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Photodegradation of Fluoxetine Applying Different Photolytic Reactors: Evaluation of the Process Efficiency and Mechanism
摘要： Photolytic degradation of fluoxetine (FLX), a medicine commonly known as Prozac?, was evaluated by using different photochemical processes. The ultraviolet/microwave (UV/MW) process showed higher efficiency in all the aspects evaluated in this study. The energy consumption was equivalent to 1.94 × 10-4 kW h mg-1 L (UV/MW), while in the UV process the value was 1.20 × 10-2 kW h mg-1 L. The degradation kinetics were applied to the FLX, with rate constant (k) = 0.15 ± 0.01 min-1 and linear correlation coefficient (R2) = 0.980 for UV, and k = 6.15 ± 0.08 min-1 and R2 = 0.998 for UV/MW. The FLX degradation of 99.16% (UV/MW 5 min) and 98.90% (UV 120 min) were observed, evidencing higher efficiency for the first process. The monitoring of transformation products (TPs) through chromatographic analysis enabled the identification of 9 TPs, proving that for the UV/MW process, the hydroxylated structures are verified in high quantity.
关键词： photolysis,fluoxetine,transformation products,photochemical reactor,kinetics
更新于2025-11-19 16:56:35
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A spark discharge generator for scalable aerosol CVD synthesis of single-walled carbon nanotubes with tailored characteristics
摘要： We have designed and built an exhaust-free spark discharge generator for robust aerosol CVD synthesis of single-walled carbon nanotubes. The systematic study has shown the generator to provide a facile and repeatable route to precisely control the size of the catalyst particle and, therefore, carbon nanotube growth. Using a comprehensive set of methods (the analysis of differential mobility of the aerosol particles, optical spectroscopy, scanning and transmission electron microscopy, Raman spectroscopy, and atomic force microscopy) we have revealed the relation between the defectiveness, length, diameter distribution of carbon nanotubes and specific features of a generator such as electrode characteristics (breakdown voltage, composition, and current) as well as the nature of the surrounding media (carrier gas nature, flow rate). The design used has resulted in separation of the nanoparticle formation and carbon nanotube nucleation processes. This provides a mutual independence of the growth parameters and the diameter distribution of the single-walled carbon nanotubes enhancing the scalability of the process. For instance, the breakdown voltage has been shown to have nearly zero effect on diameter and length distribution of carbon nanotubes produced while strictly governing the yield. We focus here on producing specifically short carbon nanotubes (l < 500nm) of pronounced defectiveness for drug delivery and transistor applications.
关键词： single-walled carbon nanotubes,differential mobility analyzer,catalyst activation,spark-discharge generator,aerosol CVD,floating bed reactor
更新于2025-11-14 17:03:37
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Photocatalytic degradation of organic pollutants from wastewater using aluminium doped titanium dioxide
摘要： The objective of this research was to study the performance of batch and continuous recirculating reactor to photo-degrade dye and synthetic wastewater. Here, Aluminium (Al) was used as the doped metal. The commercially available TiO2 P-25 and Al (NO3)3 was used as a Ti-precursor and doping agent, respectively, via the impregnation method. Various parameters such as the concentration of the doping agent, and calcination temperature were studied. The TiO2 nanocrystal doped with Al was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analyzer (TGA). The photocatalytic performance of Al-doped nanoparticle was quantified by the degradation of methylene blue (MB) solution under a visible light irradiation condition. Its performance was compared against undoped-nano-TiO2. The results showed that Al (NO3)3 solution with a concentration of 0.25% and volume of 100 cm/ml, and calcined at 300 C for 4 h, was the optimum condition of Al-doped nano-TiO2. Furthermore, the highest pseudo-first-order kinetic rate was 0.096 where the doped Al(NO3)3 of 0.75 w/v was used in the batch reactor. The Al-doped nano-TiO2 that was obtained has the potential for use as a photocatalyst for degradation organics pollutant from wastewater under the visible light irradiation. The highest removal of organic pollutants from synthetic wastewater was 75% using TiO2 P-25 alone at 2 g/L dosage. In addition, the removal of organic pollutant by TiO2/doped with Al was 80% at a dosage of 0.5 g/L and was 85% at a dosage of 1 g/L.
