scholarly journals Adsorption/desorption performance of Pb2+ and Cd2+ with super adsorption capacity of PASP/CMS hydrogel

2021 ◽  
Author(s):  
Hao Wang ◽  
Baiyun Zhao ◽  
Li Wang
Keyword(s):  
Single Layer ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Polyaspartic Acid ◽  
Adsorption Effect ◽  
Initial Concentration ◽  
Aqueous Solution Polymerization ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Adsorption Desorption

Abstract Super-absorbent polyaspartic acid/carboxymethyl salix psammophila powder (PASP/CMS) hydrogel was prepared by aqueous solution polymerization. PASP/CMS hydrogel was characterized by FT-IR, XRD, SEM and XPS. The results show that PASP/CMS hydrogel is prepared by graft copolymerization of the -COOH of polyaspartic acid (PASP) and the -CH2OH of carboxymethyl salix psammophila powder (CMS). The surface of that hydrogel becomes dense from loose porosity, and Pb2+ and Cd2+ are adsorbed onto the surface of hydrogel. The crystallinity of CMS is destroyed by the addition of PASP. The initial concentration of Pb2+ and Cd2+, pH, adsorption time and adsorption temperature on the adsorption effect were studied through experiments. And results showed that hydrogel has a good removal effect on Pb(II) and Cd(II) ions. Pseudo-second-order kinetic and Langmuir isotherm models are represented in the process, which are spontaneous, exothermic and decrease of randomness, and it's a single layer chemical adsorption. At the same time, the effect of desorption experimental parameters (HNO3 initial concentration, desorption time, and desorption temperature) on the experiment was studied and optimized.

scholarly journals Zeolites in Phenol Removal in the Presence of Cu(II) Ions—Comparison of Sorption Properties after Chitosan Modification

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 643 ◽  
Author(s):  
Lidia Bandura ◽  
Małgorzata Franus ◽  
Jarosław Madej ◽  
Dorota Kołodyńska ◽  
Zbigniew Hubicki
Keyword(s):  
Nitrogen Adsorption ◽  
Isotherm Models ◽  
Phenol Removal ◽  
Experimental Conditions ◽  
Kinetics Of Adsorption ◽  
Initial Concentration ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Adsorption Desorption ◽  
Kinetics Of

Nowadays, the contamination of water with phenol is a serious environmental problem. This compound occurs very often with heavy metal ions which makes purification of water even more difficult. This article presents the problem of the removal of phenol from aqueous solutions in the presence of Cu(II) ions on synthetic zeolite NaP1 and zeolite NaP1 modified with chitosan. The adsorbents were determined with the use of Fourier transform infrared spectroscopy (FT-IR), nitrogen adsorption/desorption isotherm, and scanning electron microscopy (SEM). The studies on isotherms and batch kinetics under diversified experimental conditions with respect to initial concentration, contact time, and pH were discussed. Both Cu(II) and phenol adsorption increases with the initial concentration. Different isotherm models correspond well with the data acquired through experiments. The kinetics of adsorption follows the pseudo-second order rate equation. The studies indicate that the obtained sorbents can be employed for efficient removal of phenol from wastewater in the presence of Cu(II) ions.

scholarly journals A Comparative Study on Hexavalent Chromium Adsorption onto Chitosan and Chitosan-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3427
Author(s):  
Rachid El Kaim Billah ◽  
Moonis Ali Khan ◽  
Young-Kwon Park ◽  
Amira AM ◽  
Hicham Majdoubi ◽  
...  
Keyword(s):  
Sio2 Nanoparticles ◽  
Analysis Data ◽  
Isotherm Models ◽  
Equilibration Time ◽  
Order Kinetic ◽  
Excellent Thermal Stability ◽  
Monolayer Adsorption ◽  
Pseudo Second Order ◽  
Chromium Adsorption ◽  
Ft Ir

