No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Carcinogenicity of Azo Colorants: Influence of Solubility and Bioavailability
Abstract
In the past, azo colorants based on benzidine, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine (o-tolidine), and 3,3'-dimethoxybenzidine (o-dianisidine) have been synthesized in large amounts and numbers. Studies in exposed workers have demonstrated that the azoreduction of benzidine-based dyes occurs in man. The metabolic conversion of benzidine-, 3,3'-dimethylbenzidine- and 3,3'-dimethoxybenzidine-based dyes to their (carcinogenic) amine precursors in vivo is a general phenomenon that must be considered for each member of this class of chemicals. Several epidemiological studies have demonstrated that the use of the benzidine-based dyes has caused bladder cancer in humans. However, in contrast to water-soluble dyes, the question of biological azoreduction of (practically insoluble) pigments has been a matter of discussion. As a majority of azo pigments are based on 3,3'-dichlorobenzidine, much of the available experimental data are focused on this group. Long-term animal carcinogenicity studies performed with pigments based on 3,3'-dichlorobenzidine did not show a carcinogenic effect. The absence of a genotoxic effect has been supported by mutagenicity studies with the 3,3'-dichlorobenzidine-based Pigment Yellow 12. Studies in which azo pigments based on 3,3'-dichlorobenzidine had been orally administered to rats, hamsters, rabbits and monkeys could generally not detect significant amounts of 3,3'-dichlorobenzidine in the urine. It, therefore, appears well established that the aromatic amine components from azo pigments based on 3,3'-dichlorobenzidine are practically not bioavailable. Hence, it is very unlikely that occupational exposure to insoluble azo pigments would be associated with a substantial risk of (bladder) cancer in man. According to current EU regulations, azo dyes based on benzidine, 3,3'-dimethoxybenzidine and 3,3'-dimethylbenzidine have been classified as carcinogens of category 2 as "substances which should be regarded as if they are carcinogenic to man". This is not the case for 3,3'-dichlorobenzidine-based azo pigments.
... 4. Benzidine dyes also cause various dermal and immunological diseases. The workers who get exposed to such dyes have urinary system problems ( Van der Zee et al. 2002;Golka et al. 2004). 5. Dyes also affect the transparency of water bodies and cause damage to the aquatic ecosystem (Rocha 1992 ...
... The highly toxic dye effect, penetration of light rays, cause deficiency of oxygen and limit the downstream beneficial uses such as recreation, irrigation and drinking water (Van der Zee et al. 2002; Golka et al. 2004). 7. Azo dyes are hazardous in nature, when they enter the body and get metabolized by microorganisms causing DNA damage (Van der Zee et al. 2002;Golka et al. 2004). ...
Rapid urbanization and industrialization result in the discharge of harmful and toxic waste into the water bodies which are not easy to degrade thereby causing environmental pollution. Out of so many waste discharges, dye waste is noxious for aquatic life and for human as well; therefore, removal of these toxic compounds from water is one of the major environmental concerns today. The reported methodology like chemical and physical process is often costly, requires higher energy, and is not eco-friendly. In today's world, biological methods are trying to minimize pollution by environment-friendly way. Mycoremediation is one of the techniques which is effective and affordable for degradation and decolorization of dye-bearing effluents. The chapter concludes the potential of mycoremediation in dye removal, its mechanism, and optimizing the conditions for efficient removal of dyes. 20.1 Introduction The earth has been called a blue planet due to abundant availability of water on its surface which approximately covers 70% of the earth's surface. About 97% of all water on earth is in oceans, sea, and bays; it means that only 3% of all water on earth is considered to be fresh. But that remaining water is not completely available for us to
... Such aqueous wastes generated from textile plantations affect the aquatic environment even in minimal concentrations [3]. In addition, they are also identified as carcinogenic substances, especially azo dyes reduction by metabolic degradation produces aromatic amines [4,5]. ...
... The white, greenish precipitate observed following heating and dropwise addition of NaOH to the solution [CuSO 4 and Zn(CH 3 COO) 2 ] was most likely caused by the formation of Zn(OH) 2 and Cu(OH) 2 (Scheme 1). Continuous heating results in the development of brown-black precipitates, indicating that CuO was formed on the crystal lattice of ZnO (Scheme 1). ...
Advanced photocatalytic degradation based on polymer/metal oxide hybrid composites can convert organic and related pollutants into an environmentally benign product. In this study, chitosan/hydroxyethyl cellulose (CS/HEC) gel immobilized polyaniline (PANI)/CuO/ZnO composite was prepared by in situ oxidative polymerization followed by ex-situ dispersion. The hybrid nanocomposite synthesized was characterized by FESEM, FTIR, EDX, XRD, TGA, and UV–Visible absorption spectroscopy. The degradation study was performed in the optimum time, pH, PANI/CuO/ZnO loading on CS/HEC gel, and catalyst dosage using 100 µM Congo red. The correlation coefficients (R²) of pseudo-second-order adsorption kinetics were higher than 0.98 at different temperatures, signifying that the model was well fitted and the chemical interaction between Congo red and the catalyst at the interface. The activation energy of 19.56 kJ/mol showed chemisorption of Congo red at the interface. The negative values of standard Gibbs free energy demonstrated that the Congo red adsorbed spontaneously to the catalyst surface. According to the Langmuir–Hinshelwood kinetics model, Congo red photocatalytic degradation followed pseudo-first-order kinetics. The decrease in degradation efficiency with the addition of ammonium oxalate and isopropyl alcohol proved that both positively charged holes and hydroxyl radicals were involved in the catalysis. The catalytic degradation efficiency of the 0.4 g/L catalysts was 99.8 and 93.7% in the 1st and 4th cycle, respectively, indicating that it is efficient, stable, and recyclable. The resulting hybrid nanocomposite is a promising photocatalyst for removing anionic dyes.
... Dye wastewater is aesthetically undesirable, toxic, mutagenic, nonbiodegradable and carcinogenic causes serious and global challenge to sustain the life in the aquatic and terrestrial habitats due to their toxicity. Moreover dysfunction of kidney, liver, brain, reproductive system and central nervous system are the effects of dyes on human being (Kaykhaii et al., 2018;Golka et al., 2004;Shojaei et al., 2017;Kadirvelu et al., 2003). Therefore removal of dyes from environment with low-cost methods is of important consideration. ...
... The presence of azo dyes in the soil has negative effects on seed germination and root development of plants as well as microbial communities [11]. In developing countries is also common that drinking water sources are affected by industrial activities [12], and research has shown that watersoluble azo dyes can cause bladder and liver cancers in humans [13,14]. ...
N-doped biochar was made using spent substrate from the cultivation of shiitake
mushrooms. Melamine was used as an N-dopant agent and phosphoric acid as
activating agent. Samples without the addition of melamine were used for comparison. The doping/impregnation process was done in 1-step, followed by pyrolysis at 700 and 900 °C for 1 h. The resulting N-doped and non-doped biochars were characterized by BET, Raman spectroscopy, XPS and SEM analysis. Reactive orange-16 (RO-16) azo dye, synthetic effluents and sewage water were used to test the biochars. Adsorbent dose, pH, kinetic and equilibrium measurements were used to characterize the biochars. The surface area (SSA) of the biochars increased with the increase of the pyrolysis temperature. Raman spectroscopic analysis showed that the N-doped biochars had more defective carbon structures than the non-doped ones. XPS analysis showed that N-doped biochars had a larger number of N-functionalities on the biochar surface. The adsorption of RO-16 was affected by the pH. The kinetics of adsorption were well represented by the Avrami model, and the isotherms by the Liu model. The maximum adsorption capacities (qmax) of RO-16 were much higher for the N-doped biochars, i.e., 120 mg/g (SMS-700°C), 216 mg/g (SMS-700°C + N), 168 mg/g (SMS900°C), and 393 mg/g (SMS-900°C + N). The adsorption of RO-16 is ruled by the pore filing, hydrogen bonding, electrostatic, π-π, and Lewis acid-base interactions. N-doped biochar samples were more effective for the removal of contaminants from synthetic effluents and sewage water
... Los colorantes además de afectar la transparencia del agua alteran su absorción y el reflejo de la luz solar, interfiriendo con la vida acuática en lagos, ríos y otros cuerpos de agua. Además afecta la demanda química de oxígeno (DQO), y muchos de estos colorantes sintéticos son tóxicos, mutagénicos y cancerígenos [4]. Dado este problema, la descarga de colorantes a nivel mundial está regulada [5][6][7]. ...
