Science topic
Advanced Oxidation Processes - Science topic
Advanced Oxidation Processes
Questions related to Advanced Oxidation Processes
Hi all, I’m researching PMS activation with a focus on confinement effects (e.g., nanoconfinement, angstrom-scale) and have solid papers like Meng et al. (2024) and Jiang et al. (2025). I’m missing how machine learning can optimize these systems—any recent studies combining ML with confinement for PMS activation? Ideally 2024–2025 papers. Thanks!
What is the impact of secondary reaction products formed from radical scavengers like tert-butanol, benzoic acid, [benzoate in alkalin media ], and nitrobenzene on the degradation rates of organic pollutants in alkaline media, and how do these products complicate the assessment of scavenger efficacy, particularly considering variations in pH that influence the stability and reactivity of these scavengers as both inhibitors and facilitators of degradation?
Can we calculate radical contribution using initial reaction rates instead of rate constants in UV/oxidant systems, particularly if the reaction shows unusual behavior at high concentrations of organic matter, affecting the rate constants?
Advanced oxidation process is usually produces carbon dioxide , is it harmful to run such setup in the lab?
I am interested to know the behavior of dyes toward light. Specifically, Blue dyes re-emit the spectrum, especially from the green zone (known as principal in LED lamps, and blue dyes are known to absorb green light), to a range <400 nm (UVA)?
Actually, in our lab, we thermally oxidize the metal films deposited on glass/quartz substrates at different temperatures and/or durations, which results in the conversion of metal to metal oxide thin films. Then we study the change in physical and chemical properties of these oxidized thin films due to different oxidation conditions. The morphology of nanoparticles sometimes drastically changes with respect to oxidation temperature. Last time, I oxidized the cobalt film at 400 °C and 500 °C and observed nanowall and nanograin morphology, respectively.
(Link :-
So I want to know the possible oxidation mechanism and energy factors which controls the oxidation growth mechnism.

I need resources that explain ways to combine membrane separation and electrochemical technologies for wastewater treatment. Explain fully including advantages and disadvantages, reactions and how to combine.
Advanced Oxidation Processes AOP, Green Sustainable Materials, and Nano Organic Materials
In a reaction like the Fenton process, which involves the use of Fe(III) and H2O2, does the concentration of Fe(II) species formed remain constant, whether there is water contamination or not?
For example, in the case of Fe(III)/H2O2/contaminant (0.5/0.5/0.05) mM, the concentration of Fe(II) formed is 0.3 mM after 60 minutes.
In the absence of a contaminant, with Fe(III)/H2O2 (0.5/0.5) mM, does the same amount of Fe(II) form after 60 minutes, or does it change?
Given that there is no reaction between the Fe(II/III) and the contaminant.
I am exploring an analytical or computational approach that can help to calculate the kinetic/thermodynamic parameters to predict the corrosion or oxidation of superalloy.
0.1mg/l is used to degrade 10mg/l solution(RhB) under white light irradiation at room temperature, ph 3 and contineous magnetic stirring during irradiation in doubled layered glass reactor with coooling system throughout the experiment.
Mineralization of organic matter takes place either by direct or indirect oxidation in an electrochemical oxidation reactor. As per literatures both occurs at same time. How can we find which one is more dominant (direct / indirect) in a particular electrode. Can OER Potential estimation can help in determining this?
Our research group cannot find suppliers of TiCl4 locally and our access to school laboratory is very limited due to pandemic. We are looking for ways on how to synthesize TiO2-rGO composite for our study using simple equipment only. Would you please help us in this?
For your reference, here is the original method:
SYNTHESIS OF TiO2@rGO COMPOSITES
The TiO2-rGO composite will be synthesized via the typical chemical method. Reduced graphene oxide (0.1 g) and 260 mL of 0.1 M titanium chloride (TiCl4) aqueous solution will be subjected to magnetic stirring for 0.5 hours at 80˚C. The mass ratio of TiO2 to rGO is based on the results of several studies indicating that the optimum concentration for the latter is 2 wt % 13,14. Slowly, 260 mL of 0.4M NaOH will be added under constant stirring for 3 h. The mixture will be washed with deionized water and ethanol five times; the former is for adjusting the pH to 7 while the latter is for better dispersion of the molecules. The formed product will be recovered using filter papers. Finally, it will be dried at 80˚C for 4 h.