Chitosan (Cs)-based composites were developed by incorporating silica (Cs–Si), and both silica and hydroxyapatite (Cs–Si–Hap), comparatively tested to sequester hexavalent (Cr(VI)) ions from water. XRD and FT-IR data affirmed the formation of Cs–Si and Cs–Si–Hap composite. Morphological images exhibits homogeneous Cs–Si surface, decorated with SiO2 nanoparticles, while the Cs–Si–Hap surface was non-homogeneous with microstructures, having SiO2 and Hap nanoparticles. Thermal analysis data revealed excellent thermal stability of the developed composites. Significant influence of pH, adsorbent dose, contact time, temperature, and coexisting anions on Cr(VI) adsorption onto composites was observed. Maximum Cr(VI) uptakes on Cs and developed composites were observed at pH 3. The equilibration time for Cr(VI) adsorption on Cs–Si–Hap was 10 min, comparatively better than Cs and Cs–Si. The adsorption data was fitted to pseudo-second-order kinetic and Langmuir isotherm models with respective maximum monolayer adsorption capacities (qm) of 55.5, 64.4, and 212.8 mg/g for Cs, Cs–Si, and Cs–Si–Hap. Regeneration studies showed that composites could be used for three consecutive cycles without losing their adsorption potential.

scholarly journals Preparation and Adsorption Properties of Biochar/g-C3N4 Composites for Methylene Blue in Aqueous Solution

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaodong Li
Keyword(s):  
Methylene Blue ◽  
Thermodynamic Parameters ◽  
Raw Materials ◽  
Order Kinetic ◽  
Adsorption Effect ◽  
Freundlich Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Doping Ratio

Using straw and urea as raw materials, biochar (BC) and g-C3N4 were prepared by oxygen-free pyrolysis at 300°C and 550°C. BC/g-C3N4 was prepared by loading different amounts of g-C3N4 onto the surface of biochar and characterized by SEM and FT-IR. The adsorption effect on methylene blue (MB) was investigated from the aspects of dosage and pH. The studies of adsorption equilibrium isotherms and the kinetic and the thermodynamic parameters on the BC/g-C3N4 adsorbents are discussed. The results showed that BC/g-C3N4 0.16 g/L with a doping ratio of 1 : 3 was added to the MB solution with an initial concentration of 50 mg/L and pH=11. The adsorption rate and adsorption amount were 96.72% and 302.25 mg/g, respectively. The adsorption process included surface adsorption and intraparticle diffusion, which conformed to the pseudo-second-order kinetic model and Langmuir-Freundlich model. Thermodynamic parameters (ΔG0<0, ΔH0>0, and ΔS0>0) showed that the adsorption reaction is spontaneous, which positively correlated with temperature.

Congo Red Dye Removal Using Ca-Al Layered Double Hydroxide: Kinetics and Equilibrium

2019 ◽  
Vol 814 ◽  
pp. 463-468 ◽  
Author(s):  
Hong Tham Nguyen Thi ◽  
Duy Chinh Nguyen ◽  
Thi Thuong Nguyen ◽  
Van Thuan Tran ◽  
Huu Vinh Nguyen ◽  
...  
Keyword(s):  
Layered Double Hydroxide ◽  
Congo Red ◽  
Removal Rate ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Red Dye ◽  
Double Hydroxide

This In this study, the Ca-Al layered double hydroxide was used as a potential adsorbent for the removal of Congo red from aqueous solutions. The effects of Initial concentration and contact time on the adsorption properties of Congo red by Ca-Al LDHs were studied. The removal rate of Conge red reached to 59.416 mg/g under room temperature with 0.2g of adsorbent, initial concentration of 50 ppm, adsorption time of 210 min, shaking speed of 90r/min. The experimental equilibrium data for the removal of Congo red were evaluated by various isotherm models. The pseudo-second-order kinetic models were found to fit the adsorption kinetics, and the equilibrium data were appropriately fitted to Langmuir and Freundlich model adsorption isotherm.

scholarly journals Adsorption of Co(II) from aqueous solution using municipal sludge biochar modified by HNO3

2021 ◽  
Author(s):  
Chunlian Hu ◽  
Wei Zhang ◽  
Yuantao Chen ◽  
Na Ye ◽  
DaWa YangJi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Order Kinetic ◽  
Adsorption Effect ◽  
Surface Areas ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Adsorption Of Co

Abstract Herein adsorption studies were proposed on a carboxylated sludge biochar (CSB) material modified by HNO3 to assess its capacity in the removal of cobalt from aqueous solution. The as-prepared sludge biochar material were characterized by Brunaure-Emmett-Teller (BET), Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), Energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The isotherm process could be well described by Langmuir isotherm model. The adsorption kinetics indicated that cobalt adsorption followed pseudo-second-order kinetic model. The mechanism between Co(II) and biochar involved electrostatic interaction, ion exchange, surface complexation and physical function. The adsorption capacity on CSB was as high as 72.27 mg·g−1, surpassing original sludge biochar (SB). This is due to the fact that CSB had abundant oxygen-containing functional groups and many hydroxyls, as well as, the BET surface areas increased when SB was modified by HNO3, which stimulate adsorption effect. Therefore, this work shows that CSB could be used as an efficient adsorbent to remove Co(II) in the wastewater.

