Preparation of Titanium-Oxide-Coated Polypropylene Granules for Photooxidation of Organic Pollutant

2013 ◽  
Vol 717 ◽  
pp. 101-107
Author(s):  
H.S. Shin ◽  
D.S. Rhee
Keyword(s):  
Methylene Blue ◽  
Titanium Dioxide ◽  
Organic Pollutant ◽  
Solar Irradiation ◽  
Order Kinetic ◽  
First Order ◽  
Degradation Rates ◽  
Order Kinetic Model ◽  
Flow Through ◽  
Pseudo First Order

Titanium dioxide was coated onto buoyant polypropylene granules. Titanium dioxide coated polypropylene granules (TCPG) had high mechanical and attritional stability as well as appreciable photocatalytic activity under solar irradiation. Chosen model pollutant, Methylene Blue (MB) could be totally decolorized and partially mineralized within 3 h of treatment. TCPG might successfully be applied as suspended in the column flow-through system. Degradation rates depended strongly on pH, initial dye concentration, and optimal media dosage, following pseudo-first-order kinetic model.

scholarly journals Enhanced photocatalytic activity of wool-ball-like TiO2 microspheres on carbon fabric and FTO substrates

2018 ◽  
Vol 38 ◽  
pp. 02014
Author(s):  
Yu Zhang ◽  
Jian Gu ◽  
Mengqi Zhang
Keyword(s):  
Hydrothermal Method ◽  
Order Kinetic ◽  
Carbon Fabric ◽  
Facile Hydrothermal Method ◽  
Sem Images ◽  
First Order ◽  
Good Crystallinity ◽  
Degradation Rate Constant ◽  
Order Kinetic Model ◽  
Pseudo First Order

The wool-ball-like TiO2 microspheres on carbon fabric (TiO2-CF) and FTO substrates (TiO2-FTO) have been synthesized by a facile hydrothermal method in alkali environment, using commercial TiO2 (P25) as precursors. The XRD results indicate that the as-prepared TiO2 have good crystallinity. And the SEM images show that the wool-ball-like TiO2 microspheres with a diameter of 2-3 μm are composed of TiO2 nanowires, which have a diameter of ~50 nm. The photocatalytic behavior of the wool-ball-like TiO2 microspheres, TiO2-CF and TiO2-FTO under ultraviolet light was investigated by a pseudo first-order kinetic model, using methyl orange (MO) as pollutant. The wool-ball-like TiO2 microspheres obtained a degradation rate constant (Kap) of 6.91×10-3 min-1 . The Kap values of TiO2-FTO and TiO2-CF reach 13.97×10-3 min-1 and 11.80×10-3 min-1, which are 2.0 and 1.7 times higher than that of pristine wool-ball-like TiO2 microspheres due to the “sum effect” between TiO2 and substrates. This study offers a facile hydrothermal method to prepare wool-ball-like TiO2 microspheres on CF and FTO substrates, which will improve the recyclability of phtocatalysts and can be extended to other fields.

Characteristics and kinetics of hexavalent chromium reduction by gallic acid in aqueous solutions

2015 ◽  
Vol 71 (11) ◽  
pp. 1694-1700 ◽  
Author(s):  
ZiFang Chen ◽  
YongSheng Zhao ◽  
Qin Li
Keyword(s):  
Kinetic Model ◽  
Gallic Acid ◽  
Hexavalent Chromium ◽  
Ph Value ◽  
Order Kinetic ◽  
First Order ◽  
Molar Ratios ◽  
Wide Range ◽  
Order Kinetic Model ◽  
Pseudo First Order

