scholarly journals Solar Active Reusable Photocatalyst Magnetite Doped Calcium Aluminate for Acid Yellow 23 Photodegradation

2020 ◽  
Vol 32 (6) ◽  
pp. 1329-1334
Author(s):  
R. Padmavathi ◽  
V. Natchimuthu ◽  
I. Sharmila Lydia
Keyword(s):  
Calcium Aluminate ◽  
Kinetic Studies ◽  
Order Reaction ◽  
Precipitation Method ◽  
Pseudo First Order Reaction ◽  
Photo Catalyst ◽  
First Order ◽  
Co Precipitation ◽  
Surface Morphologies ◽  
The Impact

Fe3O4 doped calcium aluminate nanoparticles were synthesized by co-precipitation method, an effective route to synthesize novel photocatalyst to enhance the photocatalytic decolourization of acid yellow 23 dye. The structural and surface morphologies were investigated using techniques such as SEM and EDAX. In this study, a degradation of acid yellow 23 dye have been carried out in the presence of sunlight. It was observed that the synthesized Fe3O4 doped calcium aluminate photo catalyst was very useful in degrading the dye entirely within a short span of time (90 min). The impact of various operating parameters on acid yellow 23 including the amount of photocatalyst, dye concentration, H2O2 concentration and temperature was thoroughly examined. The kinetic studies explained that the degradation of photocatalytic reaction showed pseudo first-order reaction.

scholarly journals Reuse of Newspaper As An Adsorbent For Cu (II) Removal By Citric Acid Modification

2018 ◽  
Vol 156 ◽  
pp. 02012 ◽  
Author(s):  
Mardiah ◽  
Rif’an Fathoni ◽  
Pratiwi Pudyaningtyas ◽  
Hamdania Gamu ◽  
Rinaldy
Keyword(s):  
Citric Acid ◽  
Adsorption Process ◽  
Kinetic Studies ◽  
Order Reaction ◽  
Acid Modification ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pseudo Second Order ◽  
Heavy Metal Adsorbent ◽  
The Impact

High Consumption of paper, bring the impact of the waste paper itself. And the utilization of the paper is limited to recycled products and crafts, whereas paper such as newspaper still contains cellulose that can be potential to be used as a heavy metal adsorbent. In this study, newspaper was dissolved in sodium bicarbonate to reduce various impurities and then was reacted with citric acid (CA). The modified adsorbent was characterized by FTIR and was tested for adsorb Cu(II) in artificial solution. After adsorption process, the solution was filtered and analysed using Atomic Absorption Spectrophotometer (AAS). The adsorption experimental data was fitted to Langmuir, Freundlich, Tempkin, and Dubinin-Radushkevich for equilibrium model and was fitted to pseudo first order reaction and pseudo second order reaction for kinetic studies. The result showed that CA-modification newspaper able to remove heavy metals Cu(II) in solution.

TiO2 Supported Clinoptilotile: Characterization and Optimization of Operational Parameters for Methyl Orange Removal

2013 ◽  
Vol 781-784 ◽  
pp. 2249-2252 ◽  
Author(s):  
Sanni O. Saheed ◽  
Sekomeng J. Modise ◽  
Allworth M. Sipamla
Keyword(s):  
Methyl Orange ◽  
Photocatalytic Degradation ◽  
Kinetic Studies ◽  
Methyl Orange Solution ◽  
Order Reaction ◽  
Operational Parameters ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Orange Solution ◽  
Degradation Of Methyl Orange

Titania dispersed on dealuminated Clinoptilotile (TiO2/HCP) was synthesized and characterized by Scanning Electron Microscope (SEM). Supporting characterization techniques reveals partly dispersion of TiO2 within the cavities of dealuminated Clinoptilotile (HCP) and TiO2 exist as nanoparticles or clusters on the HCP surface ascribed to lower loading of TiO2. The photocatalytic degradation of methyl orange solution was conducted under UV-irradiation in the presence of TiO2/HCP. The photocatalytic degradation of methyl orange in the presence of the photocatalyst was optimized at lower loading of TiO2, at a lower initial dye concentration (30 ppm), calcination temperature of 873K and nitrate ion accelerates degradation activities of methyl orange. Kinetic studies depict the photocatalytic degradation of methyl orange follows the pseudo-first order reaction.

scholarly journals Kinetic Studies for the Biosorption of Chromium Using Cherry Leaves (Muntingia calabura L.)

