Adsorptive removal of chromium (VI) from synthetic waters using magnetic lignocellulosic composites

Abstract The removal of heavy metals from water is one of the major challenges that humanity must address to avoid negative potential impacts on the environment and human health. During the last few years, several adsorbents have been examined, in a search for highly efficient and cost-effective materials. In this work, we investigated the use of laurel, canelo and eucalyptus lignocellulosic sawdust residues (LRs) impregnated with magnetite nanoparticles (MNP), to remove Cr6+ ions. Each LR was added to an aqueous solution in which MNP were being synthesized by coprecipitation. Two composite adsorbents were obtained, with LR:MNP ratios of 1:1 and 3:1. The materials obtained were characterized by X-ray diffraction, scanning and transmission electron microscopy, and infrared and Raman spectroscopy. The results obtained showed that the laurel composite was the best adsorbent, reaching a maximum removal efficiency and capacity of 99.8 % and 30.5 mg/g, respectively. The optimal contact time was 30 min and the process fitted the Langmuir isotherm model, showing small effects of the fraction of sawdust residues used to support the MNP. Further studies will be performed to optimize the composition of the composites aiming to reduce the amount of costly MNP used while ensuring a high removal performance.

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Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽

10.3390/min11060611 ◽

2021 ◽

Vol 11 (6) ◽

pp. 611

Author(s):

Celia Marcos ◽

María de Uribe-Zorita ◽

Pedro Álvarez-Lloret ◽

Alaa Adawy ◽

Patricia Fernández ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Crystallite Size ◽

Archaeological Sites ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Infrared And Raman Spectroscopy ◽

First Time ◽

Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

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Removeal of Arsenic(III) from Water by Using a New Class of Zero-Valent Iron Modified Mesoporous Silica Molecular Sieves SBA-15

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.356-360.423 ◽

2011 ◽

Vol 356-360 ◽

pp. 423-429

Author(s):

Meng Ye ◽

Jin Huang ◽

Rui Chen ◽

Qi Zhuang He

Keyword(s):

Molecular Sieves ◽

Cost Effective ◽

Zero Valent Iron ◽

Preparation Process ◽

X Ray Diffraction ◽

Wet Impregnation ◽

X Ray ◽

New Class ◽

Transmission Electron ◽

Removal Of Arsenic

An elevated arsenic (As) content in groundwater imposes a great threat to people worldwide. Thus, developing new and cost-effective methods to remove As from groundwater and drinking water becomes a priority. Using Zero-Valent iron (ZVI) to remove As from water is a proven technology. In this study, ZVI modified SBA-15 mesoporous silicamolecular sieves (ZVI-SBA-15), was prepared, characterized, and used for removing arsenic from water. Wet impregnation, drying, and calcination steps led to iron inclusion within the mesopores. Iron oxide was reduced to ZVI by NaBH4, and the ZVI modified SBA-15 was obtained. Fourier-transform infrared spectroscopy conﬁrmed the preparation process of the nitrate to oxide forms. The structure of the materials was conﬁrmed by Powder X-ray diﬀraction. Its data indicated that the structure of ZVI-SBA-15 retained the host SBA-15 structure. Brunauer-Emmett-Teller analysis revealed a decrease in surface area and pore size, indicating ZVI-SBA-15 coating on the inner surfaces. Transmission electron micrographs also conﬁrmed that modiﬁed SBA-15 retained the structure of the parent SBA-15 silica.It has a high uptake capability(more than 90 pecent) make it potentially attractive absorbent for the removal of arsenic from water.

