scholarly journals Photodegradation of Orange Green by Fe(III)–Aqua Complex

2012 ◽  
Vol 60 (1) ◽  
pp. 43-46 ◽  
Author(s):  
Md Mufazzal Hossain ◽  
Md Rashedul Islam Rasel ◽  
Md Safiqul Islam
Keyword(s):  
Uv Light ◽  
Solar Light ◽  
Aqua Complex ◽  
Average Intensity ◽  
Light Illumination ◽  
Light Sources ◽  
Initial Concentration ◽  
Aqua Complexes

The photodegradation of orange green (OG) by excitation of Fe (III)-aqua complexes has been investigated under UV and solar light illumination. The rate of degradation has been found to be strongly influenced by the pH of the solution, initial concentration of Fe(III) and the nature of the light sources. The progress of removal of OG from solution has been monitored by recording the change of absorbance at ?max = 480 nm, (? = 1.27 × 104 L mol-1cm-1 at 30°C), with time. The pH has been varied from 1.2 to 3.5. The initial concentration of Fe (III) was between 9.0 × 10-4 mol L-1 and 2.4 × 10-3 mol L-1. The intensity of the UV artificial source was 14 Wm-2, whereas the average intensity of the solar light during the experiments was about 700 Wm-2. An optimistic result was obtained, when OG was irradiated by solar light. About 92% degradation of 1.5 × 104 mol L-1 OG solution has been done within 70 minutes by photodegradation using Fe(III)-aqua complex at pH 2.5 by UV light whereas about 86% degradation has been recorded by the solar light under the same conditions.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10334  Dhaka Univ. J. Sci. 60(1): 43-46 2012 (January)

scholarly journals Characteristics of Carbon Monoxide Oxidization in Rich Hydrogen by Mesoporous Silica with TiO2Photocatalyst

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Akira Nishimura ◽  
Yutaka Yamano ◽  
Tomokazu Hisada ◽  
Masafumi Hirota ◽  
Eric Hu
Keyword(s):  
Carbon Monoxide ◽  
Mesoporous Silica ◽  
Concentration Ratio ◽  
Uv Light ◽  
Polymer Electrolyte Fuel Cell ◽  
Light Illumination ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
Loading Ratio ◽  
The Impact

Hydrogen (H2) is normally used as the fuel to power polymer electrolyte fuel cell (PEFC). However, the power generation performance of PEFC is harmed by the carbon monoxide (CO) in the H2that is often produced frommethane (CH4). The purpose of this study is to investigate the experimental conditions in order to improve the CO oxidization performance of mesoporous silica loaded with TiO2. The impact of loading ratio of TiO2and initial concentration ratio of O2to CO on CO oxidization performance is investigated. As a result, the optimum loading ratio of TiO2and initial concentration ratio of O2to CO were 20 wt% and 4 vol%, respectively, under the experimental conditions. Under this optimumexperimental condition, the CO in rich H2in the reactor can be completely eliminated from initial 12000 ppmV after UV light illumination of 72 hours.

scholarly journals Fe(III)-Aqua Complex Mediated Photodegradation of Methylene Blue Dye

2021 ◽  
Vol 12 (4) ◽  
pp. 112-117
Author(s):  
Ashfeen Nawar ◽  
◽  
Md. Ataur Rahman ◽  
Md. Mufazzal Hossain
Keyword(s):  
Methylene Blue ◽  
Uv Light ◽  
Low Cost ◽  
Degradation Process ◽  
Aqua Complex ◽  
Blue Dye ◽  
Light Sources ◽  
Experimental Conditions ◽  
Environment Friendly ◽  
Set Up

Industrialization in the current times has become extremely rapid. Some of these industries are responsible for discharging dye-containing wastewater into natural water bodies and hence causing environmental deterioration. The purpose of this research is to investigate an inexpensive and easy-to-set-up photodegradation process for the mineralization of methylene blue (MB) dye. The optimum conditions required for maximum degradation of the dye were explored by varying different experimental parameters such as the initial concentration of Fe(III) and dye, pH of the reaction mixture, nature of light sources, and intensity of ultraviolet (UV) light. Approximately 97% photodegradation of methylene blue was recorded at pH 2.30 for the optimum concentration of MB of 3.00 × 10−5 M and Fe(III) aqueous solution of 8.00 × 10−4 M when irradiated under UV light of intensity 3.31 × 10−9 Ein cm−3 s−1. Under sunlight, with similar experimental conditions, 73% degradation of the dye was achieved. This is an environment-friendly, efficient, and low-cost degradation process of methylene blue.

