scholarly journals FAU—Type Zeolite Synthesis from Clays and Its Use for the Simultaneous Adsorption of Five Divalent Metals from Aqueous Solutions

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3738
Author(s):  
Ifeoma V. Joseph ◽  
Lubomira Tosheva ◽  
Gary Miller ◽  
Aidan M. Doyle

In this research, a vermiculite-kaolinite clay (VK) was used to prepare faujasite zeolites via alkaline fusion and hydrothermal crystallisation. The optimal synthesis conditions were 1 h fusion with NaOH at 800 °C, addition of deionised water to the fused sample at a sample to deionised water mass ratio of 1:5, 68 h of non-agitated ageing of the suspension, and 24 h of hydrothermal treatment at 90 °C. The efficacy of the prepared faujasite was compared to raw clay and a reference zeolite material through adsorption experiments of aqueous solutions containing five divalent cations—Cd, Co, Cu, Pb, and Zn. The results showed that in the presence of competing cations at concentrations of 300 mg L−1 and adsorbent loading of 5 g L−1, within the first 10 min, about 99% of Pb, 60% of Cu, 58% of Cd, 28% of Zn, and 19% of Co were removed by the faujasite prepared from clay. Two to four parameter nonlinear adsorption isotherms were used to fit the adsorption data and it was found that overall, three and four parameter isotherms had the best fit for the adsorption process.

2014 ◽  
Vol 805 ◽  
pp. 581-584 ◽  
Author(s):  
Débora Martins Aragão ◽  
Maria de Lara P.M. Arguelho ◽  
Carolina Mangieri Oliveira Prado ◽  
José do Patrocinio Hora Alves

Natural kaolinite clay collected in the State of Sergipe (northeast Brazil) was used as an adsorbent for the ions Pb2+, Cd2+, and Cu2+present in aqueous solution. Adsorption equilibrium was reached rapidly, enabling use of a contact time of 30 minutes, and maximum adsorption was achieved at pH 7.0. For all three metal ions, the adsorption data could be fitted using the Langmuir isotherm and the adsorption process obeyed a pseudo-second order kinetic model.


2018 ◽  
Vol 56 (6) ◽  
pp. 688 ◽  
Author(s):  
Nguyen Thuy Chinh ◽  
Hoang Thai ◽  
Trang Do Mai Tran ◽  
Tuyet Thi Nguyen ◽  
Oanh Nhat Nguyen ◽  
...  

In this study, fly ash was treated with NaOH solution (FAN) before modifying with (3-mercaptopropyl) triethoxysilane - MPTMS (FAMPS). By using FTIR, FESEM, XRD, EDX, and BET techniques, the change in structure, composition and morphology of FAN and FAMPS was evaluated. The FTIR spectra of FAN and FAMPS showed that there is no chemical reaction between the MPTMS and FAN. After modification, the FAMPS has a rough surface with composition difference from the FAN. Mercuric ion adsorption behavior as well as adsorptionisotherm models (Langmuir and Freundlich) of the FAN and FAMPS were also investigated and discussed. Thanks to FAN modification, the mercuric ion removal percent of the FAMPS was higher than that of the FAN. Owing to the adsorption data, Freundlich isotherm modelwas fitted for the mercuric ion adsorption process.


2018 ◽  
Vol 69 (5) ◽  
pp. 1233-1239
Author(s):  
Raluca Madalina Senin ◽  
Ion Ion ◽  
Ovidiu Oprea ◽  
Rusandica Stoica ◽  
Rodica Ganea ◽  
...  

In this study, non-irradiated and weathered multiwalled carbon nanotubes (MWCNTs) obtained through irradiation, were studied as adsorbents for BPA, both nanomaterials being characterized before and after the adsorption process. The objectives of our investigation were to compare the characteristics of non-irradiated and irradiated MWCNTs, to evaluate the adsorption capacity of BPA by pristine and irradiated MWCNTs and to determine the variation of the kinetic, sorption and thermodynamic parameters during sorption process using both sorbents.


2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.


2021 ◽  
Author(s):  
Liang Wang ◽  
Peng Gao ◽  
Mengxin Liu ◽  
Ziqing Huang ◽  
Shixia Lan ◽  
...  

Monodisperse polypyrrole/SBA-15 composite (PPy/SBA-15) was fabricated by in-situ polymerization and used for Cr(Ⅵ) adsorption from aqueous solution. PPy/SBA-15 was characterized by numerous approaches. Factors affecting the Cr(Ⅵ) adsorption process included...


