scholarly journals Combination of TiO2-Film Photocatalysis and Ultrafiltration to Treat Wastewater

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Shu-Hai You ◽  
Ming-Hua Guo
Keyword(s):  
Organic Matter ◽  
Uv Light ◽  
Liquid Crystal Display ◽  
Sol Gel ◽  
Operating Time ◽  
Dip Coating ◽  
Feed Water ◽  
Secondary Effluent ◽  
Operating Pressure ◽  
Permeate Flux

In this study, a combination of TiO2-film photocatalysis reactor and ultrafiltration was used treat the secondary effluent from the manufacturing of thin film transistor-liquid crystal display (TFT-LCD). TiO2particles, as a photocatalyst, were immobilized on silica glass to form TiO2-film by the sol-gel and dip coating methods. TiO2-film photocatalysis was done within three parameters, including number of coating times of TiO2-film, wavelengths of UV light source, and operating time. During ultrafiltration, the operating pressure and feed water temperature were controlled at 300 KN/m2and 25°C, respectively. It was found that TiO2-film photocatalysis followed by ultrafiltration increased the removal of total organic carbon (TOC) to 47.13% and 49.94% for 5 KDa and 10 KDa membranes, respectively. It was also found that the process increased the permeate flux rate (ca 23%) for 10 KDa membrane after 6 hours of operation, since some larger organic matter had been broken into small organic matter and some small organic matter had been mineralized into CO2following TiO2-film photocatalysis. Therefore, combining TiO2-film photocatalysis reactor and ultrafiltration can improve organic wastewater quality and increase the permeate flux of ultrafiltration membrane, which may enhance the recycling and reuse of wastewater.

scholarly journals Fouling Removal of UF Membrane with Coated TiO2Nanoparticles under UV Irradiation for Effluent Recovery during TFT-LCD Manufacturing

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
S. H. You ◽  
C. T. Wu
Keyword(s):  
Uv Irradiation ◽  
Membrane Fouling ◽  
Liquid Crystal Display ◽  
Membrane Surface ◽  
Thin Film Transistor ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Secondary Effluent ◽  
Operating Pressure ◽  
Permeate Flux

An ultrafiltration (UF) membrane process was employed to treat the secondary effluent discharged from a manufacturing of thin film transistor-liquid crystal display (TFT-LCD) in this study. A bench-scale system was performed to evaluate the fouling removal of a UF membrane with coated titanium dioxide (TiO2) nanoparticles under UV irradiation. The operating pressure and feed temperature were controlled at 300 KN/m2and 25°C, respectively. It was found that the optimum operating conditions were attained with TiO2concentrations of 10 wt% for both 5 KD and 10 KD MWCO. Continuous UV irradiation of 5 KD MWCO improved the permeate flux rate from 45.0% to 59.5% after 4 hours of operation. SEM-EDS analysis also showed that the photocatalytic effect had reduced the average thickness of cake fouling on the membrane from 6.40 μm to 2.70 μm for 5 KD MWCO and from 6.70 μm to 3.1 μm for 10 KD MWCO. In addition, the membrane contact angle was reduced from 54° to 44°. The photocatalytic properties of TiO2apparently increased the hydrophilicity of the membrane surface, thereby reducing membrane fouling.

scholarly journals Sol-Gel Synthesis of TiO2/SiO2 and ZnO/SiO2 Composite Films and Evaluation of Their Photocatalytic Activity towards Methyl Green

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. L. Chandraboss ◽  
B. Karthikeyan ◽  
J. Kamalakkannan ◽  
S. Prabha ◽  
S. Senthilvelan
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Methyl Green ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Coating Method ◽  
Dip Coating Method

The TiO2/SiO2 and ZnO/SiO2 composite films were prepared by sol-gel dip coating method. The surface morphology and crystal structure of thin films were characterized by means of scanning electron microscopy (SEM) with elementary dispersive X-ray analysis (EDX) and X-ray diffractometer (XRD). Optical properties of films have been investigated using ultraviolet and visible spectroscopy (UV-visible spectroscopy). The photocatalytic activity was established by testing the degradation and decolorization of methyl green (MG) from aqueous solution with artificial UV-light.