En el Ecuador la elaboración de productos hechos a base de paja toquilla se ha convertido en un referente de exportación del país. Para teñir estos productos se emplean tintas tipo anilina cuyos efluentes coloreados son descargados a los ríos sin previo tratamiento. En esta investigación se planteó un proceso de remoción de color. La primera etapa consistió en la determinación de la mejor relación entre Fe 2+ y H 2 O 2 para el proceso Fenton, aplicando un diseño experimental factorial (3 2); el mejor resultado se obtuvo con los niveles alto y medio de FeSO 4 .7H 2 O y H 2 O 2 al 30 %v/v, respectivamente. El proceso Fenton establecido fue aplicado para remediar soluciones preparadas con los tres colorantes tipo anilina: azul, rojo y negro, que son los más usados en el teñido de paja toquilla. Para cada colorante, se determinó el porcentaje de remoción y su cinética, en todos los casos fue superior al 90 % y de segundo orden. Finalmente, los efluentes tratados fueron neutralizados para evaluar su eco toxicidad en un ensayo con Daphnia Magna en el cual se comprobó que el agua puede ser descargada sin riesgo de ecotoxicidad acuática luego de aplicado el proceso. Palabras clave: Fenton, Remoción de colorantes, Teñido paja toquilla, Efluentes. Abstract In Ecuador, making products of "paja toquilla" has become an export benchmarch. To dye, these products, aniline dyes are used, and the effluents of these processes are discharged to rivers without treatment. This investigation explores a process for color removal. The first stage involved the determination of the optimal relation between Fe 2+ y H 2 O 2 for a Fenton process using an experimental factorial design (3 2). The best result was reported with the higher and medium levels of FeSO 4 .7H 2 O and H 2 O 2 at 30%v/v, respectively. The Fenton process designed was applied to treat solutions of three aniline dyes: blue, red, and black, which are the most used in paja toquilla dyeing. For each dye, the percentage of removal and the kinetics were determined, in all cases was above 90% and of second order. Finally, the effluents were neutralized to assess their ecotoxicity with Daphnia Magna, which demonstrated that the effluent could be discharged without aquatic ecotoxicity after the applied process.
... As such, azobenzene disperse dyes are known to be aquatic environmental pollutants and enter the environment via pathways such as textile ☆ This paper has been recommended for acceptance by Charles Wong. effluents and other waterways, as documented extensively in literature (Balakrishnan et al., 2016;Carneiro et al., 2010;Chequer et al., 2015;Chung and Stevens, 1993;De Aragão Umbuzeiro et al., 2005;Golka et al., 2004;Ohe et al., 2004;Vacchi et al., 2017;Vacchi et al., 2016;Zhang et al., 2012). However, little is known about the occurrences of azobenzene disperse dyes in the indoor environment. ...
... They comprise 50% of the 0.9 million metric tonnes of synthetic dye produced globally per annum, 21 15% of which is estimated to be released into the environment. 22 In addition to aesthetic concerns, azo dyes are suspected human carcinogens [23][24][25] and are recalcitrant to natural degradation and conventional treatment methods. 26,27 Porous Ti 4 O 7 electrodes operating at 10 mA cm −2 for 2 hours reduced the COD of industrial dyeing and finishing wastewater (183 mg COD L −1 ; 1,042 mg Cl L −1 ) by 68.8% with a current efficiency of 12.8% and an energy consumption of 32 kWh m −3 . ...
Inexpensive electrode materials and effective cell designs are needed to advance electrochemical technologies for the oxidative treatment of wastewater. Novel vanadium-doped Ti 4 O 7 porous transport layers (PTLs) used in a compact wastewater electrolyzer are developed and characterized and their performance for the electrochemical oxidation of synthetic wastewater is evaluated. An analytical model predicting performance with the apparent mass transfer coefficient and cell potential is developed. The influence of operating parameters such as volumetric flow, current density, and PTL composition on performance is investigated. Decolorization and chemical oxygen demand (COD) removal of 100 mg L ⁻¹ of methyl orange (MO), an azo dye, in 1,500 mg NaCl L ⁻¹ is rapid with mass transfer coefficients as great as 377 ± 24 µm s ⁻¹ for MO at 15 mA cm ⁻² . After 2.5 Ah L ⁻¹ at 10 mA cm ⁻² , >99% decolorization and >98% COD removal are achieved with a current efficiency of 19.2% and with specific and volumetric energy consumption of 120 and 84.1 kWh kg ⁻¹ for MO and COD, respectively, and 1.34 ± 0.09 and 6.45 ± 0.97 kWh m ⁻³ , respectively. A more energy-efficient electrochemical cell design for industrial wastewater treatment using less expensive high oxidation power electrode materials is demonstrated with these results.
... Consequently, it is essential to follow proper safety and disposal procedures when using these dyes, as they can be hazardous to human health and the environment if not handled correctly. Therefore, they must be removed from the wastewater to fulfill effluent regulations before disposal [11][12][13][14]. To comply with strict environmental regulations, many techniques have been adopted to remove dyes from water and wastewater [15][16][17][18][19][20][21][22][23]. ...
Natural zeolite is a widely used material with excellent environmental cleaning performance, especially in water and wastewater treatment. Natural zeolite (Zini) calcined by CO2-laser radiation (ZL) was tested as a catalyst for the photodegradation and the adsorption of industrial azo dye Lanasol Yellow 4G (LY4G) in water. Morphology, chemical structure, and surface composition of Zini and ZL were analyzed by XRD, SEM, EDS, and XPS. UV/Visible spectrophotometry was used to evaluate the photocatalytic activity of Zini and ZL. The photocatalytic activity of the studied zeolites was associated with the presence of Fe oxides in their composition. Laser-treated natural zeolite showed higher efficiency as a photocatalyst compared to untreated natural zeolite.
... In a broader sense, prolonged exposure to coloured textile effluents may cause immune suppression, circulatory, respiratory and neurobehavioral disorders presage as allergy, multiple myeloma, autoimmune diseases, leukemia, hyperventilation, vomiting, insomnia, salivation, profuse diarrhea, cyanosis, quadriplegia, jaundice, tissue necrosis, eye and skin infections, etc. (Foo and Hameed 2010). Benzidine, a well-known carcinogen and parent component of most azo dyes, poses a greater threat to living organisms (Golka et al. 2004). It is reported that Malachite Green (MG) can cause serious harm to human immune and reproductive systems (Sudova et al. 2007). ...
The textile sector is regarded as one of the most polluting industries in terms of volume and effluent composition. The production of various textile products requires the employment of multiple dyes and auxiliary chemicals in many industrial processes, resulting in wastewater with complicated and highly variable characteristics, making treatment particularly difficult. Textile dyes cause severe detrimental impacts on all life forms due to their carcinogenicity and mutagenicity. Therefore, dye-rich textile effluent must be treated before its discharge. Physico-chemical treatment methods can hamper economic and environmental sustainability and full-scale implementation due to technology intensiveness, need for a reliable power supply, high energy and chemical requirements and generation of secondary pollutants. Constructed wetlands (CWs) have been successfully used to treat a wide variety of wastewaters. They are eco-friendly, cost-effective and provide a potential alternative technology for textile wastewater treatment. In CWs, pollutant removal occurs through complex physical, chemical and biological mechanisms that may occur sequentially or simultaneously as wastewater passes through the inter-related network of wetland media, attached biofilms and plant roots. This review illustrates various physico-chemical and biological methods to treat textile effluents with an emphasis on CWs. Design parameters and operational conditions of CWs are also discussed.KeywordsTextile wastewaterAzo dyesColour removalBiological treatment methodsConstructed wetlandsMacrophytesWetland substrates
... However, the environmental damage does not depend only on the quantity of the disposed dye; it also depends on the composition of the dye mixture, with various common constituents having toxic characteristics [64]. Colored wastewater from synthetic dyes sometimes contains dye that is visible to the naked eye (<1 ppm) [65,66]. When discharged into surface water or groundwater bodies, it causes a decrease in the concentration of dissolved oxygen in the water and an increase in the values of physicochemical and biological parameters, such as COD [67], BOD, total dissolved solids, total N, total phosphorus (P), and nonbiodegradable organic compounds. ...