Gallic acid (GA) is a naturally occurring plant polyphenol compound. Experiments were conducted to study the kinetics and effects of pH, temperature, irradiation, and initial hexavalent chromium (Cr(VI)) concentration on Cr(VI) reduction by GA. Results indicated that Cr(VI) could be reduced to chromium oxide (Cr(III)) with GA in a wide range of pH values from 2.0 to 8.5. The reaction followed a pseudo-first-order kinetic model with respect to Cr(VI) and GA in acid conditions (pH 2.0–5.0). However, the reaction did not follow the pseudo-first-order kinetic model at pH 6.5 and 8.5. Removal efficiencies and reaction rate constants of Cr(VI) significantly increased with decreasing pH value and increasing temperature. The effect of irradiation on Cr(VI) reduction increased with increasing pH, and irradiation improved the removal efficiency of Cr(VI) by 11.29% at pH 6.5. At pH 2.0, nearly all molar ratios of GA required for the reduction of Cr(VI) were 1:2 (±0.1) under different initial Cr(VI) concentrations; however, the molar ratios of GA required for the reduction of Cr(VI) were 1:1.29, 1:1.43, and 1:1.69, respectively, when the initial Cr(VI) concentrations were 10, 25, and 50 mg/L at pH 5.5.

Sorption of Pb2+ on Mg-Al-Fe Hydrotalcite-Like Compounds

2012 ◽  
Vol 573-574 ◽  
pp. 86-91
Author(s):  
Xue Feng Liang ◽  
Wan Guo Hou ◽  
Ying Ming Xu ◽  
Lin Wang ◽  
Yue Bing Sun
Keyword(s):  
Kinetic Model ◽  
Rate Increase ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Sorption Mechanism ◽  
Chemical Binding ◽  
First Order ◽  
Maximum Sorption ◽  
Order Kinetic Model ◽  
Pseudo First Order

Hydrotalcite-like compounds containing Mg2+, Al3+ and Fe3+ with a constant M2+/M3+ ratio but varying Al3+/Fe3+ ratios have been prepared. The effects of iron contents on the structural and sorption of Pb2+ by Mg-Al-Fe HTlc samples were investigated. The maximum sorption amounts were about 88-201 mg/g for Mg-Al-Fe HTlc samples. The sorption isotherm and kinetic processes can be described with Freundlich isotherm and pseudo first order kinetic model, respectively. The sorption amounts and rate increase with the increase of iron contents in HTlc samples. The sorption mechanism of Pb2+ on Mg-Al-Fe HTlcs may be the surface-induced precipitation and chemical binding adsorption.

Kinetic Study of the Adsorption of Dye onto Cotton in SDS-CTAB Reverse Micelles

2015 ◽  
Vol 723 ◽  
pp. 591-595
Author(s):  
Zu Lan Liu ◽  
Lan Qian Li ◽  
Yi Ping Liu ◽  
Ming Lu
Keyword(s):  
Kinetic Study ◽  
Adsorption Kinetics ◽  
Reverse Micelles ◽  
Adsorption Kinetic ◽  
Order Kinetic ◽  
First Order ◽  
Reactive Blue 19 ◽  
Order Kinetic Model ◽  
Pseudo First Order ◽  
Kinetics Of

Adsorption kinetic study of C.I. reactive blue 19 onto cotton was carried out in SDS-CTAB reverse micelles. The data of adsorption kinetics were examined using pseudo first-and second-order kinetic models. It was found that the adsorption kinetics of dye on cotton with diffusion controlling follows the pseudo first-order kinetic model.

Effects of ultraviolet intensity and wavelength on the photolysis of triclosan

2007 ◽  
Vol 55 (1-2) ◽  
pp. 209-216 ◽  
Author(s):  
H.-S. Son ◽  
S.-B. Choi ◽  
K.-D. Zoh ◽  
E. Khan
Keyword(s):  
Kinetic Model ◽  
Hydroxyl Radicals ◽  
Direct Photon ◽  
Order Kinetic ◽  
First Order ◽  
Photodegradation Rate ◽  
Order Kinetic Model ◽  
Pseudo First Order ◽  
First Time ◽  
Subordinate Role

The effects of ultraviolet (UV) intensity and wavelength on triclosan (TCS) photodegradation kinetic, efficiency, mechanisms and pathway were studied. The TCS photodegradation followed the pseudo-first order kinetic model at all UV intensities examined at the wavelengths of 254 and 365 nm and the photodegradation rate increased with increasing UV intensity. TCS photodegradation efficiencies of 90 to 98% and 79 to 90% were obtained at the wavelengths of 254 and 365 nm, respectively. TCS was degraded mainly by photon induced hydroxyl radicals while the direct photon reaction with TCS played a subordinate role. Chlorophenol, dichlorophenol and phenol were the intermediates detected in all experiments conducted. Dibenzodichloro-p-dioxin and dibenzo-p-dioxin were observed as the intermediates only at lower UV intensities investigated at the wavelength of 365 nm. Based on these intermediates, a complete TCS photolysis pathway was proposed for the first time.