Zinc Oxide Thin Film Synthesized by Sol-Gel Method

2020 ◽  
Vol 307 ◽  
pp. 51-57
Author(s):  
Amna Afiqah Nasution Hakim ◽  
Affa Rozana Abdul Rashid ◽  
N. Arsad ◽  
Aisyah Hanim Surani
Keyword(s):  
Thin Film ◽  
Uv Light ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Dip Coating ◽  
Oxide Thin Film ◽  
Gel Method ◽  
Sol Gel Method ◽  
Crystallite Sizes ◽  
Surface Morphologies

ZnO thin films have been prepared by the dip coating sol gel method. Zinc acetate dihydrate, 2-methoxyethanol and monoethanolamine (MEA) were used as precursor, solvent and stabilizer respectively. The synthesized sample was coated on glass substrate as the molarity of the solution was kept constant at 0.1 M. The structural properties and surface morphologies of ZnO thin film were characterized by XRD and FESEM. The optical properties such as transmittance, absorbance, reflectance and refractive index were studied by using UV-Vis. The functional group of the synthesized sample were verified by using FTIR. Average crystallite sizes of the samples were calculated by using Debye-Scherrer's formula. Next, ZnO is coated on POF in order to examine the reaction towards UV light.

scholarly journals Improving performance of low pressure reverse osmosis systems by intermittent autoflushing

2018 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
I N Widiasa ◽  
N Sinaga ◽  
D Ariyanti
Keyword(s):  
Reverse Osmosis ◽  
Membrane Surface ◽  
Magnesium Silicate ◽  
Operating Mode ◽  
Low Pressure ◽  
Calcium Sulphate ◽  
Feed Water ◽  
Low Grade ◽  
Operating Pressure ◽  
Permeate Flux

Improving performance of low pressure reverse osmosis systems by intermittent autoflushing Scaling formation on the membrane surface in the form of calcium carbonate, calcium sulphate, silica, and/or magnesium silicate is a main problem of the reverse osmosis (RO) application for upgrading low grade water. Scaling in RO system is generally controlled by softening the feed water, limiting the recovery and/or the addition of antiscalants which is impractical for household RO system. In this work, the feasibility of intermittent autoflushing to prevent scale formation in household RO systems was investigated. All experiments were carried out using commercially available RO membrane (CSM RE-1812LP) which operated for 6 hours under operating pressure 5 kg/cm2 and total recycle operating mode. Model solution of feed water contain CaCl2 and NaHCO3 were prepared to meet various LSI values in the range of 0 to 1.5. Duration and interval time of autoflush were in the range of 60 to 15 s and 5 to 60 min respectively. The results shown that the permeate flux of the system which operated using intermittent autoflushing relatively stable. It is emphasized that intermittent autoflushing may improve the performance of household reverse osmosis systems.Keywords: Autoflushing, scaling, physical cleaning, reverse osmosis  Abstrak Pembentukan kerak (scaling) pada permukaan membran berupa kerak kalsium karbonat, kalsium sulfat, silika dan atau magnesium silikat merupakan permasalahan utama pada aplikasi sistem membran reverse osmosis (RO) pada proses pemurnian air. Scaling pada sistem RO umumnya dikontrol dengan melakukan pretreatment terhadap air umpan seperti softening, menambahkan zat antiscalant pada saat proses pemisahan serta membatasi tingkat recovery, dimana proses-proses tersebut tidak praktis apabila diaplikasikan pada sistem RO skala rumah tangga. Penelitian ini bertujuan untuk melihat kemungkinan metode intermittent autoflush dapat diaplikasikan untuk menghambat terjadinya scaling pada sistem RO skala rumah tangga. Penelitian ini dilakukan dengan menggunakan satu unit membran spiral wound jenis CSM RE-1812LP yang dioperasikan dengan tekanan operasi 5 kg/cm2 dan waktu operasi ± 6 jam. Larutan umpan sintesis dibuat dengan melarutkan CaCl2 dan NaHCO3 hingga nilai LSI mencapai kisaran 0-1,5. Durasi dan interval dari metode intermittent autoflush divariasikan pada kisaran 60-15 detik dan 5-60 menit. Hasil penelitian menunjukkan bahwa fluks permeat relatif stabil pada sistem RO yang menggunakan metode intermittent autoflush. Hal ini menandakan bahwa metode intermittent autoflush ini dimungkinkan untuk meningkatkan kinerja dari sistem RO skala rumah tangga.Kata Kunci: Autoflushing, scaling, physical cleaning, reverse osmosis

