Dispersive solid phase extraction of copper and lead from water and lichen samples with an activated carbon@Fe/Mn/O composite derived from sucrose-based activated carbon

2019 ◽  
Vol 11 (41) ◽  
pp. 5311-5319 ◽  
Author(s):  
Veysel Berkdemir ◽  
Şerife Tokalıoğlu ◽  
Süleyman Yıldız ◽  
Şaban Patat

In this study, an activated carbon@Fe/Mn/O composite was synthesized and characterized by X-ray diffraction, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, Brunauer, Emmett, and Teller surface area and zeta potential measurements.

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8641-8652
Author(s):  
Jing Geng ◽  
Lu-Fei Li ◽  
Wen-Liang Wang ◽  
Jian-Min Chang ◽  
Chang-Lei Xia ◽  
...  

Characteristics of the char produced in the co-pyrolysis of used rubber and larch sawdust were studied in the conversion of low-valued pyrolysis char into value-added activated carbon using two-step co-pyrolysis, namely pyrolysis and activation processes. The physicochemical characteristics of the chars were examined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM). The results revealed that after the two-step co-pyrolysis, the upgraded carbon had BET surface areas ranging from 600 m2 g−1 to 900 m2 g−1, which were higher than the requirements for activated carbon (American Water Works Association B600 standard). Additionally, as the sawdust/rubber ratio increased, the BET value increased accordingly. A possible reaction mechanism is proposed based on the experimental results during the activation process.


Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1515
Author(s):  
Halyna Klym ◽  
Ivan Karbovnyk ◽  
Andriy Luchechko ◽  
Yuriy Kostiv ◽  
Viktorija Pankratova ◽  
...  

BaGa2O4 ceramics doped with Eu3+ ions (1, 3 and 4 mol.%) were obtained by solid-phase sintering. The phase composition and microstructural features of ceramics were investigated using X-ray diffraction and scanning electron microscopy in comparison with energy-dispersive methods. Here, it is shown that undoped and Eu3+-doped BaGa2O4 ceramics are characterized by a developed structure of grains, grain boundaries and pores. Additional phases are mainly localized near grain boundaries creating additional defects. The evolution of defect-related extended free volumes in BaGa2O4 ceramics due to the increase in the content of Eu3+ ions was studied using the positron annihilation lifetime spectroscopy technique. It is established that the increase in the number of Eu3+ ions in the basic BaGa2O4 matrix leads to the agglomeration of free-volume defects with their subsequent fragmentation. The presence of Eu3+ ions results in the expansion of nanosized pores and an increase in their number with their future fragmentation.


2012 ◽  
Vol 466-467 ◽  
pp. 458-462
Author(s):  
Ying Jie Zhang ◽  
Shu Fen Xu ◽  
Xia Liao ◽  
Rong Yang ◽  
Da Peng Li

A new heterogeneous Fenton-like catalyst of Fe/S/GAC was prepared by granular activated carbon (GAC) soaked in solution of (NH4)2S2O8 and Fe(NO3)3. The effect of the concentration of (NH4)2S2O8 , Fe(NO3)3, drying temperature and different catalysts on the catalytic reactivity of catalyst was discussed. The removal rate of Orange IV was used to express the catalytic reactivity of the catalyst. The prepared catalysts were characterized by X-ray diffraction (XRD), specific surface area (BET) and scanning electron microscopy (SEM). The removal rate of Orange IV followed second-order kinetics. The catalyst of Fe/S/GAC has higher catalytic activity than that of Fe/GAC.


2013 ◽  
Vol 781-784 ◽  
pp. 243-246
Author(s):  
Guang Jian Wang ◽  
Jian Kang Zhang ◽  
Hui Liu

Deep desulfurization via π-complexation adsorption is a promising method for the purification of diesel. Activated carbon (AC) with copper and palladium deposited on their surfaces were investigated as adsorbents to remove benzothiophene (BT) from model diesel fuel. The adsorbents were prepared by ultrasonic-assisted impregnation and characterized using X-ray diffraction (XRD) and Scanning Electron Microscopy with Energy-dispersive X-ray Spectroscopy (SEM/EDS). The adsorption isotherms of BT were also investigated.


