Photocatalytic degradation of azo dyes in aqueous solutions under uv irradiation using nanostrontium titanate as the nanophotocatalyst. Desalination 250 2010 345350 contents lists available at sciencedirect desalination j o u r n a l h o m e p a g e. Decolorisation and detoxification of widely used azo dyes. Peroxidases that have been used for treatment of aqueous aromatic contaminants and degradation of dyes include horseradish peroxidase hrp, lignin peroxidase lip and a number of other peroxidases from different sources. Pdf decolorization and degradation of textile dyes by. Studies and research in zoology, scott christian college autonomous, nagercoil 629 003, kanyakumari district, tamil nadu, india. Thus, to understand the mechanism of azo dyes degradation by bacterial consortium which doesnt produce aromatic amines under sequential microaerophilicaerobic processes.
Degradation of azo dyes in aqueous solution by h2o2fe2. Decolourization of azo dyes by a newly isolated klebsiella. Azo compounds constitute the largest and the most diverse group of synthetic dyes and are widely used in a number of industries such as textile, food, cosmetics and paper printing. Azo dyes are considered as xenobiotic compounds, which are often recalcitrant to be biodegraded. Nikam2 1department of environmental science, savitribai phule pune university, pune 411 007ms, india 2department of botany, savitribai phule pune university, pune 411 007ms, india. Decolorisation and detoxification of widely used azo dyes by fungal species isolated from textile dye contaminated site s. Daizong cui, a guofang li, a min zhao, a, and song han a. Study of degradation products and degradation pathways of. The environmental, health and economic impacts of textile azo dyes. A convenient and efficient method is developed to massively synthesize naluminumdoped zinc oxide azotio 2 nanocomposites ncs with good visible light photoresponse and photocatalytic activity. Author links open overlay panel ruixia yuan sadiqua n. Dyes catalytic degradation using modified tiniv oxide and. The release of dyes in natural media is of concern due to their high persistence, toxicity and potential to the bioaccumulate in living organisms.
Photocatalytic degradation of hydrolyzed reactive orange 16 ro16 using titanium dioxide tio 2 was analyzed in our study. Degradation of azo dyes by laccase and ultrasound treatment. Some azo dyes with this property and which can revert slowly to the trans isomer in the dark are used in sunglasses and car sunroofs. Decolorization and degradation of azo dye remazol black b by newly isolated pseudomonas putida s. The dye degradation efficiency in uvtio 2 process was investigated as a. The first step in the bacterial degradation of azo dyes, in either anaerobic or aerobic conditions, is the reduction of the n n bond. Furthermore the dyes andor their degradation products may be toxic to ora and fauna talarposhti et al. The shortened band gap of the interstitial ndoped ncs led to a much easier electron excitation and effectively inhibited the recombination of the photoexcited electrons and holes, thus. Degradation of azo dye by an uvh2o2 advanced oxidation.
In particular, the most commercialized and carcinogenic azo dyes, that pocess a benzidine function, needs urgent. Photocatalytic degradation of dyes or other orga nic pollu tants is an i ntensively pursued research exercise mainly from the last quarter half of the 20 th century 17. Photocatalytic degradation of a series of direct azo dyes using immobilized tio 2 a major qualifying project submitted to faculty of worcester polytechnic institute. Decolourization of azo dyes by a newly isolated klebsiella sp.
Efficient hydrogenoxygen evolution and photocatalytic dye degradation and reduction of aqueous crvi by surfactant free hydrophilic cu 2 znsns 4 nanoparticles. Analysis of bacterial degradation of azo dye congo red using hplc d. Research article photodegradation of eosin y using silverdoped magnetic nanoparticles emanalzahrani chemistry department, faculty of science, taif university, p. The cell free supernatant of the decolourised dye and the. In this study, two model dyes are synthesized and used for stimulating the photodegradation processes of azo and hydrazone dyes, respectively. Photocatalytic degradation of some organic dyesnano. Photocatalytic degradation and chlorination of azo dye in saline wastewater. Effective dye degradation by graphene oxide supported. Comparative photocatalytic degradation of monoazo and diazo. Photocatalytic degradation of a series of direct azo dyes. Pdf classifications, properties and applications of. Dhandayuthapani2 and mazher sultana3 1department of zoology, manonmanium sundaranar university, tirunalvalli, tamil nadu, india. Deliyanni 1, 1 laboratory of chemical technology, department of chemistry, aristotle university of thessaloniki, 54124 thessaloniki, greece. Bacterial decolorization and degradation of azo dyes under certain environmental conditions has gained momentum as a method of.
Many azo dyes, like sudan red and scarlet red, can be used as biological dyes because they are fat soluble and can be absorbed into fat cell tissues on microscope slides. The effects of various parameters, such as photocatalyst amount, ro16 concentration, light intensity, and temperature on photocatalytic degradation were investigated. Bacterial degradation of dyes is often initiated under anaerobic conditions by an enzymatic biotransformation. Shamsuddin1 1department of applied chemistry and chemical engineering, university of dhaka, dhaka, bangladesh. Enzymatic decolorization and degradation of azo dyes a. This research is very important as the visible light forms substantial part of the solar radiation, which is available for free and in an inexhaustible amounts. Using dyes for evaluating photocatalytic properties. Tio2, metals, nonmetals, azo dyes, photocatalytic degradation, sol gel method. Photocatalytic degradation of some organic dyes under. These dyes are the most important and largest class of synthetic dyes used in commercial. Amorphous alloys, degradation performance of azo dyes. Additionally, the location of the reactions can be either. Mechanistic study of a diazo dye degradation by soybean peroxidase.