Fabrication and Photocatalytic Decolorization Performance of ZnO

2011 ◽  
Vol 396-398 ◽  
pp. 823-826
Author(s):  
Jie Cheng ◽  
Jian Zhang Li ◽  
Jun Bo Zhong ◽  
Wei Hu
Keyword(s):  
Methyl Orange ◽  
Kinetic Model ◽  
Uv Irradiation ◽  
Precipitation Method ◽  
Order Kinetic ◽  
First Order ◽  
Photocatalytic Decolorization ◽  
Langmuir Hinshelwood Mechanism ◽  
Order Kinetic Model ◽  
Pseudo First Order

Paralled flaw precipitation method has been employed to synthesize nanostructured ZnO. The prepared photocatalyst was characterized by BET, XRD. The paper reveals that Methyl Orange (MO) can be decolorized effectively in ZnO suspension system under UV irradiation. The optimal loading of photocatalyst in our experimental condition for the decolorization of MO is 1g/L. The present study, on the base of Langmuir-Hinshelwood mechanism, illustrates that the decolorization reaction is a pseudo first order kinetic model with the limiting rate constant of 8.48×10-2 mgL-1min-1 and equilibrium adsorption constant 0.335 L/mg, respectively.

scholarly journals Methylene Blue Dye Adsorption from Wastewater Using Hydroxyapatite/Gold Nanocomposite: Kinetic and Thermodynamics Studies

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1403
Author(s):  
Kashma Sharma ◽  
Shreya Sharma ◽  
Vipasha Sharma ◽  
Pawan Kumar Mishra ◽  
Adam Ekielski ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Dye Adsorption ◽  
Precipitation Method ◽  
Diffusion Method ◽  
Blue Dye ◽  
Order Kinetic ◽  
Economic Point ◽  
X Ray ◽  
First Order ◽  
Pseudo First Order

The present work demonstrates the development of hydroxyapatite (HA)/gold (Au) nanocomposites to increase the adsorption of methylene blue (MB) dye from the wastewater. HA nanopowder was prepared via a wet chemical precipitation method by means of Ca(OH)2 and H3PO4 as starting materials. The biosynthesis of gold nanoparticles (AuNPs) has been reported for the first time by using the plant extract of Acrocarpus fraxinifolius. Finally, the as-prepared HA nanopowder was mixed with an optimized AuNPs solution to produce HA/Au nanocomposite. The prepared HA/Au nanocomposite was studied by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) analysis. Adsorption studies were executed by batch experiments on the synthesized composite. The effect of the amount of adsorbent, pH, dye concentration and temperature was studied. Pseudo-first-order and pseudo-second-order models were used to fit the kinetic data and the kinetic modeling results reflected that the experimental data is perfectly matched with the pseudo-first-order kinetic model. The dye adsorbed waste materials have also been investigated against Pseudomonas aeruginosa, Micrococcus luteus, and Staphylococcus aureus bacteria by the agar well diffusion method. The inhibition zones of dye adsorbed samples are more or less the same as compared to as-prepared samples. The results so obtained indicates the suitability of the synthesized sample to be exploited as an adsorbent for effective treatment of MB dye from wastewater and dye adsorbed waste as an effective antibacterial agent from an economic point of view.

scholarly journals Kinetics and reaction mechanism of photochemical degradation of diclofenac by UV-activated peroxymonosulfate

RSC Advances ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 6804-6817
Author(s):  
Yunlan Peng ◽  
Hongle Shi ◽  
Zhenran Wang ◽  
Yongsheng Fu ◽  
Yiqing Liu
Keyword(s):  
Reaction Mechanism ◽  
Kinetic Model ◽  
Order Kinetic ◽  
Photochemical Degradation ◽  
First Order ◽  
Order Kinetic Model ◽  
Pseudo First Order

