Oxidative Decolorization of Azo Dyes with Copper Phthalocyanine Supported Mg-Al Hydrotalcites

2016 ◽  
Vol 703 ◽  
pp. 306-310
Author(s):  
Min Hong Xu ◽  
Jian Li Ma ◽  
Meng Xia Qian ◽  
Hui Na Qin
Keyword(s):  
Molecular Structure ◽  
Methylene Blue ◽  
Methyl Orange ◽  
Azo Dyes ◽  
Acidic Solution ◽  
Copper Phthalocyanine ◽  
Ph Value ◽  
Influence Factors ◽  
Amido Black ◽  
Initial Ph

Oxidative decolorization of azo dyes with a heterogeneous catalyst copper phthalocyanine supported Mg-Al hydrotalcites was studied and the influence factors such as initial pH value, temperature, H2O2 and CuPc-LDHs/H2O2 system were discussed. The results indicated that acidic solution and high temperature were conducive to oxidative decoloration of methyl orange. CuPc-LDHs/H2O2 system showed excellent oxidative decoloration capacity to remove azo dyes. The effects of oxidative decolorization of azo dyes were related to the molecular structure and weight of azo dyes. Oxidative decoloration effects followed the order as congo red > amido black > methyl blue> methyl orange> methylene blue.

scholarly journals The Removal of Methylene Blue Dye from Aqueous Solutions Using Activated and Non-Activated Bentonites

2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah
Keyword(s):  
Methylene Blue ◽  
Ph Value ◽  
Sodium Dodecyl ◽  
Freundlich Isotherm ◽  
Blue Dye ◽  
Batch Adsorption ◽  
Ionic Surfactant ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Initial Ph

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.

scholarly journals Neem Leaves as Adsorbent for Dye Waste water Treatment

2019 ◽  
Vol 8 (9) ◽  
pp. 3071-3073
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Ph Value ◽  
Low Cost ◽  
Waste Water Treatment ◽  
Blue Dye ◽  
Aqueous Streams ◽  
Neem Leaves ◽  
Initial Ph ◽  
Adsorbent System

In the present investigation , neem leaves are obtained from the agricultural fields and its potential for the removal of dye is tested with the model system of methylene blue in water . The MB has health hazards, its been reported that exposures to the dyes cause allergic reactions, and hence its reflected as toxic. The results obtained from batch experiments are quite useful in giving information about the efficacy of dye-adsorbent system. The influence of factors such as the initial pH value, adsorbent dose, and time of contact was investigated. The results indicate that the percentage removal also increased with the rise in the adsorption capacity (qe). 82% of colour elimination can be obtained at the dose of 100g/l NLP for methylene blue of 10mg/l concentration. The optimal parameters for this experiment were 10mg/l for initial dye concentration, 5gm/50ml adsorbent dosage and pH 8. In the batch system, the adsorption capacity was increased when the parameters were increased until it achieved the equilibrium. Langmuir adsorption isotherm graphics plotted with l/qevis 1/Ce. Trend lines for the adsorption data of different concentration of methylene blue with neem leave as adsorbent is plotted. The linear regression was piloted using plot l/qevis 1/Ce; it was found that R2 value are quite closer to 1 signifying Langmuir isotherm as a good fit for this experimental data. Results indicated that neem leaves has potential to remove Methylene Blue Dye from aqueous streams and can be successfully used as a low cost adsorbent.

scholarly journals Molecular Modeling of Acidic Treated PSTM-3T Polymer for Removal of Heavy Metal Ions by Experimental and Computational Studies

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Natsagdorj Narantsogt ◽  
Gunchin Burmaa ◽  
Adiya Perlee-Oidov ◽  
Nyamdorj Shurkhuu ◽  
Namsrai Javkhlantugs
Keyword(s):  
Molecular Structure ◽  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Density Functional ◽  
Acidic Solution ◽  
Ph Value ◽  
Density Functional Theory Method ◽  
Structure Change ◽  
Sorption Efficiency

The synthesized poly[N,N′-bis(3-silsesquioxanilpropyl)-thiocarbamide] (PSTM-3T) was used and the surface morphology and microstructure of it were analyzed by scanning electron microscopy with energy dispersive spectrometer (SEM/EDS). The molecular structure change of the PSTM-3T polymer of the PSTM-3T after treatment by acidic solution with different pHs was revealed using FT-IR experiments andab initiocalculations with density functional theory method. The sorption efficiency of the heavy metal ions depends on the molecular structure change of PSTM-3T after treatment of different pH aqueous solutions. After the treatment of acidic solution (pH = 2) of PSTM-3T, the polymer formed the tautomer state to increase the sorption efficiency for chromate ion. For the increment of pH value for acidic solution, the PSTM-3T polymer was dissociated to increase the sorption efficiency for copper ion.