Which method is easier to measure PFAS in water?
Microplastics (MPs) pollution has become a global environmental concern because of their severe threat to biota. However, limited studies on the elimination of MPs pollution were reported. The conventional treatment methods such as coagulation, sedimentation, screening, and flotation were not suitable for MPs owing to their smaller size than plastic items. Hence many methods for MPs treatment, including AOPs (direct photodegradation, photocatalytic oxidation, and electrochemical oxidation) and biodegradation, have been examined.
Hello,
I want to start experiments using sulfate AOPs. In many papers, there is used for example : 1 mM of potassium persulfate. Can ayone help me how to prepare this solution?
For example:
I have 100 mL of methylene blue (10 mg/L) solution. I want to add 1 mM of potassium persulfate. Should I add 27 mg of solid potassium persulfate and then fill it up to 100 mL with my methylene blue solution, or can I use 0,1 M potassium persulfate solution and add 1 ml of this solution and then fill it up to 100 mL with methylene blue solution ?
Thanks for answers
Juraj
I'm working on an industrial wastewater mainly composed by DMF and alcohols. I'm treating samples with hydrodynamic cavitation, hydrodynamic cavitation/H2O2 or hydrodynamic cavitation/O3 but at the end of each process the COD value is slightly higher than the wastewater one. I tried to remove excess of H2O2 by heating the samples at 90°C or adjusting pH to 10-11 and then heating at 45°C because of its interference, but also other samples have same problem Hannah Instrument COD kits are used to determine COD values.
According to below articles about kinetic modelling of ODH reactions by G. Che-Galicia and et al. there are some problems need your guidance and advices:
- "The Main article"
- https://www.sciencedirect.com/science/article/abs/pii/S1385894715008384
- https://www.sciencedirect.com/science/article/abs/pii/S1385894714004744
Q.A
- According to the nomenclature and equation 13, Kn (absorption equilibrium coefficient) should have the unit of 1 / Pa, but by referring to equation 19 Kn is unitless. why?
- According to Equation 18, the first statement in the exp function has the unit of mmol / (g.h), but the second statement is unitless, so we think A' must be outside the exp function. why?
- The quantity of Cps (solid heat capacity) and Kez (effective thermal conductivity in axial coordinate) did not reported in the main article and the references mentioned in the context of article. how can we calculate or get this property?
we emailed to authors but don't received any response !
Thank you for the time you spent reading.
Respectfully
Dear Colleagues,
I’m pleased to inform you that open access journal /Catalysts/ (ISSN 2073-4344, Impact Factor: 3.444) is planning to publish a Special Issue on the topic of "Trends in Catalytic Advanced Oxidation Processes". The submission deadline is 31 July 2020.
Detailed information regarding this issue, please follow the link below to the Special Issue website at:
This Special Issue is dedicated to novel achievements in the field of catalytic advanced oxidation processes. The contributions should be related to the listed topics:
· Catalytic processes in water and wastewater treatment
· Developments in Fenton-like AOPs
· Activation of Persulfates for AOPs
· Formation of sulfate radicals
· Catalytic cavitation-based AOPs (hydrodynamic cavitation and acoustic cavitation)
· Sonocatalysts
· Catalytic ozonation
· Photocatalysts—including visible light and UV applications
· Catalytic wet air oxidation (CWAO)
· Catalytic–electrochemical AOPs
· Carbon catalysts for AOPs
· Nanocatalysts
· Risk of by-product formation during water and wastewater treatment
· Developments in process control of catalytic AOPs (analytical methods, chromatographic, and spectroscopic techniques)
· Methods of catalysts characterization
· Post-process assessment of effluents toxicity
· Application of nanobubbles in AOPs
· Economic analysis of catalytic AOPs application and catalysts life cycle assessment (LCO)
· Industrial catalytic wastewater treatment
· Modelling and optimization of catalytic processes
· Green chemistry aspects in catalytic water and wastewater treatment
Detailed information regarding this issue, please follow the link below to the Special Issue website at:
Sincerely hope this invitation will receive your favorable consideration.