关键词： Batch reactor,Photo-catalyst,Titanium dioxide,Advanced oxidation process
更新于2025-09-23 15:23:52
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Artificial neural network modeling of a pilot plant jet-mixing UV/hydrogen peroxide wastewater treatment system
摘要： This study deals with the modeling and simulation of an efficient pilot plant photo-chemical wastewater treatment reactor. Treatment of an azo dye (i.e. direct red 23) was performed using a UV/H2O2 process in a jet mixing photo-reactor with 10-L volume. To model the reactor and simulate the treatment process, six important, influential physical and chemical factors such as nozzle angle (hN), nozzle diameter (dN), flow-rate (Q), irradiation time (t), H2O2 initial concentration ([H2O2]0), and pH, were taken into account. In this regard, artificial neural networks (ANNs) were employed as a powerful modeling methodology. Six different ANN architectures were constructed and most appropriate numbers for hidden neuron and learning iteration were determined based on minimization of the mean square error (MSE) function related to the testing data sets. Furthermore, simulation of the reactor efficiency, as well as sensitivity analysis, was performed via the cross-validation outputs. It was found that a three-layered feed-forward ANN composes ten hidden neurons, calibrated at 100th iteration using “trainlm” as learning algorithm and “tansig” and “purelin” as transfer functions in the hidden and output layers can model the process as the best case. The order of importance for variation of the key factors were indicated as [H2O2]0 > t > pH > Q > hN > dN.
关键词： dyes,simulation,wastewater treatment,Advance oxidation process,neural networks,photodegradation,batch reactor
更新于2025-09-23 15:23:52
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Photocatalytic degradation of pharmaceutical micro-pollutants using ZnO
摘要： This research paper presents the results of an experimental investigation of the degradation of three different contaminants including progesterone (PGS), ibuprofen (IBU), and naproxen (NAP) using ZnO as the photocatalyst and ultraviolet (UV) light as a source for catalysts activation. Two operating parameters, namely, catalyst loading and initial concentration of contaminants, were tested in a batch photocatalytic reactor. To demonstrate the large-scale applications, experiments were also conducted in a submerged membrane photocatalytic reactor. It has proven that ZnO photocatalyst degraded the three contaminants very efficiently under almost all the studied experimental conditions, with efficiency rates of 92.3, 94.5, and 98.7 % for PSG, IBU, and NAP, respectively. The photodegradation kinetics study was performed to calculate the reaction rate constant, which is found to follow pseudo-first order kinetics. The membrane photocatalytic reactor was efficient to remove pollutants and it is observed that the degradation rate increases with increasing the membrane oscillation frequency approaching that of the stirred reactor.
关键词： Photocatalytic degradation,Progesterone,Ibuprofen,Photocatalytic batch reactor,Naproxen,Oscillatory membrane reactor,ZnO
更新于2025-09-23 15:22:29
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[IEEE 2018 International Ural Conference on Green Energy (UralCon) - Chelyabinsk (2018.10.4-2018.10.6)] 2018 International Ural Conference on Green Energy (UralCon) - Determination of the Parameters of the Solar System to Compensate for the Thermal Losses of a Single-chamber Vertical Cylindrical Reactor
摘要： The purpose of this study is to analyze the feasibility of using the solar system to partially compensate for the heat losses of the methanogenesis reactor of the bioenergy station "EcoVoltAgro" with a volume of 25 m3. In the process of research, the method of comparative analysis was used. Calculation of the available solar radiation was carried out on the basis of the information of the climatological database of the National Aeronautics and Space Administration of the United States for coordinates corresponding to the geographical location of Orenburg. Optimal parameters of the solar system are proposed to compensate for the heat losses of a single-chamber vertical cylindrical methane-genesis reactor, the required surface area and the number of solar collectors for each month of the year are determined. In order to reduce the cost of creating a solar system with a large number of solar collectors, a schematic diagram of a heating system for a methane-genesis reactor based on solar collectors and a boiler operating on biogas is proposed. The calculation of biogas savings for each month of the year is made using the proposed scheme.
关键词： bioenergetic station,solar collectors,solar system,methanogenesis reactor,alternative energy sources
更新于2025-09-23 15:22:29
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Study on supercritical water oxidation of o-dichlorobenzene in a quartz micro-reactor with in situ microscope and Raman spectroscopy
摘要： The supercritical water oxidation (SCWO) of o-dichlorobenzene (o-DCB) in a fused quartz capillary reactor was studied by in situ microscope combined with Raman spectroscopy. The influence of oxidant dosage, reaction temperature and time on the o-DCB degradation efficiency was investigated and the reaction kinetics for CO2 yield was explored as well. The obvious phase change of o-DCB-H2O/H2O2 system was observed during the heating and cooling process. The increase in H2O2 dosage, temperature and time enhanced the o-DCB degradation efficiency. The degradation of o-DCB could be attributed to the simultaneous oxidation induced by HO· and O2. The effect of temperature on the o-DCB degradation efficiency and the CO2 yield was not significant at the lower temperature stage but turned to be important at the higher temperature stage. When the oxidant dosage was twice that of chemometry and the temperature and time were 440.0 °C and 4 min, respectively, the o-DCB degradation efficiency reached approximately 100%. Under the same conditions, the CO2 yield was lower than the o-DCB degradation efficiency, indicating that the degradation of o-DCB was a multi-step reaction. The reaction kinetics showed that the kinetics of CO2 production in SCWO followed the pseudo-first order and the apparent activation energy was 172.4 kJ mol?1.
