scholarly journals Removal of Malachite Green Dye using Keggin Polyoxometalate Intercalated ZnAl Layered Double Hydroxide

2021 ◽  
Vol 18 (10) ◽  
Author(s):  
Aldes LESBANI ◽  
Tarmizi TAHER ◽  
Neza Rahayu PALAPA ◽  
Risfidian MOHADI ◽  
Mardiyanto Mardiyanto ◽  
...  

The ZnAl Layered double hydroxides (LDHs) have been successfully synthesized by the coprecipitation method, followed by intercalation using Keggin ion of α-dodecatungstosilicic acid [α-SiW12O40]4- to form ZnAl-[α-SiW12O40] LDHs. The prepared ZnAl-[SiW12O40] LDHs were characterized by using X-Ray, FTIR, and BET surface area analyses, which were, then, used as adsorbents of malachite green dye from aqueous solution. The synthesized ZnAl LDH showed a typical diffraction peak of the layered compound at 11o (003) with an interlayer space of 8.59 Å. After intercalation, it was recorded that the interlayer space of ZnAl-[SiW12O40] LDH increased to 10.65 Å. Moreover, the specific surface area of the intercalated LDH increased from 1.9685 to 14.0422 Å. The adsorption study revealed that the adsorption capacity of ZnAl-[SiW12O40] LDH toward malachite green dye was higher (37.514 mg.g-1) than the pristine ZnAl LDH (32.845 mg.g-1). The adsorption kinetics study showed that malachite green adsorption onto both pristine and intercalate LDH followed the pseudo-2nd-order model. The adsorption thermodynamic investigation indicated that adsorption of malachite green onto ZnAl-[SiW12O40] LDH was a spontaneous process and was classified as physical adsorption with activation energy ranging from 10.074 to 15.476 kJ.mol-1. HIGHLIGHTS ZnAl LDH intercalated by Keggin ion has been successfully synthesized by facile coprecipitation followed by ion exchange method The basal spacing of the intercalated ZnAl LDH increased up to 10.65 A The intercalated ZnAl LDH exhibited higher adsorption capacity for malachite green dye removal compared with the original ZnAl LDH

2020 ◽  
Vol 15 (3) ◽  
pp. 653-661
Author(s):  
Neza Rahayu Palapa ◽  
Novie Juleanti ◽  
Normah Normah ◽  
Tarmizi Taher ◽  
Aldes Lesbani

Cu-Al layered double hydroxide (LDH) was intercalated with Keggin ion of polyoxometalate           K4[a-SiW12O40] to form Cu-Al-SiW12O40 LDH. The obtained materials were analyzed by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR) spectroscopy, and Brunaur-Emmett-Teller (BET) surface area analysis. Furthermore, the materials were used as adsorbents of malachite green from aqueous solution. Some variables for adsorption, such as: effect of adsorption times, malachite green concentration, and also adsorption temperature, were explored. The results showed that diffraction at 11.72° on Cu-Al LDH has interlayer distance of 7.56 Å. The intercalation of that LDH with [a-SiW12O40]4− ion resulted increasing interlayer distance to 12.10 Å. The surface area of material was also increased after intercalation from 46.2 m2/g to 89.02 m2/g. The adsorption of malachite green on Cu-Al and          Cu-Al-SiW12O40 LDHs followed pseudo second order kinetic and isotherm Langmuir model with adsorption capacity of Cu-Al and Cu-Al-SiW12O40 LDHs was 55.866 mg/g and 149.253 mg/g, respectively. That adsorption capacity is equal with increasing interlayer space and surface area properties of material after intercalation. Thus, the adsorption of malachite green on Cu-Al and Cu-Al-SiW12O40 LDHs is unique and dominantly occurred on interlayer space of LDH as active site adsorption. Copyright © 2020 BCREC Group. All rights reserved


2020 ◽  
Vol 15 (2) ◽  
pp. 525-537 ◽  
Author(s):  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Bakri Rio Rahayu ◽  
Risfidian Mohadi ◽  
Addy Rachmat ◽  
...  