Studies on photocatalytic activity of the synthesised TiO2 and Ag/TiO2 photocatalysts under UV and sunlight irradiations

2011 ◽  
Vol 63 (3) ◽  
pp. 377-384 ◽  
Author(s):  
R. Vaithiyanathan ◽  
T. Sivakumar
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Solar Light ◽  
Light Sources ◽  
Tio2 Photocatalysts ◽  
First Order ◽  
First Order Kinetics ◽  
Radiation Sources ◽  
Silver Metal ◽  
Comprehensive Study

Photocatalytic decolorisation and degradation of Reactive Red 120 (RR 120) has been investigated under UV (365 nm) and solar light as radiation sources using synthesised nano titania catalyst prepared via sol-gel method. The study encompassed calcination of synthesised titania catalyst at a range of temperature up to 1,000°C. The effects of calcination temperature on titania catalyst have been evaluated on the decolorisation of RR 120. The analysis revealed complete decolorisation of dye solution in 100 min under UV light with the TiO2 catalyst calcined at 200°C. Only a maximum of 47% dye decolorisation was achieved under sunlight in 4 h with no improvement even after prolonged irradiation. In an endeavour to improve the catalytic activity, bare titania was modified with silver metal and a comprehensive study on the characteristics of silver modified catalyst was made. The result was an enhancement of the rate of decolorisation of dye under both UV and solar light sources. All the catalysts were characterised by XRD and BET analyses. Optimisation of the degradation of RR 120 has been carried out using the unmodified catalyst by varying the amount of catalyst, substrate concentration, pH of dye solution. Effects of addition of small amounts of various oxidants such as H2O2, KBrO3 and (NH4)2S2O8 have also been studied. Pseudo first order kinetics was observed in the photocatalytic decolorisation of dye. The mineralisation of RR 120 was monitored by TOC analysis.

scholarly journals Photodegradation of Chlordane in Soil and Water Matrix Using Induced UV and Solar Light

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 30
Author(s):  
Alexander C. Sioson, Jr ◽  
Dr. Susan M. Gallardo
Keyword(s):  
Solid Phase ◽  
Uv Light ◽  
Parent Compound ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Soil Samples ◽  
Solar Light ◽  
Initial Concentration ◽  
Water Matrix ◽  
Soil And Water

The photodegradation of chlordane in soil and water matrix using induced ultraviolet (UV) radiation and solar light was evaluated in this study. A batch photolytic reactor equipped with a low-pressure mercury lamp (17 W) sterilight ultraviolet (UV) lamp with a supplied wavelength of 254nm was used in the photodegradation experiments. The pesticide’s initial concentration in water was varied using three different concentrations (0.80, 2.60, and 8.0 mg/L) and soil samples were prepared at three different dosages (0.20, 2.0, and 4.0 mg/kg). At preferred time intervals, samples were withdrawn from the reactor. The pH and temperature of the samples were continuously monitored. Samples were extracted using solid-phase extraction (SPE) and the degradation of components was verified using a GC-ECD setup. Solar experiments were conducted during the months of April and May (140 33.971’N, 1200 59.515’E); with a mean sunlight intensity of 85,187.5 lux. Results of the photodegradation experiments using the batch photolytic reactor showed an average of 91.65% degradation of the chlordane pesticide dissolved in water after hours of exposure to UV light. High degradation efficiencies were achieved at higher chlordane initial concentrations. For solar photodegradation experiments, an average of 71.59% degradation was achieved. Photodegradation in soil showed an average of 62.54% degradation of the compound. As such, percentage degradation increases as the initial concentration of the pollutant increases. Further, solar photodegradation experiments in soil samples showed an approximate 56.35% degradation of the compound throughout the duration of the experiment. Chloride-ion analysis using high-performance liquid chromatography (HPLC) equipment was conducted at chlordane aqueous solution. At higher chlordane concentrations, higher chloride ion concentrations in the solution were achieved. As such, more chloride ions detached themselves from the parent compound every two hours of sampling time and soon reached an almost steady state concentration at a maximum exposure time of eight hours.

Immobilization of ZnO Suspension on Glass Substrate to Remove Filtration During the Removal of Remazol Red R from Aqueous Solution

2016 ◽  
Vol 12 (6) ◽  
pp. 4127-4133
Author(s):  
Nazmul Kayes ◽  
Jalil Miah ◽  
Md. Obaidullah ◽  
Akter Hossain ◽  
Mufazzal Hossain
Keyword(s):  
Aqueous Solution ◽  
Glass Substrate ◽  
Uv Light ◽  
Aqueous Suspension ◽  
Light Irradiation ◽  
Zno Films ◽  
Light Sources ◽  
Zno Film ◽  
Semiconductor Oxides ◽  
Remazol Red

Photodegradation of textile dyes in the presence of an aqueous suspension of semiconductor oxides has been of growing interest. Although this method of destruction of dyes is efficient, the main obstacle of applying this technique in the industry is the time and cost involving separation of oxides from an aqueous suspension. In this research, an attempted was made to develop ZnO films on a glass substrate by simple immobilization method for the adsorption and photodegradation of a typical dye, Remazol Red R (RRR) from aqueous solution. Adsorption and photodegradation of  RRR were performed in the presence of glass supported ZnO film. Photodegradation of the dye was carried out by varying different parameters such as the catalyst dosage, initial concentrations of RRR, and light sources. The percentage of adsorption as well as photodegradation increased with the amount of ZnO, reaches a maximum and then decreased. Maximum degradation has been found under solar light irradiation as compared to UV-light irradiation. Removal efficiency was also found to be influenced by the pre-sonication of ZnO suspension.