2020 ◽  
Vol 9 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Yola Azli Perdana ◽  
Rahma Joni ◽  
Emriadi Emriadi ◽  
Hemansyah Aziz

Karbon aktif dari cangkang kelapa sawit sebagai bahan elektroda superkapasitor telah diteliti. Superkapasitor dirangkai dengan metoda plat/sandwich yang dipisahkan oleh separator. Untuk mendapatkan nilai kapasitansi yang besar dilakukan variasi jumlah aktivator terhadap karbon menggunakan aktivator KOH. Sifat fisikokimia dari karbon aktif diteliti dengan melakukan karakterisasi menggunakan XRD (X-Ray Diffraction), SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-Ray) dan SAA (Surface Area Analyzer) dan sifat elektrokimianya diteliti dengan pengukuran CV (Cyclic Voltammetry). Karbon aktif dengan perbandingan 1:5 memiliki luas permukaan yang paling besar yaitu 793,326 m2/g dan nilai kapasitansi spesifik tertinggi yaitu 99,151 F/g. The activated carbon from oil palm kernel shell as an electrode material for supercapacitors has been investigated. The supercapasitor was assembled by plate/sandwich methods. Both electrodes were separated by using a separator. To increase the capacitancy value, variations in the number of activators on carbon were carried out using KOH activator. The physicochemical properties of activated carbon were investigated by characterizing using XRD (X-Ray Diffraction), SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-Ray) and SAA (Surface Area Analyzer) and the electrochemical properties were investigated by measuring CV (Cyclic Voltammetry). Activated carbon with a ratio of 1:5 has the largest surface area of 793,326 m2/g and the highest specific capacitance value is 99,151 F/g.Keywords: activated carbon, supercapasitor, activator, surface area, specific capacitance


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ledwaba Harry Moloto ◽  
Sunnyboy Stanley Manzini ◽  
Ezekiel Dixon Dikio

The reduction behaviour of magnetite using graphite under ball-milling conditions (using a planetary mono mill, Fritsch Pulverisette 6) has been investigated. The reaction of magnetite and graphite at different milling conditions leads to the formation of Fe2+and Fe3+species, the former increasing at the expense of Fe3O4. Fe3O4completely disappeared after a ball to powder ratio of 50 : 1 and beyond. The Fe2+species were confirmed to be due to FeO using Mössbauer Spectroscopy and X-ray diffraction techniques. Scanning electron microscopy and transmission electron microscopy analyses confirm the reduction of magnetite to wüstite.


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.


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


2018 ◽  
Vol 21 (7) ◽  
pp. 495-500 ◽  
Author(s):  
Hassan A. Almarshad ◽  
Sayed M. Badawy ◽  
Abdalkarem F. Alsharari

Aim and Objective: Formation of the gallbladder stones is a common disease and a major health problem. The present study aimed to identify the structures of the most common types of gallbladder stones using X-ray spectroscopic techniques, which provide information about the process of stone formation. Material and Method: Phase and elemental compositions of pure cholesterol and mixed gallstones removed from gallbladders of patients were studied using energy-dispersive X-ray spectroscopy combined with scanning electron microscopy analysis and X-ray diffraction. Results: The crystal structures of gallstones which coincide with standard patterns were confirmed by X-ray diffraction. Plate-like cholesterol crystals with laminar shaped and thin layered structures were clearly observed for gallstone of pure cholesterol by scanning electron microscopy; it also revealed different morphologies from mixed cholesterol stones. Elemental analysis of pure cholesterol and mixed gallstones using energy-dispersive X-ray spectroscopy confirmed the different formation processes of the different types of gallstones. Conclusion: The method of fast and reliable X-ray spectroscopic techniques has numerous advantages over the traditional chemical analysis and other analytical techniques. The results also revealed that the X-ray spectroscopy technique is a promising technique that can aid in understanding the pathogenesis of gallstone disease.


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