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Enzyme Mimetic Activity of ZnO-Pd Nanosheets Synthesized via a Green Route

Molecules ◽

10.3390/molecules25112585 ◽

2020 ◽

Vol 25 (11) ◽

pp. 2585 ◽

Cited By ~ 1

Author(s):

Ravi Mani Tripathi ◽

Dohee Ahn ◽

Yeong Mok Kim ◽

Sang J. Chung

Keyword(s):

Electron Microscopy ◽

Cost Effective ◽

Enzyme Mimics ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Green Route ◽

Protease Digestion ◽

Recent Developments ◽

Atomic Spacing

Recent developments in the area of nanotechnology have focused on the development of nanomaterials with catalytic activities. The enzyme mimics, nanozymes, work efficiently in extreme pH and temperature conditions, and exhibit resistance to protease digestion, in contrast to enzymes. We developed an environment-friendly, cost-effective, and facile biological method for the synthesis of ZnO-Pd nanosheets. This is the first biosynthesis of ZnO-Pd nanosheets. The synthesized nanosheets were characterized by UV–visible spectroscopy, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray. The d-spacing (inter-atomic spacing) of the palladium nanoparticles in the ZnO sheets was found to be 0.22 nm, which corresponds to the (111) plane. The XRD pattern revealed that the 2θ values of 21.8°, 33.3°, 47.7°, and 56.2° corresponded with the crystal planes of (100), (002), (112), and (201), respectively. The nanosheets were validated to possess peroxidase mimetic activity, which oxidized the 3,3′,5,5′-tetramethylbenzidine (TMB) substrate in the presence of H2O2. After 20 min of incubation time, the colorless TMB substrate oxidized into a dark-blue-colored one and a strong peak was observed at 650 nm. The initial velocities of Pd-ZnO-catalyzed TMB oxidation by H2O2 were analyzed by Michaelis–Menten and Lineweaver–Burk plots, resulting in 64 × 10−6 M, 8.72 × 10−9 Msec−1, and 8.72 × 10−4 sec−1 of KM, Vmax, and kcat, respectively.

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Fabrication and Characterization of Titanium Based Nanotubes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.581 ◽

2009 ◽

Vol 79-82 ◽

pp. 581-584 ◽

Cited By ~ 2

Author(s):

Li Ang Song ◽

Li Xin Cao ◽

Ge Su ◽

Wei Liu ◽

Hui Liu ◽

...

Keyword(s):

Diffuse Reflectance Spectroscopy ◽

Cost Effective ◽

Outer Diameter ◽

X Ray Diffraction ◽

X Ray ◽

Amorphous Phases ◽

Selected Area Electron Diffraction ◽

Transmission Electron ◽

Inner Diameter

Titanium based nanotubes (8-12nm outer diameter and 4-6nm inner diameter) were successfully fabricated by a simple and cost-effective hydrothermal method. The nanotube-like amorphous phases TNT(Na) and TNT(H) were obtained with different post treatment. The samples were characterized by means of high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), selected area electron diffraction (SAED), energy dispersive X-ray spectrum (EDS) and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activities of the nanotubes were evaluated using photo-oxidation of methyl orange.

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Coordination of Lead (II) and Cadmium (II) Ions to Nylon 6/flax Linum Composite as a Route of Removal of Heavy Metals

10.21203/rs.3.rs-521570/v1 ◽

2021 ◽

Author(s):

NT Moja ◽

SB Mishra ◽

SS Hwang ◽

TY Tsai ◽

Ajay Kumar Mishra

Keyword(s):

