scholarly journals Fe(III)/TiO2-Montmorillonite Photocatalyst in Photo-Fenton-Like Degradation of Methylene Blue

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Is Fatimah ◽  
Iwan Sumarlan ◽  
Tuty Alawiyah

A photodegradation process of methylene blue (MB) in aqueous solution using Fe(III)/TiO2-montmorillonite photocatalyst is presented. The photocatalyst material was prepared using Indonesian natural montmorillonite in TiO2pillarization process followed by Fe(III) ion exchange. Kinetic study on MB degradation was conducted and evaluated by three kinetic models: the pseudo-first- and second-order equations and the Elovich equation. From the results, it is concluded that the degradation under the photo-Fenton-like process utilizing Fe(III)/TiO2-montmorillonite photocatalyst conformed to the Elovich kinetic model.

2010 ◽  
Vol 7 (s1) ◽  
pp. S419-S427 ◽  
Author(s):  
C. Chakrapani ◽  
Ch. Suresh Babu ◽  
K. N. K. Vani ◽  
K. Somasekhara Rao

Activated carbons (ACs) were prepared from the peels ofCitrus documana, Citrus medicaandCitrus aurantifoliafruits. Adsorption of fluoride onto these activated carbons was investigated. Effect of contact time in the removal of fluoride from aqueous solution at neutral pH was studied. Five kinetic models; the pseudo first- and second-order equations, intraparticle diffusion, pore diffusion and the Elovich equation, were selected to follow adsorption process. Adsorption of fluoride onto adsorbents could be described by pseudo second-order equation. Kinetic parameters; rate constants, equilibrium adsorption capacities and correlation coefficients, for each kinetic equation were calculated and discussed. The good fitting of kinetic data to pore diffusion and Elovich equations indicate that pore diffusion plays a vital role in controlling the rate of the reaction.


2012 ◽  
Vol 549 ◽  
pp. 207-211 ◽  
Author(s):  
Qun Li An

The adsorption of methylene blue (MB) from an aqueous solution by MCM-41 was investigated. It was found that the adsorption of MB on MCM-41 could be described by Freundlich isotherm and second-order kinetic model. The adsorbed amount of MB on MCM-41 reached to 24.5 mg g-1 within 30 min.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jhonatan R. Guarín ◽  
Juan Carlos Moreno-Pirajan ◽  
Liliana Giraldo

Currently, there is a great pollution of water by the dyes; due to this, several studies have been carried out to remove these compounds. However, the total elimination of these pollutants from the aquatic effluents has represented a great challenge for the scientific community, for which it is necessary to carry out investigations that allow the purification of water. In this work, we studied the bioadsorption of methylene blue on the surface of the biomass obtained from the algae D. antarctica. This material was characterized by SEM and FTIR. To the data obtained in the biosorption experiments, different models of biosorption and kinetics were applied, finding that the best fit to the obtained data is given by applying the pseudo-second-order models and the Toth model, respectively. It was also determined that the maximum adsorption capacity of MB on the surface of the biomass is 702.9 mg/g, which shows that this material has great properties as a bioadsorbent.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joshua N. Edokpayi ◽  
Samson O. Alayande ◽  
Ahmed Adetoro ◽  
John O. Odiyo

In this study, the potential for pulverized raw macadamia nut shell (MNS) for the sequestration of methylene blue from aqueous media was assessed. The sorbent was characterized using scanning electron microscopy for surface morphology, functional group analysis was performed with a Fourier-transform infrared spectrometer (FT-IR), and Brunauer–Emmett–Teller (BET) isotherm was used for surface area elucidation. The effects of contact time, sorbent dosage, particle size, pH, and change in a solution matrix were studied. Equilibrium data were fitted using Temkin, Langmuir, and Freundlich adsorption isotherm models. The sorption kinetics was studied using the Lagergren pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion models. The feasibility of the study was established from the thermodynamic studies. A surface area of 2.763 m2/g was obtained. The equilibrium and kinetics of sorption was best described by the Langmuir and the pseudo-second-order models, respectively. The sorption process was spontaneous (−ΔG0=28.72−31.77 kJ/mol) and endothermic in nature (ΔH0=17.45 kJ/mol). The positive value of ΔS0 (0.15 kJ/molK) implies increased randomness of the sorbate molecules at the surface of the sorbent. This study presents sustainable management of wastewater using MNS as a potential low-cost sorbent for dye decontamination from aqueous solution.


