scholarly journals Degradation of Minocycline by the Adsorption–Catalysis Multifunctional PVDF–PVP–TiO2 Membrane: Degradation Kinetics, Photocatalytic Efficiency, and Toxicity of Products

2021 ◽  
Vol 18 (23) ◽  
pp. 12339
Author(s):  
Chengzhi Zhou ◽  
Yanlong Sun ◽  
Fan Zhang ◽  
Yuandong Wu
Keyword(s):  
Polyvinylidene Fluoride ◽  
Degradation Kinetics ◽  
Electrical Energy ◽  
Esr Spectra ◽  
Inorganic Anions ◽  
Photocatalytic Decomposition ◽  
Decomposition Rate Constant ◽  
Fiber Mats ◽  
Tio2 Fiber ◽  
Electrical Energy Per Order

The photocatalytic degradation of minocycline was studied by using polyvinylidene fluoride–polyvinylpyrrolidone–TiO2 (PVDF–PVP–TiO2) fiber mats prepared by an electrospinning technology. The influences of the TiO2 dosage, minocycline concentrations, inorganic anions, pH values, and dissolved organic matter (DOM) concentrations on the degradation kinetics were investigated. A mass of 97% minocycline was degraded in 45 min at 5% TiO2 dosage. The corresponding decomposition rate constant was 0.069 min−1. The inorganic anions affected the minocycline decomposition in the order of HCO3− > Cl− > SO42− > NO3−, which was confirmed by the results of electron spin resonance (ESR) spectra. The lowest electrical energy per order (EEO) was 6.5 Wh/L. Over five cycles, there was no change in the photocatalytic performance of the degrading minocycline. Those investigations suggested that effective degradation of minocycline could be reached in the PVDF–PVP–TiO2 fiber mats with a low energy consumption, good separation and, good recovery. Three photocatalytic decomposition pathways of minocycline were proposed: (i) hydroxyl substitution of the acylamino group; (ii) hydroxyl substitution of the amide group, and (iii) a cleavage of the methyl groups and further oxidation of the amino group by OH. Potential risks caused by TP159 and TP99 should not be ignored, while the TP90 are nontoxic. Tests indicated that the toxicity of the photocatalytic process may be persistent if minocycline and its products were not mineralized completely.

Comparative studies of mineralization and detoxification of Mordant Black 17 in aqueous solution by UV light induced Mn+/H2O2 and Mn+/S2O82− systems

2018 ◽  
Vol 77 (12) ◽  
pp. 2917-2928 ◽  
Author(s):  
Mihir Kumar Sahoo ◽  
John E. Kumar ◽  
Bhauk Sinha ◽  
Morten Marbaniang ◽  
Rajeshwar N. Sharan
Keyword(s):  
Escherichia Coli ◽  
Aqueous Solution ◽  
Energy Efficiency ◽  
Energy Efficient ◽  
Uv Light ◽  
Electrical Energy ◽  
Ammonium Persulphate ◽  
Upper Limit ◽  
Cost Efficient ◽  
Electrical Energy Per Order

Abstract The present study reports a process for simultaneous mineralization and detoxification of Mordant Black 17 with high electrical energy efficiency. Hydrogen peroxide and ammonium persulphate (APS) were used for the generation of hydroxyl and sulphate radicals using UV light (λ = 254 nm) and Fe2+ and Ag+ ions as catalysts. The detoxification and energy efficiency of various processes were measured by monitoring growth inhibition of Escherichia coli and Electrical Energy per Order (EE/O) applicable for low concentration contaminants respectively. Systems catalyzed by Fe2+ are more energy efficient and possess higher mineralization and detoxification efficiency than that of Ag+. The concentration of the catalysts and oxidants were found to strongly influence the EE/O of the systems. The most cost efficient processes for simultaneous mineralization and detoxification are Fe2+/APS/UV at pH 3.00 and Fe2+/H2O2/UV at pH 3.00 and 5.78. The upper limit concentration of Fe2+ is fixed at 0.01 mM for complete detoxification. The treated solutions start detoxifying at this concentration, above which they remain more toxic than the original dye solution irrespective of the extent of mineralization. On the contrary, no such limit could be established for Ag+ systems for complete detoxification even after 91% mineralization.

