Removal of Cr by Modified Biochar Derived from Corn Husk

2021 ◽  
Vol 21 (7) ◽  
pp. 3965-3970
Author(s):  
Hyungjoo Kim ◽  
Jin Sun Cha ◽  
Jieun Park ◽  
Young-Min Kim ◽  
Young-Kwon Park

In this study, the physicochemical properties of modified biochar using different methods, such as physical (CO2, steam) and chemical (KOH and H3PO4) methods, were estimated by X-ray diffraction, N2 adsorption-desorption, field-emission scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The performance of chars was evaluated using a Cr adsorption performance test. Among various chars modified in this study, CHC-P modified by H3PO4 showed the highest chromium adsorption efficiency. The adsorption efficiency was affected by the high nano-porosity, large surface area, and surface oxygen-containing functional groups.

2013 ◽  
Vol 743-744 ◽  
pp. 434-437
Author(s):  
Miao Lv ◽  
Guo Tong Qin ◽  
Wei Wei

TiO2aerogel fibers have been fabricated by electron span combined supercritical drying technique. Polyvinylpyrrolidone (PVP)/TiO2composite fibers are prepared by electrospinning PVP and TiO2precursor Ti (OC4H9)4. TiO2aerogel fibers are obtained by supercritical drying PVP/TiO2composite fibers using ethanol as media. Structural of the aerogel fibers was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and N2adsorption at 77 K. The effect of mass ratio of PVP/TiO2was investigated. SEM shows that pore structure of nanofibers was well developed, with the diameter of nanofibers about 2 μm. N2adsorption/desorption data show that the highest surface area of aerogel fibers reached 241.6 m2/g with the average pore diameter about 10 nm. The aerogel fibers were anatase type TiO2.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Ruiyu Wang ◽  
Fei Wang ◽  
Ling Liu

Activated carbon (AC) was modified by H2SO4 and used as a support for catalyst. The Fe2S3/AC-T catalyst was prepared by deposition-precipitation method and used to catalyze hydrocracking of coal-related model compound, di(1-naphthyl)methane (DNM). The properties of catalyst were studied by N2 adsorption-desorption, X-ray diffraction, and scanning electron microscopy. The result showed that ferric sulfate and acidic centers had synergetic effect on hydrocracking of DNM when using Fe2S3/AC-T as catalyst, the optimal loading of Fe is 9 wt.%. Hydroconversion of the extraction residue from Guizhou bituminous coal was also studied using Fe2S3/AC-T as the catalyst. The reaction was conducted in cyclohexane under 0.8 Mpa of initial hydrogen pressure at 310°C. The reaction mixture was extracted with petroleum ether and analyzed by GC/MS. Amounts of organic compounds which fall into the categories of homologues of benzene and naphthalene were detected. It suggested that the catalyst could effectively catalyze the cleavage of C-C-bridged bonds.


2019 ◽  
Vol 79 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Patrícia Grassi ◽  
Caroline Reis ◽  
Fernanda C. Drumm ◽  
Jordana Georgin ◽  
Denise Tonato ◽  
...  

Abstract An inactive biomass of a new fungus recently discovered, Diaporthe schini, was evaluated for the biosorption of crystal violet (CV) in simulated textile effluents. The characterization assays were performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms. The influences of pH and biosorbent dosage on the biosorption capacity were evaluated. Kinetics, equilibrium and thermodynamic studies were also carried out. Characterization techniques showed an amorphous biosorbent, with a rough surface containing irregular particles and surface area of 6.5 m2 g−1. The most adequate values of pH and biosorbent dosage were 7.5 and 0.4 g L−1, respectively. The Elovich kinetic model and the Sips equilibrium model were suitable to fit the experimental data. The biosorption capacity increased with temperature, reaching a maximum biosorption capacity of 642.3 mg g−1 at 328 K. The biosorption was a spontaneous and endothermic process. Diaporthe schini inactive biomass was an interesting biosorbent to treat colored effluents, presenting efficiency of 87% in the decolorization of a simulated dye house effluent.


2013 ◽  
Vol 742 ◽  
pp. 448-451
Author(s):  
Ming Feng Wang ◽  
Tou Gen Liao ◽  
Bao Kun Zhu ◽  
Yao Wang ◽  
Yan Qing Duan ◽  
...  

Mesoporous TiO2 with anatase crystalline structure (MTiO2) has been synthesized by using Lac Red as template. The synthesized mesoporous titania samples were characterized by a combination of various physicochemical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), N2 adsorption/desorption. It was found that without any external doping MTiO2 exhibited significant high adsorption abilities for adsorbing the gaseous acetaldehyde by the adsorption ratio of 39.15%.


2014 ◽  
Vol 852 ◽  
pp. 51-55 ◽  
Author(s):  
Tie Ben Song ◽  
Yan Bo Wu ◽  
Peng Sun ◽  
Jun Bi

The TiO2-activated carbon fiber (ACF) was successfully prepared by electrospinning and thermal treatment. The nanofiber was characterized by scanning electron microscopy (SEM), thermogravimetric-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) and Brunner-Emmett-Teller method (BET). The results showed that the average diameter of ACF was in the range 200-500 nm, and the preoxidation temperature and carbonation temperature were 250°C and 500°C, and the anatase TiO2 appeared in fiber after carbonation, and TiO2-ACF specific surface area was 1146.7 m2/g. The TiO2-ACF was used for adsorption of low concentration SO2. The results showed that the adsorption rate increased with an increase in SO2 concentration, furthermore the adsorption rate increased with prolonged adsorption time, the high adsorption rate was 67.6% after 40 min. While temperature was below 60°C, the adsorption rate decreased as the temperature increased, however when temperature was above 60°C, there was a slight increase of adsorption rate as the temperature increased.


