scholarly journals Amino-Thiol Bifunctional Polysilsesquioxane/Carbon Nanotubes Magnetic Composites as Adsorbents for Hg(II) Removal

2021 ◽  
Vol 2 ◽  
Author(s):  
Ting Xu ◽  
Rongjun Qu ◽  
Ying Zhang ◽  
Changmei Sun ◽  
Ying Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Sol Gel ◽  
Adsorption Properties ◽  
Langmuir Model ◽  
Order Model ◽  
Magnetic Composites ◽  
Adsorption Capacities ◽  
Amino Thiol ◽  
Pseudo Second Order ◽  
Optimal Ph

Amino-thiol bifunctional polysilsesquioxane/carbon nanotubes (PSQ/CNTs) magnetic composites were prepared by sol-gel method with two types of functional siloxanes coating on carboxyl CNTs simultaneously. The composites were served as efficient adsorbents for removing Hg(II) in aqueous solution and the adsorption properties were investigated systematically. The optimal pH of bifunctional composites for Hg(II) removal is at pH 4.5. The thermodynamic fitting curves are more consistent with the Langmuir model and the adsorption capacities of the bifunctional composites for Hg(II) varied from 1.63 to 1.94 mmol g−1 at 25°C according to the Langmuir model. The kinetics curves are more fitted to the pseudo-second-order model and the composites could selectively adsorb Hg(II) in a series of binary metal ions solution. The elution regeneration tests showed that the adsorption rate could still reach 78% after repeat cycle three times. It is expected that the bifunctional PSQ/CNTs magnetic composites can be potentially applied to remove low concentration Hg(II) from waste water.

The removal of Cu(II) and Pb(II) ions from aqueous solutions by temperature-sensitive hydrogels based on N-isopropylacrylamide and itaconic acid

2021 ◽  
pp. 1-19
Author(s):  
Bengi Özkahraman ◽  
Eren Yıldırım ◽  
Serkan Emik ◽  
Işıl Acar
Keyword(s):  
Aqueous Solutions ◽  
Adsorption Kinetics ◽  
Itaconic Acid ◽  
Competitive Adsorption ◽  
Adsorption Properties ◽  
Temperature Sensitive ◽  
Order Model ◽  
Ion Removal ◽  
Adsorption Capacities ◽  
Pseudo Second Order

This study deals with the potential use of poly(N-isopropylacrylamide-co-itaconic acid) temperature-sensitive hydrogels as an adsorbent for the removal of Cu(II) and Pb(II) ions from aqueous solutions. For this aim, the adsorption properties of hydrogels were examined by adsorption capacities, adsorption isotherm, and adsorption kinetics experiments. To describe the adsorption characteristics of hydrogels, the obtained experimental data were evaluated by Langmuir, Freundlich, Redlich-Peterson, and Dubinin-Radushkevich isotherm models. Adsorption kinetics experiments were carried out not only in single systems but also in binary systems where both ions were at equal initial concentrations for competitive adsorption studies. To predict the behaviors of the competitive and non-competitive adsorption process of ions onto hydrogels, the experimental adsorption data were analyzed by the pseudo-first-order model and the pseudo-second-order model. According to non-competitive ion removal findings, the adsorption capacities followed order Cu(II) >  Pb(II) for all hydrogels, and the pseudo-second-order kinetic model explained the adsorption properties of the hydrogels. Competitive ion removal studies showed that all hydrogels were selective to Cu(II) ion. Furthermore, in the case of comparative investigations both of competitive Cu(II) and competitive Pb(II) removal by hydrogels, the metal ion removal capacity of N10 hydrogel was found as a bit higher than that of N7.5 and N5 in 48 h. That is, as the acidic group content increased in the hydrogel network, the adsorption capacity values also increased. In addition, the reusability of temperature-sensitive hydrogels seems possible without regeneration or after regenerating with acid, in case the temperature is increased above the LCST. Furthermore, even if it cannot be reused, these hydrogels that retain metal ions reach very small volumes by shrinking when the LSCT is exceeded, and thus they can be eliminated more easily than other conventional gels due to their small size. As a result, this temperature-sensitive hydrogel may propose as an alternative environmentally friendly adsorbent candidate for can be used for water purification and wastewater treatment.