Green plants are one of nature's factories, fixing inorganic chemicals into organic compounds through photosynthesis and other reactions. Microbes are one of the nature's most effective tools, converting organic materials-dead plants and animals-into inorganic forms through decomposition and mineralization. Together, green plants and microbes are responsible for maintaining a balance between the organic and inorganic worlds, but pollutants, such as synthetic dyes, can upset this balance. Compared with synthetic dyes, natural dyes are safer and more environmentally friendly, but they are also costlier and more difficult to apply, so they are not viable in most commercial applications. Azo dyes are low cost and have high intensity and color fastness, so they are the most frequently used class of synthetic dyes. The main threats related to the dumping of untreated azo dyes into the environment come from their primary byproducts-aromatic amines-which result from the cleavage of the central azo bonds, and which have been classified as significant carcinogenic compounds, representing a great risk to humans as well as the environment. To address this threat, the degradation of synthetic azo dyes is showing promise as an approach to treating azo-dye wastewater. In this review, the classification of azo dyes and their color mechanism is presented first, and then an overview of the research on their environmental impacts is provided, including their effects on biochemical and chemical oxygen demand, water ecosystems, plants, and crops. Finally, the legislation and guidelines on azo dyes and their byproducts are discussed.
... 3,7,8 For instance, the risk of bladder cancer has been reported to be as high as 6.8 and 3.4 times than the expected rate among dye applicators in Japan and Britain respectively. 9,10 However, despite the long history of textile dyeing in Abeokuta, only few studies have been conducted among this group of workers to assess the impact of dye exposure. While a previous study has assessed the worker's knowledge of hazards, no attempt was made in that study to identify the determinants of knowledge. ...
Background:
Identification of potential hazards, their adverse health effects, and predisposing factors in the workplace are critical to improving safety. The objective of the study was to assess the knowledge of occupational hazards, the prevalence of perceived health problems and their predictors among textile dye workers in Abeokuta Nigeria who work in unsupervised settings.
Materials and methods:
In this cross-sectional study, data were collected from 199 participants using a validated semi-structured interviewer-administered questionnaire. Multiple linear regression analysis was used to determine the predictors of knowledge while Pearson Chi-square was employed to test the association between perceived health problems, sociodemographics and work environment characteristics.
Results:
The mean age of the respondents was 40 (SD=12) years with an average work experience of 19 years. The majority of respondents 139 (69.8%) had lower than average scores on knowledge of 25 questions on chemical hazards. There was no correlation between knowledge score and work experience (P=0.492) or age (P=0.462) but the knowledge was significantly associated with exposure score (P=0.004), gender (P=0.002) and adherence to instructions on chemicals usage (P=0.041) after adjusting for safe practice. The most frequent health problems among the dye workers were respiratory disorders (53.8%), allergies (51.8%), and skin disorders (24.1%). Airborne gaseous pollutants from the mixing of chemicals were associated with allergies (P=0.045), circulatory (P=0.02) and skin disorders (P=0.049) while air-borne textile fiber/dye particles could predict allergies (P=0.028).
Conclusions:
Findings revealed that exposure, gender and adherence to instruction labels on dye/chemical containers could determine knowledge of chemical hazards while physical work environment characteristics could determine health problems.
... Dyes have been used for thousands of years and approximately 0.7 million tons of dyes are synthesized annually worldwide. Azo dyes are a group of compounds containing one or more R 1 -N-R 2 bonds, some of the reduced products of the dyes are carcinogenic (Golka K, Kopps S, Myslak ZW, 2004). Azo dyes represent the majority of all the dyes used in today ' s society, because the azo bond facilitates π-electron delocalization, which gives rise to the absorption at visible spectrum wavelengths (Levine WG, 1991). ...
The gut microbiota in human gene pool and contributes to xenobiotic metabolism. Azo dye compounds represent a large group of colouring chemicals which are widely used in many industries. Although the commonly used azo dyes are not mutagenic in the standard Ames Plate Assay they are reduced by azo reductases from intestinal bacteria and, to a lesser extent, by enzymes of the cytosolic and microsomal fractions of the liver.
The first catabolic step in the reduction of azo dyes, which is accompained by a decrease in the visible light absorbance of the dye and then decolorization of the dye, is the reduction of the azo bridge to produce aromatic amines.
In this study, we developed a plate assay capable of detecting the specific bacteria from human intestinal flora that participate in the reduction of azodyes. The methods we used to conclude the result by the optical density value by using the galvanometer.
Key words: Human gut microbes, azoreductase activity, ames plate assay method, decolorizarion of dye, optical density value (OD Value), galvanometer.
... (b) FTIR spectrum of collagen in interaction with Sunset Yellow The interaction of food dyes with collagen [45,70] can be studied by FTIR spectroscopy. Sunset Yellow belongs to the azoic group of dye compounds, from which, by the interaction with the environment where they are processed and employed, is possible formation of carcinogenic aromatic amines and amides [1,[71][72][73][74][75][76][77][78][79][80]. ...
... Carmoisine can reduce fuel metabolism in the liver (98). In brief, hydrophobic azo dyes are not safe for use due to their ability to induce tumors in the body systems (99). ...
: Azo dyes, as a major group of the synthetic colorants, are added to food products not only to make them aesthetic but also to preserve their appearance. However, the use of azo dyes in food has been banned worldwide due to side effects on human health. The search was conducted using PubMed, Scopus, Web of Science, Europe PMC beta, Science Direct, and Springer database considering all articles published up to 9 July 2021. The inclusion criteria were double-blind, randomized, cohort studies, placebo-controlled trials, case reports, non-controlled trials, and case series. Several studies suggest that azo dyes induce oxidative stress, which subsequently increases the concentration of malondialdehyde and reduces superoxide dismutase (SOD) activity and glutathione (GSH) concentration in brain tissue. Also, results showed the adverse effects of azo dyes on the brain parts such as the prefrontal cortex, cerebellum, and cerebrum which, are accompanied by changes in brain function. It can be concluded that azo dyes with an increase in oxidative stress affect the most important parts of the brain and cause brain dysfunction. This study aimed to evaluate the effects of the food additive azo dyes on brain tissues.
... These constitute about one-half of all dyes synthesized and are predominantly used as synthetic dyes [1,2]. Because azo dyes are structurally stable, hazardous, and potentially carcinogenic, their widespread use in the leather, textile and printing industries poses a significant risk to the environment and human health [3][4][5]. Electron withdrawing groups in these molecules make them resistant to degradation leading to their gradual accumulation in the environment up to a hazardous level [6]. ...
... Water quality is greatly affected by color, and even a small percentage of dye can be visible and cause a color sensation in the water [5]. These seemingly 'innocent pollutants' are harmful to fish and other aquatic organisms, are potentially carcinogenic, and can cause acute or chronic diseases to exposed living beings [6,7]. Moreover, dyes exhibit resistance to light, The weight percentage of alginate's contribution in each composite was only 2% and did not affect the sorption process. ...
