scholarly journals Catalytic Oxidation of Methylene Blue by Use of Natural Zeolite-Based Silver and Magnetite Nanocomposites

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 471 ◽  
Author(s):  
Aldiyar Kuntubek ◽  
Nurassyl Kinayat ◽  
Kulyash Meiramkulova ◽  
Stavros G. Poulopoulos ◽  
Joseph C. Bear ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Catalytic Oxidation ◽  
Natural Zeolite ◽  
Reaction Rate ◽  
Silver Oxide ◽  
Reaction Order ◽  
Physical Adsorption ◽  
Metallic Silver ◽  
H2o2 Concentration ◽  
20 Nm

This work reports the synthesis of natural zeolite-based silver and magnetite nanocomposites and their application for the catalytic oxidation of methylene blue in water. The zeolite was impregnated with 5.5 wt.% Fe in the form of magnetite nanoparticles with size of 32 nm, and with 6.4 wt.% Ag in the form of silver oxide and metallic silver nanoparticles with sizes of 42 and 20 nm, respectively. The results showed that physical adsorption contributed to the removal of methylene blue by 25–36% and that Fe3O4@NZU is superior to Ag2O@NZU and Ag0@NZU, leading to 55% removal without oxidant and 97% in the presence of H2O2. However, there is no evidence of significant mineralization of methylene blue. The application of reaction rate models showed that the reaction order changes from zero to first and second order depending on the H2O2 concentration.

scholarly journals Preparation of Manganese Dioxide Nanoparticles on Laterite for Methylene Blue Degradation

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Thu-Huong Le ◽  
Thu Hong Anh Ngo ◽  
Van Thuan Doan ◽  
Le Minh Tri Nguyen ◽  
Manh Cuong Le
Keyword(s):  
Methylene Blue ◽  
Manganese Dioxide ◽  
Catalytic Oxidation ◽  
High Efficiency ◽  
Physical Adsorption ◽  
Degradation Efficiency ◽  
Heterogeneous Fenton ◽  
Immersion Method ◽  
Manganese Dioxide Nanoparticles

The laterite-coating manganese dioxide nanoparticle material (M2) prepared by the immersion method was used for the efficient removal of methylene blue (MB) from aqueous solution. The adsorption and heterogeneous Fenton catalytic oxidation experiments of M2 were investigated by changing the effective factors such as time, pH, amount of M2, and concentration of MB. The adsorption data of M2 showed good fitting with the Langmuir isotherm, suggesting that the adsorption of MB on the surface of M2 is a heterogeneous and physical adsorption process. Degradation of MB was also carried out to evaluate the heterogeneous Fenton catalytic oxidation characterization of a new catalytic oxidation material (M2). The results show that the M2 material has both adsorption and heterogeneous Fenton catalytic oxidation. However, the heterogeneous Fenton catalytic oxidation of the M2 material is the main performance. Hence, our groups have investigated the ability of the catalytic column treatment with high efficiency of 98–100% and the degradation efficiency after the sample running through the column almost does not change much. This proves that heterogeneous Fenton catalytic activity of the catalytic column is completely unaffected and reused many times after oxidizing MB. Specifically, even if the M2 material is reused for five times, the degradation efficiency still reaches 98.86%.

scholarly journals Synthesis of KAlSiO4 by Hydrothermal Processing on Biotite Syenite and Dissolution Reaction Kinetics

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Jiangyan Yuan ◽  
Hongwen Ma ◽  
Zheng Luo ◽  
Xi Ma ◽  
Qian Guo
Keyword(s):  
Reaction Rate ◽  
Reaction Order ◽  
Dissolution Behavior ◽  
Precipitation Process ◽  
Hydrothermal Processing ◽  
Hydrothermal Conditions ◽  
Effective Utilization ◽  
Comprehensive Utilization ◽  
Dissolution Reaction ◽  
Significant Process

To make potassium from K-bearing rocks accessible to agriculture, processing on biotite syenite powder under mild alkaline hydrothermal conditions was carried out, in which two types of KAlSiO4 were obtained successfully. The dissolution-precipitation process of silicate rocks is a significant process in lithospheric evolution. Its effective utilization will be of importance for realizing the comprehensiveness of aluminosilicate minerals in nature. Two kinds of KAlSiO4 were precipitated in sequence during the dissolution process of biotite syenite. The crystal structures of two kinds of KAlSiO4 were compared by Rietveld structure refinements. The kinetics model derived from geochemical research was adopted to describe the dissolution behavior. The reaction order and apparent activation energy at the temperature range of 240–300 °C were 2.992 and 97.41 kJ/mol, respectively. The higher dissolution reaction rate of K-feldspar mainly relies on the alkaline solution, which gives rise to higher reaction order. During the dissolution-precipitation process of K-feldspar, two types of KAlSiO4 with different crystal structure were precipitated. This study provides novel green chemical routes for the comprehensive utilization of potassium-rich silicates.