Best regards,
Guest Editor
Prof. Grzegorz Boczkaj, PhD. Sc. Eng. Assoc. Prof.
Email: grzegorz.boczkaj@pg.edu.pl
Department of Process Engineering and Chemical Technology, Faculty of
Chemistry, Gdansk University of Technology, 80-233 Gdansk, Poland
Caroline Zhan
Assistant Editor
Email: caroline.zhan@mdpi.com
Catalysts (IF 3.444, http://www.mdpi.com/journal/catalysts)
It is hypothesized that the nature/energies/electron distribution of the frontier orbitals of a molecule changes under external field condition. Under applied bias, the molecule can be oxidised/reduced and this changes its electronic distribution and eventually the molecules ability to conduct current. Can we model such an hypothesis using DFT in Turbomole? Some information in this regard is very welcome.
During electrocoagulation of biomethanated distillery spent wash, almost all of the spent wash converts into froth, leaving behind little amount of water. What could be the reasons for this and how to prevent this?
Electrodes used - Aluminum/Iron/Graphite
Input current - DC, 24 V, 2-3 A
Dear Colleagues,
I’m pleased to inform you that open access journal /Catalysts/ (ISSN 2073-4344, Impact Factor: 3.444) is planning to publish a Special Issue on the topic of "Trends in Catalytic Advanced Oxidation Processes". The submission deadline is 30 March 2020.
This Special Issue is dedicated to novel achievements in the field of catalytic advanced oxidation processes. The contributions should be related to the listed topics:
· Catalytic processes in water and wastewater treatment
· Developments in Fenton-like AOPs
· Activation of Persulfates for AOPs
· Formation of sulfate radicals
· Catalytic cavitation-based AOPs (hydrodynamic cavitation and acoustic cavitation)
· Sonocatalysts
· Catalytic ozonation
· Photocatalysts—including visible light and UV applications
· Catalytic wet air oxidation (CWAO)
· Catalytic–electrochemical AOPs
· Carbon catalysts for AOPs
· Nanocatalysts
· Risk of by-product formation during water and wastewater treatment
· Developments in process control of catalytic AOPs (analytical methods, chromatographic, and spectroscopic techniques)
· Methods of catalysts characterization
· Post-process assessment of effluents toxicity
· Application of nanobubbles in AOPs
· Economic analysis of catalytic AOPs application and catalysts life cycle assessment (LCO)
· Industrial catalytic wastewater treatment
· Modelling and optimization of catalytic processes
· Green chemistry aspects in catalytic water and wastewater treatment
Detailed information regarding this issue, please follow the link below to the Special Issue website at: https://www.mdpi.com/journal/catalysts/special_issues/catalytic_aop
By publishing with Catalysts, you will take advantage of the following attributes:
*Fast Publication*:
First decision provided to authors approximately 13.4 days after submission; acceptance to publication is undertaken in 5.5 days (median values for papers published in this journal in the second half of 2018).
The papers will be processed immediately upon receipt. A Special Issue (SI) is not an issue of the journal. It is a collection of articles on a common topic. These articles are published in the regular issues of the journal when they are accepted (no delay) but additionally labelled with the Special Issue name (including a link). A single click on the link will organize all the articles on the Special Issue webpage.
*High Impact*:
According to Web of Science data, the impact factor for Catalysts 2018 was 3.444. The five-year impact factor was 3.808. Catalysts now ranks in Q2 of the "Chemical, Physical" category.
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To enable the journal to make all of its content open access, Catalysts levies an article processing charge (APC) of CHF 1600 for each manuscript accepted after peer review in 2019 which compares well with other journals.
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In order to plan for the whole paper project, I appreciate you could inform me within three weeks as to whether you would be willing to contribute. I also encourage you to send a short abstract to me (grzegorz.boczkaj@pg.edu.pl) or to Caroline Zhan (caroline.zhan@mdpi.com) in advance.
Sincerely hope this invitation will receive your favorable consideration.
Best regards,
Guest Editor
Prof. Grzegorz Boczkaj, PhD. Sc. Eng. Assoc. Prof.