2014 ◽  
Vol 25 ◽  
pp. 6-11 ◽  
Author(s):  
R. Aathithya ◽  
J. Rajani Sowparnika ◽  
V. Balakrishnan
Keyword(s):  
Regression Coefficient ◽  
Kinetic Studies ◽  
Order Reaction ◽  
First Order Reaction ◽  
Standard Errors ◽  
Second Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
Muntingia Calabura

Biosorption is an attractive technology which is used for the sorption of substances by a biomaterial. In this present work the heavy metal chromium was subjected to biosorption because of their non-degradability nature and causes water and land pollution. Cherry leaves were used as a biomaterial for the biosorption. Kinetic studies were performed for the biosorption experiment. From the experiment it was found that the reaction follows pseudo first order reaction because of the larger value of regression coefficient R2 and lower value of standard errors (χ2) for pseudo first order reaction than second order reaction.

scholarly journals Direct red 83 textile dye degradation using photoperoxidation and photo-fenton: kinetic studies, toxicity and neural networks modeling

2020 ◽  
Vol 42 ◽  
pp. e41
Author(s):  
Nataly Daiany de Oliveira Amorim ◽  
Graziele Elisandra do Nascimento ◽  
Lívia Vieira Carlini Charamba ◽  
Rayany Magali da Rocha Santana ◽  
Pollyanna Michelle da Silva ◽  
...  
Keyword(s):  
Wastewater Treatment Plants ◽  
Dye Degradation ◽  
Kinetic Studies ◽  
Order Reaction ◽  
Textile Dye ◽  
Pseudo First Order Reaction ◽  
Rapid Decay ◽  
First Order ◽  
Physical Chemical ◽  
Oxidative Processes

Textile dyes have been observed in aquatic matrices that receive effluents from different textile industries. These compounds have the peculiarity of being resistant to the physical, chemical and biological treatments commonly used in wastewater treatment plants. Thus, alternative treatments such as advanced oxidative processes (AOP) have been considered in order to promote the degradation of this type of pollutant, being the photoperoxidation and photo-Fenton processes the most used. Therefore, the present work evaluated the efficiency of these AOP in the degradation of direct red 83 dye. It was found a greater efficiency of the photoperoxidation process, especially in the degradation of functional groups observed at 289 nm. This AOP presented a pseudo first order reaction kinetics, with rapid decay in the first minutes. The MLP (5-21-2) neural network model was able to satisfactorily predict the degradation of the dye under study. Finally, it was found that the proposed process showed no adverse effects when studying the toxicity in bacteria.

Multifactorial optimization of the decolorisation parameters of wastewaters resulting from dyeing flowers

2009 ◽  
Vol 59 (7) ◽  
pp. 1361-1369 ◽  
Author(s):  
Edison Gil Pavas ◽  
Miguel Ángel Gómez-García
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Matter ◽  
Experimental Design ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Effluent Standards ◽  
Degradation Of Dyes ◽  
Pseudo First Order ◽  
Dyes Mixture

This work deals with the treatment of the wastewaters resulting from the process of dyeing flowers. In some local cases for growing flowers near to Medellín (Colombia), wastewater color was found to be one of the main problems in meeting local effluent standards. Wastewaters were treated by photodegradation process (which includes photocatalysis) to achieve the degradation of dyes mixture and organic matter in the wastewater. A multifactorial experimental design was proposed, including as experimental factors the following variables: pH, and the concentration of both catalyst (TiO2) and hydrogen peroxide (H2O2). According to the obtained results, at the optimized variables values, it is possible to reach a 99% reduction of dyes, a 76.9% of mineralization (TOC) and a final biodegradability of 0.834. Kinetic analysis allows proposing a pseudo first order reaction for the reduction, the mineralization, and the biodegradation processes.

scholarly journals Photocatalytic Degradation of Alizarin Red-S by Fe-Co Nanoparticles Prepared By Chemical Co-precipitation Method

