Selective Removal of Hg2+ Ions from Water Using New Functionalized Silica Resin: Equilibrium, Thermodynamics and Kinetic Modeling Studies

2021 ◽  
Vol 43 (4) ◽  
pp. 436-436
Author(s):  
Nida Shams Jalbani Nida Shams Jalbani ◽  
Amber R Solangi Amber R Solangi ◽  
Shahabuddin Memon Shahabuddin Memon ◽  
Ranjhan Junejo Ranjhan Junejo ◽  
Asif Ali Bhatti Asif Ali Bhatti
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Solid Phase ◽  
Maximum Adsorption Capacity ◽  
Adsorption Phenomenon ◽  
Column Adsorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Wastewater Samples ◽  
Ft Ir Spectroscopy

In current study, the diphenylaminomethylcalix[4]arene (3) was synthesized and immobilized onto silica surface to prepare a selective, regenerable and stable resin-4. The synthesized resin-4 has been characterized by FT-IR spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and Brunauer-Emmett-Teller (BET) techniques. To check the adsorption capacity of resin-4, the batch and column adsorption methodology were applied and it has observed that the resin-4 was selectively removed Hg2+ ions under the optimized parameters. The maximum adsorption capacity was obtained at pH 9 using 25 mg/L of resin-4. Under the optimal conditions, different equilibrium, kinetic and thermodynamic models were applied to experimental data. The results show that adsorption mechanism is chemical in nature following Langmuir model with good correlation coefficient (R2=0.999) and having 712.098 (mmol/g) adsorption capacity. The energy of calculated from D-R model suggests the ion exchange nature of the adsorption phenomenon. Dynamic adsorption experiments were conducted using Thomas model. The maximum solid phase concentration (qo) was 7.5 and rate constant was found to be 0.176 with (R2=0.938) for Hg2+ ions. The kinetic study describes that the adsorption mechanism follows pseudo second order (R2=0.999). The thermodynamic parameters such as ∆H (0.032 KJ/mol) and ∆S (0.127 KJ/mol /K) and ∆G (-5.747,-6.306, -7.027 KJ/mol) shows that the adsorption of Hg2+ ion is endothermic and spontaneous. The reusability of resin-4 was also checked and it has observed that the after 15 cycle only 1.2 % adsorption reduces. Moreover, the resin-4 was applied on real wastewater samples obtained from local industrial zone of Karachi, Sindh-Pakistan.

scholarly journals Silica-Coated Magnetic Nanocomposites for Pb2+ Removal from Aqueous Solution

2020 ◽  
Vol 10 (8) ◽  
pp. 2726 ◽  
Author(s):  
Roxana Nicola ◽  
Otilia Costişor ◽  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Radu Lazău ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Adsorption Capacity ◽  
Aqueous Media ◽  
Physical Stability ◽  
Absorption Capacity ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Similar Materials ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Magnetic iron oxide-silica shell nanocomposites with different iron oxide/silica ratio were synthesized and structurally characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), small-angle neutron scattering, magnetic and N2-sorption studies. The composite that resulted with the best properties in terms of contact surface area and saturation of magnetization was selected for Pb2+ adsorption studies from aqueous media. The material presented good absorption capacity (maximum adsorption capacity 14.9 mg·g−1) comparable with similar materials presented in literature. Its chemico-physical stability and adsorption capacity recommend the nanocomposite as a cheap adsorbent material for lead.

scholarly journals Adsorption of Copper(II) and Mercury(II) Ions onto Chemically-Modified Chitosan Membranes: Equilibrium and Kinetic Properties

2012 ◽  
Vol 30 (1) ◽  
pp. 1-21 ◽  
Author(s):  
R.B. Rabelo ◽  
R.S. Vieira ◽  
F.M.T. Luna ◽  
E. Guibal ◽  
M.M. Beppu
Keyword(s):  
Adsorption Capacity ◽  
Metal Ion ◽  
Batch Process ◽  
Second Order ◽  
Infrared Spectrometry ◽  
Maximum Adsorption Capacity ◽  
Kinetic Properties ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Chitosan Membranes

