Potential Evaluation of Gray Clay as Adsorbent of Heavy Metals Zinc (II) and Lead (II)

2014 ◽  
Vol 798-799 ◽  
pp. 622-627
Author(s):  
Wellington Siqueira Lima ◽  
José Vanderley Nascimento Silva ◽  
Aline Cadigna Lima Patrício ◽  
Guilherme Costa Oliveira ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Heavy Metals ◽  
Factorial Design ◽  
Metal Removal ◽  
Physical Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Capacity ◽  
Adsorption Of Nitrogen ◽  
Potential Evaluation ◽  
Good Percentage

The problems caused by contamination of heavy metals generate a growing need to implement technologies to reduce or eliminate them. This work aims to evaluate the potential of gray clay, the process of removal of zinc and lead from synthetic effluents in finite bath system. The clay was characterized by: X-ray diffraction, X-ray Spectroscopy Energy Dispersive and Physical Adsorption of Nitrogen. The tests were performed finite bath following a 22 factorial design, with the variables: pH and initial concentrations of metal. The clays were evaluated for their removal capacity and rate of metal removal. After the characterization and evaluation, it was found that the gray clay comprises clay of the groups of kaolinite and mica. The results of the factorial design shown that the adsorption of the metals zinc and lead can be developed with good percentage of removal.

Synthesis of Ni-Mo-W Sulfide Nanorods as Catalyst for Hydrodesulfurization of Dibenzothiophene

2008 ◽  
Vol 8 (12) ◽  
pp. 6406-6413 ◽  
Author(s):  
F. Paraguay-Delgado ◽  
R. García-Alamilla ◽  
J. A. Lumbreras ◽  
E. Cizniega ◽  
G. Alonso-Núñez
Keyword(s):  
Electron Microscopy ◽  
Physical Adsorption ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Precursor ◽  
Transmission Electron ◽  
Adsorption Of Nitrogen ◽  
Diffraction Patterns ◽  
Scanning Electron

Two trimetallic sulfurs, MoWNiS and MoWSNi, were synthesized to be used as a catalyst in hydrodesulfurization reactions. The mixed oxide mesoporous nanostructured MoO3-WO3 with an Mo:W atomic ratio of 1:1 was used as the precursor. The first catalyst was prepared by impregnating nickel in the oxide precursor and then subsequent sulfiding with an H2S/H2 mix at 400 °C for 2 hours. The second catalyst was prepared by sulfiding the precursor and then impregnating the nickel, and finally reducing the material with a H2/N2 at 350 °C. In both catalysts the Mo:W:Ni atomic ratio was maintained at 1:1:0.5. The materials obtained were characterized by physical adsorption of nitrogen, X-ray diffraction, scanning electron microscopy, transmission electron microscopy. Furthermore, the materials obtained were evaluated by a dibenzothiophene hydrodesulfuration reaction. The diffraction patterns show that both materials are polycrystalline and mainly of MoS2 and WS2 phases.

Evaluation of Bentonite Clay Type in the Chocobofe Zinc Adsorption in Finite Bath System

2015 ◽  
Vol 820 ◽  
pp. 539-544
Author(s):  
J.V. do N. Silva ◽  
Janaína Rafaella Scheibler ◽  
M.G.F. Rodrigues
Keyword(s):  
Physical Adsorption ◽  
Bentonite Clay ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Promising Alternative ◽  
X Ray ◽  
Smectite Clays ◽  
Bet Method ◽  
Adsorption Of Nitrogen ◽  
Percentage Removal

In this work the smectite clays Chocobofe from the state of Paraíba was investigated to evaluate their affinity and capacity for removal of zinc using a finite bath system. The clay was characterized by means of X-Ray Diffraction (XRD), Infrared Spectroscopy in the Region (IV) and Cation Exchange Capacity (CEC) and Physical Adsorption of Nitrogen (BET method). A 22 factorial design was conducted with three center points in a finite bath system to determine the percentage removal (% Rem) and removability (qeq) of the clay. Values of 83.35 to 98.83% and the percentage removal from 3.83 to 4.24 mg / g removal were achieved in experiments, indicating that the use of clay Chocobofe appears as a promising alternative to remove of Zn2+

Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Sem Micrograph ◽  
Pseudo Second Order ◽  
Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