Email: grzegorz.boczkaj@pg.edu.pl
Department of Process Engineering and Chemical Technology, Faculty of
Chemistry, Gdansk University of Technology, 80-233 Gdansk, Poland
Caroline Zhan
Assistant Editor
Email: caroline.zhan@mdpi.com
Catalysts (IF 3.444, http://www.mdpi.com/journal/catalysts)
dear friends, what is the most suitable iron complex to work with photo-Fenton without needing to stabilize the pH between 2.5 and 3?
I would like to work with the reaction at a pH between 4.5 and 6, would it be possible using some iron complex? like for example ferrioxalate?
Actually I have faced a significant quantity of nanocatalyst loss during immobilization on glass surface. Though I have used ethanol(volatile) to spread the catalyst effectively towards the surface of a glass but somehow found significant drop of catalyst outside the glass.
I am trying to understand the nature of a H2O2 neutral loss in HCD fragmentation data of cysteic acid containing peptides. The y-series showing the neutral loss is complete so we believe it must be true. Can anyone make sense out of it? Thanks!
As a promising electrochemical advanced oxidation processes (EAOPs), electro-Fenton (EF) process has been widely used in various environmental remediation applications. The type of cathode determines the perfromance of EF process from the following two aspects:
(1) H2O2 production through 2-electron oxygen reduction reaction (2eORR);
(2) Fe3+ electroreduction;
Currently, majority of work focus on the cabonaceous cathode materials on their catalytic performance on H2O2 production. Various factors such as degree of graphitilization, porosity, surface chemistry, and heteroatoms have all been examined to maximize the catalytic performance.
However, I am curious that few work focused on the discussion on Fe3+ electroreduction. What properties of carbon materials (porosity, surface chemistry......) determines the performance on Fe3+ reduction?
This question is also important in carbon-assisted water electrolysis process, because Fe2+/Fe3+ cycle is also used, and the effective Fe3+ reduction by carbon is the decesive factor of system performance.
Hello,
I want to know whether or not the Zeta potential can give me an idea about the stirring degree in an electrochemical reactor, since i m dealing with a petroleum refinery wastewater.
I'm looking for this material from an accessible source that I can conduct my experiences. Basing on my research, I found that it is used in the electronic devises, but I don't have a clear idea about it, so I'm asking if anyone has ever thought about it.
I have synthesized bismuth doped titania (Bi-TiO2). Now i am confused about the position of Bismuth. whether it should be above the valence band of TiO2 or below the conduction band of TiO2. Considering the energy level of Bi dopant, please discuss its position with proper reason and references.
Please check the attached image.

In seedlings it is important to verify that ozone does not cause damage, because plants are more sensitive to ozone in juvenile stages (Timonen et al., 2004).
Ozone, applied diluted in water and sprinkled on seedlings of ornamental perennial species such as Salix integra, Hydrangea paniculata or Spiraea japonica, has proven to be a very effective treatment against fungal foliar diseases, ultimately causing a saving of chemical products. This fact in a world that increasingly requires more ecological treatments, and in which the demands for reducing the residues of fungicides and other pesticides are increased not only in fruits but also in foods processed with them (Edder et al., 2009 ).
Ozone is considered as a possible organic biocide because apart from not leaving chemical residues, it acts in two ways, a direct and an indirect way through the ROS species (Zotti et al., 2008). Toxic doses in sprinkler irrigation were observed from 1.5 ppm on the mentioned perennial seedlings, in applications of 7.5 minutes of irrigation / day (approx 1L per plant / day) for 6 weeks. The non-toxic dose was observed in concentrations below 1.5 ppm, such as 0.5 ppm. At these levels, an elimination of algae and biofilm is ensured, without showing phytotoxic effects (Graham et al., 2009).
In hydroponic or semi-hydroponic systems, water (30%) and fertilizer (40%) were saved by recycling leached or closed-circuit water (Runia, 1988, 1993, 1994; McDonald, 2007).