scholarly journals A Field Pilot Study on Treating Groundwater Contaminated with Sulfolane Using UV/H2O2

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1200 ◽  
Author(s):  
Linlong Yu ◽  
Sobhan Iranmanesh ◽  
Ian Keir ◽  
Gopal Achari
Keyword(s):  
Water Flow ◽  
Cost Model ◽  
Electrical Energy ◽  
Pilot Scale ◽  
Process Efficiency ◽  
Contaminated Groundwater ◽  
Operational Parameters ◽  
Flow Rates ◽  
Electrical Energy Per Order ◽  
H2o2 System

Sulfolane is an emerging contaminant in the groundwater and soil nearby gas plants, which has attracted much attention from many researchers and regulatory agencies in the past ten years. In this paper, a field pilot-scale ultraviolet (UV)/hydrogen peroxide (H2O2) system was investigated for treating sulfolane contaminated groundwater. Different groundwater, as well as different operational parameters such as influent sulfolane concentration, H2O2 dosage, and water flow rates, were studied. The results showed that a pilot-scale UV/H2O2 system can successfully treat sulfolane contaminated groundwater in the field, although the presence of iron and other groundwater limited the process efficiency. The lowest electrical energy per order of reduction for treating sulfolane in groundwater by using the pilot-scale UV/H2O2 system was 1.4 kWh m−3 order−1. The investigated sulfolane initial concentrations and the water flow rates did not impact the sulfolane degradation. The enhancement of sulfolane degradation in an open reservoir by adding ozone was not observed in this study. Furthermore, an operational cost model was formulated to optimize the dosage of H2O2, and a stepwise procedure was developed to determine the power necessary of the UV unit.

scholarly journals Core-Shell Nanofibers of Polyvinylidene Fluoride-based Nanocomposites as Piezoelectric Nanogenerators

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2344
Author(s):  
Deepalekshmi Ponnamma ◽  
Mariem Mohammed Chamakh ◽  
Abdulrhman Mohmmed Alahzm ◽  
Nisa Salim ◽  
Nishar Hameed ◽  
...  
Keyword(s):  
Polyvinylidene Fluoride ◽  
Wearable Electronics ◽  
Hybrid Nanocomposite ◽  
Mechanical Vibrations ◽  
Electrospinning Technique ◽  
Fiber Mats ◽  
Semiconducting Metal Oxides ◽  
Soft Electronics ◽  
Human Motions ◽  
Piezoelectric Nanogenerators

Flexible piezoelectric nanogenerators (PENG) are widely applied to harvest sustainable energy from multiple energy sources. The rational and simple design of PENG have great potential in soft electronics. Here we design a highly flexible PENG using the polyvinylidene fluoride (PVDF) and its copolymer, polyvinylidene hexafluoropropylene (PVDF-HFP) with two nanoarchitectures of semiconducting metal oxides, TiO2 and ZnO. The nanotubes of TiO2 and nanoflowers of ZnO are embedded in these different polymeric media by solvent mixing, and new fiber mats are generated by coaxial electrospinning technique. This process aligns the dipoles of polymers and nanomaterials, which is normally a pre-requisite for higher piezo potential. With excellent mechanical strength and flexibility, the tailored lightweight fiber mats are capable of producing good output voltage (a maximum of 14 V) during different mechanical vibrations at various frequencies and in response to human motions. The hybrid nanocomposite PENG is durable and inexpensive and has possible applications in wearable electronics.

scholarly journals Efficient Degradation of Acesulfame by Ozone/Peroxymonosulfate Advanced Oxidation Process

