◽  
Sorption Process ◽  
Order Kinetic ◽  
Adsorption Removal ◽  
Intra Particle Diffusion ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Equilibrium Process ◽  
Presence And Absence ◽  
Rate Limiting

The sorption performance of tetracycline on zeolite under different conditions was investigated in presence and absence of Cu(Ⅱ).The presence of Cu(Ⅱ) greatly increased the adsorption of tetracycline on zeolite. Adsorption kinetics and adsorption equilibrium isotherms were studied by conducting series of batch experiments. The kinetic analysis indicated that the pseudo-second-order kinetic model was well described the sorption equilibrium process of tetracycline onto zeolite in the presence and absence of Cu(Ⅱ), and intra-particle diffusion was not the only rate-limiting in the sorption process. The qmax value calculated from Langmuir model were 17.37 and 68.26 mg/g in the absence and the presence of Cu(Ⅱ). The value of E calculated from Dubinin-Radushkevich (D-R) model confirmed that the adsorption in the absence and presence of Cu(Ⅱ) were mainly controlled by physical combined with chemical adsorption mechanism. The tetracycline sorption amount decreased in the absence of Cu(Ⅱ) and increased in the presence of Cu(Ⅱ) as the pH increasing. The adsorption removal rate of wastewater containing 0.1 mmol/L tetracycline was 95.5% in the presence of Cu(Ⅱ) and 34.5% in the absence of Cu(Ⅱ) when the dosage of zeolite was 0.05g.

scholarly journals The Influence of the Chemical Structures of Chitosan and Acid Dye on the Adsorption Process

2012 ◽  
Vol 9 (4) ◽  
pp. 2415-2423
Author(s):  
Hayet Ben Ali ◽  
Salma Besbes Hentati ◽  
Salem S. Al-Deyab ◽  
Mohamed Rzaigui ◽  
M'henni Mohamed Farouk
Keyword(s):  
Adsorption Process ◽  
Order Kinetic ◽  
Chemical Structures ◽  
Enthalpy Changes ◽  
Adsorption Processes ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Rate Limiting ◽  
Best Fit ◽  
Efficient Adsorbent

The objective of this paper is the study of the influence of the chemical structures of adsorbent and adsorbate on the adsorption process. By using of crab shell chitosan (CC) and deep-pink shrimp chitosan (CP) for removal of acid 183 and AR114 from aqueous solutions, it is shown that CP, which corresponds to the highest molecular weight, is the most efficient adsorbent material. In addition, the best extent of decolorization is obtained for AR 183 that is the smallest molecule. Langmuir model represents the best fit of the experimental data, indicating monolayer coverage of chitosan outer surface. Pseudo-second order kinetic model describes accurately the adsorption processes, suggesting chemical rate limiting steps. The positive values of the enthalpy changes indicated endothermic attachment of dyes to the biomaterials. CP/AR183 system corresponds to the most energetically favorable phenomenon. Besides, desorption of AR from chitosan was found to be very low in acidic aqueous medium for all couples.

scholarly journals Equilibrium, Kinetics and Thermodynamics of the Bleaching of Palm Oil Using Activated Nando Clay

2018 ◽  
pp. 1-13
Author(s):  
Nwabanne, Joseph T. ◽  
Onu, Chijioke E. ◽  
Nwankwoukwu, Okwudili C.
Keyword(s):  
Palm Oil ◽  
Order Kinetic ◽  
Adsorbent Dosage ◽  
Bleaching Efficiency ◽  
Rate Limiting Step ◽  
Equilibrium Data ◽  
Intra Particle Diffusion ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
Rate Limiting

The effectiveness of Nando clay in the bleaching of palm oil was studied in this work. The clay was prepared by activating it with hydrochloric acid. The bleaching was carried out at different temperatures, adsorbent dosage and particle sizes. The result suggests that increase in temperature and adsorbent dosage increases the bleaching efficiency while the increase in particle size decreases the bleaching efficiency. Both the pseudo-first-order and the pseudo-second-order kinetic models describe efficiently the experimental data of the bleaching process. Intra-particle diffusion though involved in the adsorptive bleaching mechanism, is not the sole rate-limiting step in the bleaching of palm oil with activated Nando clay. The equilibrium data were described better by Langmuir and Freundlich models. The enthalpy, entropy and activation energy were determined to be 6.127 KJ/mol, 3.982 KJ/mol and 15.281 KJ respectively. The free energy was found to vary between- 3.999 to- 3.760 KJ/mol. The result indicates that bleaching efficiency of up to 96% can be obtained with the activated clay as an adsorbent.

scholarly journals Kinetics and adsorption studies of lead (II) onto activated carbon using low cost adsorbents

2018 ◽  
Vol 20 (2) ◽  
pp. 381-388 ◽  
Keyword(s):  
Low Cost ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Rate Limiting Step ◽  
Bambusa Vulgaris ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Fagopyrum Esculentum Moench