scholarly journals Adsorption-Oxidation Mechanism of δ-MnO2 to Remove Methylene Blue

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ge Yan ◽  
Pu Wang ◽  
Yuqian Li ◽  
Zhangjie Qin ◽  
Shuai Lan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Mechanism ◽  
Ph Value ◽  
Oxidation Mechanism ◽  
Superior Performance ◽  
Adsorption Ability ◽  
Initial Ph ◽  
Effects Of Ph ◽  
Ph Conditions ◽  
Positively Charged

The material, δ-MnO2, has exhibited superior performance on the removal of methylene blue (MB), but the process is significantly impacted by pH, and the impacting mechanism is still unclear. In this study, the effects of pH on the removal mechanism of MB using synthesized δ-MnO2 were investigated by distinguishing the adsorption and oxidation of MB by δ-MnO2 during the removal process in the dark. The results show that the total removal efficiency of MB by δ-MnO2 decreased significantly with an increase in the pH. MB could be removed by δ-MnO2 via an adsorption mechanism and oxidation mechanism, and the proportion of adsorptive removal and oxidative removal was different under different pH conditions. With an increase in the initial pH from 2.00 to 8.05, the redox potential of δ-MnO2 decreased, and its oxidation ability for the removal of MB also gradually decreased. In contrast, the surface negative charges of δ-MnO2 increased with an increase in the pH, and the adsorption ability towards positively charged MB also gradually increased. This indicates that the effects of pH on the removal of MB by δ-MnO2 are primarily dominated by its influence on the oxidation ability of δ-MnO2. In addition, it is further proved that the pH value has a significant effect on the oxidation and adsorption of MB on δ-MnO2. Moreover, the significant effects of pH on the oxidation of MB by δ-MnO2 are further demonstrated by observing the changes in Mn2+ and the UV-Vis spectra of intermediate products during the reaction, as well as the changes in the FTIR and XPS characterizations of δ-MnO2 after the reaction.

scholarly journals Taguchi Optimization of Catalytic Ozonation Process Using Modified Bone Char Ash for Removal of Methylene Blue from Aqueous Solution

2020 ◽  
Vol 7 (2) ◽  
pp. 66-71
Author(s):  
Ghorban Asgari ◽  
Somaye Akbari
Keyword(s):  
Methylene Blue ◽  
Reaction Time ◽  
Textile Industry ◽  
Ph Value ◽  
Catalytic Ozonation ◽  
Bone Char ◽  
Operational Parameters ◽  
Taguchi Optimization ◽  
Initial Ph ◽  
Ozonation Process

Methylene blue (MB) dye is an environmental contaminant that has been mostly used in textile industry. Taguchi orthogonal array design was employed as an optimization method to reduce the number of experiments. In this research, bone char ash modified by MgO-Fe catalyst was applied for degradation of MB in catalytic ozonation process (COP) system and operational parameters including initial MB dosages, initial pH, catalyst dose, and contact time were optimized with Taguchi method. Accordingly, the best condition for the removal of MB obtained at initial MB concentration of 20 mg/L, reaction time of 15 minutes, initial pH value of 10, and catalyst concentration of 0.1 g/L. Additionally, optimization of experimental set-up showed that the MB concentration had a notable effect on MB degradation in COP process (55.6%), and reaction time had a negligible effect (1.98%). At this condition, total organic carbon (TOC) removal was determined to be 31% but in longer time, its removal increased to 65%.

Study on the treatment of simulated azo dye wastewater by a novel micro-electrolysis filler

2019 ◽  
Vol 79 (12) ◽  
pp. 2279-2288 ◽  
Author(s):  
Zhen-Zhu Sun ◽  
Zhong-Hai Liu ◽  
Le Han ◽  
Dong-Ling Qin ◽  
Gang Yang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Methyl Orange ◽  
Degradation Rate ◽  
Ph Value ◽  
Aeration Rate ◽  
Layer By Layer ◽  
Dye Wastewater ◽  
Operational Parameters ◽  
Initial Ph ◽  
New Type