These free radicals are highly reactive towards diverse contaminants. Under certain conditions, the ccformed dimers can take part in coupling reactions. Decolorization of textile dyes and degradation of monoazo. Monitoring the lightinduced decomposition course of azo dyes is essential to understand their degradation pathways and mechanisms.
The purpose of this study was to assess the capability of photocatalytic degradation of cationic, anionic monoazo and di. Degradation of azo dyes by trametes villosa laccase over. In general, however, they absorb in the visible wavelength region and are not suitable for nir absorbing dyes. The capabilities of several bacterial isolates were explored for the degradation of textile azo. Decolorization and degradation of textile dyes by bacterial isolates. This type of dye is used in many different dye classes in the textile dyeing industry and generally absorbs between 350 and 650 nm. The optimal oxidation of monoazo and disazo dyes is at. Rapid reductive degradation of azo dyes by a unique structure of amorphous alloys. Firstly, the dyes are highly stable to biological oxidation and secondly the poor adsorption of the dyes on to the activated sludge greaves et al.
Mechanistic study of a diazo dye degradation by soybean. Titanium dioxide films for photocatalytic degradation of methyl. Among the photocata lysts, tio2 has demonstrated to be the most popular. Analysis of bacterial degradation of azo dye congo red. Bacteria present in the untreated textile effluents might have capabilities to degrade textile reactive dyes.
Ongoing investigations focus on the structures of the intermediates formed by laccase and ultrasound to elucidate the. Many dyes are relevant for staining in industries, especially. Instigated by the german azo ban, measures were taken. Removal of dyes from effluent of textile using amorphous alloys has been studied extensively by many researchers. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes is the largest group of synthetic colorants and the most usual synthetic dyes released into the environment 2.
Searching for more efficient light sources is a way to improve aops efficiency. The effects of physicochemical parameters on the methyl red degradation by the strain were determined. But when the tio 2 catalyst was added to the rb solution under solar. Degradation azo dyes by environmental microorganisms and. Simultaneous photocatalytic and microbial degradation of dye. Biological degradation of azo dyes in an anaerobic system by cynthia mary carliell submitted in fulfilment of the academic requirements for the degree of master of science in engineering in the department of chemical engineering, university of natal. Toxicity assessment and microbial degradation of azo dyes. Bacterial decolorization and degradation of azo dyes. There is about 700,000 tonnes of dyes, of more than 10,000 types, that are used as coloring agents in industries, mainly for textile. Enzymatic decolorization and degradation of azo dyes has been proved to be the best option for degradation of these dyes. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities.
Biodegradation and detoxification of textile azo dyes by. Preparation and photocatalytic performance of nazotio2. Photocatalytic degradation of dyes using tio nanoparticles. Decolorization and degradation of azo dye remazol black b. Author links open overlay panel loghman karimi a salar zohoori b mohammad esmail yazdanshenas b. Our findings show the possibility of saving time and energy by applying a simultaneous combination of laccase and ultrasound treatments for decolorization of azo dyes. The enzymatic mechanisms involved in the bacterial degradation of azo dyes, the identification of metabolites by using. Azo dyes are characterized by one or more azo groups which nitrogen to nitrogen double bond nn and it absorb light in the visible spectrum directly to. Research article photodegradation of eosin y using silver. Decoloration of azo dyes by hydrogen peroxide catalyzed by. Amaranth was used as model azo dye to test the degradation efficiency and mechanism by a. The environmental, health and economic impacts of textile. Degradation of azo dyes by trametes villosa laccase over long periods of oxidative conditions. Identification and isolation of an azoreductase from enterococcus faecium article pdf available in current issues in molecular biology 121.
Photocatalytic degradation and chlorination of azo dye in. Mechanochemical modification of lowdispersed sno2 and highdispersed sno oh2 powders with specific surface area 6 and 198 m2 g. Photocatalytic degradation of textile dyes in atio2uv system aidic. Decolorization and biodegradation of reactive sulfonated. Solar assisted photocatalytic degradation of reactive azo dyes in presence of anatase titanium dioxide mohammad alamin1,shaikat chandra dey1, taslim ur rashid1, md. The results indicated that strain y3 exhibited a good. Photodegradation of monoazo dye blue using advanced.
They are generally recalcitrant to biodegradation due to their. Pdf decolorization and degradation of reactive azo dyes. Azo dyes are aromatic compounds with one or more n n groups. Application of candida tropicalis jks2 in treatment of the synthetic medium containing rb5 indicated complete decolorization of the dye with 200 mgl in less than 24 h. Photocatalytic degradation of dyes department of applied chemistry, cusat 77 reactive oxygen radicals, whereas the holes in the valence band become trapped by the surface bound hydroxyl radicals that at produced on oxidation of either the surface hydroxyl group andor the surface bound water molecules. Azo dyes are one of the most widely used chromophores in dye chemistry. Pdf identification and isolation of an azoreductase from. Pdf bacterial decolorization and degradation of azo dyes. Decolorization and biodegradation of reactive sulfonated azo dyes by a newly isolated brevibacterium sp. Bacterial decolourization and degradation of azo dye. Photocatalytic degradation of azo dye reactive orange 16.
This rate increased with the presence of sulfate groups and decreased with. Watersoluble manganese porphyrins are catalysts for the decoloration of azo dyes by hydrogen peroxide under mild conditions ph 8. Solar assisted photocatalytic degradation of reactive azo. Phenolic radicals can be further oxidized to yield oligomeric products.
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