Environmental pollution has been a reality for many decades, with its contamination intensifying daily due to rapid urbanization and the ever-increasing world population. Dyes, and especially synthetic ones, constitute a category of pollutants that not only affect the quality of water but also exhibit high toxicity toward living organisms. This study was thoroughly planned to explore the removal of two toxic dyes, namely the methylene blue (MB) and methyl orange (MO) compounds from contaminated aqueous media. For this purpose, we designed and synthesized two new composite materials based on ammonium-functionalized Zr4+ MOF (MOR-1 or UiO-66-NH3+) and naturally occurring sorbents, such as bentonite and clinoptilolite. The composite materials displayed exceptional sorption capability toward both MB+ and MO− ions. A key finding of this study was the high efficiency of the composite materials to simultaneously remove MB+ and MO− under continuous flow conditions, also showing regeneration capability and reusability, thus providing an alternative to well-known mixed bed resins.
... In any case, the natural harm does not depend interestingly on the sum of color released; moreover, it depends on the colors blended with the other substances, all with harmful properties that make up the emanating from the industries (Tkaczyk, 2020;Clarke, 1980). The colored wastewater, sometimes contains dyes, evident to the bare eye (<1 ppm) (Golka, et al. 2004;Mojsov, et al. 2016), released into surface or groundwater bodies, diminish the concentration of broken up oxygen within the water (Ali, 2010). It increments the values of physicochemical and biological parameters such as the 1 The chemical structures were elaborated in the software ACD/ChemSketch, version 2020.1.2, ...
COVID-19 has disrupted all aspects of human life. To mitigate the impact of the pandemic, several efforts have been taken, including by Indonesian scholars abroad. This book entitled Indonesia Post-Pandemic Outlook: Environment and Technology Role for Indonesia Development explores environment and technology issues and topics related to the COVID-19 pandemic and discusses post-pandemic recovery efforts in Indonesia. Comprising of 19 chapters, this book is divided into four sections. The first section, disaster and greening management development, discusses insights for a better solution in disaster prevention and development of greening management. Second, waste and pollution management development, explores options in development of waste and pollution management such as potentials uses of membrane technology, remediation of textile dyes, biochar industry, and also discussion on persistent organic pollution and microplastics. Third, food defense and security development, explores the potentials of food security and management in utilizing the potential of coastal sand marginal land resources, IoT and smart packaging, and smart food supply chain. The last part, human resource and public service development, discuses developments on management of education system, public transportation, e-government, and health information system. We hope that this book can be a valuable reference for stakeholders, policymakers, as well as society to recover from the pandemic crisis and find better solutions to benefit future generations.
... Azo dyes are synthetic organic dyes typically produced by combining a diazonium compound with phenol or aromatic amine. They are commonly used in various consumer goods such as leather, textiles, and foodstuff [1]. Azo dyes have high resistance to microbial degradation and excellent photolytic stability [2]. ...
The interaction between Reactive Yellow 145 (RY145) and human serum albumin (HSA) under physiological conditions was studied by the methods of multiple spectroscopic, molecular docking, and molecular dynamic (MD) simulation. Fluorescence data revealed that the fluorescence quenching of HSA by RY145 resulted from the formation of the RY145–HSA complex. According to the modified Stern–Volmer equation, the effective quenching constants (KA) between RY145 and HSA at two different temperatures were obtained to be 114.15×10⁴, and 52.55×10⁴ L mol⁻¹, respectively. ΔH and ΔS were determined to be negative, showing that van der Waals force and hydrogen bonds were the governing intermolecular force in stabilizing the complex. The outcomes of UV– visible spectra, fluorescence spectroscopy, and CD spectra exhibited apparent modifications in the microenvironment and conformation of HSA, particularly for the secondary structure. The MD simulation and molecular docking supported experimental findings.
... Recently, in the industrialized modern societies and the quick hike of human population, the result is depletion in water resources. Additionally, the scarce freshwater is not ample to meet up the necessities of massive population (Golka et al. 2004). ...
In the sight of the ever-increasing significance of green-based iron nanoparticles especially in wastewater treatment applications is a compelling reason for their use in a waste prevention opportunity, safer environment and benign precursor materials become the vital considerations. Hence, in the current investigation, an efficient co-precipitation technique was applied to prepare highly active chitosan-coated magnetic iron oxide that is applied for wastewater remediation. In the current investigation, chitosan coupled with magnetite nanoparticles namely CS-M was attained by coupling chitosan (CS) with magnetite nanoparticles via simple co-precipitation in different weight proportions and the attained samples labeled as CS-M-(2:1), CS-M-(3:1) and CS-M-(1:2). The structure, morphology and characteristics of the prepared samples were characterized using X-ray diffraction spectroscopy and transmission electron microscopy (TEM). The catalytic oxidation activity of the prepared samples was investigated to eliminate Basic Blue 9 (BB9) dye from aqueous effluent as simulated textile polluted stream. The experimental data exposed almost BB9 dye emanation. The system parameters revealed the maximal BB9 oxidation (99%) was attained within 2 h of irradiance time. Box-Behnken design factorial design based on response surface methodology was applied to optimize the Fenton's system (CS-M-(2:1)/H 2 O 2) parameters to maximize the efficiency 2.4 and 767 mg/L of CS-M and H 2 O 2, respectively, at pH 7.0. The experimental data exposed that CS-M-(2:1) is signified as the optimal catalyst mixture. The kinetic data verify the oxidation system follows the second-order reaction kinetic model. Further, thermodynamic variables predicted that the reaction is endothermic and non-spontaneous in nature. Hence, the catalyst could be environmental benign and the evaluation introduces the role of engineers and chemists in a world for a sustainable material use.
... (b) FTIR spectrum of collagen in interaction with Sunset Yellow The interaction of food dyes with collagen [45,70] can be studied by FTIR spectroscopy. Sunset Yellow belongs to the azoic group of dye compounds, from which, by the interaction with the environment where they are processed and employed, is possible formation of carcinogenic aromatic amines and amides [1,[71][72][73][74][75][76][77][78][79][80]. ...
Sunset Yellow (E110) is an azoic dye synthetized from aromatic hydrocarbons, which is used to improve the physical–chemical properties of food products and their conservation; its chemical formula is C16H10N2Na2O7S2. Here, in order to characterize this azoic dye in powder and solution form, five spectral techniques were employed: Fourier Transform Infrared (FTIR), UV–Vis, Raman, Laser fluorescence and Terahertz (THz) spectroscopy. The Sunset Yellow’s morphology, structure and its chemical composition were studied by scanning electron microscopy (SEM), X-ray diffraction and energy-dispersive X-ray spectroscopy (EDXS). The thermal behaviour of Sunset Yellow was studied in correlation with its physical (refractive index, electric susceptivity, optical anisotropy) and chemical (acidity) properties. Thermal analysis effectuated in air indicates the evaporation of absorbed and physically bonded water up to 188 °C, after which the material possesses thermal stability up to 330 °C. The oxidative decomposition takes place in four exothermic steps of which the strongest between 510 and 643 °C develops a heat of 4519.6 J g−1; at 913 °C, a residue of 31.77% is obtained. The study of optical properties of Sunset Yellow shows that the refractive indexes are decreasing when the temperature of the solution increases. The optical anisotropy of Sunset Yellow was studied under polarized light at room temperature. Sunset Yellow exhibits the phenomenon of birefringence on resulted crystallites by drying and crystallization at RT from aqueous solutions with concentrations of 1% and 5%. THz spectroscopy identified the THz spectral “signature” of Sunset Yellow at a few wavelengths. Sunset Yellow has biophysical properties when interacting with proteins (bovine serum albumin (BSA) and collagen). The biological properties of Sunset Yellow were observed through its antioxidant activity and phytotoxicity; while the antioxidant activity is proportional with increasing its concentration, the phytotoxicity study indicates that the Sunset Yellow does not present wheat (Triticum aestivum) growth phytotoxicity at low concentrations (when treating with aqueous solutions of 0.01–0.05%, it could increase its resistance to drought conditions), but at concentrations of 0.25% or higher, there are negative changes in wheat growth.