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2874 ◽  
Author(s):  
Yu Shao ◽  
Zhicheng Pang ◽  
Lili Wang ◽  
Xiaowei Liu
Keyword(s):  
Hydroxyl Radical ◽  
Active Sites ◽  
Emerging Contaminants ◽  
Water Solubility ◽  
Advanced Oxidation Process ◽  
Negative Impact ◽  
Degradation Products ◽  
Electrical Energy ◽  
Sulfate Radical ◽  
Electrical Energy Per Order

Artificial sweeteners (ASWs), a class of emerging contaminants with good water solubility, have attracted much attention recently because of their wide use and negative impact on the aquatic environment and drinking water. Efficient technologies for removing ASWs are in urgent need. This study investigated degradation of typical ASW acesulfame by ozone-activated peroxymonosulfate process (O3/PMS) in prepared and real waters. O3/PMS can degrade >90% acesulfame in prepared water within 15 min at a low dosage of O3 (60 ± 5 µg∙min−1) and PMS (0.4 mM). Ozone, hydroxyl radical (HO•), and sulfate radical (SO4•−) were identified as contributors for ACE degradation and their contribution proportion was 27.1%, 25.4%, and 47.5% respectively. O3/PMS showed the best degradation performance at neutral pH and were sensitive to constituents such as chloride and natural organic matters. The qualitative analysis of degradation products confirmed the involvement of hydroxyl radical and sulfate radical and figured out that the active sites of ACE were the C=C bond, ether bond, and C-N bond. The electrical energy per order ACE degradation were calculated to be 4.6 kWh/m3. Our findings indicate that O3 is an efficient PMS activator and O3/PMS is promising due to its characteristic of tunable O3−HO• SO4•− ternary oxidant involving.

Low cost UVA-LED as a radiation source for the photo-Fenton process: a new approach for micropollutant removal from urban wastewater

2017 ◽  
Vol 16 (1) ◽  
pp. 72-78 ◽  
Author(s):  
I. de la Obra ◽  
B. Esteban García ◽  
J. L. García Sánchez ◽  
J. L. Casas López ◽  
J. A. Sánchez Pérez
Keyword(s):  
Energy Efficiency ◽  
Radiation Source ◽  
Low Cost ◽  
Electrical Energy ◽  
Fenton Process ◽  
Urban Wastewater ◽  
New Approach ◽  
Micropollutant Removal ◽  
Electrical Energy Per Order

A UVA-LED driven photo-Fenton process is shown as a feasible technology for micropollutant removal. The photoreactor design, which strongly depends on the energy efficiency and LED wavelength, needs to be carried out using parameters such as Electrical-Energy-per-Order (EEO).

scholarly journals Comparison of advanced oxidation processes in the decomposition of diuron and monuron – efficiency, intermediates, electrical energy per order and the effect of various matrices

2018 ◽  
Vol 4 (9) ◽  
pp. 1345-1360 ◽  
Author(s):  
János Farkas ◽  
Máté Náfrádi ◽  
Tamás Hlogyik ◽  
Bartus Cora Pravda ◽  
Krisztina Schrantz ◽  
...  
Keyword(s):  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
Electrical Energy ◽  
Heterogeneous Photocatalysis ◽  
Uv Photolysis ◽  
Oxidation Processes ◽  
Electrical Energy Per Order

The efficiency of UV-photolysis, ozonation, their combination and heterogeneous photocatalysis was investigated and compared in various matrices.

scholarly journals Influence of inorganic oxidants and metal ions on photocatalytic activity of prepared zinc oxide nanocrystals

2013 ◽  
Vol 11 (4) ◽  
pp. 535-545
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Metal Ions ◽  
Raw Materials ◽  
Electrical Energy ◽  
Primary Objective ◽  
Precipitation Method ◽  
Negative Effects ◽  
Zno Nanocrystals ◽  
Electrical Energy Per Order