In hydroponic tomato cultivation with nutritive solution + ozone, larger tomato plants were obtained than in nutritive solution - ozone. It was demonstrated in this work that the concentration of macro and micronutrients of the nutrient solution is not modified: there is no variation in the levels of Calcium, Potassium, Magnesium, Phosphate, Ammonium, Nitrate, Copper, Molybdenum or Zinc depending on the dose increasing ozone up to 10 ppm. There is a drastic decrease in Manganese (from 0.5 ppm) and Iron (from 5 ppm). To avoid that, Terazoe (2001) proposed the ozonation of the water in a separate tank before adding the nutrients or separating the irrigation with ozone and the irrigation of nutrients. Despite this drastic decrease in the irrigation solution, there are no differences in the content of these nutrients in the leaves, which is not negatively affecting their normal development. There is a notable decrease in the incidence of root rot, typical of hydroponic cultivation (Ohashi-Kaneko et al., 2009).
Questions:
So, everything seems quite good in that way, but many questions comes to my mind:
1) Given the potential of this tool, why is ozone not an essential tool in agriculture today?
2) Are we still in a time of transition to tools such as ozone in agriculture? Or, on the other hand, do people distrust this technology due to unethical actions carried out by certain companies in the manufacturing sector of ozone generators and other innovative technologies?
3) Are there few studies in agriculture with ozone application? Or perhaps the studies show very contradictory results among them?
Feel free to discuss and propose your own questions/answers,
Thank you!
JD
References:
Edder, P., Ortelli, D., Viret, O., Cognard, E., Montmollin, A. D., & Zali, O. (2009). Control strategies against grey mould (Botrytis cinerea Pers.: Fr) and corresponding fungicide residues in grapes and wines. Food Additives and Contaminants, 26(5), 719-725.
Graham, T., Zhang, P., Zheng, Y., & Dixon, M. A. (2009). Phytotoxicity of aqueous ozone on five container-grown nursery species. HortScience, 44(3), 774-780.
Ohashi-Kaneko, K., Yoshii, M., Isobe, T., Park, J. S., Kurata, K., & Fujiwara, K. (2009). Nutrient solution prepared with ozonated water does not damage early growth of hydroponically grown tomatoes. Ozone: Science & Engineering, 31(1), 21-27.
Timonen, U., Huttunen, S., & Manninen, S. (2004). Ozone sensitivity of wild field layer plant species of northern Europe. A review. Plant Ecology, 172(1), 27-39.
Zotti, M., Porro, R., Vizzini, A., & Mariotti, M. G. (2008). Inactivation of Aspergillus spp. by ozone treatment. Ozone: Science and Engineering, 30(6), 423-430.
Does the dye degredation reaction with H2O2 over a heterogeneous catalyst can follow a zero order with respect to dye?
I'll be carrying a Fenton reaction and I will be taking around 5 samples in the duration of the reaction. I would like to quench the reaction in the samples until I make TOC, COD and other analyses without affecting it. Total number of samples at a time would be 15, as I will be having 3 parallel cells. What should I use as quencher?
Best regards,
Omar
A dyeing plant produces a very high concentration of wastewater, and I'm looking for a low-cost method, requiring low space and, if possible, a high-speed process.
Removing or separating colors is one of the most important parameters of this factory.
Some colors of this factory can be applied to the coagulation and flocculation process (with FeCl3 and Ca(OH)2), but for a very high concentration of black, it will be costly ...
I’m planning to treat a highly contaminated petroleum refinery wastewater of local petroleum refinery. I would like to work on a project focused on the Combined chemical oxidation and biological treatment of highly contaminated petroleum refinery or petrochemical effluents (recalcitrant or refractory compounds). The chemical process would be used as a pre-treatment in order to enhance the biodegradability index (BOD5/COD) of wastewater. I plan on reading some literature related to my work and perhaps find a gap for novelty in my thesis
Any prospective leads and suggestions would be highly appreciated.
Thank you.
Saeed Molaei
I was wondering the future direction of new perspectives for Advanced Oxidation Processes(AOPs) treatment of industrial wastewater, especially used for treatment of highly contaminated petroleum refinery or petrochemical effluents, such as electro-Fenton, Fenton, photo-electro-Fenton and ... system.
Any prospective leads and suggestions would be highly appreciated.
Thank you.
Saeed Molaei
I’m planning to treat a highly contaminated petroleum refinery or petrochemical effluents with recalcitrant or refractory compounds.
I would like to work on a project focused on the Combined chemical oxidation and biological treatment.