... In particular, wastewater from industrial production facilities, especially wastewater from textile dyeing factories, poses a severe threat to the environment. The presence of dyes in wastewater is a major concern because of their toxicity and unaesthetic that can cause adverse effects on biological life, including cancer and genetic mutations [1][2][3]. In addition, the presence of bacteria in water also affects the environment, especially strains of enterobacteria and Gram-negative, anaerobic bacteria, including Escherichia coli (E. ...
In this work, the zinc/cobalt-based zeolite imidazolate frameworks ((Co/Zn)ZIFs) were synthesized with the solvothermal method. The obtained material was characterized by utilizing scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis diffusive reflectance spectroscopy, and nitrogen adsorption-desorption isotherms. XRD and SEM analyses show that (Co/Zn)ZIFs are composed of nanocrystals with polyhedral shapes of around 50–100 nm and belong to the I-43m space group as those of ZIF-8 and ZIF-67. Optical studies demonstrate a red shift in the absorbance spectrum of (Co/Zn)ZIFs compared with individual components of ZIF-67 or ZIF-8. (Co/Zn)ZIF composite was utilized as photocatalytic material to treat a model aqueous solution containing rhodamine B and bacteria. It was found that (Co/Zn)ZIFs could simultaneously degrade rhodamine B and inhibit bacteria (E. coli and S. aureus). The manufactured composite could catalyze the mineralization of rhodamine B and also exhibited good antibacterial activity against Gram-negative E. coli (93.32% inhibition rate) and Gram-positive S. aureus (90.86% inhibition rate) in the visible-light region within four hours of irradiation. Gram-negative bacteria were more resistant to (Co/Zn)ZIFs than Gram-positive bacteria. (Co/Zn)ZIFs can be used as light-driven catalysts for water and environmental detoxification from organic compounds like dyes and bacteria.
... Under certain conditions, azo dyes undergo breakdown, forming aromatic amines [58,59]. Some of these amines are proven to be potential carcinogenic agents [60,61] and cause cancer in humans [62]. The EU has prohibited the use of azo dyes in all textiles since they emit cancer-causing amines. ...
Use of dyes as well as colorants in industrial processes has extensively increased. Effluents from various industries such as textile, paint, food, etc. are reported to have a diverse range of colorants. The effluents from these industries are often released into natural water bodies, causing serious water and environmental pollution, to which humans and other species are constantly exposed. Continued changes in climate have also affected water availability for people around the world. Thus, advanced treatments and removal of harmful contaminants from municipal and industrial wastewater are becoming increasingly important. Removal of dyes and colorants from wastewater can be done in a variety of ways, including physical, chemical, and biological treatments. These technologies, however, differ in terms of efficiency, cost, and environmental effect. There are many technological and economic challenges for the wastewater treatment methods currently available. The search for the most suitable strategy for successful degradation or removal of dyes from effluents is an urgent requirement. Previously published research suggests that the use of enzymes for dye removal is a more economic and effective strategy as compared to traditional techniques. Nanoparticles, with their exceptional physicochemical features, have the potential to tackle the problem of wastewater purification in a less energy-intensive way. However, extensive standardization would be a necessity for the use of different nanoparticles. Therefore, intense research in the use of enzymes and nanoparticle-based technologies may provide much needed technological solution for the remediation of a diverse range of dyes from wastewater.
... Adicionado a esto, se aumenta la posibilidad de indicios de toxicidad ya que los colorantes azoicos pueden ser cancerígenos debido a su producto desdoblado: la bencidina. Esta sustancia induce varios tumores humanos y animales, asimismo, la reducción de la bencidina produce aminas aromáticas que afectan la salud humana, causando alergias y en animales de laboratorio se han observado efectos negativos en el hígado, riñones, sistemas inmunitario y nervioso 3,4 . ...
Cada día es evidente como un recurso natural tan imprescindible para el desarrollo de la vida, como es el agua, se ve amenazado por diversos factores de contaminación; debido a diferentes procesos industriales necesarios para atender sus demandas (industria textil, alimenticia y cosmética)1 . Tal es el caso de la contaminación causada por los colorantes de tipo azoico, que son compuestos químicos nitrogenados, y que se caracterizan por la presencia de un grupo azo (-N=N-) en la molécula que une, al menos, dos anillos aromáticos. Son utilizados ampliamente en la industria textil ya que proporcionan una coloracion intensa a las telas, algunos de ellos son mencionaodos en la figura 1 (con su estructura química)2. Estos colorantes presentan como principal consecuencia la contaminación de agua obstaculizando el paso de la luz, provocando que organismos autótrofos no produzcan su alimento y de esta manera interrumpan la cadena trófica en ecosistemas acuaticos. Adicionado a esto, se aumenta la posibilidad de indicios de toxicidad ya que los colorantes azoicos pueden ser cancerígenos debido a su producto desdoblado: la bencidina. Esta sustancia induce varios tumores humanos y animales, asimismo, la reducción de la bencidina produce aminas aromáticas que afectan la salud humana, causando alergias y en animales de laboratorio se han observado efectos negativos en el hígado, riñones, sistemas inmunitario y nervioso.3,4
... Due to the industrial waste from these industries, light penetration can be reduced [2]. Many dyes have been classified as carcinogenic and toxic because they have negative effects on human health and the environment [3,4]. MB dye (its chemical name is tetramethylthionine chloride) is also known as methylthioninium chloride and has a significant blue color in its oxidized form; it is colorless in its reduced form [5], as shown in Figure 1. ...
Due to their higher specific area and, in most cases, higher adsorption capacity, nanomaterials are noteworthy and attractive adsorbents. Agricultural products that are locally available are the best option for removing methylene blue (MB) dye from aqueous solutions. Because it is self-anionic, FT-IR and SEM investigations of biosorption have confirmed the role of the functional group and its contribution to the formation of pores that bind cationic dye. It is endothermic if the adsorption of MB by an adsorbent is high as the temperature increases; on the other hand, exothermic if it is high as the temperature decreases. A basic medium facilitates adsorption with respect to pH; adsorption is proportional to the initial concentration at a certain level before equilibrium; after equilibrium, adsorption decreases. A pseudo-second-order model applies for certain agricultural products. As per plotted graph for the solid-phase concentration against the liquid-phase concentration, the Langmuir adsorption isotherm model is favored; this model describes a situation in which a number of molecules are adsorbed by an equal number of available surface sites, and there is no interaction between adsorbate molecules once all sites are occupied. In contrast, the Freundlich model depicts non-ideal multi-layer sorption onto heterogeneous surfaces via numerical analysis; with a value of n = 1, the result is a linear isotherm. If the value of n < 1 or n > 1, then it is chemical or physical adsorption, respectively. Based on an EDX analysis, relevant elements are confirmed. BET analysis confirms the surface area. Nanoproducts categorized as agricultural products exhibit the aforementioned tendency. Even though nanoparticles show positive outcomes in terms of higher adsorption, a high specific area for the targeted pollutant is needed in real-world applications. In the relevant sections herein, the behavior of thermodynamic parameters, such as enthalpy, entropy, and Gibbs free energy, are examined. There is some question as to which form of agricultural waste is the most effective adsorption medium. There is no direct answer because every form of agricultural waste has its own distinct chemical and physical characteristics, such as porosity, surface area, and strength.
... Hence those must be degraded/mineralized before releasing into the environment. In aerobic conditions, most of the dyes are non-biodegradable and due to their high molar absorptivity with conjugated carbon skeleton, they are also photochemically active [4,5]. Semiconductor material-based photocatalytic mineralization of organic dye molecules from water bodies is a promising approach. ...