2018 ◽  
Vol 25 (2) ◽  
pp. 353-361
Author(s):  
Zefei Zhang ◽  
Cholhwan Kim ◽  
Carlos Fernandez ◽  
Manickam Minakshi Sundaram ◽  
Thippeswamy Ramakrishnappa ◽  
...  

AbstractWe report the preparation and employability of carbon-coated Fe3O4(Fe3O4/C) microspheres functionalized with chloroacetic acid (CAA) for the removal of methylene blue (MB) in aqueous solution. The prepared magnetic microspheres (Fe3O4/C-CAA) were characterized by the following techniques: X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectrometer, vibrating sample magnetometry, and Brunauer-Emmett-Teller. The characterization results showed that Fe3O4/C microspheres were modified by CAA without any phase change. Fe3O4/C-CAA microspheres have higher adsorption capacity for MB compared to Fe3O4/C microspheres. The Langmuir, Freundlich, and Temkin adsorption models were applied to describe the equilibrium isotherms, and the Langmuir adsorption model fitted well with the equilibrium data. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetics data. However, the pseudo-second-order kinetic model fitted better with the adsorption kinetics data.


1981 ◽  
Vol 17 (2) ◽  
pp. 107-111 ◽  
Author(s):  
S. Solar ◽  
N. Getoff ◽  
W. Solar ◽  
F. Mark

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Ewelina Kusiak-Nejman ◽  
Agnieszka Sienkiewicz ◽  
Agnieszka Wanag ◽  
Paulina Rokicka-Konieczna ◽  
Antoni W. Morawski

This work investigated for the first time the role of adsorption in the photocatalytic degradation of methylene blue and Orange II dyes in the presence of 3-aminopropyltriethoxysilane (APTES)-modified TiO2 nanomaterials. It has been demonstrated that the decrease in adsorption has a detrimental effect on photocatalytic activity. APTES/TiO2 photocatalysts were successfully prepared by solvothermal modification of TiO2 in a pressure autoclave, followed by heat treatment in an inert gas atmosphere at the temperature range from 300 °C to 900 °C. It was observed that functionalization of TiO2 via APTES effectively suppressed the anatase-to-rutile phase transformation, as well as the growth of crystallites size during calcination, and reduction of specific surface area (APTES modification inhibits sintering of crystallites). The noted alterations in the adsorption properties, observed after the calcination, were generally related to changes in the surface characteristics, mainly surface charges expressed by the zeta potential. Positively charged surface enhances adsorption of anionic dye (Orange II), while negatively charged surface was better for adsorption of cationic dye (methylene blue). The adsorption process substantially affects the efficiency of the photocatalytic oxidation of both dyes. The methylene blue decomposition proceeded according to the pseudo-first and pseudo-second-order kinetic models, while the degradation of Orange II followed the zero, pseudo-first, and pseudo-second order kinetic models.


2020 ◽  
Vol 42 (1) ◽  
pp. 10-18
Author(s):  
Tae Hyun Gil ◽  
Wang Heon Lee ◽  
Johng-Hwa Ahn

Objective : Present research discussed the utilization of pumpkin-seed residue (PSR) after oil extraction with methanol as an adsorbent for methylene blue (MB) removal from aqueous solution.Method : The experiment was carried out to evaluate the influence of PSR adsorbent dose (7.5-25 g/L), initial MB concentration (25-200 mg/L), contact time (30-120 min), pH (3-11), and temperature (293-333 K). Adsorption isotherms were modeled with the Langmuir, Freundlich, and Temkin isotherms. The kinetic data were analyzed using pseudo-first-order and pseudo-second-order models.Results and Discussion : A pseudo-equilibrium state was reached within 30 min of contact time at low initial MB concentration (25-50 mg/L) and 90 min at high concentration (100-200 mg/L). Increasing pH and temperature caused an increase in adsorption capacity. Thermodynamic studies demonstrated that the adsorption process was spontaneous with Gibb’s free-energy values ranging between -15.78 to -13.87 kJ/mol and endothermic with an enthalpy value of 0.011 kJ/mol. The adsorption equilibrium data fitted well with the Freundlich adsorption isotherm. The maximum monolayer adsorption capacity was 20.33 mg/g. Tempkin isotherm model clarified that the heat of sorption process was 6.28 J/mol. The adsorption kinetics was found to follow the pseudo-second order kinetics model and its rate constant was 0.002-0.278 g/mg・min.Conclusions : Findings of the present study indicated that the PSR can be successfully used for removal of MB from aqueous solution. Therefore, the PSR was shown to have good potential as a biosorbent for MB removal.


Sign in / Sign up

Export Citation Format

Share Document