Zinc oxide nanocrystals were prepared by precipitation method using ZnSO4.7H2O and NaOH as raw materials. The prepared ZnO nanocrystals were characterized by powder X-ray diffraction (XRD). Primary objective was to focus on the influence of inorganic oxidants, metal ions and anions on photocatalytic activity of prepared ZnO nanocrystals. The study on the effects of oxidants such as IO−4 , 2 S2O8− , BrO3− and ClO3− reveal that periodate ion is more efficient than others in improving the photocatalytic properties of ZnO nanocrystals. An investigation on the influence of metal ions on photocatalytic activity reveals that the removal of pollutant increases in the presence of Fe3+ and Cu2+. But negative effects are observed in the presence of anions. The possible roles of the additives on the reaction and the possible mechanisms of effect were discussed. The quantum yield ( ϕ ) and electrical energy per order (EEO) were estimated and compared for UV/ZnO/Oxidant catalytic system.

scholarly journals An Optimal Piezoelectric Beam for Acoustic Energy Harvesting

2021 ◽  
Author(s):  
Amir Panahi ◽  
Alireza Hassanzadeh ◽  
Ali Moulavi ◽  
Ata Golparvar
Keyword(s):  
Energy Harvesting ◽  
Polyvinylidene Fluoride ◽  
Maximum Yield ◽  
Electrical Energy ◽  
Point Sources ◽  
Acoustic Energy ◽  
Highway Traffic ◽  
Piezoelectric Beam ◽  
Optimum Placement ◽  
Acoustic Energy Harvesting

This study presents a novel piezoelectric beam structure for acoustic energy harvesting. The beams have been designed to maximize output energy in areas where the noise level is loud such as highway traffic. The beam consists of two layers (copper and polyvinylidene fluoride) that convert the ambient noise’s vibration energy to electrical energy. The piezoelectric material’s optimum placement have been studied, and its best positon is obtained on the substrate for the maximum yield. Unlike previous studies, which the entire beam substrate used to be covered by a material, this study presents a modest material usage and contributes to lowering the harvester’s final production cost. Additionally, in this study, an electrical model was developed for the sensor and a read-out circuitry was proposed for the converter. Moreover, the sensor was validated at different noise levels at various lengths and locations. The simulations were performed in COMSOL Multiphysics® and MATLAB® and report a maximum sound pressure of 140 dB from 100 dB point sources in an enclosed air-filled cubic meter chamber.

Effects of Downstream Structures on Aero Elastic Energy Harvesters From Wake-Induced Vibration

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Pakorn Uttayopas ◽  
Chawalit Kittichaikarn
Keyword(s):  
Cantilever Beam ◽  
Polyvinylidene Fluoride ◽  
Bluff Body ◽  
Electrical Energy ◽  
Load Resistance ◽  
High Amplitude ◽  
Triangular Prism ◽  
Energy Harvesters ◽  
Amplitude Vibration ◽  
And Behavior

An upstream cylindrical bluff body connected to a tip body via an aluminum cantilever beam was tested as energy harvester in a wind tunnel. The characteristics and behavior of the different tip body configurations and lengths of aluminum cantilever beam were studied to optimize design to extract wind energy. Particular attention was paid to measure vibration amplitude and frequency response as a function of reduced velocity. Dynamic response showed that the device's behavior was dependent on both tip body shape and cantilever beam length. Flow visualization tests showed that high amplitude vibration was obtainable when a vortex was fully formed on each side of the downstream tip body. This was exemplified in a symmetrical triangular prism tip body at L/D1 = 5, where its structure's vibration frequency was close to its natural frequency. At such configuration, electrical energy was captured using a polyvinylidene fluoride (PVDF) piezoelectric beam of different load resistances, where an optimized load resistance could be found for each Reynolds number. Although power output and efficiency obtained were considerably weak when compared to those of traditional wind turbine, the design merits further research to improve its performance under various circumstances.

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