Synergistic Degradation of Methylene Blue By Novel Fe-Co Bimetallic Catalyst Supported On Waste Silica in Photo-Fenton-Like System

Author(s):  
Khyle Glainmer Quiton ◽  
Ming-Chun Lu ◽  
Yao-Hui Huang

Abstract The environment is affected by agricultural, domestic, and industrial activities that lead to drastic problems such as global warming and wastewater generation. Wastewater pollution is of public concern, making the treatment of persistent pollutants in water and wastewater highly imperative. Several conventional treatment technologies have been applied to water and wastewater remediation, but each has numerous limitations. To address this issue, treatment using bimetallic systems has been extensively studied. Synergistic effects between the two metals are highly desirable because they usually offer enhanced activity, selectivity, and stability relative to their monometallic counterparts. In this study, a novel method to fabricate bimetallic Fe-Co catalyst supported on waste silica was investigated for the treatment of methylene blue dye as model pollutant. Under the optimum conditions of pHi 3.0, 3.0 mM H2O2, 1.0 g L-1 Fe-Co/SiO2 catalyst, and 20 mg L-1 initial dye concentration, the maximum response for the decoloration and mineralization efficiencies of methylene blue were 100% and 64.57%, respectively. Superoxide radical was unveiled to be the dominant reactive oxygen species in the photo-Fenton-like system over Fe-Co/SiO2 catalyst. Compared to the contrastive catalyst, the Fe-Co/SiO2 synthesized using fluidized-bed crystallization exhibited comparable decoloration and mineralization efficiencies, and relatively lower metal leaching.

Plasma ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 59-91 ◽  
Author(s):  
Emile Salomon Massima Mouele ◽  
Jimoh. O. Tijani ◽  
Milua Masikini ◽  
Ojo. O. Fatoba ◽  
Chuks P. Eze ◽  
...  

Advanced oxidation technologies (AOTs) focusing on nonthermal plasma induced by dielectric barrier discharge are adequate sources of diverse reactive oxygen species (ROS) beneficial for water and wastewater treatment. In this study, indigo, peroxytitanyl sulphate and terephthalic acid methods were used to approximate the concentrations of O3, H2O2 and OH produced in a double cylindrical dielectric barrier discharge (DCDBD) plasma configuration. The effect of pH and scavengers as well as the amount of chemical probes on the generation of oxidants was investigated. The efficiency of the DCDBD reactor was further evaluated using methylene blue (MB) as model pollutant. The results demonstrated that the formation of oxidants O3, H2O2 and OH in the DCDBD reactor was pH-dependent. Furthermore, the presence of scavengers such as phosphates, bicarbonates and carbonates in the solution diminished the amount of OH in the system and hence could impact upon the degree of detoxification of targeted pollutants during water and wastewater treatment. The MB simulated dye was totally decomposed into H2O, dissolved CO2 and simpler aqueous entities. Herein the DCDBD design is an adequate AOT that can be used worldwide for effective decontamination of water and wastewater.


Author(s):  
Saraa Muwafaq Ibrahim ◽  
Ziad T. Abd Ali

Batch experiments have been studied to remove methylene blue dye (MB) from aqueous solution using modified bentonite. The modified bentonite was synthesized by replacing exchangeable calcium cations in natural bentonite with cationic surfactant cetyl trimethyl ammonium bromide (CTAB). The characteristics of modified bentonite were studied using different analysis such as Scanning electronic microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and surface area. Where SEM shows the natural bentonite has a porous structure, a rough and uneven appearance with scattered and different block structure sizes, while the modified bentonite surface morphology was smooth and supplemented by a limited number of holes. On other hand, (FTIR) analysis that proved NH group aliphatic and aromatic group of MB and silanol group are responsible for the sorption of contaminate. The organic matter peaks at 2848 and 2930 cm-1 in the spectra of modified bentonite which are sharper than those of the natural bentonite were assigned to the CH2 scissor vibration band and the symmetrical CH3 stretching absorption band, respectively, also the 2930 cm-1 peak is assigned to CH stretching band. The batch study was provided the maximum removal efficiency (99.99 % MB) with a sorption capacity of 129.87 mg/g at specified conditions (100 mg/L, 25℃, pH 11 and 250rpm). The sorption isotherm data fitted well with the Freundlich isotherm model. The kinetic studies were revealed that the sorption follows a pseudo-second-order kinetic model which indicates chemisorption between sorbent and sorbate molecules.


2018 ◽  
Vol 8 (3) ◽  
pp. 502-513
Author(s):  
Saravanan Narayanan ◽  
Rathika Govindasamy

2019 ◽  
Author(s):  
Chem Int

The study aims to use an adsorbent natural based of Moroccan oil shale of Timahdit area (Y layer) in a physical-chemical adsorption process for treating industrial discharges colorful. The used adsorbent is the insoluble party of the sub-critical extraction of decarbonized oil shale of Timahdit. The tests performed on the methylene blue (MB), showed a strong elimination in the first 10 minutes. The influences of various experimental parameters were studied: mass ratio of adsorbent, time and temperature of thermal treatment, contact time, pH of MB and heating temperature of solution on the parameters of material were studied. The experimental results have shown that the adsorption of methylene blue dye by the adsorbent is more than 90% at initial pH a range 6-7 at room temperature for 30 minutes. The process is simple and the adsorbent produced is a new material with interesting adsorption capacities of moderate cost which does not require an activating agent and can be used as industrial adsorbent for the decontamination of effluents containing organic pollutants.


2021 ◽  
Vol 170 ◽  
pp. 375-389
Author(s):  
Alexandra Cemin ◽  
Fabrício Ferrarini ◽  
Matheus Poletto ◽  
Luis R. Bonetto ◽  
Jordana Bortoluz ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1985
Author(s):  
Irina Plesco ◽  
Vladimir Ciobanu ◽  
Tudor Braniste ◽  
Veaceslav Ursaki ◽  
Florian Rasch ◽  
...  

A new type of photocatalyst is proposed on the basis of aero-β-Ga2O3, which is a material constructed from a network of interconnected tetrapods with arms in the form of microtubes with nanometric walls. The aero-Ga2O3 material is obtained by annealing of aero-GaN fabricated by epitaxial growth on ZnO microtetrapods. The hybrid structures composed of aero-Ga2O3 functionalized with Au or Pt nanodots were tested for the photocatalytic degradation of methylene blue dye under UV or visible light illumination. The functionalization of aero-Ga2O3 with noble metals results in the enhancement of the photocatalytic performances of bare material, reaching the performances inherent to ZnO while gaining the advantage of the increased chemical stability. The mechanisms of enhancement of the photocatalytic properties by activating aero-Ga2O3 with noble metals are discussed to elucidate their potential for environmental applications.


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