scholarly journals Decolorization and Detoxification of Synthetic Dyes by Mexican Strains of Trametes sp.

2019 ◽  
Vol 16 (23) ◽  
pp. 4610
Author(s):  
Levin ◽  
Hernández-Luna ◽  
Niño-Medina ◽  
García-Rodríguez ◽  
López-Sadin ◽  
...  
Keyword(s):  
Raphanus Sativus ◽  
Dye Degradation ◽  
Degradation Products ◽  
Ligninolytic Enzyme ◽  
Reactive Black 5 ◽  
Synthetic Dyes ◽  
Redox Mediators ◽  
Liquid Media ◽  
Solid Media ◽  
Mexican Strains

Laccases have attracted a great deal of interest because of their remarkable ability for the degradation of synthetic dyes present in wastewaters. New laccase producing sources with robust operational and functional properties are being continuously explored. In this work, the potential for the decolorization and detoxification of synthetic dyes was evaluated in two Mexican strains of the genus Trametes. The decolorization capacity of Trametes maxima LE130 and Trametes sp. LA1 was tested in solid and liquid media. The phytotoxicity of the degradation products was determined using Raphanus sativus and Pisum sativum seeds. In solid media, both strains showed a higher decolorization capacity (p ≤ 0.05) than Phanerochaete chrysosporium ATCC 24725, which is known to be very efficient in lignin and dye-degradation. They produced laccase as the main ligninolytic enzyme; T. maxima LE130 secreted a single isoform of 43.9 kDa, while Trametes sp. LA1 produced three isoforms of 67.3, 58.6 and 52.7 kDa, respectively. Trametes sp. LA1 culture fluids were capable of decolorizing and detoxifying chemically diverse dyes (anthraquinonic dye Remazol Brilliant Blue R, azoic Reactive Black 5 and triphenylmethane Crystal Violet) without the addition of redox mediators. Therefore, this could be considered as a new laccase source which could be potentially competitive in the bioremediation of dye-containing wastewaters.

Degradation of an Azo Dye by Fenton Type Processes Assisted with UV Irradiation

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Natalija Koprivanac ◽  
Dinko Vujevic
Keyword(s):  
Uv Irradiation ◽  
Azo Dye ◽  
Dye Degradation ◽  
Degradation Products ◽  
Batch Reactor ◽  
Process Efficiency ◽  
Molar Ratio ◽  
Synthetic Dyes ◽  
Ambient Conditions ◽  
Treatment Methods

Organic synthetic dyes are widely produced and used today. Significant losses of organic and inorganic content occurs during the manufacturing and application of dyes and its discharge in the effluent presents a threat to the eco-systems due to general toxicity and resistance to destruction by biological treatment methods. Particularly azo dyes are of special environmental concern due to their degradation products such as aromatic amines, which are considered highly carcinogenic. So, dyes have to be removed from coloured wastewater before discharge. However, traditional treatment methods (adsorption, coagulation/flocculation) mainly transfer the contaminants from wastewater to secondary waste. Therefore, advanced oxidation processes seem to be sustainable and clean technology to decolorize and minimize organic dyes content from wastewater. In this paper, degradation of an azo dye C.I. Direct Orange 39 (DO39) using Fenton type processes (Fe2+/H2O2, Fe3+/H2O2and Fe0/H2O2) has been performed. The molar ratio of Fenton’s type reagents has been varied in the range of 1 : 5 up to 1 : 50 at 0.5 and 1.0 mM concentrations of iron salts and iron powder. Experiments have been conducted for two hours in a batch reactor with magnetic stirring, ambient conditions and pH 3. The process efficiency and formation of degradation by-products have been determined on the basis of results obtained by UV/VIS spectrophotometric, total organic carbon (TOC) and high performance liquid chromatography (HPLC) analyses. The optimal Fenton and Fenton ``like" processes parameters have been applied in the photo reactor, too. It has been observed that simultaneous utilization of UV irradiation with Fenton's and Fenton ``like" reagents increases the degradation of DO39 dye. Degradation of the dye in dilute aqueous solution follows pseudo-first order kinetics. The maximal decolourization of 20 mg L-1 DO39 in water of 93.2% and TOC degradation of 76.9% were obtained using Fe3+/H2O2= 1 : 5 molar ratio. The results indicate that the treatment of DO39 dye wastewater with UV/Fe3 +/H2O2 system was found to be the most efficient.

