Activated Carbon as Heterogeneous Catalyst of Catalytic Ozonation Activity for Improvement RB 49 Dye Degradation

2016 ◽  
Vol 860 ◽  
pp. 105-110 ◽  
Author(s):  
Suntree Sangjan ◽  
Montri Sratongin ◽  
Atit Kawpakpor ◽  
Pornrung Ampha ◽  
Laksika Jamtanom ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Heterogeneous Catalyst ◽  
Rate Constant ◽  
Dye Degradation ◽  
Degradation Kinetics ◽  
Order Rate Constant ◽  
Catalytic Ozonation ◽  
Catalyst Loading ◽  
Visible Spectroscopy ◽  
Uv Visible

Activated carbon (AC) catalyst was successfully improved activity for the degradation of Reactive blue 49 dye (RB 49) in catalytic ozonation system. The degradation of the RB 49 dye was visualized by UV-Visible spectroscopy. As the RB 49 degradation kinetics were investigated by different initial parameters, initial RB 49 concentrations, AC catalyst loading, H2O2 dosage and additives. The degradation efficiency of AC catalytic ozonation towards RB 49 was found to be 95% when compared to 45% using pure ozone. The concentration of AC catalyst ranged from 0, 0.01, 0.05 and 0.1 g/L. We found that the maximum pseudo first and second order rate constant were 0.186 min-1 and 1.416 L.mg-1min-1 for 0.05 g/L AC. The results showed that the optimum of AC concentration in system was 0.05 g/L. In addition, this research studied the effect of auxiliary chemicals such as NaCl, Na2CO3, Na2SO4 and H2O2 upon dye degradation in AC catalytic ozonation system.

Formation and spectra of flavin radicals in the presence of β-mercaptoethanol at pH 9 and 10

1984 ◽  
Vol 62 (3) ◽  
pp. 580-585 ◽  
Author(s):  
Parminder S. Surdhar ◽  
Rizwan Ahmad ◽  
David A. Armstrong
Keyword(s):  
Rate Constant ◽  
Rate Constants ◽  
Order Rate Constant ◽  
Second Order ◽  
Radical Species ◽  
Spectral Changes ◽  
Order Rate ◽  
Visible Spectra ◽  
Uv Visible ◽  
Presence And Absence

Spectral changes and rates of reaction of flavins and several radical species have been investigated at pH 7, 9, and 10 in the presence and absence of β-mercaptoethanol. The radicals •CO2−, eaq−, and [Formula: see text] reacted with FAD at pH 10 to give a spectrum of FAD •Fl− with rate constants of 7 ± 1 × 108 and 4 ± 1 × 108 M−1 s−1 for •CO2− and [Formula: see text] respectively. At pH 7 only •FlH was observed and at pH 9 a mixture of •FIH and •Fl−.Interactions between flavin radicals and sulphydryl at 10−4 M concentration did not cause perturbations in the uv–visible spectra until either the radical and/or the sulphydryl were ionized. With FAD at pH 9 or 10 and LFl at pH 10 the 370 nm peak of •Fl− was enhanced by about 15% and a second larger growth occurred near 450 nm in the presence of 10−4 to 10−2 M sulphydryl. We attribute this to the formation of labile intermediate RSHFl•−, which must also be involved in the reduction of Fl by [Formula: see text] at pH 9 or 10.The second order rate constant k13 for reaction of [Formula: see text] with FAD at pH 9 and 10 was found to be 4.2 ± 0.5 × 108 M−1 s−1 and 2.0 ± 0.4 × 108 M−1 s−1 respectively. The rate constant for the reaction between [Formula: see text] and LFl at pH 10 was slightly faster, 7 ± 1 × 108 M−1 s−1, probably reflecting the fact that LFl lacks the bulky negatively charged adenine dinucleotide group of FAD.

scholarly journals Congo Red and Nigrosine Dye Degradation using Dimethyl Dioxirane as an Oxidising Agent

2021 ◽  
Vol 37 (5) ◽  
pp. 1221-1228
Author(s):  
S. Vinotha ◽  
A.Leema Rose
Keyword(s):  
Congo Red ◽  
Room Temperature ◽  
Functional Group ◽  
Dye Degradation ◽  
Visible Spectroscopy ◽  
Before And After ◽  
Ft Ir ◽  
Combined Action ◽  
Uv Visible ◽  
Ft Ir Spectroscopy

