scholarly journals Photocatalytic degradation efficiency of hazardous macrolide compounds using an external UV-light irradiation slurry reactor

2020 ◽  
Vol 82 (4) ◽  
pp. 695-703
Author(s):  
Amel Ounnar ◽  
Abdelkrim Bouzaza ◽  
Lidia Favier ◽  
Fatiha Bentahar
Keyword(s):  
Light Intensity ◽  
Uv Light ◽  
Irradiation Time ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Light Irradiation ◽  
Main Process ◽  
Uv Light Irradiation ◽  
Stirring Rate ◽  
Catalyst Dosage

Abstract The current work investigates the removal of two hazardous macrolide molecules, spiramycin and tylosin, by photodegradation under external UV-light irradiation conditions in a slurry photoreactor using titanium dioxide as a catalyst. The kinetics of degradation and effects of main process parameters such as catalyst dosage, initial macrolide concentration, light intensity and stirring rate on the degradation rate of pollutants have been examined in detail in order to obtain the optimum operational conditions. It was found that the process followed a pseudo first-order kinetics according to the Langmuir–Hinshelwood model. The optimum conditions for the degradation of spiramycin and tylosin were low compound concentration, 1 g L−1 of catalyst dosage, 100 W m−2 light intensity and 560 rpm stirring rate. Then, a maximum removal (more than 90%) was obtained after 300 min of irradiation time. Furthermore, results show that the selection of optimized operational parameters leads to satisfactory total organic carbon removal rate (up to 51%) and biochemical oxygen demand to chemical oxygen demand ratio (∼1) confirming the good potential of this technique to remove complex macrolides from aqueous solutions.

Nanotribological Investigation of Magnetic Rigid Disks Lubricated with Perfluoropolyether Lubricant Under Varying Conditions

2008 ◽  
Vol 8 (5) ◽  
pp. 2719-2723 ◽  
Author(s):  
E. Liu ◽  
K. S. Tan ◽  
H. I. Tan
Keyword(s):  
Mechanical Properties ◽  
Uv Irradiation ◽  
Uv Light ◽  
Irradiation Time ◽  
Experimental Results ◽  
Light Irradiation ◽  
Loading Conditions ◽  
Uv Treatment ◽  
Uv Light Irradiation ◽  
Rigid Disks

This paper studies the nanotribological behavior of magnetic rigid disks dip-coated with ultra thin perfluoropolyether (PFPE) Z-Dol 4000 lubricant layers up to 4 nm thick prior to or after exposure to ultraviolet (UV) light irradiation. Lube bonding ratios (LBRs) of 43–91% were achieved by varying the UV irradiation time. The nanotribological and mechanical properties of the disks were measured with a nanotribometer under varying loading conditions. The effect of the LBR on the nanotribological behavior of the disks was also elucidated. We found that the lubricated disks after UV treatment performed better compared to the lubricated disks without UV treatment. The experimental results indicated that the LBR of about 50% could achieve the best contact-start–stop and flyability performances.

scholarly journals The Utilization of Modified Chitosan from Shrimp Shell As Photodegradation of Pesticides Paraquat Dichloride

2021 ◽  
Vol 6 (3) ◽  
pp. 204-208
Author(s):  
Risfidian Mohadi ◽  
Neza Rahayu Palapa ◽  
Rudi Hartono ◽  
Nurlisa Hidayati ◽  
Rozirwan
Keyword(s):  
Uv Light ◽  
Irradiation Time ◽  
Light Irradiation ◽  
Modified Chitosan ◽  
Uv Light Irradiation ◽  
Shrimp Shell

In this study, the chitosan modification of shrimp shell has been made by impregnated the chitosan from shrimp shell with Ti/ZrO2 and ZrO2 to formed composite of chitosan-Ti/ZrO2 and chitosan-ZrO2. These composites were made by immobilization technique and characterized by FTIR and SEM-EDX. The chitosan-Ti/ZrO2 and chitosan-ZrO2 composite were used as a catalyst to degrade the pesticide paraquat dichloride in the presence of UV light (????= 257 nm). The photodegradation process of paraquat dichloride takes place under 10 watts UV light irradiation and was measured using spectrophotometer UV. The maximum degradation percentage of pesticide paraquat dichloride photodegradation by chitosan-Ti/ZrO2 and chitosan-ZrO2 composites are 61.97% and 57.97% within 30 minutes irradiation time.

scholarly journals Preparation of TiO2/Activated Carbon Composites for Photocatalytic Degradation of RhB under UV Light Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Baolin Xing ◽  
Changliang Shi ◽  
Chuanxiang Zhang ◽  
Guiyun Yi ◽  
Lunjian Chen ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Activated Carbon ◽  
Electron Microscope ◽  
Uv Light ◽  
Removal Rate ◽  
Sol Gel ◽  
Light Irradiation ◽  
X Ray ◽  
Uv Light Irradiation ◽  
Loading Amount

Photocatalysts comprising nanosized TiO2particles on activated carbon (AC) were prepared by a sol-gel method. The TiO2/AC composites were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analysis, nitrogen adsorption, scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive X-ray (EDX). Their photocatalytic activities were studied through the degradation of Rhodamine B (RhB) in photocatalytic reactor at room temperature under ultraviolet (UV) light irradiation and the effect of loading cycles of TiO2on the structural properties and photocatalytic activity of TiO2/AC composites was also investigated. The results indicate that the anatase TiO2particles with a crystal size of 10–20 nm can be deposited homogeneously on the AC surface under calcination at 500°C. The loading cycle plays an important role in controlling the loading amount of TiO2and morphological structure and photocatalytic activity of TiO2/AC composites. The porosity parameters of these composite photocatalysts such as specific surface area and total pore volume decrease whereas the loading amount of TiO2increases. The TiO2/AC composite synthesized at 2 loading cycles exhibits a high photocatalytic activity in terms of the loading amount of TiO2and as high as 93.2% removal rate for RhB from the 400 mL solution at initial concentration of 2 × 10−5 mol/L under UV light irradiation.