Magnetic photocatalyst-based dye degradation under visible light is a promising approach due to the ease of catalyst separation and recycling provided the catalyst is robust and cost-effective. To scrutinize and find a highly efficient and cost-effective magnetic photocatalyst, we have synthesized a series of X metal-doped Iron oxide-based nanocomposites XFe2O3 [X = Cobalt(Co), Zinc(Zn), Chromium(Cr), Strontium(Sr), Nickel(Ni), Cupper(Cu), Barium(Ba), Bismuth(Bi) and Manganese(Mn)] by simple precipitation based large scale feasible synthetic procedures. Afterward, those were meticulously characterized by various techniques such as UV–vis, Raman, Fourier Tranform Infrared Spectroscopy (FT-IR), Powder X-ray Diffraction (P-XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM) and Vibrating Sample Magnetometer (VSM). The magnetic susceptibility measurements showed that these XFe2O3 nanocomposites are ferromagnetic at room temperature. We tested their efficacy for photocatalytic dye (Methylene Blue) degradation under visible light irradiation and found that they can all be active at different pHs. Under natural sunlight also, the photocatalytic efficiency of ZnFe2O3 and CuFe2O3 for the removable of Methyl Orange was much higher than all other catalysts. A comparison of their relative cost and catalytic activity was plotted and BaFe2O3, MnFe2O3 and ZnFe2O3 were found to be the best magnetic photocatalysts for dye degradation under visible light while under sunlight, ZnFe2O3, CuFe2O3 and BaFe2O3 were found to be the best magnetic photocatalysts. The proposed formula clearly shows that, in addition to the percentage of degradation, the pricing of the catalyst is a crucial aspect to consider when selecting a catalyst. We also found that by maintaining the correct pH, the percentage of degradation increased efficiently.
... These materials are widely used to treat dyes such as Titan yellow (TY) and Congo red that are released into the environment from industrial and textile effluents. Despite wide application, some studies show a toxicity assay [20][21][22]. ...
In this work, we present magnetic nanoparticles based on iron oxide doped with zinc synthesized using the wet co-precipitation method for environmental application. The morphology of the samples was revealed by SEM and TEM, which showed particles of granular shape and size of about 15 nm. The specific surface areas of the materials using the BET method were within the range of 85.7 to 101.5 m 2 g −1 depending on the zinc content in the superparamagnetic iron oxide nanoparticles (SPIONs). Magnetometry was performed to determine the magnetic properties of the particles, indicating superparamagnetism. Synthesized magnetic nanoparticles with different amounts of zinc dopant were used as an adsorbent to remove model pollutant Titan yellow (TY) from the aqueous solutions. Adsorption was determined by investigating the effects of sorbent amount, dye concentration, and contact time. The synthesized material removed Titan yellow quickly and efficiently within the physical adsorption. The adsorption isotherms were consistent with the models proposed by Langmuir and Redlich-Peterson. The monolayer adsorption capacities were 30 and 43 mg g −1 for Fe3O4 and Fe3O4@10%Zn, respectively, for the removal of TY. However, that of Congo red is 59 mg g −1 by Fe3O4@10%Zn. The proposed nanoparticles offer fast and cost-effective water purification, and they can be separated from solution using magnets.
... Dyes contribute to water toxicity and represent an increasing danger for the environment, humans, and animals. [1][2][3] They are generally resistant to light, oxidizing agents, and many chemicals and therefore difficult to degrade once released into aquatic systems. Thus, one of the major environmental problems related to the numerous industrial applications of dyes is their removal from effluents. ...
In this paper, the adsorption of Evans blue (EB) and methyl orange (MO) azo dyes on four greenly synthesized magnetite nanoparticles has been studied to investigate the effect of the mediating plant extract's acidity on magnetite surface reactivity in azo dye adsorption. Magnetite surface reactivity has been studied through the analysis of preferential attachment of dye chromophore and auxochrome groups on magnetite nanoparticles, and adsorption yields. According to the contents of chromophore and auxochrome groups in dye structures, the mediating plant extract's acidity effect on acid site types and densities was also deduced. Used plants for the green synthesis were: Artemisia herba-alba (L), Matricaria pubescens (L), Juniperus phoenicea (L), and Rosmarinus officinalis (L), and their extract pHs were respectively 5.25, 5.05, 4.63, and 3.69. The four greenly synthesized samples of magnetite were characterized by XRD, SEM, ATR-FTIR, and UV-Vis techniques. The novelty of this paper lies in highlighting the influence of the mediating plant extract's acidity on the greenly synthesized magnetite surface reactivity towards the preferential attachment of chromophore and auxochrome functional groups in azo dye adsorption, where obtained results show that the mediating plant extract's acidity has a clear effect on the preferential attachment of chromophore and auxochrome groups on magnetite surfaces as well as on azo dyes' adsorption yields and capacities. Indeed, the decrease in the plant extract's acidity leads to an increase in the attachment of chromophore groups and a decrease in the attachment of auxochrome groups. So, it leads to an increase in Lewis acid site density and a decrease in Brønsted acid site density of magnetite surfaces. Also, the decrease of the plant extract's acidity leads to an increase in the studied dye adsorption yields, and this is because the majority of functional groups of MO and EB dyes are chromophores that attach to Lewis acid sites. The difference found in adsorption yields of EB and MO on all four magnetite samples is due to the fact that the ratio of chromophore/ auxochrome groups in EB is remarkably greater than that in MO. The linear and non-linear pseudo-first-order and pseudo-second-order kinetics of the adsorption as well as the intra-particle diffusion mechanism have been analyzed. Obtained results indicate that in all adsorption processes the adsorption kinetics followed a linear pseudo-first-order kinetic model, and film diffusion is the step that controlled adsorption mechanisms. The thermodynamic studies of EB and MO adsorption processes on the four magnetite surfaces have been analyzed in the temperature range of 303.15-318.15 K. Obtained results reveal the endothermic nature of the adsorption in all cases.
... They can be ecotoxic and have an impact on the transparency and gas solubility of water bodies. By absorbing sunlight that enters the water, they change the growth of aquatic organisms and impede photosynthesis, disrupting natural ecosystems (Golka et al. 2004). The annual output of textile dyes is projected to be 700,000 ton, with nearly half of this amount spent on dyeing cotton and cellulosic fibers (Robinson et al. 2001;Hao et al. 2021). ...
In the current investigation, the removal of Levafix Fast Red CA (LFR) and Levafix Amber CA (LA) azo-dyes from aqueous media using the Fenton/adsorption processes has been carried out. The water treatment by-product, namely alum sludge (AS), was successfully collected and calcined to various temperatures, i.e., 400, 600 and 800 °C, then tested for use as a catalyst in the Fenton/adsorption processes. Fourier transform infrared (FT-IR) transmittance spectrum analysis and Transmission electron microscopy techniques (TEM) were applied to investigate the structural and morphological properties of such a catalyst. The results displayed that the calcined AS at 400 °C (AS400) showed the best photocatalytic activity under ultraviolet illumination and sunlight irradiation. The results indicated that the adsorption/Fenton’s oxidation systems are efficient for treatment and eliminating such types of reactive dyes. The oxidation reaction using Fenton’s reagent reached 99.9 and 86% removal for LFR and LA dyes, respectively. The operating conditions revealed that the reaction was maximized at the operational parameters of 1 g/L and 800 mg/L for AS400 and H 2 O 2 at acidic pH (3.0). The process of single dyes was studied either from thermodynamic and kinetic viewpoints and the data exhibited that the reaction is followed a pseudo-second- order kinetic model and an exothermic reaction nature. The practical application of such byproduct waste used as a photocatalyst source through using natural solar radiation introduces an industrial ecology approach in treating dye effluents for safer environment.
... Sự có mặt thậm chí một lượng rất nhỏ thuốc nhuộm trong nước, ít hơn 1 mg/L đối với một số thuốc nhuộ m cũng rất dễ nhìn thấy [1]. Nước thải chứa thuốc nhuộm là rất độc hại, là tác nhân gây ra ung thư và đột biến gen [2,3]. Bên cạnh đó sự tồn tại của vi khuẩn trong nước cũng gây ảnh hưởng nhất định đến môi trường, đặc biệt là các chủng vi khuẩn thuộc nhóm Enterobacteria, nhóm vi khuẩn Gram âm, kỵ khí có khả năng gây các bệnh trên đường ruột ở người và động vật, với đại diện phổ biến nhất là Escherichia coli (E.coli). ...
