scholarly journals Adsorptive removal of phosphate by a Fe–Mn–La tri-metal composite sorbent: Adsorption capacity, influence factors, and mechanism

2020 ◽  
Vol 38 (7-8) ◽  
pp. 254-270
Author(s):  
Yuanrong Zhu ◽  
Xianming Yue ◽  
Fazhi Xie
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Phosphate Removal ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Metal Composite ◽  
Order Kinetic ◽  
Composite Sorbent ◽  
Composite Adsorbent

Reducing input of phosphorus is the key step for control of eutrophication and algal blooming in freshwater lakes. Adsorption technology is a cost-effective technology for phosphate removal in water for the purpose. Thus, in this study, a novel Fe–Mn–La tri-metal composite sorbent was developed, and then evaluated for phosphate removal. The results showed that the maximum adsorption capacity could be approached to 61.80 mg g−1 at 25°C under pH of 6.03. Adsorption of phosphate by Fe–Mn–La tri-metal composite adsorbent fitted better by pseudo-second-order kinetic equation and Langmuir model, which suggested that the adsorption process was surface chemical reactions and mainly in a monolayer coverage manner. The thermodynamic study indicated that the adsorption reaction was an endothermic process. The phosphate removal gradually decreased with the increasing of pH from 3.02 to 11.00. The sequence of coexisting anions competing with phosphates was that CO32− > Cl− > SO42− > NO3−. Dissolved organic matter, fulvic acid as a representative, would also decrease adsorption capacities of phosphate by Fe–Mn–La tri-metal composite adsorbents. Adsorption capacity would be decreased with increasing addition of adsorbents, while removal efficiency would be increased in this process. The Fe–Mn–La tri-metal composite adsorbent showed a good reusability when applied to removal of dissolved phosphate from aqueous solutions. The Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy analyses indicated that some hydroxyl groups (–OH) on the surface of adsorbent were replaced by the adsorbed PO43−, HPO42−, or H2PO4−. Aggregative results showed that the novel Fe–Mn–La tri-mental composite sorbent is a very promising adsorbent for the removal of phosphate from aqueous solutions.

scholarly journals Facile Synthesis of Polyethylene Glycol@Tannin-Amine Microsphere towards Cr(VI) Removal

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1035
Author(s):  
Chengbing Yuan ◽  
Yan Zhang ◽  
Jinshui Yao ◽  
Qinze Liu ◽  
Fan-Gong Kong
Keyword(s):  
Polyethylene Glycol ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Sewage Treatment ◽  
Maximum Adsorption Capacity ◽  
Hydroxyl Groups ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Synthetic Strategy ◽  
Order Kinetic Model

Herein, a synthetic strategy for a rough microsphere Cr(VI)-adsorbent via the reaction of tannic acid (TA) and 1,6-hexanediamine (HA) and using polyethylene glycol (PEG) as surface modifier was presented. This adsorbent was characterized by a Fourier Transform Infrared spectrometer (FTIR), thermogravimetic analysis (TGA), X-ray photoelectron spectroscopy (XPS), etc. Certain factors, including contact time, PEG@poly(tannin-1,6-hexanediamine) (PEG@PTHA) dosage, initial concentration, and experimental temperature affecting the Cr(VI) adsorption performance of adsorbent were explored. PEG@PTHA can adsorb Cr and the Cr(VI) was reduced up to Cr(III) due to the existence of phenolic hydroxyl groups. Its adsorption capacity can reach up to 300 mg/g within 10 min and approximately 100% removal percentage below the initial concentration of 100 mg/L. Its behavior matched well with the Langmuir isotherm model and pseudo-second-order kinetic model. A PEG@PTHA adsorbent with maximum adsorption capacity (450 mg/g) has great prospects in Cr(VI)-sewage treatment.

scholarly journals Fabrication of Carboxymethylcellulose/Metal-Organic Framework Beads for Removal of Pb(II) from Aqueous Solution

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 942 ◽  
Author(s):  
Huo-Xi Jin ◽  
Hong Xu ◽  
Nan Wang ◽  
Li-Ye Yang ◽  
Yang-Guang Wang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Photoelectron Spectroscopy ◽  
Langmuir Isotherm ◽  
Adsorption Equilibrium ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
X Ray ◽  
Metal Organic ◽  
Langmuir Isotherm Model

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.

scholarly journals Removal of Cu(II) from Aqueous Solutions Using Amine-Doped Polyacrylonitrile Fibers

2020 ◽  
Vol 10 (5) ◽  
pp. 1738
Author(s):  
Kay Thwe Aung ◽  
Seung-Hee Hong ◽  
Seong-Jik Park ◽  
Chang-Gu Lee
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Equilibrium Studies ◽  
Naoh Solution ◽  
Surface Modified ◽  
Pan Fibers

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.

scholarly journals Sorptive removal of phenanthrene from aqueous solutions using magnetic and non-magnetic rice husk-derived biochars

2018 ◽  
Vol 5 (5) ◽  
pp. 172382 ◽  
Author(s):  
Wei Guo ◽  
Shujuan Wang ◽  
Yunkai Wang ◽  
Shaoyong Lu ◽  
Yue Gao
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Functional Groups ◽  
Rice Husk ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Data ◽  
Magnetic Modification ◽  
Pseudo Second Order ◽  
Rice Husk Biochar