scholarly journals Degradation of Synthetic Dyes by Laccases – A Mini-Review

2016 ◽  
Vol 15 (1) ◽  
pp. 90-106 ◽  
Author(s):  
Barbora Legerská ◽  
Daniela Chmelová ◽  
Miroslav Ondrejovič
Keyword(s):  
Azo Dyes ◽  
Dye Degradation ◽  
Degradation Products ◽  
Synthetic Dyes ◽  
Enzymatic Reactions ◽  
Degradation Mechanisms ◽  
Anthraquinone Dyes ◽  
Chemical Structures ◽  
Wide Range ◽  
Biodegradation Efficiency

Abstract Laccases provide a promising future as a tool to be used in the field of biodegradation of synthetic dyes with different chemical structures. These enzymes are able to oxidize a wide range of phenolic substrates without the presence of additional co-factors. Laccases have been confirmed for their potential of synthetic dye degradation from wastewater and degradation products of these enzymatic reactions become less toxic than selected dyes. This study discusses the potential of laccase enzymes as agents for laccase-catalyzed degradation in terms of biodegradation efficiency of synthetic dyes, specifically: azo dyes, triphenylmethane, indigo and anthraquinone dyes. Review also summarizes the laccase-catalyzed degradation mechanisms of the selected synthetic dyes, as well as the degradation products and the toxicity of the dyes and their degradation products.

Analysis of Primary Degradation and Decolourization of Dyes in Water by an H2O2/UV Advanced Oxidation Process

2008 ◽  
Vol 11 (3) ◽  
Author(s):  
Amaia Menendez ◽  
Jose Ignacio Lombraña ◽  
Ana de Luis
Keyword(s):  
Dye Removal ◽  
Advanced Oxidation Process ◽  
Rhodamine 6G ◽  
Dye Degradation ◽  
Water Solution ◽  
Synthetic Dyes ◽  
Dye Wastewater ◽  
First Order ◽  
Textile Dyeing ◽  
Colour Photography

AbstractSynthetic dyes are extensively used in textile dyeing, paper printing, colour photography, pharmaceuticals, food, cosmetics and other industries. In spite of their diversity there are a certain number of properties common to many dye compounds, such as aromatic constitution, chromophore groups and others. Similarly to other dyes and due to the formation of colour intermediates, in the case of Rhodamine 6G colour capacity is maintained in the initial steps of dye degradation. For this reason in the degradation of a dye it is necessary to distinguish between two processes that take place simultaneously: dye removal and decolourization. This study was conducted by using a water solution of 50 mg/L of Rhodamine 6G (Rh-6G), as a model of a dye wastewater, in the hydrogen peroxide/UV system. The kinetic model proposed in this paper for the removing of Rh- 6G is a sequential first-order reaction. This model describes acceptably the changes in two kinds of compound for a wide interval of H

Decolorization of azo dye C.I. Reactive Black 5 by ozonation in aqueous solution: influencing factors, degradation products, reaction pathway and toxicity assessment

2015 ◽  
Vol 73 (7) ◽  
pp. 1500-1510 ◽  
Author(s):  
Qing Zheng ◽  
Yong Dai ◽  
Xiangyun Han
Keyword(s):  
Aqueous Solution ◽  
Degradation Products ◽  
Reaction Pathway ◽  
Degradation Mechanism ◽  
Exchange Chromatography ◽  
Computational Method ◽  
Photobacterium Phosphoreum ◽  
Toxicity Tests ◽  
Reactive Black 5 ◽  
Oh Groups

In this study, ozonation treatment of C.I. Reactive Black 5 (RB5) was investigated at various operating parameters. The results showed that the aqueous solution initially containing 200 mg/L RB5 was quickly decolorized at pH 8.0 with an ozone dose of 3.2 g/h. Reaction intermediates with m/z 281, 546, 201, 350, 286 and 222 were elucidated using liquid chromatography-mass spectrometry, while sulfate ion, nitrate ion and three carboxylic acids (i.e., oxalic acid, formic acid, and acetic acid) were identified by ion exchange chromatography. Thus, the cleavage of the azo bond and the introduction of OH groups in the corresponding positions were proposed as the predominant reaction pathway. The detachment of sulfonic groups was also commonly observed during the ozonation treatment. The proposed degradation mechanism was confirmed by frontier electron density calculations, suggesting the feasibility of predicting the major events in the whole ozonation process with the computational method. Compared with RB5 degradation, the reduction of total organic carbon (TOC) proceeded much more slowly, and approximately 54% TOC was removed after 4 h of ozonation. Acute toxicity tests with Photobacterium phosphoreum showed that the toxicity of reaction solution was firstly increased and then decreased to a negligible level after 160 min.

