scholarly journals Enhancement of Iron-Based Photo-Driven Processes by the Presence of Catechol Moieties

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 372
Author(s):  
Javier Moreno-Andrés ◽  
Iván Vallés ◽  
Paula García-Negueroles ◽  
Lucas Santos-Juanes ◽  
Antonio Arques
Keyword(s):  
Fenton Reaction ◽  
Advanced Oxidation Processes ◽  
Salt Water ◽  
Degradation Process ◽  
Contaminants Of Emerging Concern ◽  
Low Salt ◽  
Aquaculture Industry ◽  
Iron Based ◽  
Ph Range ◽  
Fenton System

Photo-induced Advanced Oxidation Processes (AOPs) using H2O2 or S2O82− as radical precursors were assessed for the abatement of six different contaminants of emerging concern (CECs). In order to increase the efficiency of these AOPs at a wider pH range, the catechol organic functional compound was studied as a potential assistant in photo-driven iron-based processes. Different salinity regimes were also studied (in terms of Cl− concentration), namely low salt water (1 g·L−1) or a salt–water (30 g·L−1) matrix. Results obtained revealed that the presence of catechol could efficiently assist the photo-Fenton system and partly promote the photo-induced S2O82− system, which was highly dependent on salinity. Regarding the behavior of individual CECs, the photo-Fenton reaction was able to enhance the degradation of all six CECs, meanwhile the S2O82−-based process showed a moderate enhancement for acetaminophen, amoxicillin or clofibric acid. Finally, a response-surface methodology was employed to determine the effect of pH and catechol concentration on the different photo-driven processes. Catechol was removed during the degradation process. According to the results obtained, the presence of catechol in organic macromolecules can bring some advantages in water treatment for either freshwater (wastewater) or seawater (maritime or aquaculture industry).

Degradation of p-hydroxyphenylacetic acid by photoassisted Fenton reaction

2001 ◽  
Vol 44 (5) ◽  
pp. 31-38 ◽  
Author(s):  
J.L. Acero ◽  
F.J. Benítez ◽  
F.J. Real ◽  
A.I. Leal
Keyword(s):  
Fenton Reaction ◽  
Advanced Oxidation Processes ◽  
Radical Reaction ◽  
Industrial Plant ◽  
Oh Radicals ◽  
Oxidation Processes ◽  
Fenton’S Reaction ◽  
Optimum Ph ◽  
Hydroxyphenylacetic Acid ◽  
Fenton System

The chemical decomposition of p-hydroxyphenylacetic acid, a phenolic pollutant present in agro-industrial plant effluents, has been investigated by means of the Fenton's reaction and the photoassisted Fenton's reaction, the so-called photo-Fenton system. The degradation levels achieved have been compared to those obtained by applying other Advanced Oxidation Processes, such as the combination UV/H2O2. The optimum pH to carry out the decomposition of this organic compound by either Fenton or photo-Fenton systems was found to be pH = 3. The presence of buffers such as phosphate impedes these processes due to the formation of ferric complexes. A reaction mechanism, which allows calculating the contribution of the radical reaction to the global process, has been proposed. According to this mechanism, the dominant way of degradation of p-hydroxyphenylacetic acid is through its reaction with the OH radicals originated in the photolysis of H2O2 and, especially, in the Fenton's reaction.

Role of Fe(III) and Oxalic Acid in the photo-Fenton System for 3-Methylphenol Degradation in Aqueous Solution under Natural and Artificial Light

2018 ◽  
Vol 16 (9) ◽  
Author(s):  
N. Seraghni ◽  
B.A Dekkiche ◽  
S. Belattar ◽  
N. Debbache ◽  
T. Sehili
Keyword(s):  
Oxalic Acid ◽  
Fenton Reaction ◽  
Aqueous Media ◽  
Oxygen Demand ◽  
Positive Role ◽  
Ph Conditions ◽  
Ph Range ◽  
Oxidative Species ◽  
Fenton System

