Mutagenicity of azo dyes: Structure-activity relationships

Chung, King‐Thom; Cerniglia, Carl E.

doi:10.1016/0165-1110(92)90044-a

Cited by 429 publications

(186 citation statements)

References 55 publications

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“…A poluição de corpos d´água com estes compostos provocam, além da poluição visual, alterações em ciclos biológicos afetando principalmente processos de fotossíntese. Além deste fato, estudos tem mostrado que algumas classes de corantes, principalmente azocorantes, e seus subprodutos, podem ser carcinogênicos e/ou mutagênicos [12][13][14] . Devido a estas implicações ambientais, novas tecnologias têm sido buscadas para a degradação ou imobilização destes compostos em efluentes têxteis.…”

Section: Introductionunclassified

Novas tendências no tratamento de efluentes têxteis

Kunz¹,

Peralta‐Zamora²,

Moraes³

et al. 2002

Quím. Nova

338

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Recebido em 25/7/00; aceito em 6/6/01 NEW TENDENCIES ON TEXTILE EFFLUENT TREATMENT. Textile effluents, when not correctly treated, cause a high impact to the environment. The main recalcitrant compounds present in textile effluent are represented by the synthetic dyes, used during the fibber dying process. Among others, the azo dyes are considered the most harmful due to its mutagenic and carcinogenic character. In the present work we reported a revision study on the new tendencies for remediation of textile effluents, mainly to degrade the recalcitrant compounds. For this purpose, chemical, physical, photochemical, biological and combined processes were investigated.Keywords: textile effluents; treatment processes; recalcitrant compounds. INTRODUÇÃONas últimas décadas, os problemas ambientais têm se tornado cada vez mais críticos e freqüentes, principalmente devido ao desmedido crescimento populacional e ao aumento da atividade industrial. Com estes ingredientes os problemas devido a ação antrópica têm atingido dimensões catastróficas, podendo ser observadas através de alterações na qualidade do solo, ar e água.Sem dúvida, a contaminação de águas naturais tem sido um dos grandes problemas da sociedade moderna. A economia de água em processos produtivos vem ganhando especial atenção devido ao valor agregado que tem sido atribuído a este bem, através de princípios como consumidor pagador e poluidor pagador recentemente incorporados em nossa legislação. Aliado a isso, temos previsões não muito animadoras para o século que se inicia, como por exemplo a previsão feita pela Companhia de Saneamento do estado de São Paulo (SABESP), que estima que já em 2010 a demanda de água será superior a capacidade hídrica dos mananciais do estado 1 . Dentro deste contexto, o setor têxtil apresenta um especial destaque, devido a seu grande parque industrial instalado gerar grandes volumes de efluentes, os quais, quando não corretamente tratados, podem causar sérios problemas de contaminação ambiental.Os efluentes têxteis caracterizam-se por serem altamente coloridos, devido à presença de corantes que não se fixam na fibra durante o processo de tingimento 2 . A importância dos corantes para a civilização humana é evidente e bem documentada 3 . Os corantes sintéticos são extensivamente utilizados na indústria têxtil, gráfica, fotográfica e como aditivos em derivados de petróleo. Aproximadamente 10.000 diferentes corantes e pigmentos são usados industrialmente, o que representa um consumo anual de cerca de 7 x 10 5 tons no mundo 4-6 e 26.500 tons somente no Brasil 7 . A molécula do corante utilizada para tingimento da fibra têxtil pode ser dividida em duas partes principais, o grupo cromóforo e a estrutura responsável pela fixação à fibra.Existem vários grupos cromóforos utilizados atualmente na sín-tese de corantes. No entanto, o grupo mais representativo e largamente empregado pertence a família dos azocorantes (Figura 1), que se caracterizam por apresentarem um ou mais grupamentos -N=N-ligados a sistemas aromáticos. Os azocorantes r...