The advanced oxidation of Congo red (CR) and Nigrosine (NI) using the combined action of dimethyl dioxirane as an oxidising agent is described in this study. The effects of several parameters, such as the concentration of the oxidising agent, the initial dye concentration, and the pH, have been investigated. At room temperature, the oxidising agent dimethyl dioxirane was employed to test the degradation of CR and NI dyes. On the degradation efficiency of CR and NI, pH’s effects, oxidising agent, and initial dye concentration were examined. The absorbance of CR and NI dyes before and after degradation was measured using UV-visible spectroscopy. The functional group existing in the dyes before and after degradation was determined using FT-IR spectroscopy.

scholarly journals Sunlight Assisted Degradation of Methylene Blue as a Model Dye using Bismuth Oxychloride Nanoparticles: Ecofriendly and Industry Efficient Photocatalysis for Waste Chemical Treatment

2019 ◽  
Vol 32 (1) ◽  
pp. 115-121
Author(s):  
Chandan Adhikari ◽  
Mandeep Kaur ◽  
Ravichandran
Keyword(s):  
Methylene Blue ◽  
Dye Degradation ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Bismuth Oxychloride ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Different Types ◽  
Photocatalytic Dye Degradation ◽  
Uv Visible

In this study, an efficient sunlight triggered dye degradation was demonstrated using methylene blue as a model dye and bismuth oxychloride nanoparticles were used as photocatalyst. Two different types of nanoparticles, nanoflower and nanodisk, were prepared to understand the effect of morphology on the photocatalysis. Both the particles were prepared following a straightforward and easy methodology from readily available chemicals. The particles were characterized using scanning electron microscope, Fourier transformed infrared spectroscopy, powder X-ray diffraction. UV-visible spectroscopy and colorimeter were used to evaluate the photocatalytic activity of the catalyst. Both the nanoparticles were able to degrade the dye completely within 3-4 h under visible light. The photocatalytic rate constant analysis demonstrates that out of two morphology, nanoflower is found to be more effective than nanodisk towards dye degradation. The sunlight was also used to understand whether the photocatalyst can degrade the dye or not in presence of sunlight only. Both nanoparticles were able to degrade the dye 100 % in presence of sunlight within maximum 4 h. The photocatalytic dye degradation in presence of sunlight was conducted in between 10 a.m. to 4 p.m. when the maximum amount of sunlight is available with high intensity and energy. The catalysts were 100 % active after the first cycle and upto four cycles the dye degradation efficiency remain around 60-80%. The study demonstrates that sunlight can degrade the dye in presence of these photocatalyst which clearly indicates its energy saving approach thus making it more economic and green methodology for the industries.

scholarly journals Simultaneous Studies of Redox Reaction of Chromium(VI) and Arsenic(III) in Aqueous Phase: A Kinetic and Mechanistic Approach

2020 ◽  
pp. 18-29
Author(s):  
Iorhuna, T. Boniface ◽  
Wuana, A. Raymond ◽  
Yiase, G. Stephen
Keyword(s):  
Aqueous Phase ◽  
Rate Constant ◽  
Rate Equation ◽  
Redox Reaction ◽  
Order Rate Constant ◽  
Chromium Vi ◽  
Mechanistic Approach ◽  
Ester Formation ◽  
Plausible Mechanism ◽  
Uv Visible

A kinetic and mechanistic approach was used to simultaneously study the oxidation of As(III) and reduction of Cr(VI) in aqueous phase, and in the presence of Fe(III). Reactions were monitored by UV-visible spectrophotometry. The stoichiometry of the reaction was . The rate equation for the reaction is proposed as  where k2 is the second order rate constant. The reaction was not affected by Fe(III) ions within the studied concentration range of 0.001 – 0.009 molL-1. From the reaction between   a plausible mechanism involving an ester formation by the reactants leading to the eventual formation of As(V) and Cr(III) was proposed.

Engineering of silver nanoparticle fabricated poly (N-isopropylacrylamide-co-acrylic acid) microgels for rapid catalytic reduction of nitrobenzene

2016 ◽  
Vol 36 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Khalida Naseem ◽  
Aysha Ijaz ◽  
Robina Begum
Keyword(s):  
Acrylic Acid ◽  
Rate Constant ◽  
Apparent Rate Constant ◽  
Reduction Method ◽  
Catalytic Reduction ◽  
Visible Spectroscopy ◽  
Uv Visible ◽  
Polymerization Method ◽  
Hybrid Microgels