The removal of Lead (II) from aqueous solutions using Fagopyrum esculentum Moench (Buckwheat) and Bambusa vulgaris (common bamboo) as adsorbents was investigated. The effects of various experimental parameters such as initial concentration, contact time and pH have been studied using batch adsorption technique. All the Adsorption isotherm models fitted well with the adsorption data. However, Freundlich isotherm displayed a better fitting model than the other two isotherm models due to high correlation coefficient (R2). This indicates the applicability of multilayer coverage of the Pb (II) on the surface of adsorbent. The adsorption kinetics was studied using four simplified models and it was found to follow the pseudo-second-order kinetic model which confirmed the applicability of the model. The adsorption mechanism was found to be chemisorption and the rate-limiting step was mainly surface adsorption.

scholarly journals Removal of Cr(VI) from wastewater by silver-loaded natural clinoptilolite

2021 ◽  
Vol 280 ◽  
pp. 06008
Author(s):  
Marinela Panayotova
Keyword(s):  
Order Kinetic ◽  
Water And Wastewater Treatment ◽  
Rate Limiting Step ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Water And Wastewater ◽  
Natural Clinoptilolite ◽  
Modified Clinoptilolite ◽  
Rate Limiting ◽  
Order Kinetic Equation

Presence of hexavalent chromium, Cr(VI), in water is an important environmental and human health problem. Natural zeolites are widely accepted as non-expensive adsorbents for sustainable remediation, however they are not effective in removing metals in anionic form. The paper presents study on use of silver (Ag) modified natural clinoptilolite to immobilize Cr(VI) ions from model and real neutral to slightly alkaline wastewater. Increasing the initial pollutant concentration increases the removed amount (80 % removal from model wastewater in 45 min at initial concentration of 30 mg Cr(VI)/L). The pseudo-second order kinetic equation best describes the Cr(VI) immobilization by the Ag-modified zeolite, which is indicative for the chemical nature of the rate-limiting step of the process. The data obtained are best fitted to the Freundlich adsorption isotherm. The Ag-modified clinoptilolite removes in 30 min over 80 % of Cr(VI), over 75 % of Cu(II) and over 70 % of Zn(II) that present simultaneously in an industrial wastewater. Due to its ability to remove Cr(VI) species, in combination with some heavy metal ions, some organic pollutants and exhibited antibacterial activity, silver loaded clinoptilolite seems to be a possible multifunctional reagent in the water and wastewater treatment and deserves further investigation.

Preparation of Magnetic Chitosan-β-Cyclodextrin Polymer and its Adsorption for Thallium (III) in Aqueous Solution

2012 ◽  
Vol 479-481 ◽  
pp. 1733-1736 ◽  
Author(s):  
Zhi Wu Zhou ◽  
Jing Song Wang ◽  
Qing Wei Guo ◽  
Zhen Cheng Xu
Keyword(s):  
Metal Ion ◽  
High Efficiency ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Metal Ion Binding ◽  
Static Tests ◽  
Magnetic Chitosan ◽  
Cyclodextrin Polymer ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Magnetic chitosan bonded β-cyclodextrin polymer was prepared, and its metal ion binding was studied using the batch static tests for thallium removal. The results indicated that magnetic chitosan-β-cyclodextrin polymer (MCS-CD) showed a high efficiency for the removal of thallium, the experiment data fitted well to the pseudo second-order kinetic model, the maximum adsorption capacity of 2.154mgg-1 was obtained according to the isothermal data.

scholarly journals Design and Characterization of a Novel ZnO–Ag/Polypyrrole Core–Shell Nanocomposite for Water Bioremediation

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1688
Author(s):  
Fatma Mohamed ◽  
Abeer Enaiet Allah ◽  
Khulood A. Abu Al-Ola ◽  
Mohamed Shaban
Keyword(s):  
High Efficiency ◽  
Interfacial Polymerization ◽  
Antimicrobial Properties ◽  
Core Shell ◽  
Order Kinetic ◽  
Mixed Solution ◽  
Adsorption Model ◽  
Operation Process ◽  
Order Kinetic Model ◽  
Enhanced Adsorption

Incorporating nanostructured metal and metal oxide in a polymer matrix is a strategic way to develop a novel candidate for water bioremediation. In this study, under microwave irradiation, a ZnO–Ag/polypyrrole (PPy) nanocomposite with a core/shell structure was prepared by interfacial polymerization of pyrrole in the presence of ZnO nanoparticles and AgNO3 as an oxidant. The antimicrobial behavior of the ZnO–Ag core combined with the electrical properties of the conducting PPy shell created a special ZnO–Ag/PPy nanocomposite with inherent adsorption behavior and antimicrobial properties. More impressively, the as-prepared ZnO–Ag/PPy displayed enhanced adsorption of Cd2+ and PO43− ions in the mixed solution. At pH 8, it had overall removal efficiencies of 95% and 75% for Cd2+and PO43− ions, respectively. The Freundlich adsorption model, rather than the Langmuir adsorption model, better fits the adsorption isotherm results. The adsorption kinetics also followed the pseudo-second-order kinetic model. Additionally, the engineered nanocomposite demonstrated antifungal activity against different fungi, as well as remarkable antibacterial activity against Gram-negative and Gram-positive bacteria. The synergistic combination of crystallinity, coherence of the ZnO–Ag core in the PPy matrix, and the negative zeta potential all contribute to this nanocomposite’s high efficiency. Our results have significant consequences in the wastewater bioremediation field using a simple operation process.

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