Novel Amphoteric Cryogels for Cd2+ Ions Removal from Aqueous Solutions

2018 ◽  
Vol 775 ◽  
pp. 376-382 ◽  
Author(s):  
Alzhan Baimenov ◽  
Dmitriy Berillo ◽  
Leila Abylgazina ◽  
Stavros G. Poulopoulos ◽  
Vassilis J. Inglezakis
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Chemical Structure ◽  
Nitrogen Adsorption ◽  
Maximum Adsorption Capacity ◽  
Cadmium Ions ◽  
Texture Analyzer ◽  
Ph Values ◽  
Amphoteric Properties ◽  
Scanning Electron

In this work, amphoteric cryogels based on N,N-dimethyl acrylamide, methacrylic acid and allylamine, crosslinked by N,N-methylenebisacrylamide were synthesized by free-radical polymerization in cryo-conditions. The synthesized cryogels were used for the removal of cadmium ions from aqueous solutions under different pH values. The chemical structure was studied by FTIR, porosity by nitrogen adsorption and morphology by scanning electron microscopy and texture analyzer. The amphoteric properties of cryogels were studied by zeta potential measurements. Adsorption tests revealed that cryogels exhibit 3 times higher adsorption capacity at pH 6.0 than at pH 4.0. The maximum adsorption capacity of the amphoteric cryogels for Cd2+ was 113 mg/g, at pH 6.0 and initial Cd2+ concentration 100 ppm. The results suggest that the predominant removal mechanism is ion exchange between sodium, which initially presents in the structure of the cryogel, and cadmium from the aqueous phase. Recovery studies suggested that the cryogels used can be regenerated and efficiently reused.

scholarly journals Enhanced Adsorption of Bisphenol A from Aqueous Solution with 2-Vinylpyridine Functionalized Magnetic Nanoparticles

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1136 ◽  
Author(s):  
Qiang Li ◽  
Fei Pan ◽  
Wentao Li ◽  
Dongya Li ◽  
Haiming Xu ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Magnetic Nanoparticle ◽  
Maximum Adsorption Capacity ◽  
Salting Out ◽  
Functionalized Magnetic Nanoparticles ◽  
Ft Ir ◽  
Fe3o4 Nanospheres ◽  
Enhanced Adsorption

In this study, a novel 2-vinylpyridine functionalized magnetic nanoparticle (Mag-PVP) was successfully prepared. The prepared Mag-PVP was characterized by transmission electronic microscopy (TEM), Fourier transform infrared spectrophotometry (FT-IR), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA), and was used for the adsorption of bisphenol A (BPA) from aqueous solutions. Mag-PVP, which is composed of Fe3O4 nanoparticles and poly divinylbenzene-2-vinylpyridine (with a thickness of 10 nm), exhibited magnetic properties (Ms = 44.6 emu/g) and thermal stability. The maximum adsorption capacity (Qm) of Mag-PVP for BPA obtained from the Langmuir isotherm was 115.87 mg/g at 20 °C, which was more than that of Fe3O4 nanospheres. In the presence of NaCl, the improved adsorption capacity of Mag-PVP was probably attributed to the screening effect of Mag-PVP surface charge and salting-out effect. In the presence of CaCl2 and humic acid (HA), the adsorption capacity of BPA decreased due to competitive adsorption. The adsorption of BPA by Mag-PVP increased slightly with the increase in pH from 3.0 to 5.0 and obtained the largest adsorption amount at pH 5.0, which was probably attributed to hydrogen bonding interactions. Moreover, in actual water, Mag-PVP still showed excellent adsorption performance in removing BPA. The high adsorption capacity and excellent reusability performance in this work indicated that Mag-PVP was an effective adsorbent for removing BPA from aqueous solutions.

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.

Ouricuri (Syagrus coronata) fiber: a novel biosorbent to remove methylene blue from aqueous solutions

2016 ◽  
Vol 75 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Lucas Meili ◽  
Társila Santos da Silva ◽  
Daniely Carlos Henrique ◽  
João Inácio Soletti ◽  
Sandra Helena Vieira de Carvalho ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Experimental Design ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Fiber Diameter ◽  
Aqueous Media ◽  
Process Efficiency ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Studies

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L−1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g−1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.

scholarly journals Adsorption Study of Cu2+ Ions from Aqueous Solutions by Bael Flowers (Aegle marmelos)

2020 ◽  
Vol 11 (4) ◽  
pp. 11891-11904
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Metal Ion ◽  
Low Cost ◽  
Sem Analysis ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Aegle Marmelos ◽  
Batch Mode ◽  
Initial Ph

In the present study, batch mode adsorption was carried out to investigate the adsorption capacity of dried bael flowers (Aegle marmelos) for the adsorptive removal of Cu(II) ions from aqueous solutions by varying agitation time, initial metal concentration, the dose of adsorbent, temperature, and initial pH of the Cu(II) ion solution. The percentage removal of 98.7% was observed at 50 ppm initial metal ion concentration, 0.5 g/100.00 cm3 adsorbent dosage, within the contact time of 120 minutes at 30 ºC in the pH range of 4 – 7. The sorption processes of Cu(II) ions was best described by pseudo-second-order kinetics. Langmuir isotherm had a good fit with the experimental data with 0.97 of correlation coefficient (R2), and the maximum adsorption capacity obtained was 23.14 mg g-1 at 30 ºC. The results obtained from sorption thermodynamic studies suggested that the adsorption process is exothermic and spontaneous. SEM analysis showed tubular voids on the adsorbent. FTIR studies indicated the presence of functional groups like hydroxyl, –C-O, –C=O, and amide groups in the adsorbent, which can probably involve in metal ion adsorption. Therefore, dried bael flowers can be considered an effective low-cost adsorbent for treating Cu(II) ions.