scholarly journals Polymeric Substitution of Triazole Moieties in Cellulosic Schiff Base for Heavy Metal Complexation Studies

2021 ◽  
Author(s):  
R MAHALAKSHMI ◽  
SARAVANAN R ◽  
P SELVAKUMAR ◽  
M S KARTHIKEYAN ◽  
L RAVIKUMAR
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Equilibrium Concentration ◽  
Sorption Process ◽  
Complexation Reaction ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Adsorption Desorption

Abstract The adsorption of metal ions from wastewater using Schiff base cellulose bearing pendulant heterocyclic chelating groups (MC-Tz) as a sorbent is the subject of this paper. Solid state 13 C-NMR, FT-IR, SEM, and XRD spectroscopy, as well as TGA and XRD were utilized to examine the adsorbent. The batch sorption process used pH, adsorbent dose, initial adsorbate concentration, temperature, as well as contact time to calculate the metal ion levels. The optimum pH-6.0, with the complexation reaction and ion exchange phase as the mechanisms at work. To investigate the equilibrium concentration and temperature-dependent rate constants, various models, such as the Langmuir, Freundlich, Temkin, and Redlich-Peterson adsorption isotherm were utilized. A Kinetic study shows that the Langmuir is more in agreement with the Pseudo-second order Kinetic model. Adsorption-Desorption experiments over four cycles demonstrated the feasibility of the sorbent's regeneration potential and the measured values of enthalpy and entropy explain the essence of the adsorption process. The objective of this research is to discover non-toxic, environmentally friendly adsorbent biodegradable components and to conduct evaluations to determine their use in wastewater treatment.

scholarly journals Synthesis and Characterisation of Graphene Oxide-Silica-Chitosan for Eliminating the Pb(II) from Aqueous Solution

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1922
Author(s):  
Sepehr Azizkhani ◽  
Ebrahim Mahmoudi ◽  
Norhafizah Abdullah ◽  
Mohd Halim Shah Ismail ◽  
Abdul Wahab Mohammad ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Contact Time ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Removal Capacity ◽  
Transmission Electron ◽  
Low Concentrations ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Heavy metal ions have a toxic and negative influences on the environment and human health even at low concentrations and need to be removed from wastewater. Chitosan and graphene oxide are suitable nano plate adsorbents with high adsorption potential because of their π-π interaction, and they are available functional groups that interact with other elements. In this study, graphene oxide was coated with silica to enhance the hydrophilicity of the adsorbent. Subsequently, the adsorbent was functionalised by various amounts of chitosan to improve the Pb(II) removal. The adsorbent was analysed using transmission electron microscopy (TEM), Raman, Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and mapping analysis techniques. An investigation of the influences of the initial concentration of Pb(II), pH and contact time were included to obtain the optimum amount of adsorption. The range of the initial Pb(II) concentration studied was from 10 to 120 mg/L. The pH factor ranged from 3 to 8 with contact time from 0 to 140 min. Freundlich, Temkin and Langmuir isotherm models were fit to the results, and a pseudo-second-order kinetic model was found to provide a good fit as well. The maximum Pb(II) removal capacity achieved was 256.41 (+/− 4%) mg/g based on Langmuir isotherms.

Preparation of novel porous Al2O3-SiO2 nanocomposites via solution-freeze-drying-calcination method for the efficient removal of uranium in solution

2021 ◽  
Author(s):  
Maoling Wu ◽  
Ling Ding ◽  
Jun Liao ◽  
Yong Zhang ◽  
Wenkun Zhu
Keyword(s):  
Adsorption Process ◽  
Interaction Mechanism ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Calcination Method ◽  
Adsorption Desorption