Heavy Metals ◽

Cell Size ◽

Nylon 6 ◽

Injection Technique ◽

X Ray Diffraction ◽

X Ray ◽

Removal Of Heavy Metals ◽

Langmuir Isotherm Model ◽

Thermographic Analysis ◽

Emission Microscopy

Abstract Nylon 6 (PA6) reinforced Flax Linum composites were synthesized by melt mix extrusion and molded through Mucell\ ® injection technique for adsorption application for removal of Cd(II) and Pb(II) metal ions. The structural morphologies of all samples were evaluated using X-ray diffraction (XRD), Transmittance emission microscopy (TEM) and Scanning emission microscopy (SEM), indicating crystallized materials with pore-like cells and Thermographic analysis (TGA) illustrated the thermally stable., Microscopic PA6 revealed the effects of Flax content on both cell density and cell size of the foamed samples. The cell size of neat PA6 (48 μm) changed to 36, 17, and 15 μm after incorporation of Flax compositions for 1.0, 3.0 and 5.0 wt%. The removal of Cd(II)and Pb(II) with PA6/Flax 1.0 wt% composite was found to follow the Langmuir isotherm model. The results indicated that PA6 1.0 wt% composite can be efficiently used as a superabsorbent for the removal of Cd(II) and Pb(II) from aqueous solution.

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Investigation the Effects of Green-Synthesized Copper Nanoparticles on the Performance of Activated Carbon-Chitosan-Alginate for the Removal of Cr(VI) from Aqueous Solution

Molecules ◽

10.3390/molecules26092617 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2617

Author(s):

Inas A. Ahmed ◽

Hala S. Hussein ◽

Ahmed H. Ragab ◽

Najla AlMasoud ◽

Ayman A. Ghfar

Keyword(s):

Electron Microscopy ◽

Activated Carbon ◽

Contact Time ◽

Sem Analysis ◽

Adsorption Efficiency ◽

X Ray Diffraction ◽

X Ray ◽

Chromium Vi ◽

Transmission Electron ◽

Freundlich Adsorption Isotherm

In the present investigation, green nano-zerovalent copper (GnZVCu), activated carbon (AC), chitosan (CS) and alginate (ALG) nanocomposites were produced and used for the elimination of chromium (VI) from a polluted solution. The nanocomposites GnZVCu/AC-CS-alginate and AC-CS-alginate were prepared. Analysis and characterization were performed by the following techniques: X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. The SEM analysis revealed that the nanocomposites are extremely mesoporous, which leads to the greatest adsorption of Cr+6 (i.e., 97.5% and 95%) for GnZVCu/AC-CS-alginate and AC-CS-alginate, respectively. The adsorption efficiency was enhanced by coupling GnZVCu with AC-CS-alginate with a contact time of 40 min. The maximum elimination of Cr+6 with the two nanocomposites was achieved at pH 2. The isotherm model, Freundlich adsorption isotherm and kinetics model and P.S.O.R kinetic models were discovered to be better suited to describe the exclusion of Cr+6 by the nanocomposites. The results suggested that the synthesized nanocomposites are promising for the segregation of Cr+6 from polluted solutions, specially the GnZVCu/AC-CS-alginate nanocomposite.

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Hydrothermal Synthesis of WO3·0.33H2O Nanorod Bundles as a Highly Sensitive Cyclohexene Sensor

Sensors ◽

10.3390/s19051257 ◽

2019 ◽

Vol 19 (5) ◽

pp. 1257 ◽

Cited By ~ 2

Author(s):

Xiaofei Liu ◽

Xintai Su ◽

Chao Yang ◽

Kongjun Ma

Keyword(s):

Cost Effective ◽

X Ray Diffraction ◽

Promising Candidate ◽

X Ray ◽

Transmission Electron ◽

New Synthesis ◽

Highly Sensitive ◽

The Cost ◽

Sensing Characteristics ◽

Better Than

In this paper, WO3·0.33H2O nanorods were prepared through a simple hydrothermal method using p-aminobenzoic acid (PABA) as an auxiliary reagent. X-ray diffraction (XRD) and transmission electron microscopy (TEM) images showed that the products with PABA addition were orthorhombic WO3·0.33H2O, which were mainly composed of nanorods with different crystal planes. The sensing performance of WO3·0.33H2O nanorod bundles prepared by the addition of PABA (100 ppm cyclohexene, Ra/Rg = 50.6) was found to be better than the WO3 synthesized without PABA (100 ppm cyclohexene, Ra/Rg = 1.3) for the detection of cyclohexene. The new synthesis route and sensing characteristics of as-synthesized WO3·0.33H2O nanorods revealed a promising candidate for the preparation of the cost-effective gas sensors.

