Synthesis, Characterization and Use of Supported Co/gama-Al2O3 for the Removal of Reactive Blue 19 from Aqueous Solutions

2018 ◽  
Vol 69 (1) ◽  
pp. 228-231
Author(s):  
Maria Larion ◽  
Emil Ioan Muresan ◽  
Cezar Doru Radu ◽  
Ion Sandu ◽  
Angela Cerempei ◽  
...  

In this study, systematic adsorption tests were carried out using Co/gama-Al2O3 adsorbents of different compositions for removal of Reactive Blue 19 dye from aqueous solutions. The adsorbent was characterized by scanning electron microscopy, X-Ray powder diffraction, diffuse reflectance UV-visible spectroscopy and EDX analysis. The influences of several parameters such as pH, adsorbent concentration, adsorption time and dye concentration on the adsorption capacity of g-Al2O3 and Co/g-Al2O3 were investigated. The obtained results indicate that the adsorption is strongly dependent on the solution pH. The maximum adsorption capacity of the Reactive blue 19 dye onto Co/gama-Al2O3 takes place at around pH 2. The adsorption process is fast in the first minutes (95% from the amount of dye being removed after 6 minutes).

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 942 ◽  
Author(s):  
Huo-Xi Jin ◽  
Hong Xu ◽  
Nan Wang ◽  
Li-Ye Yang ◽  
Yang-Guang Wang ◽  
...  

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.


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.


2014 ◽  
Vol 805 ◽  
pp. 284-290
Author(s):  
José Vanderley do Nascimento Silva ◽  
Guilherme Costa de Oliveira ◽  
Meiry Gláucia Freire Rodrigues

As minimization process control pollution by heavy metals, adsorption can play an important environmental role. Therefore, many adsorbents can be used as effective alternatives. This work presents a study that aims to evaluate the removal of lead in liquid effluent through adsorption process using a finite bath system and with the adsorbent clay Chocobofe. The clay in its natural form was characterized by the techniques of X-Ray Diffraction (XRD), Cation Exchange Capacity (CEC), Chemical Analysis by X-Ray Spectrometry by Energy Dispersive (EDX), moreover, the natural clay was subjected to test adsorption capacity to analyze the behavior the same in certain organic solvents. Was performed to assess the effectiveness of the natural clay in the process of removal of Pb2+ present in solutions based on a factorial design 23 + 3 replicates at the central point, with the analysis variables solution pH (3.0, 4.0 and 5.0) and the initial concentration of lead (10, 30 and 50 ppm). The studies showed this material as promising in the removal of Pb2+ ions in synthetic wastewater and that the adsorption capacity showed that the organic solvents tested.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3054
Author(s):  
Yiming Zhou ◽  
Te Li ◽  
Juanli Shen ◽  
Yu Meng ◽  
Shuhua Tong ◽  
...  

This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.


2019 ◽  
Vol 12 (02) ◽  
pp. 1950014 ◽  
Author(s):  
Wei Yang ◽  
Sheng Guo ◽  
Jinyi Chen ◽  
Abdul Naeem ◽  
Hussain Fida ◽  
...  

Iron-modified montmorillonite (Mt) composites with controlled interlayer spacing were successfully synthesized through Fenton-like process with the addition of different concentrations of Rhodamine B (RhB). The physicochemical properties of the resulting samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It was worth noting that the adsorption efficiency of the composite for tetracycline hydrochloride (TC) increased with the increase of the RhB concentration during preparation. The maximum adsorption capacity of the as-prepared composite toward TC was 192.4[Formula: see text]mg/g, which was much higher than that of the Mt (144.9[Formula: see text]mg/g). Moreover, the as-prepared adsorbent showed high adsorption capacity of TC in a wide pH range of 3.0–9.0. The adsorption process followed the pseudo-second-order equation and the Langmuir isotherm model, suggesting the mono-layer chemisorption of the adsorption process. The present work may provide a new strategy for the design and fabrication of functional clay-based materials.


2019 ◽  
Vol 80 (11) ◽  
pp. 2218-2231
Author(s):  
George O. Achieng ◽  
Chrispin O. Kowenje ◽  
Joseph O. Lalah ◽  
Stephen O. Ojwach

Abstract The preparation and applications of Tilapia (Oreochromis niloticus) fish scale biochars (FSB) as an adsorbent in the removal of indigo carmine dye (ICD) from aqueous solutions is described. The biochars were prepared through pyrolysis over a temperature range of 200 °C–800 °C and characterized for surface charge, functional groups, thermal stability, particle size and morphology, elemental composition, crystallinity, and surface area by using pHpzc, Fourier transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA), transmission electron microscopy/scanning electron microscopy (TEM/SEM), energy dispersive X-ray (EDX) spectroscopy, powder X-ray diffraction (PXRD) and Brunauer-Emmett-Teller (BET) techniques, respectively. Batch experiments were carried out to determine the variation of adsorption process with initial dye concentration, contact time, initial solution pH, adsorbent load, temperature and adsorbent pyrolysis temperature on the removal of the dye. The percentage removal increased with increase in initial dye concentration and adsorbent dosage. A pH of 2 was the most appropriate for the adsorption experiments. The equilibrium data fitted pseudo-first-order kinetics and Freundlich models, while the thermodynamic parameters confirmed that the adsorption process was endothermic.