Degradasi Gas Benzena Melalui Proses Pemangkinanfoto Saput Tipis TiO2

2012 ◽  
Author(s):  
Wan Azelee Wan Abu Bakar ◽  
Mohd Yusof Othman ◽  
Noor Khaida Wati Mohd Saiyudi ◽  
Keiichi Tanaka
Keyword(s):  
Thin Film ◽  
Light Source ◽  
Tio2 Thin Film ◽  
Uv Light ◽  
Wave Length ◽  
Sol Gel ◽  
Dip Coating ◽  
Optimum Ratio ◽  
Coating Method ◽  
Dip Coating Method

Pengoksidaanfoto benzena fasa gas menggunakan saput tipis TiO2 yang disinari lampu ultralembayung telah dikaji. Saput tipis ini disediakan melalui kaedah celup angkat menggunakan sol–gel TiO2. Tindak balas yang sama juga telah dijalankan menggunakan saput tipis TiO2 yang didop dengan Cu2+ dan Fe3+ dengan nisbah mol TiO2 terhadap ion logam 1:0.005, 1:0.001, 1:0.0005 dan 1:0.0003. Hasil kajian menunjukkan mangkin TiO2 dengan pancaran cahaya UV (354 nm) mendegradasikan gas benzena sebanyak 90% dalam masa 55 minit. Walau bagaimanapun penambahan ion Fe3+ dengan nisbah 1:0.0005 meningkatkan peratusan degradasi benzena kepada 98% dalam masa 55 minit, sebaliknya penambahan Cu2+memberikan kesan negatif kepada aktiviti foto TiO2. Kajian juga memperoleh satu nilai optimum dengan aktiviti pemangkinan adalah tertinggi bagi kedua-dua ion Fe3+ dan Cu2+. Pengaruh panjang gelombang cahaya ke atas aktiviti foto TiO2 juga telah dikaji dengan menggunakan mangkin TiO2 dop Fe3+ dengan nisbah optimum. Hasil kajian menunjukkan bahawa degradasi gas benzena meningkat dengan pengurangan tenaga cahaya yang dipancarkan. Kata kunci: Pemangkinanfoto; pengoksidaanfoto; saput tipis; TiO2 The gas phase photooxidation of benzene was investigated using TiO2 thin film irradiated with UV light source. The thin film was prepared via TiO2 sol gel dip coating method. The same reaction was also carried out using TiO2 doped with Cu2+ and Fe3+ with 1:0.005, 1:0.001, 1:0.0005 and 1:0.0003 mole ratios. The results showed that 90% of benzene was degraded after 55 minutes UV (354 nm) irradiation of the TiO2 thin film. However the addition of Fe3+ ions with 1:0.0005 mole ratio degraded 98% of benzene within 55 minutes. In contrast, Cu2+ ions however give a detrimental effect to the photoactivity of TiO2. An optimum ratio of dopant, where TiO2 showed the highest activity, was determined for both Fe3+ and Cu2+. The effect of different wave-length light source was also carried out using TiO2 doped Fe3+ with optimum ratio. The degradation of benzene was found to increase with decreasing light energy. Key words: Photocatalysis; photooxidation; TiO2 thin film

scholarly journals Development of Photocatalytic Ceramic Materials through the Deposition of TiO2 Nanoparticles Layers