Removal of Pb (II) by CS2 Modified Kenaf Powder

2014 ◽  
Vol 970 ◽  
pp. 7-11 ◽  
Author(s):  
Siti Raihan Zakaria ◽  
Megat Ahmad Kamal Megat Hanafiah ◽  
Siti Norhafiza Mohd Khazaai ◽  
Zurhana Mat Hussin ◽  
Wan Khaima Azira Wan Mat Khalir ◽  
...  
Keyword(s):  
Industrial Applications ◽  
Langmuir Model ◽  
Hibiscus Cannabinus ◽  
Order Model ◽  
Freundlich Model ◽  
Isotherm Study ◽  
Adsorption Capacities ◽  
Good Potential ◽  
Pseudo Second Order ◽  
Adsorbent Characterization

Kenaf (Hibiscus cannabinus) is a hardy crop that has wide industrial applications such as insulator, paper, carpet padding, bedding and a good adsorbent for oil. This study investigated the ability of carbon disulfide (CS2) modified kenaf (CMK) to remove toxic Pb (II) from waste water. Adsorbent characterization was carried out by Field Emission Scanning Electron Microscope and Energy Dispersive X-ray Spectroscope (FESEM-EDX) analysis. The adsorption kinetic data was well described by pseudo-second-order model and the adsorption isotherm study indicated that Langmuir model fitted well with the experimental data than the Freundlich model. Based on the Langmuir model, the maximum adsorption capacities of Pb (II) (qmax) was 63.3 mg g-1 .This study suggested that CMK has a good potential to be used as an adsorbent material for Pb (II) removal from aqueous solutions.

Fluoride removal using a MgFe hydrotalcite and a MgFe oxide

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3239-3246
Author(s):  
Jessica G López-Castillo ◽  
Guadalupe Macedo-Miranda ◽  
Sonia Martínez-Gallegos ◽  
Eduardo Ordoñez- Regíl ◽  
Sonia Álvarez-García ◽  
...  
Keyword(s):  
Langmuir Model ◽  
Crystalline Form ◽  
Fluoride Removal ◽  
Order Model ◽  
Adsorption Study ◽  
Bet Method ◽  
Pseudo Second Order ◽  
Iron Based ◽  
Crystalline Forms ◽  
Optimal Ph

AbstractThe present study investigates the adsorption of fluorides (F) by a hydrotalcite MgFe (HT MgFe) and an iron-based metal oxide (MgFe oxide). Both materials were synthesized by the coprecipitation method and were calcined at the same temperature HT MgFe, HTC MgFe, oxide MgFe and oxide MgFeC. Both solids were characterized by the XRD technique. Materials showed typical crystalline forms; in the case of HT MgFe, an octahedral crystalline form and for the oxide MgFe cubic crystalline form, the analysis of the BET method classifies the materials as mesoporous. In the adsorption study, it was determined that the optimal pH for adsorption is 7. Regarding the adsorption kinetics, the HTC MgFe and oxide MgFeC samples were adjusted to the pseudo-second order model, which describes the process as chemiadsorption; meanwhile, for the samples, isotherms were adjusted to the Langmuir model, which describes the material as homogeneous with a strong interaction between the sorbate and the sorbent.

scholarly journals Removal of lead(II) ions by an adsorption process with the use of an advanced SiO2/lignin biosorbent

2017 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Łukasz Klapiszewski ◽  
Przemysław Bartczak ◽  
Tomasz Szatkowski ◽  
Teofil Jesionowski
Keyword(s):  
Experimental Data ◽  
Contact Time ◽  
Adsorption Process ◽  
Langmuir Model ◽  
Order Model ◽  
Multifunctional Material ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Maximal Sorption Capacity ◽  
Optimal Ph

