scholarly journals Combustion Synthesis of Semiconductor Oxides and Evaluation of Adsorption and Photocatalysis Properties

Author(s):  
Matheus Gomes Ferreira ◽  
Henrique Cesar Abreu do Nascimento Telles Rodrigues ◽  
Francisco Manoel dos Santos Garrido ◽  
Marta Eloisa Medeiros

Improper disposal of effluent contaminated with organic dyes may cause environmental problems. In this context, the ZnO semiconductor and the ZnO/ZnFe2O4 magnetic composite were prepared by the combustion method. The synthesized materials showed adsorption and photocatalysis properties for elimination of methylene blue dye from aqueous medium. About 88% of the methylene blue was eliminated by ZnO and 63% by the composite. In the photocatalysis process, a low cost visible light source was used. These materials can be regenerated by a photo-Fenton process. Moreover, the ZnO/ZnFe2O4 composite can be separated from the reaction medium by a magnetic field.

2021 ◽  
Author(s):  
T.H AlAbdulaal ◽  
Manal AlShadidi ◽  
Mai Hussien ◽  
Ganesh Vanga ◽  
Abdel-Fatah Bouzidi ◽  
...  

Abstract In this study, a combustion method as an efficient, easy, low-cost, and eco-friendly technique was used to synthesize nano-ZnO as a matrix with different yttrium doping ratios with different doping concentrations. Not only X-ray diffraction (XRD), but also scanning electron microscopy (SEM), and Fourier transformation Infrared spectroscopy (FT-IR) technique employed to characterize the structural and surface morphology of the Y2O3-ZnO nanocomposites. The obtained results supported ZnO's growth from crystalline to satisfactory nanoparticle structure by changing the yttrium doping concentrations inside ZnO nanoparticles. Moreover, UV-Vis diffuse reflectance spectroscopy, AC electrical conductivity, and current-voltage characteristics were considered to characterize the effects of yttrium doping on the energy bandgaps and electrical/dielectric properties and discussed the parameters of the ceramic varistors of the studied Y2O3-ZnO nano-complex oxides. The photocatalytic degradation efficiency of phenol, Methylene Blue, and Rhodamine B was investigated using all prepared Y2O3-ZnO nanostructured samples. As the yttrium doping ratios increased, the photocatalytic efficiency increased. After the addition of moderate Y3+ ions-doping, Further generation of hydroxyl radicals over ZnO. For Y2O3-ZnO (S5), the optimal photocatalyst is a degradation of 100 % of phenol, Methylene Blue, and Rhodamine B solutions compared to 80% of photocatalysis for ZnO stand alone. The prepared Y2O3-ZnO nanostructured materials are considered novel potential candidates in broad nano-applications ranging from biomedical and photocatalytic degradation for organic dyes and phenol to environmental and varistor applications.


2014 ◽  
Vol 699 ◽  
pp. 221-226
Author(s):  
Nurul Hanim Razak ◽  
Md. Razali Ayob ◽  
M.A.M. Zainin ◽  
M.Z. Hilwa

Eggshells and rice husk, two types of notable agricultural waste were used as bioadsorbent to remove Methylene Blue dye (MBD) in aqueous solution. This study was to investigate the performance of these two bioadsorbents in removing MBD. The removal percentage, adsorption capacity, and porosity characterization were examined. The method applied was a physical filtration. UV-VIS Spectrophotometer was used to determine the efficiency of the bioadsorbents in MBD adsorption. The highest removal percentage at the most concentrated MBD were 51% and 98% for eggshells and rice husks respectively. Meanwhile the characterization of rice husks pore size and volume proves that higher adsorptivity towards dye compares to eggshells porosity. It was concluded that the eggshells and rice husks bioadsorbents was successful to treat industrial textile wastewater with rice husks as the most efficient bioadsorbent in removing MBD.


2013 ◽  
Vol 65 (1) ◽  
Author(s):  
Norzita Ngadi ◽  
Chin Chiek Ee ◽  
Nor Aida Yusoff

Dyes contain carcinogenic materials which can cause serious hazards to aquatic life and the users of water. Textile industry is the main source of dye wastewater which results in environmental pollution. Many studies have been conducted to investigate the use of low cost adsorbent as an alternative technique for the adsorption of dye. The objective of this study is to determine the potential of eggshell powder as an adsorbent for methylene blue removal and find out the best operating conditions for the color adsorption at laboratory scale. The adsorption of cationic methylene blue from aqueous solution onto the eggshell powder was carried out by varying the operating parameters which were contact time, pH, dosage of eggshell powder and temperature in order to study their effect in adsorption capacity of eggshell powder. The results obtained showed that the best operating condition for removal of methylene blue was at pH 10 (78.98 %) and temperature 50°C (47.37 %) by using 2 g of eggshell powder (57.03 %) with 30 minutes equilibrium time (41.36 %). The kinetic studies indicated that pseudo-second-order model best described the adsorption process.