2012 ◽  
Vol 18-19 ◽  
pp. 165-176 ◽  
Author(s):  
J.O. Carneiro ◽  
V. Teixeira ◽  
S. Azevedo ◽  
F. Fernandes ◽  
J. Neves
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Porous Ceramic ◽  
Sol Gel ◽  
Research Work ◽  
Construction Materials ◽  
Dip Coating ◽  
Human Beings ◽  
Ceramic Surfaces ◽  
Self Cleaning

Urbanism and communities centralization enlarges atmospheric pollution that affects both human beings as well as their constructed buildings. Different scientific and technological studies are being conducted, both in academic and construction industry, aiming the development of new construction materials with properties that can decrease visual pollution of cities, reducing also the number of cleanings required. The present research work aims the study and the production of self-cleaning ceramic surfaces in an economical and viable way without changing aesthetical aspect of material substrates used. The use of TiO2 nanoparticles (TiO2-NNPs) represents an attractive way to generate self-cleaning surfaces, therefore promoting the degradation of pollutant agents and reducing cleaning maintenance costs. In order to impart self-cleaning properties to ceramic surfaces, TiO2-NNPs based layers were deposited on different ceramic material substrates using the dip-coating method. The Photocatalytic activity (degradation of pollutants adsorbed on the surface) of the TiO2-NNPs based layers was characterized via the decomposition rate of an aqueous solution of Methylene blue (MB) under UV light irradiation. Colourless layers were successfully produced onto gray and white ceramic substrates using this sol-gel technique, without changing their aesthetical appearance. It was observed that the best photocatalytic activity was exhibited by the most porous ceramic substrate (gray); nevertheless, all the TiO2-NNPs coated ceramic surfaces showed good photocatalytic efficiency.

scholarly journals Hydrogen Separation Using Silica-Based Composite Membranes

2014 ◽  
Vol 1051 ◽  
pp. 107-111 ◽  
Author(s):  
Mohammed Nasir Kajama ◽  
Ngozi Claribelle Nwogu ◽  
Edward Gobina
Keyword(s):  
Sol Gel ◽  
Composite Membranes ◽  
Dip Coating ◽  
Gas Permeation ◽  
Hydrogen Gas ◽  
Silica Layer ◽  
Permeate Flux ◽  
Free Silica ◽  
Feed Pressure ◽  
Ar Gas

Silica sol-gel membranes have been developed for moderate temperature (300 °C) separation of hydrogen (H2) from nitrogen (N2), methane (CH4) and argon (Ar) gas molecules. Tubular ceramic support with 15 nm nominal pore diameter and 45% porosity was modified by dip-coating method. Gas permeation characteristics were evaluated. Defect free silica layer over the substrate for hydrogen gas separation was obtained. Hydrogen gas permeate flux of 4.82x10-1mol/sec m2at 1.0 barg feed pressure was obtained. Selectivities of H2over N2, CH4and Ar of 3.07, 2.23 and 3.75 at 300 °C, 200 °C and 300 °C and 0.9 barg were obtained with the silica membranes. The gas permeation and the selectivity performance of the membrane were evaluated.

scholarly journals The Impact of Amount of Cu on CO2 Reduction Performance of Cu/TiO2 with NH3 and H2O

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 610
Author(s):  
Akira Nishimura ◽  
Yoshito Sakakibara ◽  
Akira Koshio ◽  
Eric Hu
Keyword(s):  
Tio2 Film ◽  
Uv Light ◽  
Sol Gel ◽  
Co2 Reduction ◽  
Dip Coating ◽  
Pulse Number ◽  
Unit Weight ◽  
Molar Ratio ◽  
Light Illumination ◽  
The Impact

This study has investigated the impact of molar ratio of CO2 to reductants NH3 and H2O as well as that of Cu loading on CO2 reduction characteristics over Cu/TiO2. No study to optimize the reductants’ combination and Cu loading weight in order to enhance CO2 reduction performance of TiO2 has been investigated yet. This study prepared Cu/TiO2 film by loading Cu particles during the pulse arc plasma gun process after coating TiO2 film by the sol-gel and dip-coating process. As to loading weight of Cu, it was regulated by change in the pulse number. This study characterized the prepared Cu/TiO2 film by SEM and EPMA. Additionally, the performance of CO2 reduction has been investigated under the illumination condition of Xe lamp with or without ultraviolet (UV) light. It is revealed that the molar ratio of CO2/NH3/H2O is optimized according to the pulse number. Since the amount of H+ which is the same as that of electron is needed to produce CO decided following the theoretical CO2 reduction reacting with H2O or NH3, larger H+ is needed with the increase in the pulse number. It is revealed that Cu of 4.57 wt% for the pulse number of 200 is the optimum condition, whereas the molar quantity of CO per unit weight of Cu/TiO2 with and without UV light illumination is 34.1 mol/g and 12.0 mol/g, respectively.