Abstract Three different poly(N-isopropylacrylamide-co-acrylic acid) [p(NIPAM-AA)] microgel samples were prepared using a precipitation polymerization method by varying the concentration of NIPAM and AA in aqueous medium. The microgels were used as microreactors to fabricate Ag nanoparticles (NPs) by in situ a reduction method. Fourier transform infrared (FTIR) and UV-visible spectroscopy were used to characterize the pure and hybrid microgels. The hybrid microgels with different AA content were used as catalysts for reduction of nitrobenzene (NB) into aniline. The progress of the reaction was monitored by a UV-visible spectrophotometer. The results show that the value of the apparent rate constant for catalytic reduction of NB decreases from 0.431 min-1 to 0.227 min-1 by increasing AA content from 3 mol% to 7 mol%, respectively. Decrease in apparent rate constant with increase of AA content can be attributed to an increase in hydrophilicity with increase of AA contents of the microgels. The increase in induction period with increase of AA contents indicates that diffusion of NB towards the catalytic surface becomes difficult due to an increase of hydrophilicity.

scholarly journals Photochromism of indolino-benzopyrans studied by NMR and UV-visible spectroscopy

2006 ◽  
Vol 2006 ◽  
pp. 1-7 ◽  
Author(s):  
S. Delbaere ◽  
J. Berthet ◽  
M. A. Salvador ◽  
G. Vermeersch ◽  
M. M. Oliveira
Keyword(s):  
Nmr Spectroscopy ◽  
Rate Constant ◽  
Colored Form ◽  
Visible Spectroscopy ◽  
Uv Visible

The synthesis of photochromic 3,3-di(4′-fluorophenyl)-3H-benzopyrans fused to an indole moiety is described. The structures of photomerocyanines elucidated by NMR spectroscopy and spectrokinetic data (λmax⁡of colored form, colorability, and rate constant of bleaching) obtained by UV-visible spectroscopy are reported.

scholarly journals Correlation for Photocatalytic Degradation Kinetics of Carboxylic Acids using Electrochemically Synthesized Al2S3 Nanoparticles and Study of Antibacterial Activity

2020 ◽  
Vol 32 (6) ◽  
pp. 1443-1450
Author(s):  
H.C. Charan Kumar ◽  
R. Shilpa ◽  
Sannaiah Ananda
Keyword(s):  
Antibacterial Activity ◽  
Carboxylic Acids ◽  
Uv Light ◽  
Degradation Kinetics ◽  
Visible Region ◽  
Volumetric Method ◽  
Isokinetic Temperature ◽  
Visible Spectroscopy ◽  
Tauc Plot ◽  
Uv Visible

Aluminium sulfide (Al2S3) nanoparticles were successfully synthesized by electrochemical method. Further, the synthesized nanoparticles were used as a photocatalyst for degradation of trichloroacetic acid, chloroacetic acid, acetic acid and degradation kinetics was studied by volumetric method using NaOH under various experimental conditions. The Al2S3 nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction and SEM-EDAX. The study of UV-visible spectroscopy indicates that Al2S3 nanoparticles shows maximum intensity peak at 222 nm in the UV region and there is no absorption peak in the visible region, therefore the synthesized nanoparticles is active under UV light and band gap energy was found to be 3.07 eV, which was calculated using Tauc plot. The structure of Al2S3 was found to be tetragonal structure and average crystal size was found to be 25.76 nm, which was calculated using Debye-Scherrer′s formula. The SEM results showed that Al2S3 appears as nanoflakes with agglomerated. The presence of aluminium and sulfur was confirmed using EDAX spectra. The photocatalytic activity of the synthesized Al2S3 nanoparticles was examined by taking three carboxylic acids by volumetric method. Taft LFER was tested, the isokinetic temperature β was calculated for oxidation of carboxylic acids. The antibacterial activity was investigated for synthesized nanoparticles by using Bacillus subtilis MTCC 2763 and Escherichia coli MTCC 40 of different bacteria.

scholarly journals Influence of Activated Carbon in the Photodegradation of Methylene Blue

2011 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Juan Matos ◽  
Karina Quintana ◽  
Andreina Garcia
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Activated Carbon ◽  
Rate Constant ◽  
Activated Carbons ◽  
Order Rate Constant ◽  
First Order ◽  
Order Rate

<p>Photodegradation of methylene blue (MB) on TiO<sub>2</sub> in presence of activated carbons (AC) was studied. Apparent first order rate constant for the degradation of MB was higher in presence of any AC indicating that the binary materials TiO<sub>2</sub>-AC showed a clear enhancement in the photocatalytic activity relative to TiO<sub>2</sub> and this enhancement was associated with the properties of AC.</p>

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