Cross-linked chitosan was synthesized with glutaraldehyde (chitosan–GLA) and epichlorohydrin (chitosan–ECH). The structures of these matrices were characterized by elemental analysis, Fourier-transform infrared spectrometry (FT-IR), the degree of de-acetylation and the surface topography as determined via scanning electron microscopy (SEM). After promoting interaction with the metal ion, the adsorbent was also studied using FT-IR and energy dispersive X-ray spectroscopy (EDXS). Adsorption studies for Cu(II) and Hg(II) ions were carried out in a batch process. The adsorption kinetics were tested using three models, viz. pseudo-first-order, pseudo-second-order and intra-particle diffusion. The experimental kinetic data were best fitted by the pseudo-second-order model for Cu(II) ions (R2 ≥ 0.98) and for Hg(II) ions (R2 = 0.99). Higher rate constants (k2) were obtained for the adsorption of Cu(II) ions onto chitosan–GLA [1.40 g/(mmol h)] and for Hg(II) ions onto raw chitosan [5.65 g/(mmol h)]. The adsorption rate depended on the concentration of Cu(II) and Hg(II) ions on the adsorbent surface and on the quantity of ions adsorbed at equilibrium. At 293 K, the Langmuir–Freundlich model provided a better fit to the adsorption isotherms on both raw and cross-linked chitosan membranes. The maximum adsorption capacity for Cu(II) ions was obtained with the chitosan–GLA matrix (2.7 mmol/g). A maximum adsorption capacity of 3.1 mmol/g was attained for Hg(II) ions onto the chitosan–ECH matrix.

scholarly journals Removal and Regeneration of Iron (III) from Water Using New Treated Fluorapatite Extracted from Natural Phosphate as Adsorbent

2021 ◽  
Vol 11 (5) ◽  
pp. 13130-13140
Keyword(s):  
Adsorption Capacity ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
Natural Phosphate ◽  
Dissolved Iron ◽  
Naturally Occurring ◽  
Ft Ir ◽  
Adsorption Desorption ◽  
Ft Ir Spectroscopy

Our study aims to evaluate the efficiency of dissolved iron (III) retention in synthetic solutions by adsorption on treated natural phosphate collected in the Khouribga region. This research focused on the valorization of phosphate, a naturally occurring resource that is abundant in Morocco. The resulting products were analyzed by various methods, including FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). In this work, we studied the effect of several parameters such as adsorbent amount, contact time, solution pH, and initial concentration of iron (III) on the adsorption process. The results of the adsorption of iron (III) indicate that the efficiency was achieved after 5 minutes, and the maximum adsorption capacity calculated from the Langmuir model was 26.18 mg g-1. The regeneration and reuse of synthesized adsorbent are effective for five cycles of adsorption-desorption cycles without reducing adsorption capacity.

scholarly journals Adsorptive removal of Ni2+ and Cd2+ from wastewater using a green longan hull adsorbent

2017 ◽  
Vol 36 (1-2) ◽  
pp. 762-773 ◽  
Author(s):  
Xingmei Guo ◽  
Sihan Tang ◽  
Yan Song ◽  
Junmin Nan
Keyword(s):  
Metal Ions ◽  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Maximum Adsorption Capacity ◽  
Adsorptive Removal ◽  
Langmuir Adsorption ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Adsorptive Mechanism ◽  
Optimized Conditions

The adsorptive removal of Ni2+ and Cd2+ at concentrations of approximately 50 mg L−1 in wastewater is investigated using an agricultural adsorbent, longan hull, and the adsorptive mechanism is characterized. The maximum adsorption capacity of approximately 4.19 mg g−1 Cd2+ was obtained under the optimized conditions of room temperature, pH 5.0, and a solid-to-liquid ratio of 1:30 in approximately 15 min. For Ni2+, the maximum adsorption capacity of approximately 3.96 mg g−1 was obtained at pH 4.7 in approximately 20 min. The adsorption kinetics for both metal ions on the longan hull can be described by a pseudo second-order rate model and are well fitted to the Langmuir adsorption isotherm. The adsorption mechanism of the longan hull to Ni2+ and Cd2+ ions is shown to be a monolayer adsorption of metal ions onto the absorbent surface. Thereinto, the longan hull adsorbent contains N–H, C–H, C=O, and C=C functional groups that can form ligands when loaded with Ni2+ and Cd2+, which reduces the fluorescence of the dried longan hull material.

scholarly journals Bagasse Cellulose Grafted with an Amino-Terminated Hyperbranched Polymer for the Removal of Cr(VI) from Aqueous Solution

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 931 ◽  
Author(s):  
Lu Xia ◽  
Zhonghang Huang ◽  
Lei Zhong ◽  
Fengwei Xie ◽  
Chak Tang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Hyperbranched Polymer ◽  
Metal Removal ◽  
Ph Value ◽  
Removal Rate ◽  
Heavy Metal Removal ◽  
Grafting Reaction ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A novel bio-adsorbent was fabricated via grafting an amino-terminated hyperbranched polymer (HBP-NH2) onto bagasse cellulose. The morphology and microstructure of the HBP-NH2-grafted bagasse cellulose (HBP-g-BC) were characterized and its adsorption capacity for Cr(VI) ions in aqueous solutions was investigated. The rough surface structure of HBP-g-BC that is beneficial for improving the adsorption capacity was observed by scanning electron microscopy (SEM). The grafting reaction was confirmed by Fourier-transform infrared (FT-IR) spectroscopy. The adsorbent performance was shown to be better with a lower pH value, a higher adsorbent dosage, or a higher initial Cr(VI) concentration. Moreover, the kinetics study revealed that the adsorption behavior followed a pseudo-second-order model. The isotherm results showed that the adsorption data could be well-fitted by the Langmuir, Freundlich, or Temkin models. Moreover, HBP-g-BC could maintain 74.4% of the initial removal rate even after five cycles of regeneration. Thus, the high potential of HBP-g-BC as a bio-adsorbent for heavy metal removal has been demonstrated.