2015 ◽  
Vol 11 (9) ◽  
pp. 3950-3958 ◽  
Author(s):  
Chandrakant Vedu Nandre ◽  
C.P. Sawant
Keyword(s):  
Photocatalytic Degradation ◽  
Contact Time ◽  
Oxygen Demand ◽  
Kinetic Studies ◽  
Water Soluble ◽  
Precipitation Method ◽  
Alizarin Red ◽  
Co Nanoparticles ◽  
Co Precipitation ◽  
Red Dye

In the present study photocatalytic degradation of hazardous water soluble alizarin red dye by using Fe-Co nanoparticles  has been investigated. Fe-Co nanoparticles was synthesized by chemical co-precipitation method and characterized by TEM, SEM, EDAX and XRD. The photocatalytic degradation have been studied with the help of variety of parameters such as catalytic dose, dye concentration, pH, contact time and most important chemical oxygen demand. It was observed that The photocatalytic degradation of alizarin red dye by using Fe-Co nanoparticles was an effective ,economic, ecofriendly and faster mode of removing dye from an aqueous solution. The optimum condition for the degradation of the dye was 50 mg/L,pH 8.0, catalyst dose 60 mg/L and contact time 60 minutes. The kinetic studies also have been studied.

scholarly journals Photocatalytic degradation of sulfamethazine in aqueous solution using ZnO with different morphologies

2018 ◽  
Vol 5 (4) ◽  
pp. 171457 ◽  
Author(s):  
Zhigang Yi ◽  
Juan Wang ◽  
Tao Jiang ◽  
Qiong Tang ◽  
Ying Cheng
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Degradation ◽  
Reaction System ◽  
Degradation Pathway ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Different Shapes ◽  
Pseudo First Order ◽  
Release Ratio

In this study, photocatalytic experiments of 20 mg l −1 sulfamethazine (SMN) in aqueous solution containing ZnO with different morphologies, tetra-needle-like ZnO (T-ZnO), flower-like ZnO (F-ZnO) and nanoparticles ZnO (P-ZnO), were performed. The results indicated that photocatalytic degradation of SMN was effective and followed the pseudo-first-order reaction, but the degree of SMN mineralization showed obvious differences using ZnO with different shapes. After 12 h irradiation, 86%, 71% and 50% of the initial total organic carbon was eliminated in SMN suspension containing T-ZnO, F-ZnO and P-ZnO, respectively. The release ratio of sulfur was close to 100% in the presence of T-ZnO, but reached to 86% and 67% in the presence of F-ZnO and P-ZnO, respectively. The release ratio of nitrogen was about 76%, 63% and 40% using T-ZnO, F-ZnO and P-ZnO as photocatalyst, respectively. The morphology of ZnO played an important role in determining its catalytic activity. Seven intermediates were observed and identified in the UV/T-ZnO reaction system by LC-MS/MS analysis, and a possible degradation pathway was proposed.

On the Chemical Reactivity of the Phytochrome Chromophore in the Pr and Pfr Form

1985 ◽  
Vol 40 (3-4) ◽  
pp. 215-218 ◽  
Author(s):  
Fritz Thümmler ◽  
Peter Eilfeld ◽  
Wolfhart Rüdiger ◽  
Doo-Khil Moon ◽  
Pill-Soon Song
Keyword(s):  
Reaction Kinetics ◽  
Rate Constants ◽  
Chemical Reactivity ◽  
Order Reaction ◽  
First Order Reaction ◽  
Limiting Factor ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Pseudo First Order ◽  
The Difference

The reactivity of the phytochrome chromophore and related tetrapyrroles towards ozone and tetranitromethane was investigated. Both oxidizing reagents cause bleaching of the main absorp­tion band of the pigment. The rate constants for this bleaching were determined under conditions of pseudo first order reaction kinetics. The rate constants for the reaction with ozone are similar for native phytochrome and for freely accessible tetrapyrroles (biliverdin, small chromopeptides from phytochrome) indicating that accessibility is not the limiting factor for the reaction with ozone. Under a variety of conditions, the Pfr chromophore reacts by about 10% faster than the Pr chromophore. This may reflect the true difference in reactivity. The rate constants for the reaction with tetranitromethane are much larger for biliverdin, bilirubin and small chromopeptides from phytochrome than for native phytochrome. The limiting factor for this reaction in native phytochrome therefore is the accessibility of the chromophore by the reagent. Previous conclusions on the difference in exposure of the tetrapyrrole chromophore in Pr and Pfr are confirmed.