2014 ◽  
Vol 917 ◽  
pp. 151-159 ◽  
Author(s):  
Nadia Riaz ◽  
Chong Fai Kait ◽  
Zakaria Man ◽  
Binay K. Dutta ◽  
Raihan M. Ramli ◽  
...  

Cu/TiO2 photocatalysts with different metal loading were prepared via modified depositionprecipitation method with the intention to reduce the band gap for Orange II degradation and mineralization under visible light radiation. The photocatalysts were characterized using thermal gravimetric analysis, powder X-ray diffraction, diffuse reflectance UV-Visible spectroscopy and field-emission scanning electron microscopy. 10 wt% photocatalysts showed the best performance compared to the bare TiO2.


2014 ◽  
Vol 878 ◽  
pp. 226-233
Author(s):  
Yu Xin Sun ◽  
Jin Zhang

Removal of phenols from waters and wastewaters is an important issue in order to protect public health and environment. In an effort to develop an effective adsorbent for removal of phenol from aqueous solutions, fly ash cenospheres (FACs), the solid wastes generated from a coal-firing power plant, were modified with an amino-terminated organosilicon (γ-aminopropyltriethoxysilane, KH550). Surface properties of the KH550-modified FACs (M-FACs) were characterized by the X-ray diffraction (XRD), the scanning electron microscopy (SEM) and X-ray photoelectron spectra (XPS). The characterized results showed that KH550 was successfully grated on the surface of FACs. The effects of various experimental parameters such as solution pH, adsorbent dose, and temperature upon the phenol adsorption onto M-FACs were evaluated. The results showed solution pH had a major impact on the phenol adsorption onto M-FACs, the optimum phenol removal was observed around pH 7-9. The kinetic studies indicated that the adsorption process was best described by the pseudo-second-order kinetics, suggesting that the mainly phenol adsorption process was predominantly controlled by chemical process. M-FACs presented more than double adsorptive capacity as compared with FACs. The adsorption capacity of the regenerated adsorbents could still be maintained at 83% by the fourth adsorption-desorption cycle.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2241
Author(s):  
Rauf Foroutan ◽  
Seyed Jamaleddin Peighambardoust ◽  
Seyed Hadi Peighambardoust ◽  
Mirian Pateiro ◽  
Jose M. Lorenzo

Activated carbon prepared from lemon (Citrus limon) wood (ACL) and ACL/Fe3O4 magnetic nanocomposite were effectively used to remove the cationic dye of crystal violet (CV) from aqueous solutions. The results showed that Fe3O4 nanoparticles were successfully placed in the structure of ACL and the produced nanocomposites showed superior magnetic properties. It was found that pH was the most effective parameter in the CV dye adsorption and pH of 9 gave the maximum adsorption efficiency of 93.5% and 98.3% for ACL and ACL/Fe3O4, respectively. The Dubinin–Radushkevich (D-R) and Langmuir models were selected to investigate the CV dye adsorption equilibrium behavior for ACL and ACL/Fe3O4, respectively. A maximum adsorption capacity of 23.6 and 35.3 mg/g was obtained for ACL and ACL/Fe3O4, respectively indicating superior adsorption capacity of Fe3O4 nanoparticles. The kinetic data of the adsorption process followed the pseudo-second order (PSO) kinetic model, indicating that chemical mechanisms may have an effect on the CV dye adsorption. The negative values obtained for Gibb’s free energy parameter (−20 < ΔG < 0 kJ/mol) showed that the adsorption process using both types of the adsorbents was physical. Moreover, the CV dye adsorption enthalpy (ΔH) values of −45.4 for ACL and −56.9 kJ/mol for ACL/Fe3O4 were obtained indicating that the adsorption process was exothermic. Overall, ACL and ACL/Fe3O4 magnetic nanocomposites provide a novel and effective type of adsorbents to remove CV dye from the aqueous solutions.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Rajaa Bassam ◽  
Achraf El hallaoui ◽  
Marouane El Alouani ◽  
Maissara Jabrane ◽  
El Hassan El Khattabi ◽  
...  

The aim of this study is the valorization of the Moroccan clays (QC-MC and QC-MT) from the Middle Atlas region as adsorbents for the treatment of water contaminated by cadmium Cd (II) ions. The physicochemical properties of natural clays are characterized by ICP-MS, XRD, FTIR, and SEM techniques. The adsorption process is investigated as a function of adsorbent mass, solution pH, contact time, temperature, and initial Cd (II) ion concentration. The kinetic investigation shows that the adsorption equilibrium of Cd (II) ions by both natural clays is reached after 30 min for QC-MT and 45 min for QC-MC and fits well to a pseudo-second-order kinetic model. The isotherm study is best fitted by a Freundlich model, with the maximum adsorption capacity determined by the linear form of the Freundlich isotherm being 4.23 mg/g for QC-MC and 5.85 mg/g for QC-MT at 25°C. The cadmium adsorption process was thermodynamically spontaneous and exothermic. The regeneration process showed that these natural clays had excellent recycling capacity. Characterization of the Moroccan natural clays before and after the adsorption process through FTIR, SEM, XRD, and EDX techniques confirmed the Cd (II) ion adsorption on the surfaces of both natural clay adsorbents. Overall, the high adsorption capacity of both natural clays for Cd (II) ions removal compared to other adsorbents motioned in the literature indicated that these two natural adsorbents are excellent candidates for heavy metal removal from aqueous environments.


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