Compared to UV alone and PMS alone systems, diclofenac was removed more efficiently in UV/PMS system at pH 7.0 due to the contribution of SO4˙− and HO˙ and its degradation followed the pseudo-first order kinetic model.

scholarly journals A Highly Efficient Ag Nanoparticle-Immobilized Alginate-g-Polyacrylonitrile Hybrid Photocatalyst for the Degradation of Nitrophenols

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3049
Author(s):  
Imran Hasan ◽  
Charu Shekhar ◽  
Walaa Alharbi ◽  
Maymonah Abu Khanjer ◽  
Rais Ahmad Khan ◽  
...  
Keyword(s):  
Irradiation Time ◽  
Analytical Techniques ◽  
Order Rate Constant ◽  
Order Kinetic ◽  
Ag Nps ◽  
Reaction Conditions ◽  
First Order ◽  
Order Kinetic Model ◽  
Pseudo First Order

Herein, we report PAN-g-Alg@Ag-based nanocatalysts synthesis via in situ oxidative free-radical polymerization of acrylonitrile (AN) using Alg@Ag nanoparticles (Alg@Ag NPs). Various analytical techniques, including FTIR, XRD, SEM, TEM, UV–Vis, and DSC, were employed to determine bonding interactions and chemical characteristics of the nanocatalyst. The optimized response surface methodology coupled central composite design (RSM–CCD) reaction conditions were a 35-min irradiation time in a 70-mg L−1 2,4-dinitrophenol (DNP) solution at pH of 4.68. Here, DNP degradation was 99.46% at a desirability of 1.00. The pseudo-first-order rate constant (K1) values were 0.047, 0.050, 0.054, 0.056, 0.059, and 0.064 min−1 with associated half-life (t1/2) values of 14.74, 13.86, 12.84, 12.38, 11.74, 10.82, and 10.04 min that corresponded to DNP concentrations of 10, 20, 30, 40, 50, 60, and 70 mg L−1, respectively, in the presence of PAN-g-Alg@Ag (0.03 g). The results indicate that the reaction followed the pseudo-first-order kinetic model with an R2 value of 0.99. The combined absorption properties of PAN and Alg@Ag NPs on copolymerization on the surface contributed more charge density to surface plasmon resonance (SPR) in a way to degrade more and more molecules of DNP together with preventing the recombination of electron and hole pairs within the photocatalytic process.

scholarly journals A Comparative Study for Adsorptive Removal of Remazol Red R and Remazol Black B from Aqueous Solution by ZnO

2018 ◽  
Vol 66 (2) ◽  
pp. 121-127
Author(s):  
AZM Mainul Islam Mazumder ◽  
Chowdhury Raihan Bikash ◽  
Md Ataur Rahman ◽  
Md Mufazzal Hossain
Keyword(s):  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Adsorptive Removal ◽  
First Order ◽  
Remazol Black B ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Remazol Red ◽  
Remazol Black

Adsorptive removal of remazol red R (RRR) and remazol black B (RBB) from aqueous solution has been investigated by using ZnO as an adsorbent. Time for adsorption equilibrium, kinetics of adsorption at different initial concentrations of dyes and adsorption isotherms at different temperatures have been studied. Adsorption capacity increased with increasing initial dye concentration. The pseudo first-order and pseudo second-order kinetics were used to describe kinetic data and the rate constants were evaluated. Experimental data fits better in the pseudo second-order kinetic model than in the pseudo first-order kinetic model for both the dyes. Langmuir and Freundlich isotherm models were applied to describe the adsorption of RRR and RBB onto ZnO powders. Langmuir isotherm model provided a better correlation for the experimental data in comparison to the Freundlich isotherm model. Adsorption of both RRR and RBB on ZnO are physical in nature and increases with decreasing temperature. The equilibrium adsorption capacity decreases from 3.43 mg/g at 200C to 2.36 mg/g at 400C for RRR whereas that in the case of RBB changes from 0.77 mg/g at 300C to 0.75 mg/g at 400C. Adsorption of RRR on ZnO was found to be three times higher than the adsorption of RBB at a particular temperature. A model for adsorption of both the dyes has been proposed. Dhaka Univ. J. Sci. 66(2): 121-127, 2018 (July)

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