Abstract We demonstrate here that lignin can be successfully combined with silica to create a multifunctional material with considerable sorption capabilities. Experiments were carried out in which a silica/lignin hybrid was used for the removal of lead(II) ions from water solutions. Adsorption kinetics were also determined and preliminary regeneration tests were performed. The effectiveness of the adsorption process depends on the following parameters: contact time of adsorbent and adsorbate (equilibrium times: 5 min for concentration 25 mg/L, 10 min for 50 and 75 mg/L, 60 min for 100 mg/L), pH (optimal pH = 5) and adsorbent mass. The kinetics of the adsorption of lead(II) ions on the SiO2/lignin biosorbent are best described by a pseudo-second-order model. Adsorption isotherms of lead(II) ions were also determined. The experimental data were found to be in agreement with the Langmuir model, and the maximal sorption capacity of the adsorbent with respect to lead(II) was 89.02 mg/g.

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.

Synthesis, Characterization and Adsorption Studies of a Graphene Oxide/Polyacrylic Acid Nanocomposite Hydrogel

2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim
Keyword(s):  
Industrial Effluents ◽  
Langmuir Model ◽  
Isotherm Models ◽  
Nanocomposite Hydrogel ◽  
Adsorption System ◽  
Order Model ◽  
Solution Ph ◽  
Freundlich Model ◽  
Dye Sorption ◽  
Pseudo Second Order

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.

scholarly journals Potential of granulated modified nanozeolites Y for MTBE removal from aqueous solutions: Kinetic and isotherm studies

2012 ◽  
Vol 14 (2) ◽  
pp. 1-8 ◽  
Author(s):  
S. Ghadiri ◽  
R. Nabizadeh ◽  
A. Mahvi ◽  
S. Nasseri ◽  
A. Mesdaghinia ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Methyl Tert Butyl Ether ◽  
Bet Surface Area ◽  
Promising Technique ◽  
Order Model ◽  
Butyl Ether ◽  
Sorption Data ◽  
Adsorption Capacities ◽  
Effective Performance ◽  
Pseudo Second Order

Potential of granulated modified nanozeolites Y for MTBE removal from aqueous solutions: Kinetic and isotherm studies Adsorption of methyl tert-butyl ether (MTBE) from aqueous solutions by granulated modified nanozeolites Y was investigated. Nanozeolite Y powders were converted into granulated zeolites and subsequently modified with two cationic surfactants (20 mmol/dm3), to be used as adsorbent. Granulated nanozeolites were characterized by BET surface area analysis, elemental analysis and X-ray diffractometer. -Hexade-cyltrimethylammonium (HDTMA-Cl) modified granulated zeolite had more effective performance than N-cetylpyridinium bromide (CPB) modified granulated zeolite. The most conventional adsorption isotherms and kinetic models were applied to describe MTBE adsorption and reaction dynamic, respectively. The equilibrium sorption data fitted the Langmuir 2 isotherm model and the kinetic study was followed the pseudo-second-order model. The maximum adsorption capacities for HDTMA-Cl modified zeolite and CPB modified granulated zeolite were 333.33 and 142.8 mg/g, respectively as calculated by the Langmuir model. This study demonstrated that the removal of mtbe by granulated modified nanozeolites Y is a promising technique.