Adsorption Capacity of Y Zeolite Using Organic Solvents such as Adsorbates

2014 ◽  
Vol 805 ◽  
pp. 641-645
Author(s):  
Ana Paula Araújo ◽  
Aline Cadigena Lima Patrício ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Small Molecules ◽  
Adsorption Capacity ◽  
Selective Adsorption ◽  
X Ray Diffraction ◽  
Y Zeolite ◽  
High Adsorption ◽  
X Ray ◽  
Low Concentrations ◽  
Adsorption Of Nitrogen ◽  
Type Zeolite

The zeolites differ from traditional adsorbents for selective adsorption of small molecules, the high adsorption capacity at low concentrations and affinity for organic compounds and unsaturated polar molecules. In this work a Y-type zeolite was synthesized, characterized by x-ray diffraction, scanning electron microscopy and adsorption of nitrogen and subjected to test adsorption capacity where it was found that the Y zeolite has the potential adsorption capacity compared to other materials being studied and marketed.

A Label-Free Electrochemical Aptasensor for the Rapid Detection of Tetracycline Based on Ordered Mesoporous Carbon–Fe3O4

2018 ◽  
Vol 71 (3) ◽  
pp. 170 ◽  
Author(s):  
Xuejia Zhan ◽  
Guangzhi Hu ◽  
Thomas Wagberg ◽  
Dongwei Zhang ◽  
Pei Zhou
Keyword(s):  
Photoelectron Spectroscopy ◽  
Mesoporous Carbon ◽  
Physical Adsorption ◽  
Differential Pulse ◽  
Ordered Mesoporous Carbon ◽  
Label Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Mesoporous ◽  
Modification Procedure

A novel aptasensor based on a tetracycline (TET) aptamer immobilized by physical adsorption on an ordered mesoporous carbon–Fe3O4 (OMC-Fe3O4)-modified screen-printed electrode surface was successfully fabricated. OMC-Fe3O4 was characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The modification procedure of the aptasensor was characterized by cyclic voltammetry. Interaction between the TET aptamer and target was determined by differential pulse voltammetry. Under optimal conditions, the proposed aptasensor exhibited good electrochemical sensitivity to TET in a concentration range of 5 nM to 10 μM, with a detection limit of 0.8 nM (S/N = 3). This aptasensor exhibited satisfactory specificity, reproducibility, and stability.

scholarly journals Exploiting the Potential in Water Cleanup from Metals and Nutrients of Desmodesmus sp. and Ampelodesmos mauritanicus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1461
Author(s):  
Roberto Braglia ◽  
Lorenza Rugnini ◽  
Sara Malizia ◽  
Francesco Scuderi ◽  
Enrico Luigi Redi ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Metal Removal ◽  
Anthropogenic Activities ◽  
Cost Effective ◽  
Single Species ◽  
Nitrogen And Phosphorus ◽  
Removal Rates ◽  
Sequential Approach ◽  
Removal Capacity ◽  
Green Microalga

Increasing levels of freshwater contaminants, mainly due to anthropogenic activities, have resulted in a great deal of interest in finding new eco-friendly, cost-effective and efficient methods for remediating polluted waters. The aim of this work was to assess the feasibility of using a green microalga Desmodesmus sp., a cyanobacterium Nostoc sp. and a hemicryptophyte Ampelodesmos mauritanicus to bioremediate a water polluted with an excess of nutrients (nitrogen and phosphorus) and heavy metals (copper and nickel). We immediately determined that Nostoc sp. was sensitive to metal toxicity, and thus Desmodesmus sp. was chosen for sequential tests with A. mauritanicus. First, A. mauritanicus plants were grown in the ‘polluted’ culture medium for seven days and were, then, substituted by Desmodesmus sp. for a further seven days (14 days in total). Heavy metals were shown to negatively affect both the growth rates and nutrient removal capacity. The sequential approach resulted in high metal removal rates in the single metal solutions up to 74% for Cu and 85% for Ni, while, in the bi-metal solutions, the removal rates were lower and showed a bias for Cu uptake. Single species controls showed better outcomes; however, further studies are necessary to investigate the behavior of new species.

Detection of accumulated continuously ethanol concentration by ZnO–SnO2 composite nanorods sensor

2021 ◽  
pp. 2150395
Author(s):  
Xiang-Bing Li ◽  
Da-Qian Mo ◽  
Xiao-Yan Niu ◽  
Qian-Qian Zhang ◽  
Shu-Yi Ma ◽  
...  
Keyword(s):  
Recovery Time ◽  
Ethanol Concentration ◽  
Physical Adsorption ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Atomic Force ◽  
Electrospinning Method ◽  
Response And Recovery ◽  
Composite Nanorods