Abstract A new type of iron-copper-carbon (Fe-Cu-C) ternary micro-electrolysis filler was prepared with a certain proportion of iron powder, activated carbon, bentonite, copper powder, etc. The effect of the new type of micro-electrolysis filler on the simulated methyl orange dye wastewater was studied. The effects of various operational parameters, such as reaction time, initial pH value, aeration rate, filler dose and reaction temperature, on the degradation rate of methyl orange were studied to determine the optimum treatment conditions, and the micro-electrolysis filler was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experimental results show that the degradation rate of 220 mL of simulated dye wastewater with a concentration of 100 mg/L reached 93.41% ± 2.94% after 60 mL/min of aeration, with an initial pH = 2, a dose of 45 g and 125 minutes of reaction at room temperature. The new micro-electrolysis filler has a high degradation rate for methyl orange solution, which is attributed to the iron and activated carbon particles sintered into an integrated structure, which makes the iron and carbon difficult to separate and affects the galvanic cell reaction. The addition of copper also greatly increases the transmission efficiency of electrons, which promotes the reaction. In addition, the surface iron is consumed, the adjacent carbon is stripped layer by layer, and the new micro-electrolytic filler does not easily passivate and agglomerate during its use.

Treatment of methyl orange dye wastewater by cooperative electrochemical oxidation in anodic–cathodic compartment

2013 ◽  
Vol 67 (3) ◽  
pp. 521-526 ◽  
Author(s):  
L. Pang ◽  
H. Wang ◽  
Z. Y. Bian
Keyword(s):  
Methyl Orange ◽  
Electrochemical Oxidation ◽  
Removal Efficiency ◽  
Ph Value ◽  
Dye Wastewater ◽  
Characteristic Absorption Peak ◽  
Divided Cell ◽  
Initial Ph ◽  
Cathodic Compartment ◽  
Degradation Of Methyl Orange

Electrochemical oxidation of methyl orange wastewater was studied using Ti/IrO2/RuO2 anode and a self-made Pd/C O2-fed cathode in the divided cell with a terylene diaphragm. The result indicated that the appropriate rate of feeding air improved the methyl orange removal efficiency. The discoloration efficiency of methyl orange in the divided cell increased with increasing current density. The initial pH value had some effect on the discoloration of methyl orange, which became not obvious when the pH ranged from 2 to 10. However, the average removal efficiency of methyl orange wastewater in terms of total organic carbon (TOC) can reach 89.3%. The methyl orange structure had changed in the electrolytic process, and the characteristic absorption peak of methyl orange was about 470 nm. With the extension of electrolysis time, the concentration of methyl orange gradually reduced; wastewater discoloration rate increased gradually. The degradation of methyl orange was assumed to be cooperative oxidation by direct or indirect electrochemical oxidation at the anode and H2O2, ·OH, O2−· produced by oxygen reduction at the cathode in the divided cell. Therefore, the cooperative electrochemical oxidation of methyl orange wastewater in the anodic–cathodic compartment had better degradation effects.

scholarly journals Decoloration of methylene blue simulated wastewater using a UV-H2O2 combined system

2011 ◽  
Vol 1 (1) ◽  
pp. 45-51 ◽  
Author(s):  
L. V. Jian-xiao ◽  
Cui Ying ◽  
Xie Guo-hong ◽  
Zhou Ling-yun ◽  
Wang Su-fen
Keyword(s):  
Methylene Blue ◽  
Ph Value ◽  
Order Kinetic ◽  
Combined System ◽  
Initial Stage ◽  
Optimum Ph ◽  
Initial Ph ◽  
Simulated Wastewater ◽  
Kinetics Of ◽  
Order Kinetic Equation

Methylene blue simulated wastewater was treated with a UV-H2O2 combined system. Influences of factors such as reaction time, initial pH value and H2O2 dosage were investigated, and the reaction kinetics of the process was explored. Results showed that the degradation of methylene blue happened only in the presence of both conditions: UV irradiation and H2O2 addition. Initial pH and H2O2 dosage had a remarkable influence on the degradation efficiency. Through several groups of univariate experiments, the optimum pH and H2O2 dosage of the photolysis process were found to be 4–5 and 0.165 mL 30% H2O2 per milligram of methylene blue, respectively. The photolysis process was relatively fast at the initial stage and, 20 min later, it was approximately in accordance with the first-order kinetic equation.

Studies on Oxidation of Noradrenaline Using CuPc as Catalyst

2012 ◽  
Vol 496 ◽  
pp. 419-422 ◽  
Author(s):  
Ming Tian Li ◽  
Rui Song Yang ◽  
Lan Yin Yu
Keyword(s):  
Spectroscopic Analysis ◽  
Copper Phthalocyanine ◽  
Ph Value ◽  
Influence Factors ◽  
Catalytic Efficiency

The oxidation of noradrenaline (NA) using copper phthalocyanine (CuPc) as catalyst was investigated by UV-Vis spectroscopic analysis. The influence factors of catalytic efficiency, such as catalytic time and temperature, the pH value of solution and the amount of CuPc, have been investigated. The results indicated that NA could be effectively catalyzed by CuPc and the product was trihydroxyl-indole

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