scholarly journals Catalytic Advanced Oxidation Processes for Sulfamethoxazole Degradation

2019 ◽  
Vol 9 (13) ◽  
pp. 2652 ◽  
Author(s):  
Jéssica Martini ◽  
Carla A. Orge ◽  
Joaquim L. Faria ◽  
M. Fernando R. Pereira ◽  
O. Salomé G. P. Soares

The degradation of sulfamethoxazole (SMX) by several advanced oxidation processes (AOPs) is carried out in the presence of different catalysts. The catalysts used consisted of carbon nanotubes (CNT), titanium dioxide (TiO2), a composite of carbon nanotubes and titanium dioxide (TiO2/CNT), and iron supported on carbon nanotubes (Fe/CNT). SMX removal was evaluated by catalytic ozonation, photocatalysis, catalytic oxidation with hydrogen peroxide, and combinations of these processes. The evolution of the SMX concentration during reaction time, the mineralization degree, the toxicity of the treated solution, and the formation of organic intermediates and ions were monitored. Ozonation catalyzed by Fe/CNT and CNT and photocatalytic ozonation in the presence of CNT presented the fastest degradation of SMX, whereas photocatalytic ozonation with CNT showed the best results in terms of organic matter removal (92% of total organic carbon (TOC) depletion). Total mineralization of the solution and almost complete reduction of toxicity was only achieved in the photocatalytic ozonation with H2O2 and Fe/CNT catalysts. The compound 3-amino-5-methylisoxazole was one of the first intermediates formed during SMX degradation. p-Benzoquinone was only formed in photocatalysis. Oxalic and oxamic acids were also detected and in most of the catalytic processes they appeared in small amounts. Ion concentrations increased with the reaction time.

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Moayede Taie ◽  
Abdolmajid Fadaei ◽  
Mehraban Sadeghi ◽  
Sara Hemati ◽  
Gashtasb Mardani

Nowadays, advanced oxidation processes, particularly photocatalyst process and catalytic ozonation by ZnO nanoparticles, are the most efficient method of eliminating pharmaceuticals. The purpose of this study was to compare the efficiency of ultraviolet/zinc oxide (UV/ZnO) and ozone/zinc oxide (O3/ZnO) techniques as advanced oxidation processes in the removal of trimethoprim (TMP) from aqueous solutions. The process consisted of 0.6 g/L of ozone (O3), pH = 7.5 ± 0.5, TMP with a concentration of 0.5–5 mg/L, ZnO with a dose of 50–500 mg/L, 5–30 min reaction time, and 30–180 min contact time with UV radiation (6 W, 256 nm) in a continuous reactor. The high removal efficiency was achieved after 25 minutes when ZnO is used in 1 mg/L TMP under an operational condition at pH 7.5. When the concentration of the pollutant increased from 0.5 to 1, the average removal efficiency increased from 78% to 94%, and then, it remained almost constant. An increase in the reaction time from 5 to 25 minutes will cause the average elimination to increase from 84% to 94%. The results showed that the efficiency of O3/ZnO process in the removal of TMP was 94%, while the removal efficiency of UV/ZnO process was 91%. The findings exhibited that the kinetic study followed the second-order kinetics, both processes. With regard to the results, the photocatalyst process and catalytic ozonation by ZnO nanoparticles can make acceptable levels for an efficient posttreatment. Finally, this combined system is proven to be a technically effective method for treating antibiotic contaminants.


RSC Advances ◽  
2021 ◽  
Vol 11 (17) ◽  
pp. 9911-9920
Author(s):  
Gabriele Capilli ◽  
Damian Rodríguez Sartori ◽  
Monica C. Gonzalez ◽  
Enzo Laurenti ◽  
Claudio Minero ◽  
...  

Under UV-Vis irradiation, the metallic impurities embedded in non-purified commercial carbon nanotubes generate radicals suitable for advanced oxidation processes. Semiconducting PPY membranes enhance the photo activity of a supported catalyst.


2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.


2015 ◽  
Vol 44 ◽  
pp. 1-9 ◽  
Author(s):  
Manhal Abouzlam ◽  
Régis Ouvrard ◽  
Driss Mehdi ◽  
Florence Pontlevoy ◽  
Bertrand Gombert ◽  
...  

2014 ◽  
Vol 35 (6) ◽  
pp. 896-905 ◽  
Author(s):  
João Restivo ◽  
Raquel P. Rocha ◽  
Adrián M.T. Silva ◽  
José J.M. Órfão ◽  
Manuel F.R. Pereira ◽  
...  