A magnetically modified rice husk biochar (MBC) was successfully prepared by a hydrothermal method from original biochar (BC) and subsequently used to remove phenanthrene (PHE) from aqueous solutions. The porosity, specific surface area and hydrophobicity of BC were significantly improved (approx. two times) after magnetic modification. The adsorption data fitted well to pseudo-second-order kinetic and Langmuir models. Compared with BC, MBC had a faster adsorption rate and higher adsorption capacity of PHE. The adsorption equilibrium for PHE on MBC was achieved within 1.0 h. The maximum adsorption capacity of PHE on MBC was 97.6 mg g −1 based on the analysis of the Sips model, which was significantly higher than that of other sources of BCs. The adsorption mechanism of the two BCs was mainly attributed to the action of surface functional groups and π–π-conjugated reactions. The adsorption of PHE on MBC mainly occurred in the functional groups of C–O and Fe 3 O 4 , but that on BC was mainly in the functional groups of –OH, N–H, C=C and C–O.

scholarly journals Core-Shell Structured Magnetic Carboxymethyl Cellulose-Based Hydrogel Nanosorbents for Effective Adsorption of Methylene Blue from Aqueous Solution

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3054
Author(s):  
Yiming Zhou ◽  
Te Li ◽  
Juanli Shen ◽  
Yu Meng ◽  
Shuhua Tong ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Carboxymethyl Cellulose ◽  
Chemical Properties ◽  
Polymer Nanocomposite ◽  
Core Shell ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Solution Ph

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.

scholarly journals Enhanced adsorption removal of anionic dyes via a facile preparation of amino-functionalized magnetic silica

2017 ◽  
Vol 75 (6) ◽  
pp. 1399-1409 ◽  
Author(s):  
Xiao-Shui Li ◽  
Yu-Han Fan ◽  
Shou-Wen Zhang ◽  
Shi-Hua Qi
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Maximum Adsorption Capacity ◽  
Reactive Black 5 ◽  
Order Kinetic ◽  
Step Method ◽  
Anionic Dyes ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Magnetic Silica

A novel amino-functionalized magnetic silica (Fe3O4@SiO2-NH2) was easily prepared via a one-step method integrating the immobilization of 3-aminopropyltriethoxysilane with a sol-gel process of tetraethyl orthosilicate into a single process. This showed significant improvement in the adsorption capacity of anionic dyes. The product (Fe3O4@SiO2-NH2) was characterized with scanning electron microscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray spectrometry, zeta potential and vibrating sample magnetometry. The adsorption performance of Fe3O4@SiO2-NH2 was then tested by removing acid orange 10 (AO10) and reactive black 5 (RB5) from the aqueous solutions under various experimental conditions including initial solution pH, initial dye concentrations, reaction time and temperature. The results indicated that the maximum adsorption capacity of AO10 and RB5 on Fe3O4@SiO2-NH2 was 621.9 and 919.1 mg g−1 at pH 2, respectively. The sorption isotherms fit the Langmuir model nicely. Similarly, the sorption kinetic data were better fitted into the pseudo-second order kinetic model than the pseudo-first order model. In addition, the thermodynamic data demonstrated that the adsorption process was endothermic, spontaneous and physical. Furthermore, Fe3O4@SiO2-NH2 could be easily separated from aqueous solutions by an external magnetic field, and the preparation was reproducible.

scholarly journals ADSORPTION OF FOOD COLORING ALLURA RED DYE (E129) FROM AQUEOUS SOLUTIONS USING ACTIVATED CARBON

2017 ◽  
Vol 3 (1) ◽  
pp. 10 ◽  
Author(s):  
Saad A Alkahtani ◽  
Samer S Abu-Alrub ◽  
Ashraf M Mahmoud
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Kinetic Models ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Factors Affecting ◽  
Allura Red

<p>The adsorption behavior of Allura red (E129)<strong> </strong>from aqueous solutions onto activated carbon was successfully investigated. All factors affecting the adsorption process were carefully studied and the conditions were optimized. Adsorption of E129 onto activated carbon was found to increase by decreasing the mass of activated carbon, pH and ionic strength of the solution and by increasing temperature. The adsorption capacity of the activated carbon for Allura red was relatively high. Under the optimum conditions, the maximum adsorption capacity for E129 dye was 72.85 mg/g. Three adsorption models; Langmuir, Freundlich and Temkin model were investigated regarding the adsorption of E129. The models’ parameters K<sub>L</sub>, qm, R2, (n) were determined and found to be 0.0222, 72.85 mg/g, 0.9057-0.9984, and 0.992, respectively. Also, pseudo first and second-order kinetic models were tested to determine the best-fit model to the adsorption of E129 dye onto activated carbon. The results showed that the adsorption of E129 onto activated carbon obeyed both the Freundlich isotherm and pseudo second-order kinetic models. Moreover, thermodynamic studies indicated that the adsorption of E129 dye onto the activated carbon was spontaneous. </p>

scholarly journals Enhanced Phosphate Removal from Water by Honeycomb-Like Microporous Lanthanum-Chitosan Magnetic Spheres