In this work, the zinc/cobalt-based zeolite imidazolate framework-67 was synthesized using solvothermal method. Their application in the RhB dye degradation and inhibition of bacteria growth were investigated. The obtained materials were characterized utilizing scanning electron microscope (SEM), X-ray diffraction (XRD), and nitrogen adsorption-desorption isotherms. Our study reported the use of (6Co/4Zn)ZIF composite for the simultaneous treatment of both Rhodamine B dye and bacteria. The result showed that the prepared composite could remove RhB dye up to 95% by both adsorption and photodegradation, and exhibited good antibacterial activity against both Gram-negative E. coli (67,7% inhibition rate) and Gram-positive S. aureus (57,6% inhibition rate) under visible-light condition. Our study indicated that 6Co/4Zn)ZIF composite could be a potential material for the waste-water treatment ain textile industry.
... Because of the various colours found in wastewater, it is considered a contaminant that is harmful to animals in the ecosystem. Some dyes have been mutagenic and carcinogenic [1]. So, removing dye molecules from the environment is of significant consideration [2][3][4]. ...
This research demonstrates the ability of cubic Ia3d aluminosilica (CAS) adsorbent prepared using a simple and repeatable one-pot synthesis technique to remove the cationic dye, such as Gentian violet (GV) from aqueous solutions. The prepared CAS adsorbent nanoarchitectonics appeared with 573 m² g⁻¹ as a BET surface area. The adsorption behaviour of GV on CAS adsorbent was investigated using the thermodynamics, kinetics, and isotherm models. According to the results, the CAS adsorbent indicated a high ability to absorb GV from an aqueous solution, and their kinetic behaviour follows a pseudo-second-order kinetic. In addition, the equilibrium study revealed that the GV adsorption by the CAS adsorbent followed the Langmuir model. Additionally, the outcomes obtained revealed adsorption of GV onto CAS adsorbent was dominated by electrostatic attraction forces, hydrogen bonding, ion-exchange, and pore filling, The maximum adsorption efficiency of GV onto CAS adsorbent was instituted to be 1.36 mmol g⁻¹ (i.e. 554.85 mg g⁻¹). The enthalpy (ΔHo), entropy (ΔGo), and Gibbs free energy (ΔSo) parameters revealed that the extraction of GV dye using CAS adsorbent was endothermic and spontaneous. The synthesised CAS adsorbent shows significant recyclability and characteristics of re-generability up to five adsorption-desorption cycles. As a proof of concept, the performance of the prepared adsorbent was evaluated for laboratory-scale purification of wastewater samples.
... Dyes contribute to water toxicity and represent an increasing danger for the environment, humans, and animals. [1][2][3] They are generally resistant to light, oxidizing agents, and many chemicals and therefore difficult to degrade once released into aquatic systems. Thus, one of the major environmental problems related to the numerous industrial applications of dyes is their removal from effluents. ...
In this paper, the adsorption of Evans blue (EB) and methyl orange (MO) azo dyes on four greenly synthesized magnetite nanoparticles has been studied to investigate the effect of the mediating plant extract's acidity on magnetite surface reactivity in azo dye adsorption. Magnetite surface reactivity has been studied through the analysis of preferential attachment of dye chromophore and auxochrome groups on magnetite nanoparticles, and adsorption yields. According to the contents of chromophore and auxochrome groups in dye structures, the mediating plant extract's acidity effect on acid site types and densities was also deduced. Used plants for the green synthesis were: Artemisia herba-alba (L), Matricaria pubescens (L), Juniperus phoenicea (L), and Rosmarinus officinalis (L), and their extract pHs were respectively 5.25, 5.05, 4.63, and 3.69. The four greenly synthesized samples of magnetite were characterized by XRD, SEM, ATR-FTIR, and UV-Vis techniques. The novelty of this paper lies in highlighting the influence of the mediating plant extract's acidity on the greenly synthesized magnetite surface reactivity towards the preferential attachment of chromophore and auxochrome functional groups in azo dye adsorption, where obtained results show that the mediating plant extract's acidity has a clear effect on the preferential attachment of chromophore and auxochrome groups on magnetite surfaces as well as on azo dyes' adsorption yields and capacities. Indeed, the decrease in the plant extract's acidity leads to an increase in the attachment of chromophore groups and a decrease in the attachment of auxochrome groups. So, it leads to an increase in Lewis acid site density and a decrease in Brønsted acid site density of magnetite surfaces. Also, the decrease of the plant extract's acidity leads to an increase in the studied dye adsorption yields, and this is because the majority of functional groups of MO and EB dyes are chromophores that attach to Lewis acid sites. The difference found in adsorption yields of EB and MO on all four magnetite samples is due to the fact that the ratio of chromophore/auxochrome groups in EB is remarkably greater than that in MO. The linear and non-linear pseudo-first-order and pseudo-second-order kinetics of the adsorption as well as the intra-particle diffusion mechanism have been analyzed. Obtained results indicate that in all adsorption processes the adsorption kinetics followed a linear pseudo-first-order kinetic model, and film diffusion is the step that controlled adsorption mechanisms. The thermodynamic studies of EB and MO adsorption processes on the four magnetite surfaces have been analyzed in the temperature range of 303.15–318.15 K. Obtained results reveal the endothermic nature of the adsorption in all cases.
... In the recent years, photocatalytic degradation was attractive as a promising tool for removal of azo dyes and organic impurities from waste water. Photocatalytic materials could effectively eliminate many stable nonbiodegradable dyes, as compared with the traditional method of processing [7]. ...
Cu–Al–O thin films were grown on Si (111) substrates by using the reactive ion-beam sputtering (RIBS) method within the temperature range 80 to 380 °C. The effect of thermal annealing of Cu–Al–O films under various regimes of cooling on the microstructure, morphology, optical properties and photocatalytic activity were examined. The properties of annealed Cu–Al–O films were studied using atomic force microscope (AFM), energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectrometry (FTIR). The X-ray diffraction patterns show appearance only CuAl2O4 phase after thermal annealing of Cu–Al–O thin films at 900 °C. Raman scattering confocal measurements have also confirmed the presence of CuO phases in annealed Cu–Al–O samples. AFM results have indicated that the greatest RMS roughness is observed in CuAl2O4 films after temperature annealing under the fast cooling regime. Photodegradation of CuAl2O4 films was investigated using methyl orange as model pollutant. Present results indicate that CuAl2O4 photocatalysts are potential candidate for the practical application in photocatalytic degradation of organic compounds.
Layered double hydroxides (LDH) have previously been extensively studied as high capacity adsorbents for the removal of dyes from water. However, a comprehensive understanding of why one dye is adsorbed more than another still remains unknown. In addition, a very little is known about how adsorption mechanisms scale when more than one dye is present in the solution. The adsorption capacity of cobalt-aluminum (CoAl) LDH was investigated for methyl orange (MO), remazol brilliant blue (RBBR) and allura red (AR), at different dye concentrations. The maximum mass of dye adsorbed was obtained for MO (2.267 mmol/g), followed by RBBR (0.258 mmol/g) and AR (0.195 mmol/g). X-Ray Diffraction and Fourier transform infrared analysis results demonstrated that surface adsorption and electrostatic interactions contributed to the adsorption while intercalation did not. In a binary solution of MO and RBBR, the highest mass of MO adsorbed was reduced to 1.521 mmol/g while the maximum RBBR mass adsorbed increased to 0.268 mmol/g. CoAl LDH had a preferential adsorption for RBBR within concentrations up to 0.026 mmol/L while MO was preferred at higher concentrations. Overall, the findings suggest that the adsorption capacity of an LDH is highly dependent on the number, characteristics and the equilibrium concentrations of dyes present in a solution.
