CuO/polypyrrole nanocomposites as a marker of toxic lead ions for ecological remediation in contrast with CuO and polypyrrole

2015 ◽  
Vol 38 (5-6) ◽  
Author(s):  
Asha Radhakrishnan ◽  
Padmavathiamma Rejani ◽  
Bhaskaran Beena

AbstractIn the present study, CuO, polypyrrole (PPy), and CuO/PPy nanocomposites were synthesized to compare the selective adsorption behavior of hazardous metal ions such as Pb(II) ions. The synthesized nanomaterials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller surface area analysis, and energy dispersive X-ray spectroscopy. The adsorption studies clearly showed that CuO/PPy nanocomposites exhibited much higher adsorption performance than individual CuO and PPy. Kinetic data followed the pseudo-second-order model. The equilibrium attained at 120 min and isotherm follows the order Sips>Langmuir>Freundlich. The adsorbed Pb(II) is desorbed using 0.1

2019 ◽  
Vol 10 (1) ◽  
pp. 64-71
Author(s):  
Ibtighaa Kadhim Radhi ◽  
Mouayed Abdulaali Hussein ◽  
Zaki Naser Kadhim

Successful removal of nigrosine, alizarin, indigo and acid fuchsin dyes from aqueous solutions using modified CaO nanoparticles has been investigated. The CaO was obtained from eggshells and modified with AgI. The adsorbents were characterized using X-ray diffraction, energy dispersive X-ray spectroscopy, scanning electron microscopy and transmission electron microscopy. The kinetic studies were also investigated, the results showed that the adsorption of alizarin dye follows the pseudo-first-order model, while the adsorption of the nigrosine, indigo, and acid fuchsin follow the pseudo-second-order model onto modified and unmodified CaO. Moreover, the photocatalytic activity of modified adsorbent was tested under sunlight. The modified adsorbent showed a strong photocatalytic activity, a 0.01 g modified adsorbent was sufficient to absorb 100% of acid fuchsin through only 5 min after exposes to sunlight.


2018 ◽  
Vol 34 (3) ◽  
pp. 1233-1239 ◽  
Author(s):  
Olushola S. Ayanda ◽  
Kehinde O. Sodeinde ◽  
P. O. Okolo ◽  
Ayomitide A. Ajayi ◽  
Simphiwe M. Nelana ◽  
...  

In this study, the adsorption of amido black (AB) dye onto kaolin was investigated. The characterization of kaolin was carried out by powder x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR). Adsorption studies showed that the adsorption of AB onto kaolin increased with increasing adsorbent dosage, contact time, pH and temperature but decreased with increasing dye concentration. Equilibrium data fitted perfectly into the Langmuir and Freundlich equilibrium models, moreover, the kinetic data followed the pseudo-second order model. The adsorption process is endothermic and approximately 60.75% AB reduction was achieved when 0.75 g of kaolin was mixed with 20 mL of 40 mg/L AB for 60 min at 200 rpm. Therefore, this study shows that kaolin can be harnessed for the treatment of textile wastewater.


2020 ◽  
Vol 82 (7) ◽  
pp. 1339-1349
Author(s):  
Fengfeng Ma ◽  
Bakunzibake Philippe ◽  
Baowei Zhao ◽  
Jingru Diao ◽  
Jian Li

Abstract Flax straw biochar (FSBC)-supported nanoscale zero-valent iron (nZVI) composite (nZVI-FSBC) combining the advantages of nZVI and biochar was synthesized and tested for Cr(VI) removal efficiency from aqueous solution. Surface morphology and structure of FSBC and nZVI-FSBC were characterized by scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller techniques, which help to clarify the mechanism of Cr(VI) removal from aqueous solution. The adsorption of Cr(VI) onto FSBC and nZVI-FSBC was best described by the pseudo-second-order and the Sips model. Compared with FSBC, nZVI-FSBC remarkably improved the performance in removing Cr(VI) under identical experimental conditions. Due to the collaborative effect of adsorption and reduction of nZVI-FSBC, the adsorption capacity of nZVI-FSBC for Cr(VI) is up to 186.99 mg/g. The results obtained by XPS, XRD, and FTIR confirmed that adsorption and reduction dominated the processes of Cr(VI) removal by nZVI-FSBC. As a supporter, FSBC not only improved the dispersion of nZVI, but also undertook the adsorption task of Cr(VI) removal. The surface oxygen-containing functional groups of nZVI-FSBC mainly participated in the adsorption part, and the nZVI promoted the Cr(VI) removal through the redox reactions. These observations indicated that the nZVI-FSBC can be considered as potential adsorbents to remove Cr(VI) for environment remediation.