Abstract The Fenton process has been widely studied in the treatment of wastewater but unfortunately this process can only work under acidic pH conditions. To overcome these disadvantages, the Fenton modified by adding chelating agents such as oxalic acid (Ferrioxalate complex (Fe(III)Ox) since its high solubility in aqueous media can broaden the available pH range of the Fenton reaction to near neutral pH. In this study, The photooxidation efficiencies of 3-methylphenol (3MP) catalyzed by Fe(III) and oxalic acid was investigated. The results show that the photodegradation Of 3MP is slow in the presence of Fe(III) or oxalic acid alone. However, it is markedly enhanced when Fe(III)Ox complex coexist. The concentration of the complex is optimized to the ratio ([Fe(III)Ox] = 3/12). Fe(III)Ox plays a positive role in the photo-Fenton system, especially at higher pH = 5.5. Oxygen is essential to the formation of oxidative species and, as a consequence, for the pollutant degradation. Additionally, the use of tertio-butanol as a scavenger confirmed the intervention of .OH in the 3MP photodegradation. 3MP degradation mechanisms have been elucidated and photoproducts are identified by comparison with authentic products. To get closer to the environmental conditions, the effect of main elements present naturally in the aquatic ecosystem such as humic substances and bicarbonates was examined. The photodegradation of 3MP through Fe(III)Ox system under solar light was significantly accelerated in comparison with artificial irradiation at 365 nm. Measuring chemical oxygen demand (COD) leads to mineralization which decreases the toxicity of 3MP solution. This work also demonstrates that this system is an encouraging method for the treatment of organic pollutants in the natural environment.

Comparative Studies of Two Fenton-Like Catalysts: Fe2O3 and Fe2O3/Attapulgite

2012 ◽  
Vol 518-523 ◽  
pp. 696-700 ◽  
Author(s):  
Ting Zhang ◽  
Yi Wang ◽  
Shu Rong Yu ◽  
Hui Xia Feng
Keyword(s):  
Comparative Studies ◽  
Fenton Reaction ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Benzene Sulfonate ◽  
Secondary Pollutants ◽  
Dodecyl Benzene Sulfonate ◽  
Anion Surfactant ◽  
Ph Range ◽  
Fenton System

Fe2O3 and Fe2O3/attapulgite(ATP) catalyst was used for Fenton reaction to degrade an anion surfactant, sodium dodecyl benzene sulfonate(SDBS)，in an aqueous solution. Comparative studies indicated that Fe2O3/ATP-catalyzed Fenton system and Fe2O3-catalyzed Fenton system have the same catalysis capability. These two systems all have a widely pH range (2-10), and the catalysts can be reused and have no secondary pollutants. It also can be seen that Fe2O3/ATP-catalyzed Fenton-like reaction has much efficiency than Fe2O3-catalyzed Fenton reaction.

Surfactant Impurities Can Explain the Jones-Ray Effect

2018 ◽  
Author(s):  
Timothy Duignan ◽  
Marcel Baer ◽  
Christopher Mundy
Keyword(s):  
Surface Tension ◽  
Electrostatic Potential ◽  
Driving Forces ◽  
Salt Water ◽  
Fundamental Property ◽  
Apparent Contradiction ◽  
Low Salt ◽  
Air Water Interface ◽  
Added Salt ◽  
Effect Of Surface

<div> <p> </p><div> <div> <div> <p>The surface tension of dilute salt water is a fundamental property that is crucial to understanding the complexity of many aqueous phase processes. Small ions are known to be repelled from the air-water surface leading to an increase in the surface tension in accordance with the Gibbs adsorption isotherm. The Jones-Ray effect refers to the observation that at extremely low salt concentration the surface tension decreases in apparent contradiction with thermodynamics. Determining the mechanism that is responsible for this Jones-Ray effect is important for theoretically predicting the distribution of ions near surfaces. Here we show that this surface tension decrease can be explained by surfactant impurities in water that create a substantial negative electrostatic potential at the air-water interface. This potential strongly attracts positive cations in water to the interface lowering the surface tension and thus explaining the signature of the Jones-Ray effect. At higher salt concentrations, this electrostatic potential is screened by the added salt reducing the magnitude of this effect. The effect of surface curvature on this behavior is also examined and the implications for unexplained bubble phenomena is discussed. This work suggests that the purity standards for water may be inadequate and that the interactions between ions with background impurities are important to incorporate into our understanding of the driving forces that give rise to the speciation of ions at interfaces. </p> </div> </div> </div> </div>

