scholarly journals FABRICATION OF Mg-Zn-Al HYDROTALCITE AND ITS APPLICATION FOR Pb2+ REMOVAL

2019 ◽  
Vol 59 (3) ◽  
pp. 260-271 ◽  
Author(s):  
Eddy Heraldy ◽  
Fitria Rahmawati ◽  
Dwi Ardiyanti ◽  
Ika Nurmawanti
Keyword(s):  
Second Order ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Adsorption Efficiency ◽  
Molar Ratios ◽  
Isotherm Adsorption ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Co Precipitation ◽  
Kinetics Of

The fabrication of Mg-Zn-Al Hydrotalcite (HT) was carried out by the co-precipitation method at various molar ratios. The Mg-Zn-Al HT compound at the optimum molar ratio was then calcined to determine the effect of calcination on the Pb2+ adsorption. The kinetics of the adsorption type was determined by applying pseudo first order and pseudo second order kinetics models. Meanwhile, to investigate the adsorption process, the Freundlich and Langmuir equations were applied to determine the adsorption isotherm. The results showed that the optimum Mg-Zn-Al HT was at a molar ratio of 3 : 1 : 1 with an adsorption efficiency of 73.16 %, while Mg-Zn-Al HT oxide increased the adsorption efficiency to 98.12 %. The optimum condition of Pb2+ removal using Mg-Zn-Al HT oxide was reached at pH 5 and a contact time of 30 minutes. The adsorption kinetics follows the pseudo second order kinetics model with a rate constant of 0.544 g/mg·min. The isotherm adsorption follows the Langmuir isotherm model with a maximum capacity of 3.916 mg/g and adsorption energy of 28.756 kJ/mol.

scholarly journals Removal of methylene blue from aqueous solution using Mg-Fe, Zn-Fe, Mn-Fe layered double hydroxide

2020 ◽  
Vol 81 (12) ◽  
pp. 2522-2532
Author(s):  
Zhongliang Shi ◽  
Yanmei Wang ◽  
Shuyu Sun ◽  
Cheng Zhang ◽  
Haibo Wang
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Langmuir Adsorption ◽  
Molar Ratios ◽  
Pseudo Second Order ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Double Hydroxides

Abstract Layered double hydroxides (LDH) with highly flexible and adjustable chemical composition and physical properties have attracted tremendous attention in recent years. A series of LDH with different M (Mg, Zn, Mn)-Fe molar ratios were synthesized by the double titration co-precipitation method. The effect of the factors, including M (Mg, Zn, Mn) : Fe molar ratio, pH, and M-Fe LDH dosage, on the ability of the prepared M-Fe LDH to remove cationic methylene blue (MB) dye from aqueous solution were investigated. Results indicated that the removal efficiency of MB (10 mg/L) was the best at the M (Mg, Zn, Mn): Fe molar ratio of 3:1 by using 2.0 g/L of M-Fe LDH at pH 6.0 under 298.15 K. Mg-Fe LDH had the highest removal performance (71.94 mg/g at 298.15 K) for MB compared to those of the Zn-Fe and Mn-Fe LDH. Zn-Fe LDH with the smallest activation energy resulted in the fastest adsorption rate of MB. The pseudo-second-order model and Langmuir adsorption isotherm were also successfully applied to fit the theory of M-Fe LDH for removal of MB.

scholarly journals Kinetic and thermodynamic adsorption of nickel (II) onto hydroxyapatite prepared from Snakehead (Channa striata) fish bone

2019 ◽  
Vol 9 (2) ◽  
pp. 85-94
Author(s):  
Poedji Loekitowati Hariani ◽  
Muryati Muryati ◽  
Muhammad Said Said
Keyword(s):  
Kinetic Model ◽  
Freundlich Isotherm ◽  
Fish Bone ◽  
Second Order ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Batch Adsorption ◽  
Thermodynamic Evaluation ◽  
Endothermic Process ◽  
Pseudo Second Order

Biomaterial exploration base on solid waste has been an attractive issue, particularly regarding economic and environmental demand. This work aimed to extract hydroxyapatite from snakehead fishbone through precipitation method and used to remove Ni(II). The hydroxyapatite product was characterized by using X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) and Brunauer Emmett Teller (BET) method. Batch adsorption experiment includes pH solution, contact time and Ni(II) concentration. Pseudo-first order and pseudo-second-order were used to investigate the reaction mechanism and kinetic model, while adsorption equilibrium was evaluated according to Langmuir and Freundlich isotherm. XRD and FTIR spectra confirmed that hydroxyapatite was successfully extracted. The molar ratio (Ca/P) of hydroxyapatite was found at 1.70. The particle size of the hydroxyapatite was 48.77 nm. The pseudo-second-order is appropriate to describe the kinetic model while the adsorption mechanism follows Langmuir isotherm, which has an adsorption capacity of 5.359mg/g. The thermodynamic evaluation suggested the adsorption of Ni(II) is spontaneous in the endothermic process.