scholarly journals Impact of Pd Loading on CO2 Reduction Performance over Pd/TiO2 with H2 and H2O

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1468
Author(s):  
Akira Nishimura ◽  
Tadaaki Inoue ◽  
Yoshito Sakakibara ◽  
Masafumi Hirota ◽  
Akira Koshio ◽  
...  
Keyword(s):  
Tio2 Film ◽  
Uv Light ◽  
Sol Gel ◽  
Co2 Reduction ◽  
Dip Coating ◽  
Unit Weight ◽  
Molar Ratio ◽  
Illumination Condition ◽  
The Impact ◽  
Lamp Illumination

This study investigated the impact of molar ratio of CO2 to reductants H2O and H2, as well as Pd loading weight on CO2 reduction performance with Pd/TiO2 as the photocatalyst. The Pd/TiO2 film photocatalyst is prepared by the sol-gel and dip-coating process to prepare TiO2 film and the pulse arc plasma method is used to dope Pd on TiO2 film. The prepared Pd/TiO2 film was characterized by SEM, EPMA, STEM, EDS, and EELS. This study also investigated the performance of CO2 reduction under the illumination condition of Xe lamp with or without ultraviolet (UV) light. As a result, it is revealed that when the molar ratio of CO2/H2/H2O is set at 1:0.5:0.5, the best CO2 reduction performance has been obtained under the illumination condition of Xe lamp with and without UV light. In addition, it is found that the optimum Pd loading weight is 3.90 wt%. The maximum molar quantities of CO and CH4 produced per unit weight of photocatalyst are 30.3 μmol/g and 22.1 μmol/g, respectively, for the molar ratio of CO2/H2/H2O = 1:0.5:0.5 under the condition of Xe lamp illumination with UV light. With UV light, C2H4 and C2H6, as well as CO and CH4 are also produced by the Pd/TiO2 film photocatalyst prepared in this study.

scholarly journals Impact of Overlapping Fe/TiO2Prepared by Sol-Gel and Dip-Coating Process on CO2Reduction

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Akira Nishimura ◽  
Xuyan Zhao ◽  
Takuya Hayakawa ◽  
Noriaki Ishida ◽  
Masafumi Hirota ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Uv Light ◽  
Sol Gel ◽  
Base Material ◽  
Visible Spectrum ◽  
Dip Coating ◽  
Coating Process ◽  
Illumination Condition ◽  
Base Materials ◽  
Materials Used

Fe-doped TiO2(Fe/TiO2) film photocatalyst was prepared by sol-gel and dip-coating process to extend its photoresponsivity to the visible spectrum. To promote the CO2reduction performance with the photocatalyst, some types of base materials used for coating Fe/TiO2, which were netlike glass fiber and Cu disc, were investigated. The characterization of prepared Fe/TiO2film coated on netlike glass fiber and Cu disc was analyzed by SEM and EPMA. In addition, the CO2reduction performance of Fe/TiO2film coated on netlike glass disc, Cu disc, and their overlap was tested under a Xe lamp with or without ultraviolet (UV) light, respectively. The results show that the concentration of produced CO increases by Fe doping irrespective of base material used under the illumination condition with UV light as well as that without UV light. Since the electron transfer between two overlapped photocatalysts is promoted, the peak concentration of CO for the Fe/TiO2double overlapping is approximately 1.5 times as large as the Fe/TiO2single overlapping under the illumination condition with UV light, while the promotion ratio is approximately 1.1 times under that without UV light.

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