Non-covalent modification of low-molecular quinones into iron-based nanoreactors enabling self-sustaining Fenton reaction-mediated chemo-dynamic therapy and resisting macrophage uptake

2021 ◽  
Vol 334 ◽  
pp. 116061
Author(s):  
Zi-Yi Zheng ◽  
Guo Xie ◽  
Gui-Liang Tan ◽  
Lin Li ◽  
Wen-Li Liu ◽  
...  
Keyword(s):  
Fenton Reaction ◽  
Covalent Modification ◽  
Dynamic Therapy ◽  
Iron Based ◽  
Macrophage Uptake

Simultaneous removal of contaminants of emerging concern and pathogens from urban wastewater by homogeneous solar driven advanced oxidation processes

2021 ◽  
Vol 766 ◽  
pp. 144320
Author(s):  
Gulnara Maniakova ◽  
Irene Salmerón ◽  
María Inmaculada Polo-López ◽  
Isabel Oller ◽  
Luigi Rizzo ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Contaminants Of Emerging Concern ◽  
Simultaneous Removal ◽  
Urban Wastewater ◽  
Oxidation Processes ◽  
Removal Of Contaminants

Highly enhanced dephosphorylation of phytic acid via pre-complexation of PA-Fe2+ in the Fenton system: High activity, wide pH range and ferryl-based mechanism

2021 ◽  
pp. 130894
Author(s):  
Yiguang Qian ◽  
Weijie Pan ◽  
Juying Li ◽  
Ke Chen ◽  
Jun Yao
Keyword(s):  
High Activity ◽  
Phytic Acid ◽  
Wide Ph Range ◽  
Ph Range ◽  
Fenton System

scholarly journals Comparison of Various Advanced Oxidation Processes for the Degradation of Bisphenol A

2017 ◽  
pp. 147
Author(s):  
Naser Jamshidi ◽  
Farzad Nezhad Bahadori ◽  
Ladan Talebiazar ◽  
Ali Akbar Azimi
Keyword(s):  
Bisphenol A ◽  
Uv Irradiation ◽  
Advanced Oxidation Processes ◽  
Irradiation Time ◽  
Advanced Oxidation ◽  
Chemical Oxidation ◽  
Photochemical Oxidation ◽  
Input Concentration ◽  
Oxidation Processes ◽  
Ph Range

Today, advanced oxidation processes (AOPs) is considered as a key and effective method for environment preservation from pollutions. In this study , advanced photochemical oxidation processes using O3/H2O2 and O3/H2O2/UV systems were investigated batch photolytic reactor in lab-scale for the degradation of bisphenol A (BPA). In ozone generator source, air, as of the initial instrument feed, changes to ozone after electrical action and reaction. The UV irradiation source was a medium-pressure mercury lamp 300 W that was immerse in the wastewater solution with in 1.5 liter volume reactor. The reaction was influenced by the pH, the input concentration of H2O2, the input concentration of BPA, ozone dosage, chemical oxidation demand (COD) and UV irradiation time. Results showed that at initial bisphenol A concentration of 100 mg/l will completely degrade after 60 minutes by using O3/H2O2 in the pH range from 9.8 to 10 and by adding UV, it will happen in less than 36 minutes in the pH range of 3 to 10. The O3/H2O2/UV process reduced COD to 75 percents.

scholarly journals Degradation of the pharmaceuticals lamivudine and zidovudine using advanced oxidation processes