scholarly journals Mechanism of methaemoglobin reduction by human erythrocytes

1980 ◽  
Vol 188 (2) ◽  
pp. 535-540 ◽  
Author(s):  
A Tomoda ◽  
M Ida ◽  
A Tsuji ◽  
Y Yoneyama
Keyword(s):  
Methylene Blue ◽  
Isoelectric Focusing ◽  
Rate Constants ◽  
Time Course ◽  
Reaction Rate ◽  
Polyacrylamide Gel ◽  
Human Erythrocytes ◽  
Redox Potentials ◽  
Reaction Rate Constants ◽  
Beta 2

The time course of methaemoglobin reduction in human erythrocytes treated with nitrite was studied at pH 7.4, 37 degrees C, in the presence or absence of Methylene Blue, and the changes in methaemoglobin, intermediate haemoglobins and oxyhaemoglobin during the reaction were analysed by isoelectric-focusing on Ampholine/polyacrylamide-gel plates. In both cases, with or without the dye, the intermediate haemoglobins were found to be present at (alpha 3+beta 2+)2 and (alpha 2+beta 3+)2 valency hybrids from their characteristic position on electrophoresis, but amounts changed consecutively with time. The amount of (alpha 3+beta 2+)2 was always greater than that of the (alpha 2+beta 3+)2 valency hybrid. This result is explained by the differences in redox potentials between alpha- and beta-chains in methaemoglobin tetramer. It was concluded that methaemoglobin was reduced in human erythrocytes through these two different pats: methaemoglobin leads to k+3 (alpha 2+beta 3+)2 leads to k+3 oxyhaemoglobin. The reaction rate constants k'+1 (= k+1+k+3) and k'+2(=k+2+k+4) were estimated from the changes in each component methaemoglobin, intermediate haemoglobins [(alpha 3+beta 2+)2+(alpha 2+beta 3+)2] and oxyhaemoglobin.

Adsorption of Methylene Blue from Solution by Natural Zeolite in Fixed-Bed Column: Effect of Bed Depth

2012 ◽  
Vol 518-523 ◽  
pp. 3115-3119
Author(s):  
Yan Qiang Li ◽  
Xiao Feng Ren ◽  
Shao Hua Chen ◽  
Xiu Rong Zhao ◽  
Run Ping Han
Keyword(s):  
Methylene Blue ◽  
Natural Zeolite ◽  
Fixed Bed ◽  
Breakthrough Curves ◽  
Form Solution ◽  
Column Height ◽  
Nonlinear Regression Analysis ◽  
Adsorption Ability ◽  
Fixed Bed Column ◽  
Linear And Nonlinear

The effect of bed depth on adsorption ability of natural zeolite to removal methylene blue (MB) from aqueous solution in the fixed-bed column was studied. The results showed that the increase in column height favored the MB removal form solution. The equilibrium uptake of MB onto unit mass zeolite increased with the bed depth growth. The experimental data were fitted to Yan model using linear and nonlinear regression analysis, respectively. The experimental points and the predicted curves using the Yan model were compared and the error analysis was performed. The results indicated that Yan model were good to predict the breakthrough curves and both two methods can be used to obtain the parameters of Yan model and to predict the breakthrough curves.

THE CATALYTIC OXIDATION OF ETHYLENE TO ETHYLENE OXIDE

1949 ◽  
Vol 27b (11) ◽  
pp. 813-827 ◽  
Author(s):  
F. L. W. McKim ◽  
A. Cambron
Keyword(s):  
Ethylene Oxide ◽  
Catalytic Oxidation ◽  
Atmospheric Pressure ◽  
Reaction Rate ◽  
Ethylene Dichloride ◽  
Complete Oxidation ◽  
Large Excess ◽  
Ethylene Concentration ◽  
Silver Catalysts ◽  
Flow Experiments

The catalytic oxidation of ethylene to ethylene oxide was investigated in flow experiments over silver catalysts at atmospheric pressure between 260° and 350 °C. Calcium oxalate and stannous oxide were used as catalyst promoters. Close temperature control was provided by mounting the catalyst on a silver support. At 270 °C. the selectivity increased from about 25%, with ethylene in large excess, to about 55%, with oxygen in large excess. With air constant and in large excess, the over-all reaction rate was found to be proportional to the square root of the ethylene concentration. With ethylene constant and in large excess, the reaction rate was found to be roughly proportional to the oxygen concentration. The presence of methane, ethane, or propane promoted the complete oxidation of ethylene to carbon dioxide and water. In the absence of paraffins the addition of traces of ethylene dichloride only served to poison the catalyst.

scholarly journals Effect of the coordination of π-acceptor 4-cyanopyridine ligand on the structural and electronic properties of meso-tetra(para-methoxy) and meso-tetra(para-chlorophenyl) porphyrin cobalt(ii) coordination compounds. Application in the catalytic degradation of methylene blue dye