2018 ◽  
Vol 929 ◽  
pp. 33-41 ◽  
Author(s):  
Nofrijon Sofyan ◽  
Adlan Mizan ◽  
Anne Zulfia Syahrial ◽  
Achmad Subhan

Used of carbon pyrolyzed from table sugar in the synthesis of LiFe(1-x)VxPO4/C for lithium ion battery cathode has been examined. The process was begun by synthesizing LiFePO4through a hydrothermal method with the precursors of LiOH, NH4H2PO4and FeSO4.7H2O. The as-synthesized LiFePO4was then mixed with various H4NO3V concentrations and fixed 3 wt.% of carbon pyrolyzed from table sugar and calcined for 2 hours at 400 °C. The result was ball-milled and was then characterized using a thermal analyzer to determine the transition temperature at which sintering temperature of 700 °C for 4 hours was obtained. X-ray diffraction (XRD) was performed to analyze the crystal structure whereas scanning electron microscope (SEM) was used to examine the microstructure and surface morphology. XRD results show that LiFe(1-x)VxPO4/C phase has been formed with an olivine-based structure. SEM results showed an even distribution of LiFe(1-x)VxPO4/C particles. The batteries were prepared from the as-synthesized materials and were tested using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge and discharge (CD) tests. The EIS results showed that carbon improved the conductivity. The performance test showed that the addition of vanadium resulted in a capacity of about 51.06 mAh/g with a potential of 3.581 V at charging and 49.42 mAh/g with a potential of 3.319 V at discharging. These results are promising in terms of using table sugar as a cheap carbon source for lithium ion battery cathode development.


2014 ◽  
Vol 575 ◽  
pp. 93-96 ◽  
Author(s):  
S. Hanim Md Nor ◽  
M. Nazri Abu Shah ◽  
Abdul Hadi ◽  
Kamariah Noor Ismail

5wt% Co deposited on a support catalyst Ce0.75Zr0.25O2 mixed oxide were prepared by combination of microemulsion and deposition-precipitation method followed by calcinations at temperature 500°C. The microemulsion component comprise of cetyl trimetyl ammonium-bromide (CTAB), 1-butanol, n-octane and aqueous solution. Sodium hydroxide (NaOH) was used as precipitation precursor for the preparation of water-in-oil microemulsions method. The particles were characterized by X-ray diffraction (XRD), N2 adsorption-desorption analysis and Field Emission Scanning Electron Microscopy (FESEM). The results showed the preparation method has significant influences on the textural and structure properties of Co/Ce0.75Zr0.25O2. The formation of Co/Ce0.75Zr0.25O2 inhibit the better performance based on the particles size, specific surface area and particle distribution of cobalt into Ce0.75Zr0.25O2.


2020 ◽  
Vol 9 (1) ◽  
pp. 88-94
Author(s):  
Tuan Nguyen Dinh Minh ◽  
Nga Phan Thi Hang

In this study, the catalytic performances of the complete oxidation of toluene over different transition metal oxides including MnO2, Co3O4 and NiO were investigated. These oxides were synthesized by hydrothermal method, followed by annealing. The catalysts were characterized by X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and Nitrogen isotherm adsorption-desorption before being evaluated their catalytic activity for the total oxidation of toluene in air. As a result, MnO2 was illustrated as the best catalyst having largest surface area and lowest activation energy, followed by Co3O4 and NiO.


2021 ◽  
pp. 73-88
Author(s):  
Hayet Tizi ◽  
Tarek Berrama ◽  
Djamila Hamane ◽  
Fatiha Ferrag-Siagh ◽  
Zoubida Bendjama

This work aims to evaluate the adsorption efficiency of p-nitroaniline (PNA) onto apricot stones activated carbon (ASAC) mixed with treated extract of amorphous SiO2 (TEAS), prepared from Algerian diatomite (AD). The best removal percentage (85%) is obtained for a ratio ASAC/TEAS (1/1). Adsorbent characteristics are investigated by the Brunauer-Emmett-Teller (BET), the scanning electron microscope (SEM), infrared spectroscopy (IR), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The impregnation of TEAS and ASAC produces good adsorbent properties towards PNA especially in the ratio (1/1) and an increase in the specific surface. The isotherm data are well fitted by the Langmuir and Freundlich models. The maximum PNA uptake obtained is 94.34 mg g-1. The performances of ASAC/TEAS for the PNA adsorption were compared with some adsorbents previously studied for the same purpose, and results show that the composite in the present work exhibit better performances. The adsorption behavior of the concerned material is explained on the basis of its chemical nature and porous texture.


2015 ◽  
Vol 1118 ◽  
pp. 242-250 ◽  
Author(s):  
Zhen Wu Ding ◽  
Si Chen ◽  
Zhong Qing Liu ◽  
Cheng Fa Jiang ◽  
Wei Chu

Mesoporous S-doped TiO2 microspheres were synthesized via hydrothermal method using Ti (SO4)2 precursor and urea as homogeneous precipitate agent. The TiO2-based catalyst samples were characterized by means of Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), N2 adsorption/desorption and UV-vis diffuse reflectance spectra (UV-vis DRS). Photo-catalytic experiments were carried out by catalytic degradation of methylene blue aqueous solution under visible light. It was found that the S-doped TiO2 microspheres gave better photo-catalytic performances. The higher absorbance in the visible region explained this phenomenon. There was an appropriate Ti (SO4)2 amount for the catalyst with better photo-catalytic degradation.


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