scholarly journals Preparation of a novel Fe3O4/HCO composite adsorbent and the mechanism for the removal of antimony (III) from aqueous solution

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jun Zhang ◽  
Ren-jian Deng ◽  
Bo-zhi Ren ◽  
Baolin Hou ◽  
Andrew Hursthouse
Keyword(s):  
Dominant Role ◽  
Second Order ◽  
Maximum Adsorption Capacity ◽  
Isothermal Adsorption ◽  
Batch Tests ◽  
Equilibrium Data ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Co Precipitation ◽  
Optical Polishing

Abstract A novel adsorbent (Fe3O4/HCO) was prepared via co-precipitation from a mix of ferriferrous oxide and a Ce-rich waste industrial sludge recovered from an optical polishing activity. The effect of system parameters including reaction time, pH, dose, temperature as well as initial concentration on the adsorption of Sb(III) were investigated by sequential batch tests. The Sb(III)/Fe3O4/HCO system quickly reached adsorption equilibrium within 2 h, was effective over a wide pH (3–7) and demonstrated excellent removal at a 60 mg/L Sb(III) concentration. Three isothermal adsorption models were assessed to describe the equilibrium data for Sb(III) with Fe3O4/HCO. Compared to the Freundlich and dubinin-radushkevich, the Langmuir isotherm model showed the best fit, with a maximum adsorption capacity of 22.853 mg/g, which exceeds many comparable absorbents. Four kinetic models, Pseudo-first-order, Pseudo-second-order, Elovich and Intra-particle, were used to fit the adsorption process. The analysis showed that the mechanism was pseudo-second-order and chemical adsorption played a dominant role in the adsorption of Sb(III) by Fe3O4/HCO (correlation coefficient R2 = 0.993). Thermodynamic calculations suggest that adsorption of Sb(III) ions was endothermic, spontaneous and a thermodynamically feasible process. The mechanism of the adsorption of Sb(III) on Fe3O4/HCO could be described by the synergistic adsorption of Sb (III) on Fe3O4, FeCe2O4 and hydrous ceric oxide. The Fe3O4/HCO sorbent appears to be an efficient and environment-friendly material for the removal of Sb(III) from wastewater.

Reusable Mn-Doped ZnS Magnetic Nanocomposite for Photodegradation of Textile Dyes

2015 ◽  
Vol 33 ◽  
pp. 72-82
Author(s):  
Van Cuong Nguyen ◽  
My Dung Luu Thi ◽  
Thi Oanh Nguyen
Keyword(s):  
Dye Degradation ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Molar Percentage ◽  
Illumination Time ◽  
Molar Ratios ◽  
Photodegradation Efficiency ◽  
Ft Ir ◽  
Co Precipitation ◽  
Mn Doped

Magnetic nanoparticles of manganese doped ZnS has been synthesized with different molar ratios of manganese and zinc by co-precipitation method. Structure of the prepared nanocomposite was investigated using FT-IR, XRD, TEM and VSM. The most excellent photodegradation efficiency of Reactive Blue 198 (RB198) was observed with the molar ratio of Mn-doped ZnS/Fe3O4 and it was 1:1 in which molar percentage of Mn2+ was 9%. The experiments of dye degradation were carried out under visible light and UV radiation. Results shown that the degradation efficiency of RB198 was up to 100% at the concentration of 200 ppm for 10 minutes when the amount of catalyst was 0.2g/l. Additionally, the effect of various parameters including initial concentration, illumination time and pH to the photodegradation efficiency of dye was also carried out. More interestingly, the reusable experiments showed that the nanocomposited exhibited high photodegradation capacity after three cycles and can be recycled conveniently from water with the assist of an external magnet because of its exceptional properties.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav
Keyword(s):  
Synergetic Effect ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Alumina Support ◽  
Co Methanation ◽  
Temperature Range ◽  
Co Precipitation ◽  
Catalyst Distribution

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

Preparation and Characterization of Nanocomposite Calcium Doped Ceria Electrolyte With Alkali Carbonates (NK-CDC) for SOFC

2010 ◽  
Author(s):  
Ghazanfar Abbas ◽  
Rizwan Raza ◽  
Muhammad Ashraf Chaudhry ◽  
Bin Zhu
Keyword(s):  
Electron Microscopy ◽  
Fossil Fuels ◽  
Electrochemical Impedance ◽  
Renewable Energy Sources ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Doped Ceria ◽  
Alternative Source ◽  
Calcium Doped ◽  
Co Precipitation

The entire world’s challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid Oxide Fuel Cells (SOFCs) are believed to be the best alternative source which converts chemical energy into electricity without combustion. Nanostructured study is required to develop highly ionic conductive electrolyte for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M = Na and K) electrolyte was prepared by co-precipitation method in this study. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology was characterized by X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). The particle size was calculated in the range of 10–20nm by Scherrer’s formula and compared with SEM and TEM results. The ionic conductivity was measured by using AC Electrochemical Impedance Spectroscopy (EIS) method. The activation energy was also evaluated. The performance of the cell was measured 0.567W/cm2 at temperature 550°C with hydrogen as a fuel.

