scholarly journals In Situ Synthesis of Structural Hierarchy Flowerlike Zeolite and Its Application for Fluoride Removal in Aqueous Solution

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Zhihan Tian ◽  
Yiqun Gan
Keyword(s):  
Ph Value ◽  
Three Dimensional ◽  
Adsorption Properties ◽  
Aluminum Silicate ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Structural Hierarchy ◽  
Hydrated Aluminum ◽  
Pseudo Second Order ◽  
Ft Ir

A three-dimensional hierarchically structured flowerlike zeolite was synthesized using naturally occurring nanohalloysite (HNT) by hydrothermal methods. Halloysite a hydrated aluminum silicate with nanohollow morphology, microporosity, and environmentally friendly properties was chosen to be the sole precursor. The morphology and structure of the composite that was prepared was characterized using XRD, FT-IR, BET, TG, SEM, HRTEM, and NMR. SEM and HRTEM images indicated that the synthesized zeolite has a flowerlike hierarchical structure, with well-defined edges and uniform pore channels. FT-IR and NMR spectra indicated that different species of silicon and aluminum were present in the synthesized zeolite. The zeolite was applied in fluoride (F-) removal from aqueous solutions. Single-factor studies, including the initial concentration of F-, initial adsorbent concentration, and the effect of pH value on the adsorption properties, were investigated to evaluate the removal behavior of F- by the zeolite. The zeolite exhibited strong adsorption properties for fluoride ions (F-), with an adsorption capacity up to 161 mg g-1. The pseudo-second-order kinetics and Freundlich models were the best fit to the kinetics and isotherm experimental data, respectively.

Nano-ZrO2/TiO2 Impregnated Orange Wood Sawdust and Peach Stone Shell Adsorbents for Cr (VI) Removal

2020 ◽  
Vol 16 (7) ◽  
pp. 880-892
Author(s):  
Şerife Parlayıcı ◽  
Kübra Tuna Sezer ◽  
Erol Pehlivan
Keyword(s):  
Contact Time ◽  
Ph Value ◽  
Order Kinetic ◽  
Adsorption Parameters ◽  
Wood Sawdust ◽  
Adsorption Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Equilibrium Status

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.

scholarly journals Preparation of chitosan/amine modified diatomite composites and adsorption properties of Hg(II) ions

2018 ◽  
Vol 77 (5) ◽  
pp. 1363-1371 ◽  
Author(s):  
Yong Fu ◽  
Yue Huang ◽  
Jianshe Hu ◽  
Zhengjie Zhang
Keyword(s):  
Schiff Base ◽  
Contact Time ◽  
Ph Value ◽  
Adsorption Properties ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Effect ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Modified Diatomite

Abstract A green functional adsorbent (CAD) was prepared by Schiff base reaction of chitosan and amino-modified diatomite. The morphology, structure and adsorption properties of the CAD were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and Brunauer Emmett Teller measurements. The effect of pH value, contact time and temperature on the adsorption of Hg(II) ions for the CAD is discussed in detail. The experimental results showed that the CAD had a large specific surface area and multifunctional groups such as amino, hydroxyl and Schiff base. The optimum adsorption effect was obtained when the pH value, temperature and contact time were 4, 25 °C and 120 min, respectively, and the corresponding maximum adsorption capacity of Hg(II) ions reached 102 mg/g. Moreover, the adsorption behavior of Hg(II) ions for the CAD followed the pseudo-second-order kinetic model and Langmuir model. The negative ΔG0 and ΔH0 suggested that the adsorption was a spontaneous exothermic process.

The Preparation and Characteristics of MMT Nanosheets

2013 ◽  
Vol 544 ◽  
pp. 152-155
Author(s):  
Cheng Chen ◽  
Hao Wu ◽  
Qiang Li
Keyword(s):  
Crystal Structure ◽  
Chemical Method ◽  
Ph Value ◽  
Luminescent Properties ◽  
Rare Earth Ions ◽  
Aluminum Silicate ◽  
Practical Applications ◽  
The Status ◽  
Hydrated Aluminum ◽  
The Impact

Montmorillonite (MMT) mainly consist of hydrated aluminum silicate. Montmorillonite has particular properties and many practical applications, because of their special crystal structure. Here, mechano-chemical method was used to prepare MMT nanosheets by controlling the pH value. MMT nanosheets were obtained by ballmilling, and the impact of pH value on the nanosheets preparing was studied. TEM was employed to emamine the microstructure of MMT nanosheets. The size are analyzed to study the status of MMT nanosheets. Different rare earth ions as a fluorescence center were assembled on nanosheets，and composites were obtained. The luminescent properties of composite materials were studied.