FIBRINOPEPTIDE B RELEASE FROM NORMAL FIBRINOGEN AND FIBRINOGEN LONDON I IN THE PRESENCE OF INHIBITORS OF FIBRIN POLYMERIZATION

1987 ◽  
Author(s):  
W Ruf ◽  
A Bender ◽  
K T Preissner ◽  
D A Lane ◽  
G Müller-Berghaus
Keyword(s):  
Initial Phase ◽  
Slow Rate ◽  
Order Reaction ◽  
Pseudo First Order Reaction ◽  
Reaction Conditions ◽  
Fibrin Polymerization ◽  
First Order ◽  
Molar Excess ◽  
Pseudo First Order ◽  
Fibrinogen Molecule

The fibrinopeptides A and B (FPA and FPB) are cleaved from the fibrinogen molecule with different rates. In the initial phase of the thrombin-fibrinogen reaction, FPB is released with a slow rate, which is enhanced upon polymerization of desA-fi-brin monomers. The aim of the present study was to further characterize the mechanism leading to the enhanced rate of FPB release during polymerization. For this purpose, the release of FPB from normal fibrinogen and from fibrinogen London I, which exhibits a polymerization defect located in the D-domain, was studied in the presence and absence of the fibrinolytic fragment D1 (D1) and of the synthetic tetrapeptide Gly-Pro-Arg-Pro (GPRP). Steady state parameters for fibrinopeptide release were determined under pseudo-first order reaction conditions. In the initial phase of the thrombin-fibrinogen reaction, the release of FPA was unchanged in the presence of D1. Furthermore, the release of FPA from fibrinogen London I did not reveal any difference in comparison to normal fibrinogen. GPRP prevented not only fibrin polymerization, but also the enhanced rate of FPB release. On the contrary, the rate of FPB release in the presence of a 16- and 32-fold molar excess of over fibrinogen did not differ from a reaction mixture with no added D1. Si-miliar to the inhibited rate of FPB release in the presence of GPRP, the release of FPB from fibrinogen London I occurred with a slow rate, which was not enhanced by the addition of a 16-fold molar excess of D1. Since the release neither from normal fibrinogen nor from ribrinogen London I was affected by D1, it was concluded that the D-E contact formed by D1 with an E-domain of a desA-fibrin molecule does not enhance the release of FPB. While GPRP keeps fibrin in monomeric form by inhibiting the polymerization sites in the D-domains, D1 does not prevent the formation of fibrin oligomers. Therefore, acceleration of FPB release is caused by a conformational change, which is induced by binding of reciprocal polymerization sites to an E-as well as a D-domain of the same desA-fibrin molecule.

Effect of Cyclodextrins on Photodegradation of 4,4-Bis(4-Hydroxyphenyl)Pentanoic Acid under UV Irradiation

2014 ◽  
Vol 665 ◽  
pp. 455-458
Author(s):  
Li Guo ◽  
Jin Huang ◽  
Jun Wu ◽  
Lei Lei Luo
Keyword(s):  
Aqueous Solutions ◽  
Fluorescence Spectra ◽  
High Efficiency ◽  
Uv Light ◽  
Order Reaction ◽  
Pentanoic Acid ◽  
Pseudo First Order Reaction ◽  
First Order ◽  
Inclusion Interaction ◽  
Pseudo First Order

The photodegradation of 4,4-bis (4-hydroxyphenyl) pentanoic acid (DPA) with two cyclodextrins (α-CD and β-CD ) in aqueous solutions induced by UV-light was studied in this paper by means of fluorescence spectra and high efficiency liquid chromatography. The result suggested that DPA with α-CD or β-CD formed inclusion compound in aqueous solutions. The photodegradation of DPA with two cyclodextrins or without cyclodextrin was pseudo-first order reaction. The photodegradation of DPA was accelerated by the addition of β-CD in aqueous solutions, but the that of DPA was inhibited in case of adding α-CD. These differences were due to the differences in inclusion interaction of DPA with α-CD or β-CD.

Sign in / Sign up

Export Citation Format

Share Document