2020 ◽  
Vol 42 ◽  
pp. e9
Author(s):  
Alex Leandro Andrade de Lucena ◽  
Daniella Carla Napoleão ◽  
Hélder Vinícius Carneiro da Silva ◽  
Rayany Magali da Rocha Santana ◽  
Beatriz Galdino Ribeiro ◽  
...  
Keyword(s):  
Lactuca Sativa ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Kinetic Studies ◽  
Degradation Process ◽  
Oxidation Processes ◽  
First Order ◽  
Input Variables ◽  
Pharmaceutical Degradation ◽  
Uv C

The existence of pharmaceuticals in nature is a growing environmental problem, turning necessary the use of efficient treatments for the degradation of these substances, as the advanced oxidation processes (AOPs). In this work the AOPs UV/H2O2 and photo-Fenton were applied to degrade the pharmaceuticals lamivudine and zidovudine in an aqueous solution using a bench reactor, composed of three UV-C lamps. It was verified that the UV/H2O2 process presented a degradation of 97.33 ± 0.14% for lamivudine and 93.90 ± 0.33% for zidovudine, after 180 min of treatment and for an initial concentratin of each pharmaceutical of  5 mg.L-1 and [H2O2] of 600 mg.L-1.  A methodology by artificial neural networks (ANNs) was used to model the photocatalytic process, with the MLP 7-23-2 ANN representing it well, and determining the relative importance (%) of each of the input variables for the pharmaceutical’s degradation process. Kinetic studies for the pharmaceutical degradation and the conversion of organic matter showed good adjustments to the pseudo first-order models with R2 raging from 0.9705 to 0.9980. Toxicity assays for the before treatment solution indicated that the seeds Lactuca sativa and Portulaca grandiflora showed growth inhibition whereas the post-treatment solution inhibited only the growth of Lactuca sativa.

Tetracycline Removal Enhancement With Fe-Saturated Nanoporous Montmorillonite in a Tripartite Adsorption/Desorption/Photo-Fenton Degradation Process

2021 ◽  
Author(s):  
Shiva Chahardahmasoumi ◽  
Seyed Amir Hossein Jalali ◽  
Mehdi Nasiri Sarvi
Keyword(s):  
Antimicrobial Activity ◽  
Visible Light ◽  
Fenton Reaction ◽  
Degradation Process ◽  
Oh Radicals ◽  
Desorption Process ◽  
High Tc ◽  
Modified Montmorillonite ◽  
Adsorption Desorption ◽  
First Time

Abstract The adsorption and photo-Fenton degradation of tetracycline (TC) over Fe saturated nanoporous montmorillonite was analyzed. The synthesized samples were characterized using XRD, FTIR, SEM, and XRF analysis, and the adsorption and desorption of TC onto these samples as well as the antimicrobial activity of TC during these processes were analyzed at different pH. The results indicated that the montmorillonite is a great adsorbent for the separation of the TC from aqueous solutions, however, after increasing the amount of TC adsorbed, the desorption process started, and up to 50% of TC adsorbed onto non-modified montmorillonite was released back to the solution with almost no changes in its antimicrobial activity. After acid treatment (for creation of nanoporous layers) and Fe saturation of the montmorillonite, almost similar great separation was achieved compared to non-modified montmorillonite. In addition, the desorption of TC from modified montmorillonite was still high up to 40% of adsorbed TC. However, simultaneous adsorption and photodegradation of TC were detected and almost no antimicrobial activity was detected after 180 min of visible light irradiation, which could be due to the photo-Fenton degradation of TC on the modified montmorillonite surface. In the porous structures of modified montmorillonite high ˙OH radicals were created in the photo-Fenton reaction and were measured using the Coumarin technique. The ˙OH radicals help the degradation of TC as proposed in an oxidation process. Surprisingly, more than 90 % of antimicrobial activity of the TC decreased under visible light (after 180 min) when desorbed from nanoporous Fe-saturated montmorillonite compared to natural montmorillonite. To the best of our knowledge, this is the first time that such a high TC desorption rate from an adsorbent with the least remained antimicrobial activity is reported which makes nanoporous Fe-saturated montmorillonite a perfect separation substance of TC from the environment.

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