The preparation of CuAl LDH and biochar (BC) composite derived from rice husk and its application as a low-cost adsorbent for enhanced adsorptive removal of malachite green has been studied. The composite was prepared by a one-step coprecipitation method and characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy - Energy Dispersive X-ray (SEM−EDX). The result indicated that CuAl LDH was successfully incorporated with the biochar that evidenced by the broadening of XRD peak at 2θ = 24° and the appearance of a new peak at 1095 cm−1 on the FTIR spectra. The BET surface area analysis revealed that CuAl/BC composite exhibited a larger surface area (200.9 m2/g) that the original CuAl LDH (46.2 m2/g). Surface morphological changes also confirmed by SEM image, which showed more aggregated particles. The result of the adsorption study indicated the composite material was efficient in removing malachite green with Langmuir maximum adsorption capacity of CuAl/BC reaching 470.96 mg/g, which is higher than the original CuAl LDH 59.523 mg/g. The thermodynamic analysis suggested that the adsorption of malachite green occurs spontaneously (ΔG < 0 at all tested temperature) and endothermic nature. Moreover, the CuAl/BC composite showed strong potential as a low-cost adsorbent for cationic dye removal since it showed not only a high adsorption capacity but also good reusability. Copyright © 2020 BCREC Group. All rights reserved


Author(s):  
Ibrahem M. A. Hasan ◽  
Ahmed R. Tawfik ◽  
Fawzy H. Assaf

Abstract Zinc oxide nanoparticles (ZnO NPs) were biosynthesized. According to GC/MS analysis, chalcone; the main phytochemical; is probably complexed with Zn ions that are then oxidized to ZnO NPs by atmospheric O2 during heating. The ZnO NPs were characterized by TG, FTIR, XRD, FESEM, TEM, eEDAX, and BET surface area analysis. Sphere-like ZnO NPs were formed with 11 nm mean crystallite size, 5.2 m2 g−1 surface area, and 0.02 cm3 g−1 total pore volume. The synthesized ZnO showed excellent photocatalytic degradation (96.5±0.24% in 1 hour at 25 °C) of malachite green (MG) in aqueous solutions under UV light at optimum conditions; pH 10, MG initial concentration of 20 mg L−1, and ZnO dose of 1.5 g L−1. Also, ZnO showed very good reusability (92.9± 0.2% after 5 runs). The experimental data obeyed pseudo-first-order kinetics (R2=0.92). The photocatalysis process is dependent on the following species in the order: OH. &gt; electron/positive hole pairs &gt; O2.−. Moreover, photodegradation efficiency decreased in the presence of CO32−, HCO3−, and Cl−, but increased in the presence of NO3−, and SO42− ions. Thus, the green synthesized ZnO NPs can be applied as an efficient photocatalyst for the removal of MG from aqueous media.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ali Q. Alorabi

In this work, magnetized activated Juniperus procera leaves (Fe3O4@AJPL) were successfully prepared via chemical activation of JPL and in situ coprecipitation with Fe3O4. A Fe3O4@AJPL nanocomposite was successfully applied for the elimination of malachite green (MG) dye from aqueous media. The prepared Fe3O4@AJPL adsorbent was characterized by SEM, EDX, TEM, XRD, FTIR, TGA, and BET surface area analyses. The BET surface area and pore size of the Fe3O4@AJPL nanocomposite were found to be 38.44 m2/g and 10.6 nm, respectively. The XRD and FTIR results indicated the formation of a Fe3O4@AJPL nanocomposite. Different parameters, such as pH of the solution (3–8), adsorbent dosage (10–100 mg), temperature (25–45°C), contact time (5-240 min), and initial MG concentrations (20–350 mg/L), for the elimination of the MG dye using Fe3O4@AJPL were optimized and found to be 7, 50 mg, 45°C, 120 min, and 150 mg/L, respectively. The nonlinear isotherm and kinetic studies exhibited a better fitting to second-order kinetic and Langmuir isotherm models, with a maximum monolayer adsorption capacity of 318.3 mg/g at 45°C, which was highly superior to the previously reported magnetic nanocomposite adsorbents. EDX analyses confirmed the presence of nitrogen on the Fe3O4@AJPL surface after MG adsorption. The calculated thermodynamic factors indicated endothermic and spontaneous processes. The desorption of MG dye from Fe3O4@AJPL was performed using a solution of 90% ethanol. Finally, it could be concluded that the designed Fe3O4@AJPL magnetic nanocomposite will be a cost-effective and promising adsorbent for the elimination of MG from aqueous media.