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.

scholarly journals Adsorption properties of a nanostructured hybrid material containing aluminium towards some metal ions

2011 ◽  
Vol 9 (5) ◽  
pp. 932-940 ◽  
Author(s):  
Albena Detcheva ◽  
Paunka Vassileva ◽  
Ralitsa Georgieva ◽  
Dimitrinka Voykova ◽  
Tsvetelina Gerganova ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Hybrid Material ◽  
Metal Ion ◽  
Ph Value ◽  
Sol Gel ◽  
Transition Metal Ions ◽  
Adsorption Properties ◽  
Adsorption Of Nitrogen ◽  
Pseudo Second Order

AbstractIn the present work the adsorption of some transition metal ions from aqueous solutions on a silica-based nanostructured hybrid material modified by aluminium was investigated. The novel organic-inorganic material was synthesized via a sol-gel method through hydrolysis and co-condensation reactions. Its structure was characterized by means of SEM, XRD and FTIR. Based on the data obtained the most probable cross-linking mechanism for the derived xerogel was proposed. The characterization of its texture parameters was carried out by low-temperature adsorption of nitrogen. The adsorption properties of this material with respect to Cu(II), Cr(III) and Pb(II) ions from single-component aqueous solutions and multi-component aqueous solutions containing also Cd(II) and Fe(III) were evaluated. The effect of contact time, acidity of initial solutions and metal ion concentrations was investigated using the batch method. Pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyze kinetic data. In all cases the adsorption was significantly affected by the pH value. Equilibrium modelling data were fitted to linear Langmuir, Freundlich and Dubinin-Radushkevich models. Best fit was observed for Langmuir model, which showed determination coefficients greater than 0.992 for all ions studied. The maximum adsorption capacities for single- and multi-component adsorption were calculated.

scholarly journals Study of Fluoride Affinity by Zirconium Impregnated Walnut Shell Carbon in Aqueous Phase: Kinetic and Isotherm Evaluation

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
M. Rajan ◽  
G. Alagumuthu
Keyword(s):  
Ph Value ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Walnut Shell ◽  
Fluoride Removal ◽  
Order Model ◽  
Intraparticle Diffusion Model ◽  
Bicarbonate Ions ◽  
Pseudo Second Order ◽  
Second Order Model

This paper examines the kinetics of fluoride removal from water by the adsorbent zirconium-impregnated walnut-shell carbon (ZIWSC), exploring the mechanisms involved. The dependence of the adsorption of fluoride on the pH of the solution has been studied to achieve the optimum pH value and a better understanding of the adsorption mechanism. The presence of bicarbonate ions in aqueous solution was found to affect the fluoride removal indicating that these anions compete with the sorption of fluoride on adsorbents. The kinetic profile has been modeled using pseudo-first-order model, pseudo-second-order model, and intraparticle diffusion model. The kinetic sorption profiles offered excellent fit with pseudo-second-order model. Adsorption isotherms have been modeled by Langmuir, Freundlich, and Temkin equations, and their constants were determined. The equilibrium adsorption data were fitted reasonably well for Freundlich isotherm model. XRD and SEM patterns of the ZIWSC were recorded to get better insight into the mechanism of adsorption process.

scholarly journals Eggshell-Derived Nanohydroxyapatite Adsorbent for Defluoridation of Drinking Water from Bofo of Ethiopia

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Kifle Workeneh ◽  
Enyew Amare Zereffa ◽  
Toshome Abdo Segne ◽  
Rajalakshmanan Eswaramoorthy
Keyword(s):  
Removal Efficiency ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Batch Adsorption ◽  
Alternative Source ◽  
Fluoride Adsorption ◽  
Initial Ph ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Eggshell Waste

Fluoride has become a notable toxicological environmental hazard worldwide because it is often found in groundwater. In the present study, hydroxyapatite adsorbent was synthesized from eggshell waste to remove fluoride from aqueous solution. XRD, FT-IR, and TGA techniques were used to characterize the prepared adsorbent. Batch adsorption studies were performed to examine the adsorption capacity of hydroxyapatite such as the effect of the initial pH of the solution, contact time, adsorbent dose, and initial fluoride concentration. The fluoride ion-selective electrode was used to determine the fluoride removal efficiency. 98.8% of fluoride was removed at pH 3.0, but at pH ~7.0, 85% of fluoride was removed; it shows that the fluoride adsorption is pH dependent. The adsorption isotherm studies (Langmuir and Freundlich models) and the experimental results for the removal of fluoride showed that the Langmuir model was more favorable and the reaction followed pseudo-second-order kinetics. In real water samples, the prepared hydroxyapatite derived from eggshell exhibited 81% removal efficiency. Our results indicate that eggshell waste-derived hydroxyapatite may be an alternative source for defluoridation in developing countries.