关键词： Microscope,Supercritical water oxidation,O-dichlorobenzene,Fused quartz micro-reactor,Raman spectroscopic
更新于2025-09-23 15:22:29
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Translucent packed bed structures for high throughput photocatalytic reactors
摘要： Translucent photocatalytic reactor structures are investigated as a possible alternative to numbering up as a method for the scale-up of microreactors. The structure and the light source design is elaborated to introduce this concept. The light field was characterized using a ray tracing algorithm. A rectangular reactor made from glass was designed using borosilicate spheres small enough to create an array of interconnected microchannels in the reactor. It was found that ray tracing can be used as a proper tool to easily design multiple-LED light sources and predict respective irradiance patterns. The performance of the reactor was assessed using the apparent rate constant, the space-time yield and the photocatalytic space-time yield, a recently introduced performance parameter which takes into account the lamp power and the reactor productivity. The apparent rate constant of the reactor for an incoming irradiance of 191 W m?2 was found to be 0.82 min?1, which is, to our knowledge, in the range of microreactors and 1–2 orders of magnitude higher than any high throughput immobilized reactor in literature. With a photocatalytic space-time yield of 0.657 m3 day?1 m?3 reactor kW?1 our reactor was amongst the best reported performers in terms of productivity and energy efficiency. This performance is related to the high specific illuminated surface area of 4267 m2 m?3 and high catalyst load of 1.9 g L?1.
关键词： Light distribution,Structured reactors,Photocatalysis,Photocatalytic degradation,LED,Reactor engineering
更新于2025-09-23 15:22:29
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Photocatalytic Hydrogen Production Under Near-UV Using Pd-Doped Mesoporous TiO2 and Ethanol as Organic Scavenger
摘要： Photocatalysis can be used advantageously for hydrogen production using a light source (near-UV light), a noble metal-doped semiconductor and an organic scavenger (2.0 v/v% ethanol). With this end, palladium was doped on TiO2 photocatalysts at different metal loadings (0.25 to 5.00 wt%). Photocatalysts were synthetized using a sol-gel method enhancing morphological properties with a soft template precursor. Experiments were carried out in the Photo-CREC Water II reactor system developed at CREC-UWO (Chemical Reactor Engineering Centre- The University of Western Ontario) Canada. This novel unit offers hydrogen storage and symmetrical irradiation allowing precise irradiation measurements for macroscopic energy balances. Hydrogen production rates followed in all cases a zero-order reaction, with quantum yields as high as 30.8%.
关键词： Quantum Yield,Photo-CREC Water II reactor,Palladium,Hydrogen production,TiO2
更新于2025-09-23 15:22:29
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A Corrugated Plate Photocatalytic Reactor for Degradation of Waterborne Organic Contaminants
摘要： A UV-C/titanium dioxide (TiO2) plate coated photocatalytic reactor using a corrugated frame system was designed for water borne organic contaminant degradation. The anticipated advantages of using the corrugated layout include a larger photocatalytic surface area per unit volume and improved photocatalytic activity. The water distribution system was designed to assist effective interactions among the water pollutant, photocatalyst, and photons. The degradation of a methylene blue solution, as a model water contaminant, was carried out at room temperature (22 °C) at different concentrations and flowrates. With an 11 mg/L methylene blue solution, 70 % was degraded within the first 10 min using TiO2 coated corrugated plates, whereas under the same conditions the degradation rate was only 12 % for a corrugated reactor without a catalyst coating, and 4 % for a no-plate reactor. The methylene blue degradation was described by the Langmuir-Hinshelwood model, and the apparent photonic efficiency of the corrugated arrangement was found to be in the range of 1.53–2.83 % when half the initial concentration was degraded. The local area specific rate of energy absorption (LASREA) profile over the plates was determined from a model developed based on UV-C light irradiation distribution and plate configuration. Light intensity measurements were carried out and were found to correlate with this model. A set of corrugated plate photocatalytic reactors with different geometries, but with the same coated area, were then analyzed and absorbed UV light intensities were integrated to determine the best geometry.
关键词： corrugated photocatalytic reactor,light absorption modelling,reaction modelling
更新于2025-09-23 15:22:29