scholarly journals Preparation of alkali-activated fly ash-based geopolymer and their application in the adsorption of copper (II) and zinc (II) ions

2019 ◽  
Vol 276 ◽  
pp. 06012 ◽  
Author(s):  
Lita Darmayanti ◽  
Suprihanto Notodarmojo ◽  
Enri Damanhuri ◽  
Grandprix T. M. Kadja ◽  
Rino R Mukti
Keyword(s):  
Fly Ash ◽  
Alkali Activation ◽  
Order Model ◽  
Sorption Data ◽  
Promising Alternative ◽  
Molar Ratios ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Langmuir And Freundlich Equations ◽  
Alkali Activated

Alkali activation of fly ash can a promising alternative of the system to improve adsorption capability of fly ash. In finding the best chemical composition of the activator solution, geopolymer has been synthesized using molar ratios of Na2O/SiO2 0.16, 0.3, and 0.5 (Gr1, Gr3, Gr5). The results indicated that the geopolymer synthesized with a ratio molar of Na2O/SiO2 0.3 (Gr3) improved the adsorption properties of fly ash substantially. Gr3 was characterized by BET, XRD, and FTIR. The batch experiment was conducted at the different duration and initial concentrations. The equilibrium sorption data were fitted for the Langmuir and Freundlich equations. The maximum sorption capacities calculated from Langmuir isotherm was 54 mg g-1 and 47 mg g-1 for Cu (II) and Zn (II) respectively. The kinetic data reveal that the pseudo-second order model was appropriate for a description of the kinetic performance.

scholarly journals Removal of Pb2+ ions from aqueous solution by P(HEA/IA) hydrogels

2016 ◽  
Vol 70 (6) ◽  
pp. 695-705 ◽  
Author(s):  
Katarina Antic ◽  
Marija Babic ◽  
Jovana Vukovic ◽  
Antonije Onjia ◽  
Jovanka Filipovic ◽  
...  
Keyword(s):  
Significant Loss ◽  
Isotherm Models ◽  
Order Model ◽  
Solution Ph ◽  
Sorption Data ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Best Fit ◽  
Sorbent Weight

A series of poly(2-hydroxyethyl acrylate-co-itaconic acid), P(HEA/IA), hydrogels with different HEA/IA ratio, were synthesized using free radical crosslinking/copolymerization and investigated as sorbents for Pb2+ ions from aqueous solutions. Hydrogels were characterized using DMA, FTIR, DSC, SEM and AFM. The adsorption was found to be highly dependent on hydrogel composition, solution pH, sorbent weight, ionic strength and contact time. Five isotherm models, Langmuir, Freundlich, Redlich-Peterson, Temkin and Dubinin-Radushkevich, were applied to the sorption data. The best fit was obtained with Redlich-Peterson isotherm. The separation factor, RL, value indicated favorable sorption for Pb2+ ions. The maximum sorption capacities were 392.2 and 409.8 mg/g for P(HEA/2IA) and P(HEA/10IA), respectively. Kinetic data showed best fit with pseudo-second-order model. Thermodynamic studies revealed that the reaction was exothermic and proceeds with a decrease in entropy. Moreover, P(HEA/IA) hydrogel showed the most pronounced sorption toward Pb2+ ions from environment containing Cu2+, Zn2+, Cd2+, Ni2+ and Co2+ ions. Sorption/desorption experiments, showed that the P(HEA/IA) hydrogels could be reused without significant loss of the initial properties even after three adsorption-desorption cycles.

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.

scholarly journals Synthesis Fe3O4/Talc nanocomposite by coprecipition-ultrasonication method and advances in hexavalent chromium removal from aqueous solution

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Low Cost ◽  
Batch Experiments ◽  
X Ray Diffraction ◽  
Order Model ◽  
X Ray ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Langmuir And Freundlich Equations

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.

scholarly journals Valorization of Uncharred Dry Leaves of Ficus benjamina towards Cr (VI) removal from Water: Efficacy Influencing Factors and mechanism

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Preeti S. Kulkarni ◽  
Varuna S. Watwe ◽  
Abubakar J. Hipparge ◽  
Sana I. Sayyad ◽  
Rutika A. Sonawane ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Maximum Adsorption Capacity ◽  
Equilibration Time ◽  
Aqueous Samples ◽  
Sorption Data ◽  
Maximum Sorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Better Than ◽  
Work Treatment