2017 ◽  
Vol 76 (8) ◽  
pp. 2242-2253 ◽  
Author(s):  
Z. Yavari ◽  
M. Noroozifar

In this study, black carbon from pine cone (BCPC) and acidic-modified BCPC (MBCPC) powder as a popular agricultural waste in the southeast of Iran were used for cadmium removal from aqueous solutions. The effect of various factors, such as surface chemistry and dosage of adsorbent, contact time, size of particles, initial concentration of cadmium, temperature, and pH of aqueous solutions, was investigated. The results show cadmium removal with usage of the mentioned adsorbents increased after acidic modification. It was noteworthy in this work that the removal percentage of pollutant was above 90% for suggested biosorbents. The obtained experimental data for optimum conditions were selected to model the adsorption behavior of the materials with usage of six isotherm equations via non-linear fitting method and the residual root mean square error estimation for each model. The adsorption of cadmium preferably fitted Khan and Langmuir–Freundlich isotherms for BCPC and MBCPC adsorbents, respectively. The kinetic studies via linear fitting method proved the second-order kinetic was the applicable model for the adsorption process. Thermodynamic studies show the adsorption process of cadmium onto BCPC and MBCPC was spontaneous and endothermic.


2016 ◽  
Vol 75 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Lucas Meili ◽  
Társila Santos da Silva ◽  
Daniely Carlos Henrique ◽  
João Inácio Soletti ◽  
Sandra Helena Vieira de Carvalho ◽  
...  

In this work, the potential of ouricuri (Syagrus coronata) fiber as a novel biosorbent to remove methylene blue (MB) from aqueous solutions was investigated. The fiber was prepared and characterized according to the fundamental features for adsorption. A 23 experimental design was used to evaluate the effects of adsorbent dosage (M), fiber diameter (D) and agitation (A) on the adsorption capacity. In the more adequate conditions, kinetic and equilibrium studies were performed. The experimental design results showed that M = 10 g L−1), D = 0.595 mm and A = 200 rpm were the more adequate conditions for MB adsorption. Based on the kinetic study, it was found that the adsorption process was fast, being the equilibrium was attained at about 5 min, with 90% of color removal. The isotherm was properly represented by the Sips model, and the maximum adsorption capacity was 31.7 mg g−1. In brief, it was demonstrated that ouricuri fiber is an alternative biosorbent to remove MB from aqueous media, taking into account the process efficiency and economic viewpoint.


2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Fernanda Rosa Assis ◽  
Rui Manuel Santos Costa de Morais ◽  
Alcina Maria Miranda Bernardo de Morais

Abstract Physalis was osmotically dehydrated with 60 °Bx sucrose or sorbitol solutions at 60 °C and with a mass ratio of sample to solution of 1:4, at atmospheric pressure or under vacuum at 150 mbar. The Crank’s, Peleg’s and Page’s models were tested to describe the mass transfer kinetics for water loss (WL) and solids gain (SG). The effective diffusivities of both water and solute were around 10-11 m2 s-1 under all conditions. Peleg’s model presented the best fit. The use of sorbitol as the osmotic agent resulted in an increase in the WL rate. In experiments with sucrose solutions, a higher WL was obtained under vacuum than at atmospheric pressure. The SG was particularly low during osmotic dehydration. Thus, the use of sorbitol as the osmotic agent was shown to be a promising alternative to sucrose.


2015 ◽  
Vol 12 (1) ◽  
pp. 148-156
Author(s):  
Baghdad Science Journal

The subject of this research involves studying adsorption to removal herbicide Atlantis WG from aqueous solutions by bentonite clay. The equilibrium concentration have been determined spectra photometry by using UV-Vis spectrophotometer. The experimental equilibrium sorption data were analyzed by two widely, Langmuir and Freundlish isotherm models. The Langmuir model gave a better fit than Freundlich model The adsorption amount of (Atlantis WG) increased when the temperature and pH decreased. The thermodynamic parameters like ?G, ?H, and ?S have been calculated from the effect of temperature on adsorption process, is exothermic. The kinetic of adsorption process was studied depending on Lagergren ,Morris ? Weber and Rauschenberg equations.


2006 ◽  
pp. 83-87 ◽  
Author(s):  
Blagica Cekova ◽  
Dragi Kocev ◽  
Elena Kolcakovska ◽  
Daniela Stojanova

The potential usage of zeolites as adsorbents for the removal of organic molecules from water was investigated in a series of experiments with aqueous solutions of lower alcohols. This could represent a simple solution to the problem of cleaning up industrial wastewater as well as recovering valuable chemicals at relatively low costs. Adsorption isotherms of the Langmuir type were applied, and calculations showed that the amount of propanol adsorbed on silicalite corresponded to approximately 70% of the pore volume. The adsorption process is simple, and recovery of the more concentrated products is easily done by heat treatment and/or at lowered pressures. Adsorption experiments with aqueous acetone showed that silicalite had approximately the same adsorption capacity for acetone as for n-propanol. Heats of adsorption were determined calorimetrically.


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