2019 ◽  
Vol 7 (2) ◽  
pp. 240-246
Author(s):  
Kaur Harpreet ◽  
Kaur Harpreet ◽  
Vandana Kamboj ◽  
Vandana Kamboj

Water is the most crucial thing to mankind and so its contamination by various agencies is posing a threat to the natural balance. So, in the present work, the efficiency of various adsorbents derived from plant waste, to remove different dyes from aqueous solution was evaluated. Parameters for study were contact time, concentration and pH. Various combinations of plant ashes were used for the study. It was found that adsorbent prepared from the combination of orange peels, pomegranate and banana peels ashes, exhibited good adsorption capacity for methylene blue, congo red and crystal violet. All these dyes were completely removed from the aqueous solution while methyl orange was not removed. Congo red was removed completely within 40 min of contact with the adsorbent while methyl orange took 3 hrs to be removed to the extent of 48% only. The adsorption coefficient of congo red was found to be 2.33 while value for methylene blue and crystal violet was 1 and 1.66 respectively. The characterization of adsorbent was done by Scanning Electron Microscopy and IR spectroscopy. SEM image revealed the surface of adsorbent to be made of differential pores. From the results it became evident that the low-cost adsorbent could be used as a replacement for costly traditional methods of removing colorants from water.


2020 ◽  
Vol 4 (2) ◽  

In the present work NiO/ZnO was synthesized from combustion method, polyaniline and the polyaniline based NiO/ZnO using chemical oxidation method. The synthesized materials were characterized using XRD and UV/Vis absorbance spectroscopy. From XRD, the formation of NiO/ZnO was confirmed. The study investigates the applicability of NiO/ZnO Nanocomposite as photo catalyst for the degradation of organic dyes. Results suggested an increase in degradation efficiency in the case of polymer nanocomposite when compared to counter parts.


Author(s):  
Juraj Michálek ◽  
Kseniya Domnina ◽  
Veronika Kvorková ◽  
Kristína Šefčovičová ◽  
Klaudia Mončeková ◽  
...  

Abstract The usage of the low-cost catalysts for methylene blue removal from wastewater was investigated. Heterogeneous Fenton-like process consists of the use of a hydrogen peroxide solution, and an iron-rich catalyst, red mud and black nickel mud were used for that purpose. The factors such as the catalyst dose and the hydrogen peroxide solution volume were monitored. The results of experiments showed that the degradation of methylene blue dye in Fenton-like oxidation process using selected catalysts can be described by a pseudo-second-order kinetic model. The highest dye removal efficiency (87.15 %) was achieved using the black nickel mud catalyst after 30 minutes of reaction.


2019 ◽  
Vol 1 (1) ◽  
pp. 213-218 ◽  
Author(s):  
Shafqat Ali ◽  
Yasir Abbas ◽  
Zareen Zuhra ◽  
Ian S. Butler

Non-toxic nanomaterials have gained significant importance recently in the treatment of industrial wastewater that sometimes contains organic dyes such as methylene blue.


2012 ◽  
Vol 60 (2) ◽  
pp. 185-189 ◽  
Author(s):  
Mohammad Arifur Rahman ◽  
S. M. Ruhul Amin ◽  
A. M. Shafiqul Alam

The possible utilization of rice husk activated carbon as an adsorbent for the removal of methylene blue dye from aqueous solutions has been investigated. In this study, activated carbons, prepared from low-cost rice husk by sulfuric acid and zinc chloride activation, were used as the adsorbent for the removal of methylene blue, a basic dye, from aqueous solutions. Effects of various experimental parameters, such as adsorbent dosage and particle size, initial dye concentration, pH and flow rate were investigated in column process. The maximum uptakes of methylene blue by activated rice husk carbon at optimized conditions (particle sizes: 140 ?m; Flow rate: 1.4 mL/min; pH: 10.0; initial volume of methylene blue: 50 mL and initial concentration of methylene blue: 4.0 mg/L etc.) were found to 97.15%. The results indicate that activated carbon of rice husk could be employed as low-cost alternatives to commercial activated carbon in waste water treatment for the removal of basic dyes. This low cost and effective removal method may provide a promising solution for the removal of crystal violet dye from wastewater.DOI: http://dx.doi.org/10.3329/dujs.v60i2.11491 Dhaka Univ. J. Sci. 60(2): 185-189, 2012 (July)


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