The chemical process would be used as a pre-treatment in order to enhance the biodegradability index (BOD5/COD) of wastewater.
Any prospective leads and suggestions would be highly appreciated.
Thank you.
Saeed Molaei
I want to design a solar photo-Fenton plant but I will not design the solar collector but rather determine the size/power require for the collectors to be installed off shell.
I'm a student in the final year of my M.Sc in Environmental Engineering. I want to work on a project focused on the feasibility of using the combined advanced oxidation and biological processes to treat highly contaminated petroleum refinery wastewater.
I want to ask you to borrow me about 10 minutes of your time and answer my question. Is anyone able to help me with this?
What topic can I use for my thesis?
Any prospective leads and suggestions would be highly appreciated.
Thank you.
Saeed Molaei
I am working on Electro-Fenton System using Air Diffusion Cathode. I am not able to produce enough amount of H2O2 in my system. My objective is to generate H2O2 at Neutral pH
Sodium thiosulfate is usally used to quench with this. However, it has an effect on the TOC of its sedimentation.
Can hydroxyl radicals be generated by using hydrogen peroxide alone in treating wastewater by AOPs?
I am going through a project about the removal of glyphosate and AMPA from water in a plasma reactor. I'm looking for some information about the rate constant for the reaction of hydroxyl radicals with aminomethylphosphonic acid (AMPA). Please, help with some published documents and literatures.
Greetings,
If the wastewater contains inorganic components comparatively more than organics in its composition is it likely to oxidize the organic compounds especially (which contributes in COD, BOD, TOC, TN, etc.,). For example, if the wastewater may contain inorganics like Fe, Ni, Cu, Cl, S, etc., the target oxidation of organic compounds should interfere by the presence of inorganics, and there will be the cause for the addition of more catalyst, and the treatment efficiency will be comparatively small.
So, is it plausible to oxidize the organic compounds specifically by the available AOP's?
these antioxidants are used to protect HDPE geomembrane from getting oxidized.
Hello,
I'm looking for a feasible industrial application to treat DENIM effluent and remove dyes (indigo and black sulfur).
Biological treatment are not good for vat days removal...
Many Advanced Oxidation Processes are able to remove recalcitrant dyes but they are too much expensive...
Any idea? any experience in full-scale application?
thanks!!
Under UV irradiation, it is normal that free radicals occur.
Meanwhile, is there some reagent that can release H+ or OH- under UV-Vis irradiation?
Thx
one of the most strongest & advanced water treatment technology is what's called "AOP" advanced oxidation process , which depends on ultraviolet radiation in presence of either ozone gas , TiO2 , or H2O2 as strong oxidants, that produces the very active OH radical which has the ability to attack org. matter...in a certain retention time
I'm currently doing research about Fenton oxidation in CSTR. So, I should feed the wastewater, Fe(II) catalyst, and hydrogen peroxide to 1-L reactor continuously.
How is the best feeding strategy for this case? I've some idea about feeding strategy in this case, but I don't know which is the best.
1) I dissolve Fe(II) in wastewater stock solution and wastewater in the reactor, then I feed hydrogen peroxide separately.
2) I just dissolve Fe(II) in wastewater stock solution and feed hydrogen peroxide separately.
3) I dissolve Fe(II) in hydrogen peroxide and feeding this Fenton's reagent and wastewater separately.
Which is the best feeding strategy? Thanks before.
As part of my Advanced Oxidation Process in water purification using UV- hydrogen peroxide, I would want to filter out the nitrate ions and permit the humic acids to enter with the rest of the feed water into the UV reactor.
Is there any suitable pre-filtration method like ion-exchange or membrane seperation that would allow me to do so.
Hello everyone;
I need to use manganese oxyde in my research but I have only the manganese powder.
could you show me the appropriate process to oxidise Mn powder totally?
Thank you in advance
I am working on degradation of organic contaminants present in water using advanced oxidation processes.
TiO2 crystallizes in rutile structure (tetragonal, space group P42/mnm) and this modification is stable under ambient conditions. Other stable under ambient conditions, however metastable thermodynamically, TiO2 polymorphs are anatase (tetragonal, I41/amd) and brookite(rhombohedral, Pbca). Moreover, it is known that transformation from anatase or brookite to rutile is irreversible.