scholarly journals Adsorption Behaviour and Kinetics of Zearalenone on Hydroxyl-Fe-Al-Intercalated Montmorillonite

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shengqiong Fang ◽  
Yueqi Xiao ◽  
Huiqiang Wang
Keyword(s):  
Adsorption Capacity ◽  
Raw Materials ◽  
Interlayer Spacing ◽  
Xrd Analysis ◽  
Maximum Adsorption Capacity ◽  
Dominant Mechanism ◽  
Molar Ratios ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Cationic Exchange

Pristine montmorillonite (Mont) was used as raw materials to prepare hydroxyl-Fe-pillared Mont, hydroxyl-Al-pillared Mont, and hydroxyl-Fe-Al-pillared Mont composites. By varying the OH/Fe and Fe/Al molar ratios during the preparation of the pillared Mont, the adsorption capacity of zearalenone (ZEA) and the kinetics were elucidated. The characterization of X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy reveals the adsorption mechanism of pristine and modified Mont. The results indicated that the ZEA adsorption capacity is Mont (0.05 mg/g) << 1.5OH/Fe-Mont (0.28 mg/g) << OH/Al-Mont (0.51 mg/g) < 0.5Fe/Al-Mont (0.56 mg/g) in the condition of pH = 8 and 37°C, in which both 0.5Fe/Al-Mont and OH/Al-Mont reached maximum adsorption capacity and 1.5OH/Fe-Mont attained 5 times the capacity of Mont. Adsorption isotherm studies revealed that Freundlich adsorption isotherms best represented the experimental data. The kinetic data for ZEA adsorption revealed that the Mont adsorption capacity for ZEA equilibrates in 1 hour and is best described using the pseudo-second-order rate equation. The XRD analysis indicated that the amplification of Fe-dominant pillared Mont interlayer spacing is the main reason for the observed increases in the adsorption capacity of ZEA, while Al-dominant pillared Mont has a relatively stable Keggin structure; therefore, interlayer spacing is not the primary mechanism for changes in the adsorption capacity of both OH/Al-Mont and Al-dominant pillared Mont. An FT-IR analysis demonstrated that cationic exchange was the dominant mechanism that allowed ZEA and hydroxyl-Al ions to enter the Mont interlayers, while this cationic exchange mechanism was not the dominant mechanism used by hydroxyl-Fe entering the Mont layers.

scholarly journals Improvement of Phosphate Adsorption Kinetics onto Ferric Hydroxide by Size Reduction

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1558
Author(s):  
Vicenç Martí ◽  
Irene Jubany ◽  
David Ribas ◽  
José Antonio Benito ◽  
Berta Ferrer
Keyword(s):  
Adsorption Capacity ◽  
Kinetic Constant ◽  
Ferric Hydroxide ◽  
Size Reduction ◽  
Phosphate Adsorption ◽  
Maximum Adsorption Capacity ◽  
Final Size ◽  
Milling Method ◽  
Pseudo Second Order ◽  
Wastewater Samples

Ball milling and ultra-sonication size reduction procedures were applied to granular ferric hydroxide (GFH) to obtain two micro-sized adsorbents. These two adsorbents and GFH were investigated to improve the removal of phosphates from water. The size reduction procedures, using the milling method, allowed a reduction of size from 0.5–2 mm to 0.1–2 µm and total disaggregation of the GFH structure. Using an ultra-sonication method yielded a final size of 1.9–50.3 µm with partial disaggregation. The Langmuir model correlated well with the isotherms obtained in batch equilibrium tests for the three adsorbents. The maximum adsorption capacity (qmax) for the milled adsorbent was lower than GFH, but using ultra-sonication was not different from GFH. The equilibrium adsorption of two wastewater samples with phosphate and other anions onto the GFH corresponded well with the expected removal, showing that potential interferences in the isotherms were not important. Batch kinetics tests indicated that the pseudo second-order model fitted the data. Long-term adsorption capacity in kinetics (qe) showed the same trend described for qmax. The application of milling and ultra-sonication methods showed 3.5- and 5.6-fold increases of the kinetic constant (k2) versus the GFH value, respectively. These results showed that ultra-sonication is a very good procedure to increase the adsorption rate of phosphate, maintaining qe and increasing k2.