2021 ◽  
Vol 19 (8) ◽  
pp. 32-41
Author(s):  
Ebtisam K. Alwan ◽  
Aqeel Mohhamed Hammoudi ◽  
Intessar K. Abd ◽  
Maryam O. Abd Alaa ◽  
Mohammed Nsaif Abbas

In the current paper, the nanoparticles of cobalt iron oxide doped by chromium (CIC) of (CrxCoFe2-xO4) formula were prepared by sol-gel method using the nitrate salts of the elements composed of this nanomaterial. The characteristic properties of CIC nanoparticles prepared were determined using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) in addition to scanning electron microscopy (SEM) and also examination of the surface area (BET). These tests showed that the CIC nanoparticle prepared was in a pure phase, in addition to having various functional groups; moreover their structural framework includes multiple pores, which was the reason for the high surface area, reached to 223.36 m2.g-1. The prepared CIC nanoparticle was applied as an adsorbent to recover the malachite green dye from aqueous contaminated solutions in a batch mode adsorption unit and under different operating conditions. Designing factors used to determine the efficiency of the CIC as an adsorption media for the organic dye included the acidic function (pH), contact time and amount of nanomaterial CIC. The obtained practical results showed that the removal efficiency of the malachite green dye using CIC nanoparticle was 88.519% at 50 ppm of the initial concentration of the contaminated solution and that the percentage removal was directly proportional to the amount of adsorbent, contact time and acidic function.


2014 ◽  
Vol 625 ◽  
pp. 98-101 ◽  
Author(s):  
Ali E.I. Elkhalifah ◽  
Mohammad Azmi Bustam ◽  
Azmi Mohd Shariff ◽  
Sami Ullah ◽  
Biruh Shimekit ◽  
...  

The present study investigates the effects of intercalation process of protonated primary, secondary and tertiary amines on structural and surface characteristics of sodium form of bentonite clay. For this purpose, sodium form of bentonite clay was prepared and then exchanged with mono-, di-and triethanolammonium cations via intercalation mechanism into the interlayer space of the clay. The prepared samples were characterized by XRD and BET techniques. An increase in the d-spacing of bentonite clay with the molar mass of amines was observed in their x-ray diffractograms, following the order of: triethanolamine > diethanolamine > monoethanolamine. The BET results showed a gradual decrease in the BET surface area with the increase in the molar mass of amines used. Based on the results obtained, it can be concluded that the molar mass of amines has significant effects on structural and surface properties of bentonite clay.


2007 ◽  
Vol 561-565 ◽  
pp. 1719-1722 ◽  
Author(s):  
Chiravoot Pechyen ◽  
Duangdao Aht-Ong ◽  
Duangduen Atong ◽  
Viboon Sricharoenchaikul

Char derived from pyrolysis of physic nut waste at 400-800°C was used for the preparation of activated carbon by chemical impregnation of phosphoric acid and potassium hydroxide. The original char exhibited the BET surface area in the range of 120-250 m2·g-1. The surface area increased to 480 and 532 m2·g-1 when activated with H3PO4 and KOH, respectively. Equilibrium adsorption data was found to be best represented by the Langmuir isotherm with maximum monolayer adsorption capacity of 560.13 mg·g-1 at 30°C. The adsorption capacity of the physic nut residue activated carbon was comparable to commercial activated carbon.


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