Is there a way of conversion Rutile to Anatase?
I plan to perform the Iron-Ferrozine Chelation Assay to determine how well my thiol prevents the formation of hydroxyl radicals but I wanted to see how well they scavenged hydroxyl radicals. I've seen protocols for the p-nitrosodimethylaniline bleaching assay but they typically didn't incorporate the volumes used for the reaction mixture itself. If anyone has a protocol that includes this I would appreciate it very much.
There is a brief and interesting question/answer on the oxidation of amorphous silicon here on Research Gate:
In relation to this discussion I am wondering about the doping dependence:
In crystalline silicon the oxidation rate actually depends also on the doping type and concentration. Both, boron doping (from concentrations >1e20cm-3) and phosphorus doping (from concentrations >1e19cm-3) increases the oxidation rate compared to non-doped or only moderately-doped silicon.
Has the effect of doping on the oxidation rate actually also been looked at for amorphous silicon?
- Do the oxidation rates or limiting oxide thicknesses of a-Si:H (hydrogenated amorphous silicon) depend on the doping concentration or dopant type?
- Does phosphorus or boron incorporation in non-hydrogenated amorphous silicon (e.g. from sputtering) also depend on doping?[...possibly despite the fact that the conductivity type may not be really affected by phosphorus or boron incorporation in non-hydrogenated silicon?]
Thank you very much in advance if you care to share your knowledge.
The free activated chloride is a mixture of Cl2, HOCl, and OCl- where the distribution of the three components is mainly defined by the pH. At pH 2, Cl2 is 50% and HOCl is 50%, where HOCl increases to 100% by pH 6; then decreases to 50% at pH 7.4, at which OCl- becomes 50%; and above pH 9, only OCl- is left.
[pKa (Cl2/HOCl) = 2; pKa (HOCl/OCl-) = 7.4
That is theoretical, but when experimenting electrochemical removal of micro-pollutants in the presence of chloride ions, the pH in the anode is low and can be lower than 2.
Can we account the removal of micro-pollutants to free active chlorine? or will this be depleted because Cl2 will escape as a gas resulting in the dominance of OH radicals instead? Or will this be accounted for with regards to the oxidation power causing the removal of organic matter?
The most widely reported redox potentials for SO4 radicals is ranging from 2.5 to 3.1 V by Neta and Huie 1988 and for OH radicals is in the range of 1.9 - 2.85 V by Wardman 1989.
Many papers mention very different single values, and that could mainly be because they are different at different pH values, but sadly, most papers mention these redox potentials without mentioning the pH.
"Standard redox potential" is defined as redox potential at pH of 0. But even this value is argued around in literature for OH radicals; some report 2.38V and other reports 2.8 V.
Is there any graph or plot to display the variations of the radicals formation as a function of pH? I am very interested to know at what pH, the redox potential of SO4 radicals is 3.1V?????
It is widely reported that 2.4 V is standard potential of SO4 (i.e. at pH 0) thus it makes sense that as pH increases the redox potential increases (building on the fact that Neta and Huie reports the range being 2.5 - 3.1V). BUT it is also widely published that at high pH (basic pH), SO4 radicals transform into OH radicals (ALTHOUGH the redox of OH radicals is reported to be high (2.8V) at pH 0, and thus expected to be lower (1.9V) at higher pH.
I am very interested to know if there any graph or plot of redox potential variations versus pH, primarily to know at what pH, the redox potential of SO4 radicals is 3.1 V !?!
Any hints/explanations would be highly appreciated!
Thanks.
wastewater treatment researchers, Supercritical water oxidation, Hydrothermal degradation
It is stabe under direct UV, but I'm not sure about this if the solution is heated up.
Very few references mention this information. Moreover, when it is avalaible, there are big differences between the values.
hi
I saw some papers they use N2 to prepare the activated carbon and the other thy use the N2 then they switched it to CO2 but they did not explain about it.
I want to know the mechanism of CO2 during activation ?
I am working on Cr (VI) + H2O2 system at acidic pH, and would like to know if there is any chemical that will stop residual OH and H2O2 without increasing the pH, and also without effecting on either Cr(VI) or the org. compound any further.