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Crown-Ether-Modified SBA-15 for the Adsorption of Cr(VI) and Zn(II) from Water

Materials ◽

10.3390/ma14175060 ◽

2021 ◽

Vol 14 (17) ◽

pp. 5060

Author(s):

Jong-Man Yoo ◽

Sung Soo Park ◽

Yong-Zhu Yan ◽

Chang-Sik Ha

Keyword(s):

Electron Microscopy ◽

Metal Ions ◽

Covalent Attachment ◽

X Ray Diffraction ◽

X Ray ◽

Langmuir Adsorption ◽

Chromium Vi ◽

Transmission Electron ◽

Ftir Spectrometry ◽

Adsorption Desorption

Recently, the release of some metal ions to the environment has been observed to cause serious damages to human health and the environment. Herein, a chromium(VI)- and zinc(II)-selective adsorbent (CB18crown6/SBA-15) was successfully fabricated through the covalent attachment of 4′-carboxybenzo-18-crown-6 (CB18crown6) as a ligand on mesoporous silica support (SBA-15). The CB18crown6/SBA-15 adsorbent was characterized by Fourier-transform infrared (FTIR) spectrometry, X-ray diffraction (XRD), N2 adsorption–desorption, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). To evaluate its ability to selectively capture Cr(VI) and Zn(II), adsorption experiments were conducted. The influences of pH, initial concentration of metal ions, and coexisting metal ions on the adsorption process were examined. The CB18crown6/SBA-15 selectively adsorbed Cr(VI) at pH 2 and Zn(II) at pH 5, respectively, from the mixed aqueous solutions of chromium, zinc, lithium, cadmium, cobalt, strontium, and cesium ions. The data for the adsorption of Cr(VI) onto the CB18crown6/SBA-15 were well explained by the Langmuir adsorption isotherm. In addition, the recycling and reuse of CB18crown6/SBA-15 was successfully achieved, and 71 and 76% reuse efficiency of Cr(VI) and Zn(II), respectively, was obtained after five cycles. This study suggests that the use of the CB18crown6/SBA-15 can be a feasible approach for the selective remediation of Cr(VI) and Zn(II) contamination.

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Eco-Friendly Synthesis of Gold Nanoparticles by Bacillus subtilis and Their Environmental Applications

Advanced Science Letters ◽

10.1166/asl.2018.12224 ◽

2018 ◽

Vol 24 (8) ◽

pp. 5942-5946 ◽

Cited By ~ 7

Author(s):

B. S Srinath ◽

K Namratha ◽

K Byrappa

Keyword(s):

Gold Nanoparticles ◽

Bacillus Subtilis ◽

Color Change ◽

Cost Effective ◽

X Ray Diffraction ◽

X Ray ◽

Gold Mines ◽

The Earth ◽

Transmission Electron ◽

Uv Visible

Biosynthesis of gold nanoparticles (GNPs) is an eco-friendly, cost effective and nontoxic alternative to chemical and physical methods. The microbe which inhabits nearly all surfaces on the earth, an attainment typically attributed to their metabolic adaptability. The organism which resides in gold mines would be having more capability to resist against soluble gold toxicity and produce gold nanoparticles efficiently. In the present study, we report for the synthesis of GNPs by a member of Bacillus subtilis isolated from Hutti gold mine, India. The synthesis of GNPs was observed by a color change from yellow to pink and confirmed by a peak around 545 nm using a UV–visible spectroscopy. The synthesized GNPs were further characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Transmission electron microscopy (TEM). The results show that synthesized GNPs are well dispersed and their size ranges 20–25 nm. The present work is aimed to use green synthesized GNPs as catalyst to degrade Methylene blue (MB) and these GNPs could be used to degrade toxic dyes in the environment.

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The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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