Adsorption of fluoride from aqueous solution by enhanced chitosan/bentonite composite

2013 ◽  
Vol 68 (9) ◽  
pp. 2074-2081 ◽  
Author(s):  
Qian Liu ◽  
Ruihua Huang ◽  
Bingchao Yang ◽  
Yanping Liu
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Fluoride Concentration ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Adsorbent Dosage ◽  
Batch System ◽  
Monolayer Adsorption

In this work, enhanced chitosan/bentonite composite was prepared by treating chitosan/bentonite composite with concentrated hydrochloric acid (HCl). The adsorption of fluoride ions from aqueous solution onto the enhanced chitosan/bentonite composite was investigated. Adsorption studies were performed in a batch system, and the effects of various parameters, such as the pH value of the solution, adsorbent dosage and initial fluoride concentration, were evaluated. The optimum operating conditions for fluoride removal by the enhanced chitosan/bentonite composite were pH = 7 or so, and adsorbent dosage =1.2 g. Increasing initial fluoride concentration reduced the adsorption of fluoride onto the enhanced chitosan/bentonite composite. Furthermore, the presence of other co-anions weakened the adsorption of fluoride onto this adsorbent. The equilibrium adsorption isotherms were well described by both the Freundlich and Langmuir models. The maximum monolayer adsorption capacity was 2.95 mg/g at 293 K.

Adsorption Characters of Mn2+ onto Palygorskites Modified by 1, 10-Phenanthroline and Triethylamine

2010 ◽  
Vol 178 ◽  
pp. 8-16
Author(s):  
Liang Dong Feng ◽  
Bo Qing Chen ◽  
Ying Ying Shi ◽  
Ying Wei Guo ◽  
Jing Huang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Contact Time ◽  
Ph Value ◽  
Order Model ◽  
Kinetics Of Adsorption ◽  
Initial Concentration ◽  
Adsorption Capacities ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Kinetics Of

1, 10-phenanthroline and triethylamine modified palygorskites were prepared by microwave irradiation, and characterized with FT-IR technique. The effects of contact time, adsorbent dosage, and pH value of the initial solution on the adsorption characters of Mn2+ were investigated. The adsorption of Mn2+ from aqueous solutions using 1, 10-phenanthroline or triethylamine modified palygorskites were investigated. Experiment results indicated that 1,10-phenanthroline and triethylamine molecules have been successfully grafted to palygorskite. The adsorption was rapid during the first 5 minuts and equilibrium were attained within 60 minutes in the initial concentration of Mn2+ of 50 and 100 mg•L-1, and fast adsorption in the first 10 minutes and slowly increased with the contact time due to the adsorption of palygorskite. The 1, 10-phenanthroline modified palygorskites had higher adsorption capacity than triethylamine modified palygorskites. Compared with natural palggorskites, the Mn2+ ions adsorption capacities of palggorskite modified by 1, 10-phenanthroline or triethylamine were significantly improved. There were less difference in the adsorption capacity between different dasages of 1, 10-phenanthroline modified palygorskites, but the adsorption capacity of Mn2+ adsorbed onto triethylamine modified palygorskites decreased with increasing the dosages. A Lagergren pseudo-second order model best described the kinetics of adsorption of Mn2+ onto the modified palygorskites.

Preparation and its Adsorption Characters of Pb2+ Ions-Imprinted Chitosan/Palygorskite Hybrid Materials

2011 ◽  
Vol 391-392 ◽  
pp. 1324-1329
Author(s):  
Ying Ying Shi ◽  
Qiang Hua Zhang ◽  
Liang Dong Feng ◽  
Qing Ping Xiong ◽  
Fei Liu
Keyword(s):  
Ph Value ◽  
Synthesis Process ◽  
Optimum Conditions ◽  
Order Model ◽  
Fast Kinetics ◽  
Kinetics Of Adsorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Ion Imprinting ◽  
Kinetics Of

By using Palygorskite as matrix and introducing the surface ion-imprinting concept to the synthesis process, a Palygorskite-supported organic–inorganic hybrid polymer for selective separation of Pb2+ from aqueous solutio was prepared. The prepared polymer was characterized with techniques of SEM, XRD and FT-IR. The effects of contact time, pH value and temperature of the initial solution on the adsorption characters of Pb2+ were investigated. Under the optimum conditions, the ions-imprinted polymer offered a fast kinetics for the adsorption of Pb2+ and the maximum capacity was 4.51 mg/g. And the pseudo-second order model bestly described the kinetics of adsorption of Pb2+ onto the as-prepared materials.

Sign in / Sign up

Export Citation Format

Share Document