RSC Advances ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 6900-6918 ◽  
Author(s):  
Mouhieddinne Guergueb ◽  
Soumaya Nasri ◽  
Jihed Brahmi ◽  
Frédérique Loiseau ◽  
Florian Molton ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Cyclic Voltammetry ◽  
Electronic Properties ◽  
Catalytic Oxidation ◽  
Coordination Compounds ◽  
Molecular Structures ◽  
Blue Dye ◽  
Methylene Blue Dye ◽  
H Nmr ◽  
Structural And Electronic Properties

Preparation and UV/vis, IR, MS, 1H NMR, cyclic voltammetry and molecular structures of two new Co(ii) complexes with para-methoxy-phenyl and para-chloro meso-porphyrins and 4-cyanopyridine ligand (1–2). Catalytic oxidation data of MB dye using 1–2.

scholarly journals Study of The Acid-Base Effect on Zeolite Activation and Its Characterization as Adsorbent of Methylene Blue Dye

2017 ◽  
Vol 2 (2) ◽  
pp. 90 ◽  
Author(s):  
Yulius Dala Ngapa
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Natural Zeolite ◽  
Blue Dye ◽  
Activation Process ◽  
Acid Base ◽  
Isothermal Adsorption ◽  
Naoh Solution ◽  
Equilibrium Process

<p>Activation is one of the processes by which are mostly done to improve the quality of natural zeolite. Activation process by zeolite will change the ratio of the Si/Al and can increase the formation of empty cavities so that the capability of zeolite as an adsorbent be optimal. In this research, natural zeolite from the district of Ende, Nusa Tenggara Timur. Activation Ende natural zeolite done chemically using HCl and NaOH solution, with variations concentrate 0,5 M; 1,5 M; and 3,0 M. Next, zeolite which has activated used to adsorb dye methylene blue. Based on the research results, chemically of activation from natural zeolite can increase the adsorption capacity to substance methylene blue. The adsorption capacity in the Ende natural and after activation is 17,289 mg/g and 19,98 mg/g respectively. The Langmuir model most closely matched the isothermal adsorption of equilibrium process.</p>

scholarly journals PENGEMBANGAN BAHAN AJAR KIMIA RINTISAN SMA BERTARAF INTERNASIONAL KELAS XI MATERI LAJU REAKSI

2012 ◽  
Vol 13 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Inova Putri Carera ◽  
I Wayan Dasna
Keyword(s):  
High School ◽  
High School Students ◽  
Reaction Mechanism ◽  
Reaction Rate ◽  
Reaction Order ◽  
Average Score ◽  
School Students ◽  
Factors Affecting ◽  
Rate Law

This study was aimed to develop teaching materials about chemical reaction rate which covered materials adapted to A-Level High School students of grade XI in Pioneer International Standard High School (RSMA-BI). The developmental research was adopting the instructional development model 4D which include four stages of development, namely define, design, develop, and disseminate. Instructional materials were written in English consist of seven topics titled: Reaction Rate Concept, The Exchange's Expressions, Rate Law and Reaction Order, Experimental Determination of a Rate Law, Reaction Mechanism, Theories of Reaction Rate, Factors Affecting Reaction Rate. Results of content validation from content experts obtained the average score of 3. 56 of 14 range of scores which means valid / good / decent. Test limited to high school students of RSBI obtained an average score of 3.35 (valid / good / decent). The results of the use of teaching materials obtained a score of 77.8 which is above the minimal passing grade (75). Therefore it can be concluded that the materials were feasible to be used in the classroom.Penelitian ini bertujuan untuk mengembangkan bahan ajar laju reaksi dengan cakupan materi yang disesuaikan dengan A-Level untuk siswa kelas XI Rintisan Sekolah Menengah Atas Bertaraf Internasional (RSMA-BI. Rancangan penelitian pengembangan mengadaptasi model pengembangan bahan ajar Model 4D yang meliputi empat tahap pengembangan, yaitu define, design, develop dan disseminate. Produk pengembangan adalah bahan ajar kimia RSMA-BI kelas XI materi laju reaksi yang ditulis dalam bahasa Inggris menggunakan pendekatan kontekstual. Bahan ajar terdiri atas empat bagian utama yaitu pendahuluan, materi, evaluasi dan penutup. Materi tersusun atas tujuh sub materi yaitu Reaction Rate Concept, The Rates Expressions, Rate Law and Reaction Order, Experimental Determination of a Rate Law, Reaction Mechanism, Theories of Reaction Rate, Factors Affecting Reaction Rate. Hasil validasi isi dari ahli materi diperoleh nilai rata-rata 3,56 dari rentang skor 1-4 dengan kriteria valid/baik/layak. Hasil uji terbatas pada siswa SMA RSBI diperoleh nilai rata-rata 3,35 dari rentang skor 1-4 dengan kriteria valid/baik/layak. Hasil uji penggunaan bahan ajar diperoleh skor sebesar 77,8. Skor ini diatas SKM (Skor Kelulusan Minimal) yaitu 75 sehingga dapat disimpulkan bahwa bahan ajar telah layak dan dapat digunakan dalam pembelajaran di kelas.

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