ZnO–SnO2 composite nanorods with rough surfaces were synthesized via a coaxially nested needle electrospinning method. The morphology and nanostructure were characterized by scanning electron microscopy, atomic force microscope, EDS mapping, nitrogen physical adsorption, and X-ray diffraction. The synthesis mechanisms of ZnO–SnO2 nanorods were discussed, which combined the gas sensitivity advantages of different materials. ZnO–SnO2 nanorods sensor with good ethanol gas sensitivity achieved accurate measurement of continuous ethanol concentration. The sensor exhibited good selectivity to ethanol in the presence of formaldehyde, methanol, acetone, acetic acid, benzene, and xylene at 290[Formula: see text]C. The response and recovery time to 100 ppm ethanol were about 13 and 35 s, respectively. The energy band, barrier, charge transfer of ZnO–SnO2 composite material was discussed, and its optimization of gas sensitivity was analyzed in detail.

scholarly journals Conversion of fisheries waste as magnetic hydroxyapatite bionanocomposite for the removal of heavy metals from groundwater

2017 ◽  
Vol 18 (4) ◽  
pp. 1406-1419
Author(s):  
F. Elmi ◽  
R. Chenarian Nakhaei ◽  
H. Alinezhad
Keyword(s):  
Heavy Metals ◽  
Freundlich Isotherm ◽  
Spectroscopic Techniques ◽  
Order Kinetic ◽  
Fish Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Order Kinetic Model ◽  
Ir Spectroscopic

Abstract This study is the first report of its type demonstrating the synthesis of mHAP on the basis of magnetic functionalization with nHAP, which were synthesized using Rutilus frisii kutum fish scale as a benign fishery waste by-product. The mHAP was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray diffraction (EDX), and Fourier transform infrared (FT-IR) spectroscopic techniques. The XRD pattern confirmed the formation of a single-phase nHAP without any extra steady phases. It was also found that the pseudo-second-order kinetic model gave a satisfactory fit to the experimental data (R2 = 0.99). The maximum removal percentages of Cu and Zn ions in optimal conditions (adsorbent dosage at 0.1 g, 30 min contact time at 25 ± 1 °C and pH = 5 ± 0.1) by mHAP were 97.1% and 93.8%, respectively. Results also demonstrated that mHAP could be recycled for up to five cycles in the case of copper and zinc. The Langmuir isotherm was proved to have a better correlation compared with that of the Freundlich isotherm. The thermodynamic parameters indicated that it was a spontaneously endothermic reaction. In conclusion, mHAP could be regarded as a powerful candidate for efficient biosorbent, capable of adsorbing heavy metals from aqueous solutions.

scholarly journals Heavy metal removal from wastewater using various adsorbents: a review

2016 ◽  
Vol 7 (4) ◽  
pp. 387-419 ◽  
Author(s):  
Renu ◽  
Madhu Agarwal ◽  
K. Singh
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Aquatic Ecosystems ◽  
Adsorption Process ◽  
Metal Removal ◽  
Low Cost ◽  
Heavy Metal Removal ◽  
Review Article ◽  
Removal Capacity ◽  
Removal Of Heavy Metals

Heavy metals are discharged into water from various industries. They can be toxic or carcinogenic in nature and can cause severe problems for humans and aquatic ecosystems. Thus, the removal of heavy metals from wastewater is a serious problem. The adsorption process is widely used for the removal of heavy metals from wastewater because of its low cost, availability and eco-friendly nature. Both commercial adsorbents and bioadsorbents are used for the removal of heavy metals from wastewater, with high removal capacity. This review article aims to compile scattered information on the different adsorbents that are used for heavy metal removal and to provide information on the commercially available and natural bioadsorbents used for removal of chromium, cadmium and copper, in particular.

XRD (X-Ray Diffraction) Analysis of the Stabilized Ash

2013 ◽  
Vol 459 ◽  
pp. 7-10
Author(s):  
Hai Ying Zhang ◽  
Shu Zhen Li
Keyword(s):  
Heavy Metals ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Leaching Toxicity ◽  
Mineralogical Compositions

MSWI (municipal solid waste incineration) fly ash, generated in incineration process of municipal solid waste, contains lots of heavy metals, which will do harm do the environment if extracted. In this work, the ash is stabilized by cement to reduce leaching toxicity of heavy metals. Besides, mineralogical compositions of the product of different cement / ash ratios after conservation for different period were analyzed by means of XRD (X-ray diffraction). It was found that major mineralogical compositions CaCO3, Ca (0H)2 and C-H-S hydration products. Content of Ca (0H)2 and C-H-S rises with increase of conservation period and cement / ash ratio.

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