Recovery of Humic-Reducing Bacteria from a Diversity of Environments

1998 ◽  
Vol 64 (4) ◽  
pp. 1504-1509 ◽  
Author(s):  
John D. Coates ◽  
Debra J. Ellis ◽  
Elizabeth L. Blunt-Harris ◽  
Catherine V. Gaw ◽  
Eric E. Roden ◽  
...  
Keyword(s):  
Humic Substance ◽  
Electron Acceptor ◽  
Microbial Reduction ◽  
Acetate Oxidation ◽  
Liquid Media ◽  
Sedimentary Environments ◽  
Sediment Types ◽  
Solid Media ◽  
The Family ◽  
Reducing Bacteria

ABSTRACT To evaluate which microorganisms might be responsible for microbial reduction of humic substances in sedimentary environments, humic-reducing bacteria were isolated from a variety of sediment types. These included lake sediments, pristine and contaminated wetland sediments, and marine sediments. In each of the sediment types, all of the humic reducers recovered with acetate as the electron donor and the humic substance analog, 2,6-anthraquinone disulfonate (AQDS), as the electron acceptor were members of the familyGeobacteraceae. This was true whether the AQDS-reducing bacteria were enriched prior to isolation on solid media or were recovered from the highest positive dilutions of sediments in liquid media. All of the isolates tested not only conserved energy to support growth from acetate oxidation coupled to AQDS reduction but also could oxidize acetate with highly purified soil humic acids as the sole electron acceptor. All of the isolates tested were also able to grow with Fe(III) serving as the sole electron acceptor. This is consistent with previous studies that have suggested that the capacity for Fe(III) reduction is a common feature of all members of theGeobacteraceae. These studies demonstrate that the potential for microbial humic substance reduction can be found in a wide variety of sediment types and suggest thatGeobacteraceae species might be important humic-reducing organisms in sediments.

Culture of Helicobacter pylori from domestic water samples – the impact of strain variation on growth on solid and in liquid media

2006 ◽  
Vol 54 (3) ◽  
pp. 147-152 ◽  
Author(s):  
R.J. Owen ◽  
S.A. Chisholm ◽  
G. Brick ◽  
J.V. Lee ◽  
S. Surman-Lee ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Culture Media ◽  
Tap Water ◽  
Clinical Isolates ◽  
Strain Variation ◽  
Liquid Media ◽  
Domestic Water ◽  
Source Of Infection ◽  
Solid Media ◽  
The Impact

Helicobacter pylori is an important global human pathogen and there is growing evidence from PCR assays that contaminated drinking water might be a possible source of infection in some circumstances. There are no validated protocols for direct isolation but various culture media have been developed for possible environmental sampling. Our aim here was to investigate how inter-strain variation might affect the interpretation of results with such media. Two laboratory adapted reference strains and four recent clinical isolates were tested on four solid media and in ten liquid media. Considerable variation was found between strains in their ability to recover on the different media after stress exposure (suspension in sterile tap water). Generally, clinical isolates were less robust than the laboratory-adapted strains and, overall, the former required longer recovery times. Our findings highlighted the importance of using a range of isolates for evaluations, as examination of laboratory-adapted strains alone did not provide an accurate representation of the utility of media that may be used to recover H. pylori from water.

Mediator-Based Decolorization of Recalcitrant Dyes with Laccase from Bacillus amyloliquefaciens LS01

2011 ◽  
Vol 183-185 ◽  
pp. 768-772 ◽  
Author(s):  
Lei Lu ◽  
Min Zhao ◽  
De Bin Li ◽  
Li Yan Zhao ◽  
Mei Hui Du ◽  
...  
Keyword(s):  
Bacillus Amyloliquefaciens ◽  
Dye Decolorization ◽  
Brilliant Blue ◽  
Reactive Black 5 ◽  
Synthetic Dyes ◽  
Remazol Brilliant Blue R ◽  
Mediator System ◽  
Laccase Mediator System

The spore laccase of Bacillus amyloliquefaciens LS01 was evaluated for its ability in decolorization of different synthetic dyes. The decolorization process was not efficient by the laccase alone. The addition of mediators could remarkably improve the efficiency of dye decolorization. Remazol Brilliant Blue R and reactive black 5 were resistant to decolorization for most mediators. Acetosyringone was proved to be the best mediator for the spore laccase, and a decolorization of 63−82% was achieved for all the tested dyes in the presence of acetosyringone. The results indicate that the spore laccase-mediator system could be used for the treatment of industrial dye effluents.

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