2021 ◽  
Author(s):  
Ali Kamel H. Al jibouri

Industrial wastewater is one of the largest environmental challenges of this century. Most of these wastewaters contain non-biodegradable pollutants which need special treatment methods. Advanced oxidation processes (AOP’s), such as, ozonation, catalytic ozonation and ozone/ hydrogen peroxide have proved their effectiveness on the degradation of bio-recalcitrant pollutants. The main drawback in these processes is the high operating cost. The objective of this study was to develop innovative continuous ozonation and ozone based processes that can effectively degrade industrial non-biodegradable pollutants. Naphthenic acids (NAs) was used as the model pollutant in this study due to its importance as a major pollutant in oil and oil sands industries. The target was to convert bio-recalcitrant NAs into biodegradable substances with minimum consumption of ozone gas (operating cost). These processes can be followed by the biodegradation process to fully remove the rest of the pollutants. This research passed through several stages including screening of operating parameters, kinetic studies, and modeling, followed by optimal control of these processes. It was found that ozone concentration had the most significant effect on the NAs degradation compared to other parameters. The kinetics of direct and indirect (radical) ozonation of NAs were investigated and rate constants and activation energies of these reactions were determined. Catalytic ozonation of NAs was explored using alumina supported metal oxides and unsupported catalysts. Activated carbon was found to be the most effective catalyst. The addition of hydrogen peroxide into the ozonation systems significantly improved the removal of NAs compared with the ozonation only process. Models based on mass balance for the ozonation and ozone/ hydrogen peroxide processes were developed to predict the concentration profiles of reacting species. Optimal control policies of ozone/oxygen gas flow rate versus time were developed and validated to minimize NAs concentration in the liquid outlet stream from the continuous ozonation and ozone/ hydrogen peroxide processes. The experimental results demonstrated that the optimal control policies successfully minimized NAs concentration in the outlet stream. At the same time, ozone gas consumption was reduced to its minimum, i.e., just enough to minimize the concentration of NAs in the outlet stream.


2018 ◽  
Vol 59 ◽  
pp. 00017
Author(s):  
Kamil Kuźmiński ◽  
Antoni W. Morawski ◽  
Magdalena Janus

In these studies advanced oxidation processes such as: photolysis, ozonation and photocatalysis for anionic and cationic surfactants decomposition were used. Nitrogen modified titanium dioxide and commercial TiO2-P25 were used for photocatalytic tests. UV-C lamp and different dose of ozone: 186, 383, 478 and 563 mg/(dm3·h) were used. The optimal system for anionic and cationic surfactants decomposition was connection of ozonation with UV-C irradiation.


2009 ◽  
Vol 9 (10) ◽  
pp. 6228-6233 ◽  
Author(s):  
M. Escobar ◽  
S. Goyanes ◽  
M. A. Corcuera ◽  
A. Eceiza ◽  
I. Mondragon ◽  
...  

2021 ◽  
Author(s):  
Ali Kamel H. Al jibouri

Industrial wastewater is one of the largest environmental challenges of this century. Most of these wastewaters contain non-biodegradable pollutants which need special treatment methods. Advanced oxidation processes (AOP’s), such as, ozonation, catalytic ozonation and ozone/ hydrogen peroxide have proved their effectiveness on the degradation of bio-recalcitrant pollutants. The main drawback in these processes is the high operating cost. The objective of this study was to develop innovative continuous ozonation and ozone based processes that can effectively degrade industrial non-biodegradable pollutants. Naphthenic acids (NAs) was used as the model pollutant in this study due to its importance as a major pollutant in oil and oil sands industries. The target was to convert bio-recalcitrant NAs into biodegradable substances with minimum consumption of ozone gas (operating cost). These processes can be followed by the biodegradation process to fully remove the rest of the pollutants. This research passed through several stages including screening of operating parameters, kinetic studies, and modeling, followed by optimal control of these processes. It was found that ozone concentration had the most significant effect on the NAs degradation compared to other parameters. The kinetics of direct and indirect (radical) ozonation of NAs were investigated and rate constants and activation energies of these reactions were determined. Catalytic ozonation of NAs was explored using alumina supported metal oxides and unsupported catalysts. Activated carbon was found to be the most effective catalyst. The addition of hydrogen peroxide into the ozonation systems significantly improved the removal of NAs compared with the ozonation only process. Models based on mass balance for the ozonation and ozone/ hydrogen peroxide processes were developed to predict the concentration profiles of reacting species. Optimal control policies of ozone/oxygen gas flow rate versus time were developed and validated to minimize NAs concentration in the liquid outlet stream from the continuous ozonation and ozone/ hydrogen peroxide processes. The experimental results demonstrated that the optimal control policies successfully minimized NAs concentration in the outlet stream. At the same time, ozone gas consumption was reduced to its minimum, i.e., just enough to minimize the concentration of NAs in the outlet stream.


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