Influence of the UV Light Intensity on the Photoelectrochemical Planarization Technique for Gallium Nitride

2010 ◽  
Vol 645-648 ◽  
pp. 795-798 ◽  
Author(s):  
Shun Sadakuni ◽  
Junji Murata ◽  
Keita Yagi ◽  
Yasuhisa Sano ◽  
Kenta Arima ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Light Intensity ◽  
Oxide Layer ◽  
Chemical Process ◽  
Solid Acid ◽  
Uv Light ◽  
Removal Rate ◽  
Solid Acid Catalyst ◽  
Acid Catalyst ◽  
Uv Light Irradiation

We have developed a novel planarization technique for gallium nitride (GaN) substrates using a photo-electro chemical process and solid acid catalyst. In this method, a GaN surface is oxidized by ultraviolet (UV) light irradiation, and the oxide layer is chemically removed by a solid acid catalyst. In the current work, the dependence of the removal rate on the UV light intensity was investigated.

scholarly journals Catalytic Degradation of Textile Wastewater Effluent by Peroxide Oxidation Assisted by UV Light Irradiation

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 509 ◽  
Author(s):  
Sarto Sarto ◽  
Paesal Paesal ◽  
Irine Bellina Tanyong ◽  
William Teja Laksmana ◽  
Agus Prasetya ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Oxide Catalyst ◽  
Uv Light ◽  
Oxygen Demand ◽  
Catalytic Degradation ◽  
Wastewater Effluent ◽  
Light Irradiation ◽  
Iron Oxide Catalyst ◽  
Uv Light Irradiation ◽  
Uv Lamp

Textile industries produce a complex wastewater which is difficult to be treated. In this work, a catalytic degradation of wastewater effluent composed of sulphur black coloring agent discharged by industry was studied. UV lamp power, peroxide concentration, pH, and iron oxide catalyst were varied to determine the best conditions for oxidative treatment. Kinetic parameters were evaluated based on the reaction model proposed. In the absence of iron oxide catalyst, chemical oxygen demand (COD) and biological oxygen demand (BOD) degradation of up to 80% and 75%, respectively, were observed as resulting from using an H2O2 concentration of 0.61 moles/L, UV lamp power of 30 watts, and pH of 6. When using an iron oxide catalyst combined with UV light irradiation, the degradation rate could be increased significantly, while similar final COD and BOD degradation percentages resulted. It is found that the reaction rate order was shifted from first order to second order when using an H2O2/UV/Fe2O3 system. The results could be an alternative for treating textile industry wastewater, and the parameters obtained can be used for equipment scale-up.

scholarly journals TiO2-Powdered Activated Carbon (TiO2/PAC) for Removal and Photocatalytic Properties of 2-Methylisoborneol (2-MIB) in Water

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1622
Author(s):  
Xiao-Pin Guo ◽  
Peng Zang ◽  
Yong-Mei Li ◽  
Dong-Su Bi
Keyword(s):  
Activated Carbon ◽  
Natural Organic Matter ◽  
Uv Light ◽  
Sol Gel ◽  
Light Irradiation ◽  
Nano Tio2 ◽  
Uv Light Irradiation ◽  
Adsorption Capacities ◽  
Taste And Odor ◽  
Composite Photocatalysts

2-methylisoborneol (2-MIB) is a common taste and odor compound caused by off-flavor secondary metabolites, which represents one of the greatest challenges for drinking water utilities worldwide. A TiO2-coated activated carbon (TiO2/PAC) has been synthesized using the sol-gel method. A new TiO2/PAC photocatalyst has been successfully employed in photodegradation of 2-MIB under UV light irradiation. In addition, the combined results of XRD, SEM-EDX, FTIR and UV-Vis suggested that the nano-TiO2 had been successfully loaded on the surface of PAC. Experimental results of 2-MIB removal indicated that the adsorption capacities of PAC for 2-MIB were higher than that of TiO2/PAC. However, in the natural organic matter (NOM) bearing water, the removal efficiency of 2-MIB by TiO2/PAC and PAC were 97.8% and 65.4%, respectively, under UV light irradiation. Moreover, it was shown that the presence of NOMs had a distinct effect on the removal of MIB by TiO2/PAC and PAC. In addition, a simplified equivalent background compound (SEBC) model could not only be used to describe the competitive adsorption of MIB and NOM, but also represent the photocatalytic process. In comparison to other related studies, there are a few novel composite photocatalysts that could efficiently and rapidly remove MIB by the combination of adsorption and photocatalysis.

Photocatalytic performance of Cu-doped titania thin films under UV light irradiation

2021 ◽  
Vol 553 ◽  
pp. 149535
Author(s):  
Elisa Moretti ◽  
Elti Cattaruzza ◽  
Cristina Flora ◽  
Aldo Talon ◽  
Eugenio Casini ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Performance ◽  
Uv Light ◽  
Light Irradiation ◽  
Uv Light Irradiation ◽  
Doped Titania
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