Probing the Dynamic Self-Assembly Behaviour of Photoswitchable Wormlike Micelles in Real Time

2018 ◽  
Author(s):  
Elaine A. Kelly ◽  
Judith E. Houston ◽  
Rachel Evans
Keyword(s):  
Real Time ◽  
Absorption Spectroscopy ◽  
Self Assembly ◽  
Uv Light ◽  
Wormlike Micelles ◽  
Tetraethylene Glycol ◽  
Light Illumination ◽  
First Time ◽  
Dependent Processes

Understanding the dynamic self-assembly behaviour of azobenzene photosurfactants (AzoPS) is crucial to advance their use in controlled release applications such as<i></i>drug delivery and micellar catalysis. Currently, their behaviour in the equilibrium <i>cis-</i>and <i>trans</i>-photostationary states is more widely understood than during the photoisomerisation process itself. Here, we investigate the time-dependent self-assembly of the different photoisomers of a model neutral AzoPS, <a>tetraethylene glycol mono(4′,4-octyloxy,octyl-azobenzene) </a>(C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>) using small-angle neutron scattering (SANS). We show that the incorporation of <i>in-situ</i>UV-Vis absorption spectroscopy with SANS allows the scattering profile, and hence micelle shape, to be correlated with the extent of photoisomerisation in real-time. It was observed that C<sub>8</sub>AzoOC<sub>8</sub>E<sub>4</sub>could switch between wormlike micelles (<i>trans</i>native state) and fractal aggregates (under UV light), with changes in the self-assembled structure arising concurrently with changes in the absorption spectrum. Wormlike micelles could be recovered within 60 seconds of blue light illumination. To the best of our knowledge, this is the first time the degree of AzoPS photoisomerisation has been tracked <i>in</i><i>-situ</i>through combined UV-Vis absorption spectroscopy-SANS measurements. This technique could be widely used to gain mechanistic and kinetic insights into light-dependent processes that are reliant on self-assembly.

Photocatalytic Discolouration of Solutions of Reactive Dyes in the Presence of H2O2

1995 ◽  
Vol 30 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Deng Nansheng ◽  
Tian Shizhong ◽  
Xia Mei
Keyword(s):  
Photochemical Reaction ◽  
Uv Light ◽  
Reactive Dyes ◽  
Solar Light ◽  
Rate Equations ◽  
Oh Radical ◽  
Test Results ◽  
Dye Molecules ◽  
First Order ◽  
Dye Solutions

Abstract Tests for the photocatalytic degradation of solutions of three reactive dyes, Red M-5B, Procion Blue MX-R and Procion Black H-N, in the presence of H2O2 were carried out. When the solutions of the three reactive dyes were irradiated by UV or solar light, the colour of the solutions disappeared gradually. A statistical analysis of the test results indicated a linear relation between the concentration of dyes and the time of irradiation. The discolouration reaction of the solutions was of the first order. Rate equations for the discolouration reactions of dye solutions were developed. The dark reactions or the dye solutions containing H2O2 were very slow, illustrating that the photochemical reaction played a very important role. It was demonstrated that UV light and solar light (300 to 380 nm) photolyzes the HO and that the resulting OH radical reacts with the dye molecules and destroys the chromophore.

Optic and Piezoelectric Coupling in the Sol-Gel PLZT Electroceramics

2012 ◽  
Vol 730-732 ◽  
pp. 129-134
Author(s):  
Lucjan Kozielski ◽  
Malgorzata Plonska
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Light Illumination ◽  
Piezoelectric Effects ◽  
Piezoelectric Coupling ◽  
Wireless Device ◽  
Organometallic Precursors ◽  
Gain Adjustment ◽  
Piezoelectric Transformers ◽  
Sintering Method

PZT ceramic system with presence of La contents, have been proposed and prepared using sol gel sintering method for practical application of photostriction, which is the superposition of photovoltaic and piezoelectric effects. Such a ceramics produced by conventional mixing oxide method does not exhibit photostrictive properties due to the defects and inhomogeneous distribution of grains and pores. In this study, an investigated lanthanium(III) doped PZT ceramics were obtained by sol-gel technique from the organometallic precursors. It was found that fabricated material were effective in the enhancement of photovoltaic and photostrictive properties. Consequently, lanthanium influence deviation of piezoelectric parameters were studied as a function UV light illumination. For the determination lighting dependancy of the transformation parameters the resonant and antiresonant method was implemented. The improved Piezoelectric Transformer structure successfully changed gain characteristics proportionally to light intensity. The authors invention of a light driven output gain adjustment in Piezoelectric Transformers (PT) yields a novel “smart” multifunctional wireless device. This new created application area can be utilized in self-adopting shutters in photo cameras due to improved sensitivity to surrounding illumination conditions.

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