scholarly journals Impact of Precipitants on the Structure and Properties of Fe-Co-Ce Composite Catalysts

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yongli Zhang ◽  
Shujuan Dai ◽  
Yanbo Zhou ◽  
Kai Lin

Fe-Co-Ce composite catalysts were prepared by coprecipitation method using CO(NH2)2, NaOH, NH4HCO3, and NH3·H2O as precipitant agents. The effects of the precipitant agents on the physicochemical properties of the Fe-Co-Ce based catalysts were investigated by SEM, TEM, BET, TG-DTA, and XRD. It was found that the precipitant agents remarkably influenced the morphology and particle size of the catalysts and affected the COD removal efficiency, decolorization rate, and pH of methyl orange for catalytic wet air oxidation (CWAO). The specific surface area of the Fe-Co-Ce composite catalysts successively decreased in the order of NH3·H2O, NH4HCO3, NaOH, and CO(NH2)2, which correlated to an increasing particle size that increased for each catalyst. For the CWAO of a methyl orange aqueous solutions, the effects of precipitant agents NH3·H2O and NaOH were superior to those of CO(NH2)2and NH4HCO3. The catalyst prepared using NH3·H2O as the precipitant agent was mostly composed of Fe2O3, CoO, and CeO2. The COD removal efficiency of methyl orange aqueous solution for NH3·H2O reached 92.9% in the catalytic wet air oxidation. Such a catalytic property was maintained for six runs.

2016 ◽  
Vol 16 (9) ◽  
pp. 10040-10047 ◽  
Author(s):  
Adriano C Rabelo ◽  
Adriane V Rosario ◽  
Marília A Trapp ◽  
Edson Rodrigues Filho ◽  
Moacir Forim ◽  
...  

2014 ◽  
Vol 931-932 ◽  
pp. 32-36 ◽  
Author(s):  
Pongsert Sriprom ◽  
Pornsawan Assawasaengrat ◽  
Arthit Neramittagapong ◽  
Sutasinee Neramittagapong

Wet-air oxidation (WAO) and catalytic wet-air oxidation (CWAO) over CuO/Al2O3 and NiO/Al2O3 catalysts for aniline removal were investigated. The oxidation reaction was carried out in a 1000-ml high-pressure batch reactor. The temperatures of 160, 200 and 260C and the pressures of 5 and 10 bars were generally applied for 120 min. CuO/Al2O3 and NiO/Al2O3 catalysts were prepared by impregnation method. It is found from the results that aniline was completely degraded at these conditions. However, aniline was converted into other organic carbons which remained in the solution. So COD was found in the solution after the reaction. It is seen from the results that 56% of COD was removed by WAO at 200C and 10 bars for 120 min. The CWAO over CuO/Al2O3 catalyst showed higher COD removal (76%) than NiO/Al2O3 catalyst (60%). The types of metal oxide had an effect to the activity of COD removal; that is, CuO showed higher COD removal than NiO. The WAO and CWAO of COD removal in aniline solution were the first-order kinetic with the constant reaction rate and activation energy for CuO/Al2O3 of 0.234 s-1 and 11.772 kJ/mol, respectively.


1997 ◽  
Vol 35 (4) ◽  
pp. 311-319 ◽  
Author(s):  
L. Lei ◽  
X. Hu ◽  
H. P. Chu ◽  
G. Chen ◽  
P. L. Yue

The treatment of dyeing and printing wastewater from the textile industry by oxidation was studied. The reaction was carried out in a two-litre high pressure reactor. In order to promote the oxidation of organic pollutants present in the wastewater, experiments were conducted using various catalysts including metal salts, metal oxides, and porous alumina supported metals. All catalysts tested were able to enhance the conversion of organic compounds in wastewater, shorten the reaction time, and lower the reaction temperature. The alumina supported catalyst has an advantage over other catalysts in that it can be easily separated from the treated wastewater by filtration and recycled. The conditions in preparing the catalyst supported by porous alumina were experimentally optimised.


Author(s):  
Mohamed Achraf Bouabdellah ◽  
Itidel Belkadhi ◽  
Lassaad Ben Hammouda ◽  
Gwendoline Lafaye ◽  
Francisco Medina Cabello ◽  
...  

2021 ◽  
Vol 23 (4) ◽  
pp. 1847-1860
Author(s):  
Christopher S. McCallum ◽  
Wanling Wang ◽  
W. John Doran ◽  
W. Graham Forsythe ◽  
Mark D. Garrett ◽  
...  

A life cycle thinking analysis (LCT) conducted on the production of vanillin via bamboo wet air oxidation compared to vanillin production from crude oil or kraft lignin.


Author(s):  
Valérie Boucher ◽  
Margot Beaudon ◽  
Pedro Ramirez ◽  
Pascal Lemoine ◽  
Kalyssa Volk ◽  
...  

Removal of pharmaceuticals from wastewater using chemical processes is a promising solution to mitigate pollution in drinking and surface waters. Non-catalytic wet air oxidation (WAO) is a highly efficient advanced...


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.


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