AbstractThe potential of uncharred biomaterial derived from dry leaves of Ficusbenjamina (Family: Moraceae,local name: Weeping Fig) plant to remove Cr(VI) from aqueous samples was investigated. In the present work, treatment of dilute acids was used for activating the adsorption centres on the biomass instead of cumbersome charring process. The plant material was characterized using FT-IR, FE-SEM and EDX. Various influencing factors such as pH of equilibrating solution, contact time, Cr (VI) concentrations, adsorbent dose and temperature were optimized to obtain maximum sorption efficacy. The interactions among the biomaterial and Cr (VI) in water were studied by fitting the sorption data in four different adsorption isotherms. The data fitting and experimental evidences indicated formation of monolayer of Cr(VI) over the biomass surface. The process followed pseudo-second order kinetics and was thermodynamically spontaneous under laboratory conditions and reached equilibrium in 24 hours. Maximum adsorption capacity of 56.82 mg/g was obtained at the pH 2 when the concentration before adsorption was 200 mg L−1 of Cr(VI) with 24 hours of equilibration time and 2.50 g L−1 of dose of biomaterial at room temperature. The sorption efficiency was found to be better than many charred bio-based materials.

Removal of Strontium Ions from Aqueous Solution by Sunflower Straw

2013 ◽  
Vol 726-731 ◽  
pp. 1922-1925 ◽  
Author(s):  
Lian Ai ◽  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Si Zhao Zhang
Keyword(s):  
Aqueous Solution ◽  
Batch Adsorption ◽  
Order Model ◽  
Solution Ph ◽  
Sorption Data ◽  
Freundlich Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Sunflower Straw ◽  
Langmuir And Freundlich Models

The sorptive potential of sunflower straw (≤125 μm) for Sr2+ from aqueous solution was evaluated. Batch adsorption experiments were carried out as a function of solution pH, adsorbent dosage, Sr2+ concentration and contact time. FT-IR spectra and SEM of sunflower straw were employed to explore the functional groups available for the binding of Sr2+ and morphology of the adsorbent. Maximum uptake capacity of sunflower straw was 17.48 mg/g occurred at around pH 3-7. The adsorption equilibrium can be achieved within 5 min and kinetic data were fitted well to pseudo-second-order model. The Langmuir and Freundlich models were applied to describe isotherm sorption data. The Langmuir model gave an acceptable fit than Freundlich model.

The Influence of Mechanical Activation of Fly Ash on the Toxic Metals Immobilization by Fly Ash-Based Geopolymers

2018 ◽  
Vol 761 ◽  
pp. 3-6 ◽  
Author(s):  
Violeta Nikolić ◽  
Miroslav Komljenović ◽  
Nataša Džunuzović ◽  
Tijana Ivanovic
Keyword(s):  
Fly Ash ◽  
Mechanical Activation ◽  
Toxic Metals ◽  
Structural Changes ◽  
Gas Adsorption ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Water Soluble ◽  
Alkali Activation ◽  
Alkali Activated

This paper investigates the influence of mechanical activation of fly ash on the toxic metals immobilization by fly ash-based geopolymers. Fly ash was firstly mechanically and then alkali-activated. Mechanical activation of fly ash was conducted in a planetary ball mill. Alkali activation of fly ash was carried out at room temperature by use of sodium silicate solution as an activator. Toxic metals (Pb and Cr) were added in the form of water soluble salts during the synthesis of geopolymers. The immobilization process was assessed via investigation of the mechanical and leaching properties of geopolymers. Structural changes of geopolymers during the toxic metals immobilization were assessed by means of gas adsorption and SEM analyses. Mechanical activation of fly ash led to a significant increase in geopolymer strength and to a reduced leaching of toxic metals from geopolymers.

scholarly journals Generation-3 Polyamidoamine Dendrimer-Silica Composite: Preparation and Cd(II) Removal Capacity

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Augustus N. Ebelegi ◽  
Nimibofa Ayawei ◽  
Azibaola K. Inengite ◽  
Donbebe Wankasi
Keyword(s):  
Freundlich Isotherm ◽  
Sorption Process ◽  
Pamam Dendrimer ◽  
Order Model ◽  
Diffusion Kinetic ◽  
Sorption Data ◽  
Removal Capacity ◽  
Pseudo Second Order ◽  
Film Layer ◽  
Solution Kinetic

Generation-3 polyamidoamine (PAMAM) dendrimer was implanted on silica to produce a very good adsorbent (G-3 PAMAM-SGA). The composite was characterized and used for the removal of Cd(II) ions from aqueous solution. Kinetic data fit the Lagergren pseudo-second-order model and also follow the intraparticle diffusion kinetic model to an extent, which is an indication that the sorption process is controlled by both mechanisms: intraparticle/film layer and adsorption inside the pores/crevices of the composite. Equilibrium sorption data of Cd(II) on G-3 PAMAM-SGA fit the Freundlich isotherm (R2 = 0.9993) which is indicative of multilayered adsorption that occurred on heterogeneous surfaces. The ΔG° values for all temperatures studied were negative, which indicated a spontaneous and feasible process. The result implies that G-3 PAMAM-SGA is a promising adsorbent for microscale scavenging of Cd(II) ions in aqueous solutions.