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1659 ◽  
Author(s):  
Rong Cheng ◽  
Liang-Jie Shen ◽  
Ying-Ying Zhang ◽  
Dan-Yang Dai ◽  
Xiang Zheng ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Active Sites ◽  
Lanthanum Oxide ◽  
Ph Value ◽  
Phosphate Removal ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Magnetic Spheres ◽  
Hierarchical Porous

The removal of phosphate in water is crucial and effective for control of eutrophication, and adsorption is one of the most effective treatment processes. In this study, microporous lanthanum-chitosan magnetic spheres were successfully synthetized and used for the removal of phosphate in water. The characterization results show that the dispersion of lanthanum oxide is improved because of the porous properties of the magnetic spheres. Moreover, the contact area and active sites between lanthanum oxide and phosphate were increased due to the presence of many honeycomb channels inside the magnetic spheres. In addition, the maximum adsorption capacity of the Langmuir model was 27.78 mg P·g−1; and the adsorption kinetics were in good agreement with the pseudo-second-order kinetic equation and intra-particle diffusion model. From the results of thermodynamic analysis, the phosphate adsorption process of lanthanum-chitosan magnetic spheres was spontaneous and exothermic in nature. In conditional tests, the optimal ratio of lanthanum/chitosan was 1.0 mmol/g. The adsorption capacity of as-prepared materials increased with the augmentation of the dosage of the adsorbent and the decline of pH value. The co-existing anions, Cl− and NO3− had little effect on adsorption capacity to phosphate, while CO32− exhibited an obviously negative influence on the adsorption capacity of this adsorbent. In general, owing to their unique hierarchical porous structures, high-adsorption capacity and low cost, lanthanum-chitosan magnetic spheres are potentially applicable in eutrophic water treatment.

scholarly journals Adsorption of lead (II) ions onto diatomite from aqueous solution: Mechanism, isotherm and kinetic studies

2015 ◽  
Vol 18 (1) ◽  
pp. 1-10 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Low Cost ◽  
Kinetic Studies ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Freundlich Model ◽  
Ph Range ◽  
Solution Mechanism ◽  
Order Kinetic Equation

<div> <p>This study presents an evaluation of diatomite as a low cost adsorbent for Pb (II) removal from aqueous solutions under various conditions. The results demonstrate that adsorption of Pb (II) is strongly dependent on the pH of the solution. The effect of pH on adsorption of Pb (II) on diatomite was studied by varying pH from 2 to 12 at 20 <sup>o</sup>C. In the pH range of 2.0-4.0, the percentage of Pb (II) adsorbed increases slightly as the pH increases. At pH&gt;4, the percentage of Pb (II) adsorbed decreases with increasing pH because hydrolysis and precipitation begin to play an important role in the sorption of Pb (II). At pH 4, the maximum adsorption capacity of diatomite was found to be 26 mg/g. The adsorption isotherms of Pb (II) on diatomite can be described well by the Freundlich model. The regression equation coefficients were calculated and the data fitted to a second-order kinetic equation for removal of Pb (II) ions. The high adsorption capacity of diatomite makes it a suitable low-cost material for the removal of Pb (II) from aqueous solutions.</p> </div> <p>&nbsp;</p>

scholarly journals Parametric Statistical Significance of Iron (II) Ions Adsorption by Coconut Shell in Aqueous Solutions

2019 ◽  
Vol 11 (1) ◽  
pp. 17-25
Author(s):  
Babatope Abimbola Olufemi ◽  
Anne Nlerum
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Contact Time ◽  
Statistical Significance ◽  
Freundlich Isotherm ◽  
Coconut Shell ◽  
Isotherm Model ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Sorption Data

The parametric statistical adsorption of chemically unmodified coconut shell powder (CSP) to adsorb iron (II) ions from aqueous solutions was examined in this work. It was observed that the adsorption capacity increased with increasing adsorbent dose, reducing adsorbate dose, increasing contact time, decreasing temperature and reducing particle size. As observed about one gram of the adsorbent was sufficient enough to remove 98 % iron (II) ions. A total contact time of about 40 minutes was sufficient for almost complete adsorption of the ions, while a pH of about 6.0 exhibited the maximum adsorption capacity. The sorption data were fitted into Langmuir, Freundlich, Temkin and the Dubinin-Radushkevich isotherms, fitted most with the Freundlich Isotherm model. The energy values obtained from the Temkin and Dubinin-Radushkevich isotherm model indicated high chemisorption phenomenon with the adsorbents. Investigation of some kinetic models confirmed that the adsorption of iron (II) ions using CSP was a pseudo-second order kinetic process, which further corroborates that chemisorption dominates the adsorption. Fourier Transform Analysis (FTIR) further established and justified the outcome of the study. The adsorption was parametrically justified statistically with Analysis of Variance (ANOVA) and Bonferroni-Holm Posthoc significance test. Conclusively, coconut shell proved strongly to be an effective and suitable adsorbent for removing iron (II) ions from aqueous solutions.

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