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2065
Author(s):  
Wei Zhang ◽  
Yili Huang

Increasing heavy metal pollution in water continues to endanger human health. The genus Shinella has potential for heavy metal bioremediation but has rarely been studied. In this study, we report that Shinella zoogloeoides PQ7 turns black in the presence of lead ions. Transmission electron microscopy (TEM), Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) indicated that PbS nanoparticles (NPs) were synthesized by PQ7. Moreover, PQ7 was used as a biosorbent to remove Pb(II) from aqueous solutions. Biosorption performance was evaluated in terms of contact time, pH, biomass dosage and initial Pb(II) concentration. The equilibrium and kinetic data were consistent with the Freundlich isotherm model (R2 = 0.986) and pseudo-second-order model (R2 = 0.977), respectively. The maximum (qmax) Pb(II) adsorption reached 222.22 mg/g, which was higher than that of other bacteria reported in previous literature. SEM–EDS, XRD and Fourier transform infrared (FTIR) analyses also confirmed the adsorption of Pb(II) by the PQ7 cells. In conclusion, PQ7 is a promising strain in removing and recovering Pb(II) from wastewater.


Author(s):  
R. Gronsky

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


2002 ◽  
Vol 716 ◽  
Author(s):  
Seok Woo Hong ◽  
Yong Sun Lee ◽  
Ki-Chul Park ◽  
Jong-Wan Park

AbstractThe effect of microstructure of dc magnetron sputtered TiN and TaN diffusion barriers on the palladium activation for autocatalytic electroless copper deposition has been investigated by using X-ray diffraction, sheet resistance measurement, field emission scanning electron microscopy (FE-SEM) and plan view transmission electron microscopy (TEM). The density of palladium nuclei on TaN diffusion barrier increases as the grain size of TaN films decreases, which was caused by increasing nitrogen content in TaN films. Plan view TEM results of TiN and TaN diffusiton barriers showed that palladium nuclei formed mainly on the grain boundaries of the diffusion barriers.


2003 ◽  
Vol 775 ◽  
Author(s):  
Donghai Wang ◽  
David T. Johnson ◽  
Byron F. McCaughey ◽  
J. Eric Hampsey ◽  
Jibao He ◽  
...  

AbstractPalladium nanowires have been electrodeposited into mesoporous silica thin film templates. Palladium continually grows and fills silica mesopores starting from a bottom conductive substrate, providing a ready and efficient route to fabricate a macroscopic palladium nanowire thin films for potentially use in fuel cells, electrodes, sensors, and other applications. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicate it is possible to create different nanowire morphology such as bundles and swirling mesostructure based on the template pore structure.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  

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.


2021 ◽  
Vol 19 (1) ◽  
pp. 745-754
Author(s):  
Khoirina Dwi Nugrahaningtyas ◽  
Eddy Heraldy ◽  
Rachmadani ◽  
Yuniawan Hidayat ◽  
Indriana Kartini

Abstract The properties of three types of CoMo/USY catalysts with different synthesized methods have been studied. The sequential and co-impregnation methods followed by activation using calcination and reduction process have been conducted. The properties of the catalysts were examined using Fourier-transform-infrared (FTIR) spectroscopy, X-ray diffraction (XRD) with refinement, and surface area analyzer (SAA). The FTIR spectrum study revealed the enhanced intensity of its Bronsted acid site, and the XRD diffractogram pattern verified the composition of pure metals, oxides, and alloys in the catalyst. The SAA demonstrated the mesoporous features of the catalyst. Scanning electron microscopy showed an irregular particle morphology. Additional analysis using the transmission electron microscopy indicated that the metal has successfully impregnated without damaging the USY structure.


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