Effect of the Synthesis Method on the Properties of Ultrafine YAG Powder

2018 ◽  
Vol 281 ◽  
pp. 40-45
Author(s):  
Jie Guang Song ◽  
Lin Chen ◽  
Cai Liang Pang ◽  
Jia Zhang ◽  
Xian Zhong Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Hydrothermal Reaction ◽  
Synthesis Method ◽  
Particle Morphology ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Synthesis Process ◽  
Powder Materials ◽  
Co Precipitation

YAG materials has a number of unique properties, the application is very extensive. In this paper, the superfine YAG powder materials were prepared by co-precipitation method and hydrothermal precipitation method. The influence of synthesis process on the morphology of the powder was investigated. The results showed that the precursor powder prepared via the co-precipitation method is mainly from amorphous to crystalline transition with the increasing calcination temperature, the precursor agglomeration is more serious, In the process of increasing the calcination temperature, the dispersibility of the roasted powder is greatly improved, which is favorable for the growth of the crystal grains, so that the particle size of the powder is gradually increased, the YAG precursor prepared by the co-precipitation method is transformed into YAG crystals, the phase transition occurs mainly between 900 and 1100°C. When the molar ratio of salt to alkali is Y3+: OH-=1: 8 via the hydrothermal reaction, the YAG particles with homogeneous morphology can be obtained. When the molar ratio of salt and alkali is increased continuously, the morphology of YAG particles is not obviously changed. The co-precipitation method is easy to control the particle size, the hydrothermal method is easy to control the particle morphology.

Adsorption Kinetics of Pb2+ Ions Using Chitosan Nanoparticles

2013 ◽  
Vol 367 ◽  
pp. 45-49
Author(s):  
Ying Hong ◽  
Ze Hui Zhong ◽  
You Shi Liu
Keyword(s):  
Adsorption Kinetics ◽  
Chitosan Nanoparticles ◽  
Second Order ◽  
Isotherm Model ◽  
Order Model ◽  
Adsorption Characteristics ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Second Order Model

Chitosan nanoparticles were prepared by crosslinkingusing TPP. SEM showed that chitosan nanoparticles were successfully obtained.The adsorption characteristics of chitosan nanoparticles were evaluated. Theresults demonstrated that chitosan nanoparticles were suitable for adsorbent toremoval Pb2+. The parameters for the adsorption of Pb2+by chitosan nanoparticles were also determined. It was shown that chitosannanoparticles were fit for Langmuir’s isotherm model and that the adsorptionkinetics of Pb2+ described by the pseudo-second-order model could bebest.

scholarly journals Comparative Study on the Adsorption of [AuCl4]– onto Salicylic Acid and Gallic Acid Modified Magnetite Particles

2018 ◽  
Vol 16 (3) ◽  
pp. 329 ◽  
Author(s):  
Maya Rahmayanti ◽  
Sri Juari Santosa ◽  
Sutarno Sutarno
Keyword(s):  
Salicylic Acid ◽  
Gallic Acid ◽  
Adsorption Process ◽  
Freundlich Isotherms ◽  
Precipitation Procedure ◽  
Initial Ph ◽  
Isotherm Adsorption ◽  
Pseudo Second Order ◽  
Magnetite Particles ◽  
Co Precipitation

Salicylic acid-modified magnetite (Mag-SA) and gallic acid-modified magnetite (Mag-GA) particles were prepared by co-precipitation procedure. Characterization results showed the interaction that occurs between the surface of magnetite with salicylic acid (Mag-SA) and gallic acid (Mag-GA) was through hydrogen bonding. Adsorption of [AuCl4]– onto Mag-SA and Mag-GA surfaces as a function of initial pH, contact time, and initial concentration of the [AuCl4]– solution were comparatively investigated. Result showed that the optimum adsorption of [AuCl4]– onto Mag-SA or Mag-GA was found at pH 3. The adsorption process were found to allow the pseudo-second order equation, both for Mag-SA and Mag-GA. The parameters in isotherm adsorption equations conformed to the Langmuir and Freundlich isotherms very well for Mag-GA, but for Mag-SA, only conformed to the Langmuir isotherm very well. The result of this study demonstrate that the ability Mag-GA to adsorb [AuCl4]– higher than Mag-SA.

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