scholarly journals Possibility of Removing Pb and Cd from Polluted Water by Modified Fly Ash

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xi Chen ◽  
Guibin Zhang ◽  
Jingtian Li ◽  
Puhui Ji
Keyword(s):  
Fly Ash ◽  
Adsorption Capacity ◽  
Polluted Water ◽  
Mass Ratio ◽  
Order Model ◽  
Adsorption Performance ◽  
Pseudo Second Order ◽  
Roasting Temperature ◽  
Polluted Wastewater ◽  
Modified Fly Ash

In this study, fly ash (FA) was modified by sodium hydroxide to prepare a new adsorption material (IP) and treat Pb2+- and Cd2+-polluted wastewater. The effect of preparation parameters (mass ratio of FA/NaOH and modification temperature) on IP adsorption performance was investigated. The results indicated that the IP4 showed the highest adsorption capacity prepared at the FA/NaOH mass ratio of 1 : 2 and the roasting temperature of 250°C. The IP4 was characterized by SEM, EDX, XRD, and FTIR analyses. The results showed that the surface morphology and microstructure of FA were significantly changed. Furthermore, in order to study the adsorption performance of Pb2+ and Cd2+ on IP4, the different initial concentrations of Pb2+ and Cd2+, pH, and contact time were analyzed, and the results indicated that IP4 has excellent adsorption capacity for heavy metals. In addition, kinetic model results demonstrated that the adsorption behavior of Pb2+ and Cd2+ on IP4 was better described by a pseudo-second-order model.

scholarly journals Influence of Concrete Sludge Addition in the Properties of Alkali-Activated and Non-Alkali-Activated Fly Ash-Based Mortars

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Fotini Kesikidou ◽  
Stavroula Konopisi ◽  
Eleftherios K. Anastasiou
Keyword(s):  
Fly Ash ◽  
Silicon Oxide ◽  
Strength Development ◽  
Alkali Activation ◽  
Early Age ◽  
Fly Ash Concrete ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Potential Synergy ◽  
Alkali Activated

This study investigated the use of concrete sludge, a by-product of the ready-mix concrete industry, in combination with high-calcium fly ash in binary cementless binders. Concrete sludge was used in substitution rates ranging from 0% to 60% in test fly ash-based mortars to determine potential synergy. The mortars were tested for fresh and hardened properties; workability, viscosity, strength development, open porosity, early-age shrinkage, and analytical tests were carried out. A mortar with 50% fly ash and 50% limestone filler as binders was used for comparison purposes. Furthermore, a series of mortars with fly ash and concrete sludge were alkali-activated in order to determine potential strength gain. In the activated mortars, two fractions of concrete sludge were used, under 75 μm and 200 μm, due to different silicon oxide contents, while one mortar was cured at 40°C to investigate the effect of heating on alkali activation. Results show that sludge contributes to the formation of C-S-H and strength development when used in combination with high-calcium fly ash even at high replacement rates. The alkali activation of fly ash-concrete sludge system contributed to early-age strength development and to early-age shrinkage reduction.

scholarly journals FLY ASH MAGNETIC ADSORBENT FOR CADMIUM ION REMOVAL FROM AN AQUEOUS SOLUTION

2021 ◽  
Vol 185 (1) ◽  
pp. 42-50
Author(s):  
Gabriela BUEMA ◽  
Nicoleta LUPU ◽  
Horia CHIRIAC ◽  
Dumitru Daniel HEREA ◽  
Lidia FAVIER ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Fly Ash ◽  
Adsorption Capacity ◽  
Second Order ◽  
Order Model ◽  
Cadmium Ion ◽  
Cadmium Ions ◽  
Ion Removal ◽  
Pseudo Second Order ◽  
Second Order Model

The fly ash generated from a Romanian power plant was used as a starting material in this study. The aim of the study was to obtain a low cost material based on the treatment of fly ash with Fe3O4 for utilization as an adsorbent for cadmium ion removal. The adsorbent that was synthesized was characterized using different techniques. The adsorption process was investigated by the batch technique at room temperature. The quantity of cadmium ion adsorbed was measured spectrophotometrically. The experimental data showed that the material can remove cadmium ions at all three working concentrations. The adsorption capacity increased with an increase in concentration, respectively contact time. The results were analyzed through two kinetic models: pseudo first order and pseudo second order. The kinetics results of cadmium adsorption onto a magnetic material are in good agreement with a pseudo second order model, with a maximum adsorption capacity of 4.03 mg/g, 6.73 mg/g, and 9.65 mg/g. Additionally, the pseudo second order model was linearized into its four types. The results indicated that the material obtained show the ability to remove cadmium ions from an aqueous solution.

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