Highly effective removal of Cu(II) in aqueous solution by using mesoporous TiO2

2019 ◽  
Vol 80 (5) ◽  
pp. 884-891
Author(s):  
Daying Chen ◽  
Nasi Tu ◽  
Changkun Si ◽  
Meilin Yin ◽  
Xiaohui Wang
Keyword(s):  
Aqueous Solution ◽  
Low Cost ◽  
Sol Gel ◽  
Mesoporous Tio2 ◽  
Adsorption Efficiency ◽  
Batch Experiments ◽  
Order Model ◽  
Effective Removal ◽  
Pseudo Second Order ◽  
Gel Processing

Abstract Mesoporous TiO2 has been prepared by a brief and simple sol–gel processing and applied for the removal of Cu(II) from aqueous solution. The adsorption behavior of mesoporous TiO2 for Cu(II) was investigated using batch experiments. Results showed that the pseudo-second-order model and Langmuir isotherm were more accurate to describe the kinetics process and adsorption isotherm. Mesoporous TiO2 adsorbent displayed excellent Cu(II) adsorption efficiency (195.52mg g−1). The thermodynamic parameters showed that the adsorption was spontaneous and endothermic. It was also found that mesoporous TiO2 could be used at least seven times without obvious loss of its original adsorption efficiency. Therefore, the obtained mesoporous TiO2 could be employed as an effective and low-cost adsorbent for removal of Cu(II) from contaminated effluents.

Adsorption of Heavy Metal Ions by Chelate-Fiber Prepared by Chemical Surface Modification

2011 ◽  
Vol 308-310 ◽  
pp. 178-181
Author(s):  
Xin Liang Liu ◽  
Li Jun Wang ◽  
Yong Li Chen ◽  
Nan Chen ◽  
Shuang Fei Wang
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Optimal Process ◽  
Order Model ◽  
Chemical Surface ◽  
Adsorption Capacities ◽  
Chemical Surface Modification ◽  
Pseudo Second Order ◽  
Mechanism Of Sorption

The bagasse fibers were activated by alkalize and etherified. 1,2-ethanediamine and carbon disulfide were used to modify the etherify fiber to get the chelate-fiber contained sulfur and nitrogen. The FTIR was used to characterize the xanthated aminating-fiber (XAF). The mechanism of sorption properties for heavy metal ions were studied. As the results shown, the optimal process to prepare the XAF was that the reaction time, concentration of NaOH and dosage of CS2 was 60min, 12% and 2mL, respectively. The chelate-fiber containing sulfur and nitrogen possessed high adsorption capacities for Cu(II) and the mechanism of sorption fitted the pseudo-second-order model well.

Adsorption Properties of Pr3+ and Nd3+ Using Silica Grafted with Larch Tannin

2012 ◽  
Vol 550-553 ◽  
pp. 1561-1565 ◽  
Author(s):  
Tian Tian Xu ◽  
Chu Rui Huang ◽  
Yuan Yuan Luo ◽  
Qiang Du ◽  
Shi Lin Zhao
Keyword(s):  
Adsorption Capacity ◽  
Ph Value ◽  
Adsorption Properties ◽  
Equilibrium Adsorption ◽  
Dynamics Model ◽  
Adsorption Capacities ◽  
Optimum Ph ◽  
Pseudo Second Order ◽  
Equilibrium Adsorption Capacity ◽  
Order Rate Equation

The new adsorption material was prepared by grafting the larch tannin onto aminated silica beads with the glutaraldehyde as the cross-linking agent. The adsorption properties of Pr3+and Nd3+on the new adsorbent material in aqueous solution were investigated. The results showed that the equilibrium adsorption capacities of this adsorbent to Pr3+, Nd3+were 402.12mg/g, 305.43mg/g at 303K when the initial concentrations of each ions were 442.7mg/L, 432.6mg/L, respectively and the pH value was 5.5; the maximum adsorption quantities of each ions were 576.34mg/g, 497.02mg/g at 303K when the initial concentrations of each ions were 704.5mg/L, 721.0mg/L, respectively and the pH value was 5.5. The effect of pH value was significant to the equilibrium adsorption capacity, the optimum pH values of this material to Pr3+and Nd3+were both 5.5; while the effect of the temperature was not obvious to the equilibrium adsorption capacity. The adsorption thermodynamics meet Freundlich equation, and the adsorption kinetics data of this adsorbent to Pr3+, Nd3+fitted with the pseudo-second-order rate equation dynamics model.

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