A functionalized tannin-chitosan bentonite composite with superior adsorption capacity for Cr(VI)

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Zhongmin Li ◽  
Peng Zou ◽  
Junzhou Yang ◽  
Miaoyang Huang ◽  
Linye Zhang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Raw Materials ◽  
Low Cost ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Initial Ph ◽  
System Part ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Xrd Patterns

AbstractA novel functionalized tannin-chitosan bentonite composite (TCBC) was successfully synthesized. The formation of the composite was confirmed by the X-ray diffraction (XRD) patterns and Fourier transform infrared spectroscopy (FT-IR) analysis. The pHpzc of TCBC was 3.38. The influences such as pH, dosage of TCBC, temperature and initial Cr(VI) concentration on adsorption capacity were investigated. The experimental data indicated that the almost saturated adsorption of the TCBC towards Cr(VI) in 100 min. The maximum adsorption capacity was 262.08 mg/g at 333 K with initial pH = 2.5. The adsorption kinetics of Cr(VI) on TCBC followed the pseudo-second-order kinetics model. The isothermal data were well described by the models of Langmuir, Freundlich and Temkin. The results revealed that the adsorption of Cr(VI) on TCBC existed comprehensive effects and mainly belong to the chemisorption. The TCBC could keep good performances (qe = 192.17 mg/g) in five runs, 1 M NaOH was used as eluent for desorption, which showed a high desorption efficiency. Studies showed TCBC prepared with low cost and green raw materials, and simple green preparation technology had high adsorption capacity, good reusability and acidic tolerance. By exploring the Cr(VI)-Cr(III) hybrid system, part of Cr(VI) was reduced to Cr(III) and adsorbed by TCBC. The optimal adsorption pH of Cr(III) was 5.0.

Hemicellulose-Based Porous Hydrogel for Methylene Blue Adsorption

2012 ◽  
Vol 560-561 ◽  
pp. 482-487 ◽  
Author(s):  
Zhan Xin Jing ◽  
Xiao Feng Sun ◽  
Qing Ye ◽  
Ya Jing Li
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Maximum Adsorption Capacity ◽  
Methylene Blue Adsorption ◽  
Monolayer Adsorption ◽  
Effects Of Ph ◽  
Alkaline Conditions ◽  
Ft Ir ◽  
Porous Hydrogel

Hemicellulose-based porous hydrogel for methylene blue adsorption from aqueous solution was studied. The surface morphology of sample was analyzed by SEM, finding that it had the porous structure. Effects of pH and initial concentration on the adsorption capacity were investigated. Isotherm studies found that the adsorption of metylene blue onto absorbent was a monolayer adsorption, and the maximum adsorption capacity was 444.44 mg/g. The adsorption mechanism was analyzed by FT-IR, and it showed that the produced -COO- groups in alkaline conditions were advantaged for adsorption process, which offers the impetus for combination of adsorbent and methylene blue. Hemicellulose-based porous hydrogel is an inexpensive and biodegradable material, and can be a promising absorbent for cationic removing from wastewater.

scholarly journals Three-dimensional double-network hydrogels of graphene oxide, alginate, and polyacrylonitrile for copper removal from aqueous solution

2019 ◽  
Vol 25 (6) ◽  
pp. 924-929 ◽  
Author(s):  
Jung-Weon Choi ◽  
Hee Jin Kim ◽  
Hayeon Ryu ◽  
Sanghwa Oh ◽  
Sang-June Choi
Keyword(s):  
Graphene Oxide ◽  
Adsorption Capacity ◽  
Adsorption Equilibrium ◽  
Three Dimensional ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Double Network ◽  
Adsorption Sites ◽  
Pseudo Second Order ◽  
Ft Ir

Three-dimensional (3D) double-network graphene oxide/alginate-polyacrylonitrile (GO/Ca-Alg2-PAN) composite hydrogels were synthesized via surface functionalization of GO to activate adsorption sites. The morphology and structure of the GO/Ca-Alg2-PAN were analyzed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA-DSC). The results of the physicochemical analyses indicated that GO/Ca-Alg2-PAN was successfully synthesized by the combination of a 2D-structured graphene oxide with the alginate which was functionalized with the PAN polymer to generate the 3D double network composites. This functionalization approach contributed to an increase in Cu<sup>2+</sup> ion adsorption capacity. The maximum adsorption capacity of the GO/Ca-Alg2-PAN for Cu<sup>2+</sup> was 5.99 mmol/g. The results of adsorption kinetic experiments indicated that the GO/Ca-Alg2-PAN reached adsorption equilibrium within 147 mins at 2 mM Cu<sup>2+</sup> in accordance with a pseudo-second-order model.

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