scholarly journals Catalytic degradation of methylene blue in aqueous solutions over Ni- and Co- oxide systems

2011 ◽  
Vol 9 (6) ◽  
pp. 1000-1007 ◽  
Author(s):  
Maria Stoyanova ◽  
Stoyanka Christoskova

AbstractThe oxidative catalytic degradation of the cationic dye methylene blue (MB) with NaOCl in aqueous solutions was studied using individual and iron modified Ni- and Co-oxide systems as catalysts. The adsorption extent and the contribution of the uncatalyzed oxidation on the overall degree of MB were determined. The results indicate that methylene blue—a representative of a class of dyestuffs resistant to biodegradation—could be successfully decolorized and degraded using nickel and cobalt oxide catalysts at room temperature. The highest catalytic activity manifests in the Co-oxide system which is consistent with the adsorption data. The oxidative degradation reaction proceeds via first-order kinetics. Temperature has a relatively small effect on the methylene blue degradation kinetics. The results obtained reveal that the catalysts investigated are suitable for oxidative destruction of methytlene blue dye in wastewaters.

2017 ◽  
Vol 14 (9) ◽  
pp. 1959-1968 ◽  
Author(s):  
A. A. Mohammadi ◽  
A. Alinejad ◽  
B. Kamarehie ◽  
S. Javan ◽  
A. Ghaderpoury ◽  
...  

2003 ◽  
Vol 21 (2) ◽  
pp. 189-198
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Rana Saeidi ◽  
Salam Abu Zaid

As in Part I, non-activated (natural) and chemically activated oak shells were evaluated for their ability to remove phenol and Methylene Blue (as a typical dye component) from aqueous solutions. Batch adsorption experiments were conducted to investigate the effect of contact time, sorbent concentration, phenol concentration and the pH of the solution on the sorption process. Activated oak shells adsorbed more phenol than natural oak shells under the same conditions. A decrease in sorbent concentration or an increase in phenol concentration or solution pH resulted in an increase in phenol uptake by the oak shells. The uptake of Methylene Blue increased with decreasing sorbent concentration and with an increase in the dye concentration, but decreased significantly with solution pH. According to the fractional factorial design technique, the sorbent type employed (natural or activated) had the most significant influence on phenol or Methylene Blue uptake followed by sorbent concentration and then sorbate concentration. Interaction amongst the different operating variables played an important role in the uptake of phenol or Methylene Blue dye by the adsorbent considered.


Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2295 ◽  
Author(s):  
Souad Rakass ◽  
Hicham Oudghiri Hassani ◽  
Mostafa Abboudi ◽  
Fethi Kooli ◽  
Ahmed Mohmoud ◽  
...  

Nano Molybdenum trioxide (α-MoO3) was synthesized in an easy and efficient approach. The removal of methylene blue (MB) in aqueous solutions was studied using this material. The effects of various experimental parameters, for example contact time, pH, temperature and initial MB concentration on removal capacity were explored. The removal of MB was significantly affected by pH and temperature and higher values resulted in increase of removal capacity of MB. The removal efficiency of Methylene blue was 100% at pH = 11 for initial dye concentrations lower than 150 ppm, with a maximum removal capacity of 152 mg/g of MB as gathered from Langmuir model. By comparing the kinetic models (pseudo first-order, pseudo second-order and intraparticle diffusion model) at various conditions, it has been found that the pseudo second-order kinetic model correlates with the experimental data well. The thermodynamic study indicated that the removal was endothermic, spontaneous and favorable. The thermal regeneration studies indicated that the removal efficiency (99%) was maintained after four cycles of use. Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM) confirmed the presence of the MB dye on the α-MoO3 nanoparticles after adsorption and regeneration. The α-MoO3 nanosorbent showed excellent removal efficiency before and after regeneration, suggesting that it can be used as a promising adsorbent for removing Methylene blue dye from wastewater.


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)


2018 ◽  
Vol 114 ◽  
pp. 297-306
Author(s):  
Liheng Liu ◽  
Hua Lin ◽  
Fei Pan ◽  
Geng Wang, ◽  
Dunqiu Wang

2018 ◽  
Vol 124 ◽  
pp. 279-286 ◽  
Author(s):  
Elif Özmetin ◽  
◽  
Mehmet Muhtar Kocakerim

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