- looking to partially degrade, not mineralize
- reduce color
- reduce BOD (Biochemical Oxygen Demand)
- return water to watershed
I am working on plant enzymes. After getting result of hydrogen peroxide scavenging activity for example control 2.23 and treatment plant 4.42(after putting formula). How do I interpret the result?
I am looking into calculating over-potential for my water oxidation catalysts at basic pHs. However, I do not see information on the thermodynamic potential at which water oxidation occurs at these pHs ( such as pH 11, 12.5, 13).
When simulate UV/H2O2 AOP process, there includes three model (turbulence, radiation and kinetics), but in kinetics there are photolysis reactions, and I cannot deal with that. Any suggestions?
My students have some troubles to collect GO from water. The size of GO is 10-100 nm. It is difficult to get its solid by centrifugation. So does membrane filtration. Could you please give some suggestions on this problem? Thanks a lot!
Regards,
wang
I am working on Fenton's oxidation and I would like to know if there is any chemical that will stop Fenton's oxidation without increasing the pH. I have seen NaOH being used but that increases pH. Any other chemicals?
Hi,
I have an activated carbon for which I need to know the isoelectrical point. Do you know any procedure for that?
I am working on advanced oxidation processes.

How do I can reduce the amount of H2S present in a liquid gas mixture made
of sulfate ? so far I 'm dealing with an enzyme, but the costs are very high, thanks!
expensive, the mixture is native to process petroleum distillate
When i mix the prepared activated carbon with the water to wash it, it never settles down, it always floating at the top so i could not remove the ashes completely from the prepared activated carbon. How this problem can be solved?
Kindly provide information regarding the usage of Spectrofluorimeter and HPLC in the estimation of MDA and AOPP
There are big autoclaves that need tons of oxygen and the whole process needs to be well controlled. What is most important to control and how? Which is the best technology?
I'm doing OH radical probing experiments in different natural waters exposed to UV with and without H2O2.
is it possible that the COD increase and then decrease with applying AOP treatment? any explanation with reference if possible?
I need to calculate theoretical COD for one organic dye molecule, I know the nitrogen and sulphur oxidized as ammonia and sulfur dioxide. Can it be converted to any other forms like nitrate, nitrite etc.?
Electrocoagulation and electro-Fenton are two well known electrolytic processes for water and wastewater treatment. In electrocoagulation, solution pH increases with increase in electrolysis time. But the change in solution pH during electro-Fenton process is insignificant. Why?
In my system the oxygen is used for ozone generator.
As a rule, UV/H2O2 gives better results in acidic medium. But I got a color removal efficiency up to 99% in Basic pH for one direct dye.
UDF (user defined Function), (AOP) advanced oxidation process
I know only the MnO2 suppress the oxidation power of H2o2 in Alkaline medium but I need the explanation about ratio and its mechanism.
The increased role of AOPs in treatment of surface waters (that is, not only wastewaters), for removal of NOM is well known. However, what about simultaneous NOM removal and disinfection?
I would like to know, what are the basic characteristics that one should look for in particular element or compound while preparing photocatalysts.
Recently, we reported a novel system in which simultaneous conversion of Cr(VI) and dyes is achieved ("Iron species in layered clay: Efficient electron shuttles for simultaneous conversion of dyes and Cr(VI)". Full-text available in https://www.researchgate.net/profile/Zhaohui_Wang12/contributions/). However, because dyes are strongly adsorbed to clay surface and interlayer, it is difficult to characterize the TOC changes. Dyes can be removed from clay using acetone solvent. But acetone leads to high "artificial" TOC value. Is there any other method to measure it?
I want to develop an acid process for removing HCN and (CN)2 from gas effluent.
Suppose WOx nanoclusters are formed on the surface of the V2O5.
What could be the mechanism for an oxidation reaction? I mean which sites will act as the most active sites since Vanadium generally used in such process?
For instance UV-mediated vs. Fenton Processes, US-activated, MW-activated, etc?
I have prepared Mo-VPO by impregnation and co-preciptation methods and carried out some oxidation reaction. How do I confirm which one is actively participate in the oxidation process?