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 Modified Chitosan for Silver Recovery—Kinetics, Thermodynamic, and Equilibrium Studies

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 657 ◽  
Author(s):  
Bogdan Pascu ◽  
Cristina Ardean ◽  
Corneliu Mircea Davidescu ◽  
Adina Negrea ◽  
Mihaela Ciopec ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Maximum Efficiency ◽  
Metallic Silver ◽  
Maximum Adsorption Capacity ◽  
Silver Recovery ◽  
Equilibrium Studies ◽  
Environment Friendly ◽  
Modified Chitosan ◽  
Materials Used

The aim of this study is to investigate the silver recovery from aqueous solutions. There are a variety of recovery methods, such as hydrometallurgical, bio-metallurgical, cementation, reduction, electrocoagulation, electrodialysis, ion exchange, etc. Adsorption represents a convenient, environment friendly procedure, that can be used to recover silver from aqueous solutions. In this paper we highlight the silver adsorption mechanism on chitosan chemically modified with active groups, through kinetic, thermodynamic, and equilibrium studies. A maximum adsorption capacity of 103.6 mg Ag(I)/g of adsorbent for an initial concentration of 700 mg/L was noticed by using modified chitosan. Lower adsorption capacity has been noticed in unmodified chitosan—a maximum of 75.43 mg Ag(I)/g. Optimum contact time was 120 min and the process had a maximum efficiency when conducted at pH higher than 6. At the same time, a way is presented to obtain metallic silver from the adsorbent materials used for the recovery of the silver from aqueous solutions.

Adsorption of chromium (VI) from aqueous solutions on activated carbon

1994 ◽  
Vol 30 (9) ◽  
pp. 191-197 ◽  
Author(s):  
R. Leyva Ramos ◽  
A. Juarez Martinez ◽  
R. M. Guerrero Coronado
Keyword(s):  
Activated Carbon ◽  
Adsorption Isotherm ◽  
Adsorption Capacity ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Experimental Adsorption ◽  
Ph Values ◽  
Chromium Vi ◽  
Adsorption Data

The adsorption isotherm of chromium (VI) on activated carbon was obtained in a batch adsorber. The experimental adsorption data were fitted reasonably well to the Freundlich isotherm. The effect of pH on the adsorption isotherm was investigated at pH values of 4, 6, 7, 8, 10 and 12. It was found that at pH < 6, Cr(VI) was adsorbed and reduced to Cr(III) by the catalytic action of the carbon and that at pH ≥ 12, Cr(VI) was not adsorbed on activated carbon. Maximum adsorption capacity was observed at pH 6 and the adsorption capacity was diminished about 17 times by increasing the pH from 6 to 10. The pH effect was attributed to the different complexes that Cr(VI) can form in aqueous solution. The adsorption isotherm was also affected by the temperature since the adsorption capacity was increased by raising the temperature from 25 to 40°C. It was concluded that Cr(VI) was adsorbed significantly on activated carbon at pH 6 and that the adsorption capacity was greatly dependent upon pH.

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 Effects of Cu(II) on the Adsorption Behaviors of Cr(III) and Cr(VI) onto Kaolin

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Juanjuan Liu ◽  
Xiaolong Wu ◽  
Yandi Hu ◽  
Chong Dai ◽  
Qin Peng ◽  
...  
Keyword(s):  
Distribution Coefficient ◽  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Saturation Index ◽  
Surface Complexation ◽  
Maximum Adsorption Capacity ◽  
Positive Correlation ◽  
Adsorption Sites ◽  
Ph Values ◽  
Adsorption Behaviors

The adsorption of Cr(III) or Cr(VI) in the absence and presence of Cu(II) onto kaolin was investigated under pH 2.0–7.0. Results indicated that the adsorption rate was not necessarily proportional to the adsorption capacity. The solutions’ pH values played a key role in kaolin zeta potential(ζ), especially the hydrolysis behavior and saturation index of heavy metal ions. In the presence of Cu(II),qmixCr(III)reached the maximum adsorption capacity of 0.73 mg·g−1at pH 6.0, while the maximum adsorption capacity for the mixed Cr(VI) and Cu(II) system (qmixCr(VI)) was observed at pH 2.0 (0.38 mg·g−1). Comparing the adsorption behaviors and mechanisms, we found that kaolin prefers to adsorb hydrolyzed products of Cr(III) instead of Cr3+ion, while adsorption sites of kaolin surface were occupied primarily by Cu(II) through surface complexation, leading to Cu(II) inhibited Cr(VI) adsorption. Moreover, Cr(III) and Cr(VI) removal efficiency had a positive correlation with distribution coefficientKd. Cr(III) and Cr(VI) removal efficiency had a positive correlation with distribution coefficientKdand that of adsorption affinities of Cr(III) or Cr(VI) on kaolin was found to beKdCr(III) <KdCr(III)-Cu(II) andKdCr(VI) >KdCr(VI)-Cu(II).

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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