scholarly journals Silver(I) Catalyzed Photochemical Oxidation of Methylene Blue and Safranine-O by Peroxydisulphate: A Green Chemical Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ravisha Chhajed ◽  
Sanyogita Sharma ◽  
Rakshit Ameta ◽  
Pinki B. Punjabi
Keyword(s):  
Methylene Blue ◽  
Light Intensity ◽  
Comparative Study ◽  
Silver Nitrate ◽  
Reaction Rate ◽  
Photochemical Oxidation ◽  
Optimum Conditions ◽  
Chemical Approach ◽  
Safranine O ◽  
Ph Concentration

In the present investigation, a comparative study of silver(I) catalysed photochemical oxidation of methylene blue (MB) and safranine-O (SO) by peroxydisulphate has been reported. The effect of different parameters, such as pH, concentration of peroxydisulphate, silver nitrate, and light intensity, on the reaction rate has been observed. The progress of the photochemical oxidation was monitored spectrophotometrically. The optimum conditions for photochemical oxidation were achieved. The dyes were completely oxidized and degraded into CO2 and H2O. A tentative mechanism for silver(I) catalyzed photochemical oxidation of these dyes by peroxydisulphate has also been proposed.

Photocatalytic Degradation of Methylene Blue on Fixed Powder Layers: Which Limitations are to be Considered?

2008 ◽  
Vol 11 (2) ◽  
Author(s):  
Jessica Tschirch ◽  
Ralf Dillert ◽  
Detlef Bahnemann
Keyword(s):  
Methylene Blue ◽  
Light Intensity ◽  
Standard Method ◽  
Reaction Rate ◽  
Incident Light ◽  
Initial Reaction Rate ◽  
Initial Reaction ◽  
Incident Light Intensity ◽  
Initial Concentration ◽  
Photonic Efficiency

AbstractOn the national (DIN) and international (ISO) level the determination of the photonic efficiency of the light-driven decolorization of methylene blue (MB) solutions in contact with a photocatalyst is currently being discussed as a standard method for testing and comparison of photocatalytic coatings. In this context it is necessary to make sure that the photocatalytic reaction of MB is a simple and robust method that meets the requirements of non-specialised laboratories in industry. Therefore, the photocatalytic degradation of methylene blue was studied using a fixed layer of Degussa P25 on soda lime glass as the photocatalyst substrate. The influence of the initial concentration of MB and of the intensity of the incident UV(A) light on the initial reaction rate and on the photonic efficiency was investigated in detail. It was observed, that both the initial concentration of MB as well as the incident light intensity strongly influences the degradation rate. Increasing the initial concentration of MB resulted in an increase of the initial reaction rate with a characteristic curvature in the direction of the concentration axis. The initial reaction rate was found to be not directly proportional to the incident light intensity. An increase of the photonic efficiency with decreasing initial MB concentration and decreasing light intensity was observed. A Langmuir-Hinshelwood rate law is used to discuss the implications of these observations with regard to the proposed standard method for testing and comparison of photocatalytic coatings.

scholarly journals Efficient reduction of methylene blue in aqueous solution using a Fenton-like catalyst of Fe3O4/Cu

2021 ◽  
Vol 947 (1) ◽  
pp. 012015
Author(s):  
Huynh-Vu-Thanh Luong ◽  
Huynh-Giao Dang ◽  
Phuong-Lan Tran-Nguyen ◽  
Diem-Trang Phan-Thi ◽  
Lam-Gia-Hao Dao
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Reaction Rate ◽  
Active Oxygen Species ◽  
Reaction Rate Constant ◽  
Active Oxygen ◽  
Oxygen Species ◽  
Optimum Conditions ◽  
Efficient Reduction ◽  
Pseudo Second Order

Abstract This work aimed to investigate the efficient reduction of methylene blue (MB) by a heterogeneous magnetic nanoparticles/copper (MNs/Cu) Fenton-like catalyst. The MNs/Cu was successfully synthesized in the presence of Citrus aurantifolia extract. The characterizations showed an effective fabrication of Cu onto the surface of MNs. The reduction of MB by the MNs/Cu Fenton-like catalyst presented an efficiency of 99.5% at the optimum conditions, including MNs/Cu dose of 0.1 mg, temperature of 25°C, contact time of 75 min, pH 4.0, and 20 mL H2O2 30%, MB initial concentration of 25 mg/L. The reduction kinetics was well fitted to pseudo-second-order with reaction rate constant of 0.0029 g/mg.min. The main mechanism of the MB reduction due to active oxygen species was pointed out. The decrease of reduction yield at high pH, catalyst dose and MB concentration was elucidated in this study.

Removal of Methylene Blue and Orange-G from Waste Water Using Magnetic Biochar

2015 ◽  
Vol 14 (04) ◽  
pp. 1550009 ◽  
Author(s):  
N. M. Mubarak ◽  
Y. T. Fo ◽  
Hikmat Said Al-Salim ◽  
J. N. Sahu ◽  
E. C. Abdullah ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Contact Time ◽  
Agitation Speed ◽  
Adsorption Kinetic ◽  
Maximum Adsorption Capacity ◽  
Optimum Conditions ◽  
Magnetic Biochar ◽  
Design Expert ◽  
Orange G ◽  
Pseudo Second Order

The study on the removal of methylene blue (MB) and orange-G dyes using magnetic biochar derived from the empty fruit bunch (EFB) was carried out. Process parameters such as pH, adsorbent dosage, agitation speed and contact time were optimized using Design-Expert Software v.6.0.8. The statistical analysis reveals that the optimum conditions for the maximum adsorption of MB are at pH 2 and pH 10, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. While for orange-G, at pH 2, dosage 1.0 g, and agitation speed and contact time of 125 rpm and 120 min respectively. The maximum adsorption capacity of 31.25 mg/g and 32.36 mg/g for MB and orange-G respectively. The adsorption kinetic for both dyes obeyed pseudo-second order.

Study on photocatalytic degradation of methylene blue by TiO2 synthesiszed from titanium slag using a new decomposition agent

2021 ◽  
Vol 11 (1) ◽  
pp. 89-93
Author(s):  
Chinh Tran Van ◽  
Anh Tran Thi Hien ◽  
Tu Ha Thi Cam ◽  
Hoai Truong Viet ◽  
Phuong Nguyen Thi Hoai ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Degradation ◽  
Acid Leaching ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Titanium Slag

This paper describes a novel process for the synthesis of TiO2 from titanium slag, which is realized via roasting titanium slag with KHSO4, acid leaching and hydrolysis. The results showed that the optimum conditions were a mass ratio of KHSO4 to titanium slag of 6, a temperature of 600 oC for 1,5 hours. Besides, this study investigated the possibility of synthesized TiO2 for photocatalytic degradation of methylene blue.

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.

Phenylonium salts as third component of the photoinitiator system safranine O/triethanolamine: A comparative study in aqueous media

Polymer ◽  
2007 ◽  
Vol 48 (8) ◽  
pp. 2355-2361 ◽  
Author(s):  
María L. Gómez ◽  
Carlos M. Previtali ◽  
Hernán A. Montejano
Keyword(s):  
Comparative Study ◽  
Aqueous Media ◽  
Safranine O

Adsorption of Methylene Blue on industrial softwood waste “Cedar” and hardwood waste “Mahogany”: comparative study

2019 ◽  
Vol 13 ◽  
pp. 812-821 ◽  
Author(s):  
M. El Hajam ◽  
N. Idrissi Kandri ◽  
A. Harrach ◽  
A. El khomsi ◽  
A. Zerouale
Keyword(s):  
Methylene Blue ◽  
Comparative Study
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