Abstract In this work, the efficient extraction of uranium in solution using Al2O3-SiO2-T was reported. Kinetics and isotherm models indicated that the removal process of uranium onAl2O3-SiO2-T accorded with pseudo-second-order kinetic model and Langmuir isotherm model, which showed that the adsorption process was a uniform mono-layer chemical behavior. The maximum adsorption capacity of Al2O3-SiO2-T reached 738.7 mg g-1, which was higher than AlNaO6Si2 (349.8 mg g-1) and Al2O3-SiO2-NT (453.1 mg g-1), indicating that the addition of template could effectively improve the adsorption performance of Al2O3-SiO2 to uranium. Even after five cycles of adsorption-desorption, the removal percentage of uranium on Al2O3-SiO2-T remained 96%. Besides, the extraction efficiency of uranium on Al2O3-SiO2-T was 72.5% in simulated seawater, which suggested that the Al2O3-SiO2-T was expected to be used for uranium extraction from seawater. Further, the interaction mechanism between Al2O3-SiO2-T and uranium species was studied. The results showed that the electrostatic interaction and complexation played key roles in the adsorption process of Al2O3-SiO2-T to uranium.

scholarly journals Sorption of Ce(III) by Silica SBA-15 and Titanosilicate ETS-10 from Aqueous Solution

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3263
Author(s):  
Inga Zinicovscaia ◽  
Nikita Yushin ◽  
Doina Humelnicu ◽  
Dmitrii Grozdov ◽  
Maria Ignat ◽  
...  
Keyword(s):  
Nitrogen Adsorption ◽  
Second Order ◽  
Isotherm Models ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Maximum Sorption Capacity ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Ph Range ◽  
Adsorption Desorption

The adsorption capacity of two sorbents, silica SBA-15 and titanosilicate ETS-10, toward Ce(III) was tested. The obtained sorbents were characterized using X-ray diffraction, nitrogen adsorption-desorption, Scanning electron microscopy, and Fourier-transform infrared spectroscopy. The effects of solution acidity, cerium concentration, time of contact, and temperature on Ce(III) sorption were investigated. The maximum Ce(III) removal by silica SBA-15 was achieved at pH 3.0 and by titanosilicate ETS-10 at a pH range of 4.0–5.0. The Freundlich, Langmuir, and Temkin isotherm models were applied for the description of equilibrium sorption of Ce(III) by the studied absorbents. Langmuir model obeys the experimentally obtained data for both sorbents with a maximum sorption capacity of 68 and 162 mg/g for silica SBA-15 and titanosilicate ETS-10, respectively. The kinetics of the sorption were described using pseudo-first- and pseudo-second-order kinetics, Elovich, and Weber–Morris intraparticle diffusion models. The adsorption data fit accurately to pseudo-first- and pseudo-second-order kinetic models. Thermodynamic data revealed that the adsorption process was spontaneous and exothermic.

Synthesis of Functionalized Magnetite Titanium Dioxide Nanocomposite for Removal of Acid Fuchsine Dye

2018 ◽  
Vol 21 (8) ◽  
pp. 583-593 ◽  
Author(s):  
Sara Rahnama ◽  
Shahab Shariati ◽  
Faten Divsar
Keyword(s):  
Titanium Dioxide ◽  
Removal Efficiency ◽  
Magnetic Core ◽  
Fractional Factorial ◽  
Order Kinetic ◽  
Sorption Data ◽  
Salt Addition ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir

Objective: In this research, a novel magnetite titanium dioxide nanocomposite functionalized by amine groups (Fe3O4@SiO2@TiO2-NH2) was synthesized and its ability for efficient removal of Acid Fuchsine as an anionic dye from aqueous solutions was investigated. Method: The core-shell structure of Fe3O4@SiO2@TiO2 was prepared using Fe3O4 as magnetic core, tetra ethyl orthosilicate as silica and tetra butyl titanate as titanium source for shell. The synthesized nanocomposites (particle size lower than 44 nm) were characterized by FT-IR, XRD, DRS, SEM and TGA instruments. The various experimental parameters affecting dye removal efficiency were investigated and optimized using Taguchi fractional factorial design. Results: The synthesized adsorbent showed the highest removal efficiency of Acid Fuchsine (99 %) at pH= 3.5, without salt addition and during stirring at contact times less than 10 minutes. The study of kinetic models at two concentration levels showed the fast dye sorption on the surface of proposed nanocomposites with pseudo second order kinetic model (R2=1). Also, the fitting of Acid Fuchsine sorption data to Freundlich, Langmuir and Temkin isotherms suggested that Freundlich model gave a better fitting than other models (R2=0.9936, n=2). Conclusion: Good chemical stability, excellent magnetic properties, very fast adsorption kinetics and high removal efficiency make the synthesized nanocomposite as a proper recoverable sorbent for removal of Acid Fuchsine dye from wastewaters.

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