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Section: Introductionunclassified

Novas tendências no tratamento de efluentes têxteis

Kunz¹,

Peralta‐Zamora²,

Moraes³

et al. 2002

Quím. Nova

338

View full text Add to dashboard Cite

show abstract

“…However, in many cases, these aromatic amines have been found to be carcinogenic in nature (Rafii & Coleman, 1999). In addition to being a threat to human health, azo dyes are also frequently found as environmental pollutants, a result of industrial processing applications (Chen, 2006;Chung & Cerniglia, 1992;Stolz, 2001). …”

Section: Introductionmentioning

confidence: 99%

“…Azo dyes are common synthetic colourants, which are used in many industries, spanning foods and beverages to textiles and paper products (Chen, 2006;Chung & Cerniglia, 1992). Azo dyes possess a namesake azo bond (-N5N-), which makes them capable of being reduced to their component aromatic amines by the azoreductase enzyme (Stolz, 2001).…”

Section: Introductionmentioning

confidence: 99%

Growth and physiology of Clostridium perfringens wild-type and ΔazoC knockout: an azo dye exposure study

Morrison

John

2016

Microbiology

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Clostridium perfringens, a strictly anaerobic micro-organism and inhabitant of the human intestine, has been shown to produce the azoreductase enzyme AzoC, an NAD(P)H-dependent flavin oxidoreductase. This enzyme reduces azo dyes to aromatic amines, which are carcinogenic in nature. A significant amount of work has been completed that focuses on the activity of this enzyme; however, few studies have been completed that focus on the physiology of azo dye reduction. Dye reduction studies coupled with C. perfringens growth studies in the presence of ten different azo dyes and in media of varying complexities were completed to compare the growth rates and dye-reducing activity of C. perfringens WT cells, a C. perfringens DazoC knockout, and Bifidobacterium infantis, a non-azoreductase-producing control bacterium. The presence of azo dyes significantly increased the generation time of C. perfringens in rich medium, an effect that was not seen in minimal medium. In addition, azo dye reduction studies with the DazoC knockout suggested the presence of additional functional azoreductases in this medically important bacterium. Overall, this study addresses a major gap in the literature by providing the first look, to our knowledge, at the complex physiology of C. perfringens upon azo dye exposure and the effect that both azo dyes and the azoreductase enzyme have on growth.

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“…The stability and the xenobiotic nature of reactive azo dyes makes them recalcitrant; hence, they are not totally degraded by conventional wastewater treatment processes that involve light, chemicals or activated sludge. [10] The dyes are therefore released into the environment, in the form of coloured wastewater. This can lead to acute effects on exposed organisms due to the toxicity of the dyes; phytoplanktons form abnormal colouration and cause reduction in photosynthesis because of the absorbance of light that enters the water.…”

Section: Introductionmentioning

confidence: 99%

Decolourisation of Direct Orange S dye by ultra sonication using iron oxide nanoparticles

Karthikeyeni

Vijayakumar

Vasanth

et al. 2013

Journal of Experimental Nanoscience

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Biosynthesised iron oxide nanoparticles (INPs) less than 100 nm were used to decolourise the textile dye, Direct Orange S by the process of ultra sonication. The parameters tested for the decolourisation of the Direct Orange S dye were the INP concentration (0.2-1g/l), pH (3-11) and H 2 O 2 concentration (2-8 ml/l). The rate of decolourisation process was performed by both stirrer and ultra sonicator method using the first-order kinetics ln(c/c 0 ). The percentage of dye removal for the optimum conditions such as INP, 1g/l (87.2%); pH, 9 (85.5%) and H 2 O 2 concentration 8 ml/l (86.5%) were observed. The Direct Orange S dye was degraded efficiently by sonolysis (60 min) than by the magnetic stirrer method (120 min). High-performance liquid chromatography results showed that the peak for Direct Orange S dye was not present when the dye sample was treated by either H 2 O 2 þ INP or INP alone. Use of biosynthesised iron NPs in Direct Orange S dye (azo dye) decolourisation by a simple non-toxic Fenton reaction is a safe and novel approach. Industrialisation of this technique will be an economical way to decolorise the textile dyes present in water systems.

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Mutagenicity of azo dyes: Structure-activity relationships

Cited by 429 publications

References 55 publications

Novas tendências no tratamento de efluentes têxteis

Novas tendências no tratamento de efluentes têxteis

Growth and physiology of Clostridium perfringens wild-type and ΔazoC knockout: an azo dye exposure study

Decolourisation of Direct Orange S dye by ultra sonication using iron oxide nanoparticles

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