The separation and detection of multi-component mixtures has always been a challenging task. Traditional detection methods often suffer from complex operation, high cost, and low sensitivity. Surface enhanced Raman scattering (SERS) technique is a high sensitivity, powerful and rapid detection tool, which can realize the specific detection of single substance components, but it must solve the problem that multi-component mixtures cannot be accurately determined. Thin layer chromatography (TLC) technology, as a high-throughput separation technology, uses chromatographic plate as the stationary phase, and could select different developing phases for separation experiments. The advantages of TLC technology in short distance and rapid separation are widely used in protein, dye and biomedical fields. However, TLC technology has limitations in detection ability and difficulty in obtaining ideal signal intensity. The combination of TLC technology and SERS technology made the operation procedure simple and the sample size small, which can achieve rapid on-site separation and quantitative detection of mixtures. Due to the rapid development of TLC-SERS technology, it has been widely used in the investigation of various complex systems. This paper reviews the application of TLC-SERS technology in food science, environmental pollution and biomedicine.
En el Ecuador la elaboración de productos hechos a base de paja toquilla se ha convertido en un referente de exportación del país. Para teñir estos productos se emplean tintas tipo anilina cuyos efluentes coloreados son descargados a los ríos sin previo tratamiento. En esta investigación se planteó un proceso de remoción de color. La primera etapa consistió en la determinación de la mejor relación entre Fe2+ y H2O2 para el proceso Fenton, aplicando un diseño experimental factorial (32); el mejor resultado se obtuvo con los niveles alto y medio de FeSO4.7H2O y H2O2 al 30%v/v, respectivamente. El proceso Fenton establecido fue aplicado para remediar soluciones preparadas con los tres colorantes tipo anilina: azul, rojo y negro, que son los más usados en el teñido de paja toquilla. Para cada colorante, se determinó el porcentaje de remoción y su cinética, en todos los casos fue superior al 90 % y de segundo orden. Finalmente, los efluentes tratados fueron neutralizados para evaluar su eco toxicidad en un ensayo con Daphnia Magna en el cual se comprobó que el agua puede ser descargada sin riesgo de ecotoxicidad acuática luego de aplicado el proceso.
Pollution of waters by azo dyes is a major global issue because some azo dyes have carcinogenic and mutagenic effects. Therefore, advanced methods are required to remove those pollutants from wastewater. For instance, electrochemical oxidation processes have been developed using various approaches to remove azo dyes from wastewater. Here, we review electrochemical processes for the oxidative degradation of azo dyes. Processes include anodic oxidation, electro-Fenton, photo-electro-Fenton, and solar photo-electro-Fenton. The influence of various parameters including process design, design of reactors, and the characteristic degradation products and their toxicity, are discussed. Low molecular weight carboxylic acids are mainly formed as by-products.
Every living being’s many life operations are mostly controlled by the environment. In general, the environment is a highly complicated entity for all sorts of living and nonliving species since a single component may affect all of the organisms in the ecosystem.
Azo dyes are one of the large classes of water soluble synthetic dyes with a wide range of colors and can be released into the environment when used. Azo dyes belong to one of the most numerous groups of synthetic dyes and are characterized by the presence of an azo group (-N=N-) with two or more symmetrical or asymmetrical aromatic radicals. Processes of photoelectrochemical oxidation using various approaches have been developed for the removal of azo dyes from wastewater. The fundamentals of different photoelectrochemical oxidation processes for azo dyes, such as photoelectrocatalytic oxidation (PEC), photoelectro-Fenton (PEF), and solar photoelectro-Fenton (SPEF) processes, are discussed. The use of different semiconductor materials as electrode materials in photoelectrocatalysis and PEF for azo dye removal, the influence of different parameters on the removal of azo dyes from wastewater, reactor design, combined photoelectrochemical oxidation, including the use of fuel cells, are also considered. The anodic, electrochemical, and photoelectrochemical oxidation processes for azo dye removal is compared. Also shows what products are mainly formed during photoelectrochemical oxidation of azo dyes and how photoelectrochemical oxidation affects the toxicity of azo dye solutions under different conditions.
The ultrafine iron hydroxide/oxide systems are fabricated by a hydrothermal approach, using iron nitrate and citric acid as precursors. The phase composition, crystal and magnetic microstructures, morphology, conductivity, and optical properties are characterized by X-ray diffraction, scanning electron microscope, impedance spectroscopy, Mössbauer spectroscopy, and UV-VIS spectroscopy. The mechanisms of phase transformation of amorphous ultrafine γ-FeOOH→ nanocomposite γ-Fe2O3/α-Fe2O3 in the temperature interval 150–350оС are established. The photocatalytic activity of samples was estimated by the degradation of methylene blue and formaldehyde under UV or visible light in an aqueous solution. The results indicate that the photocatalytic degradation activities of amorphous γ-FeOOH and nanocomposite γ-Fe2O3/α-Fe2O3 are higher than that of phase pure γ-Fe2O3. The photocatalytic property of samples is related to their conductivity and band gap. This implies that a synergistic effect exists between the conductivity and the photocatalytic activity in the ultrafine iron hydroxide/oxide systems. In addition, it can be attributed to the active heterogeneous Fenton process for γ -FeOOH and the microstructure of γ-Fe2O3/α-Fe2O3, which is probably caused by a successful combination of electronic structures of the phases of magnetite and hematite.
Our environment is greatly endangered by the accumulation of various toxic organic pollutants that are continually produced through unavoidable human needs and the industrialization process. Herein, we report highly active gold nanoparticles (AuNPs) immobilized on two-dimensional (2D) TiO2 nanosheets (AuNPs-TiO2NSs) as a catalyst for the catalytic reduction of nitroarenes (NAs) such as 4-nitroaniline (4-NA), 4-(4-nitrophenyl)morpholine (4-NM), 4-(2-fluoro-4-nitrophenyl)morpholine (4-FNM) and rhodamine B (RhB) dye in the presence of sodium borohydride (NaBH4) medium. Initially, TiO2NSs are prepared by the hydrothermal treatment followed by the modification with 3-aminopropyl-trimethoxysilane (APTMS) coupling agent for strong anchoring of the AuNPs. HR-TEM images exhibit that AuNPs (2.30 ± 0.06 nm) are immobilized on the surface of ultrathin 2-dimensional TiO2NSs. AuNPs-TiO2NSs catalyst shows excellent catalytic activity towards the reduction of various NAs (4-NA, 4-NM and 4-FNM) and RhB dye with maximum conversion efficiency of >98 %. Moreover, the pseudo-first-order rate constants are estimated as 5.50 × 10⁻³ s⁻¹, 7.20 × 10⁻³ s⁻¹, 6.40 × 10⁻³ s⁻¹ and 4.30 × 10⁻³ s⁻¹ for the reduction of 4-NA, 4-NM, 4-FNM, and RhB, respectively. For large-scale industrial applications, AuNPs-TiO2NSs catalyst embedded in a continuous flow-fixed bed reactor for the catalytic reduction of 4-NA and RhB dye under optimized reaction conditions. AuNPs-TiO2NSs catalyst shows high conversion rates for 4-NA (>99 %) and RhB (>99%) along with excellent recyclability over 12 cycles in continuous flow fixed bed reactor. The mechanism of synthetic pathway and catalytic reduction of NAs and RhB dye over AuNPs-TiO2NSs catalyst are also proposed. This study may lead to the use AuNPs-TiO2NSs catalyst with superior recyclable catalytic efficiency in various catalytic reactions.
The presence of persistent organic pollutants in industrial wastewaters is becoming a problem of major concern. In the present study we explored the degradation of azo dyes, well‐known common hazardous contaminants, by a green and efficient procedure using continuous flow photooxidative degradation. In particular, carbon dots synthesized from fishery waste (bass‐CDs) were used as a cheap and readily available photocatalyst in combination with oxygen and UV light. Methyl orange, acid red 18, amaranth, sunset yellow and chromotrope were chosen as model substrates and their degradation was studied both in batch and in continuous flow conditions. All the azo dyes were fully degraded with both techniques highlighting the suitability of bass‐CDs for the decontamination of wastewater. The main advantages are of using a “disposable” photocatalyst, in aqueous solvent and in continuous flow. In particular, continuous flow operation allowed faster decompositions: ca. 2 min versus 1‐3 hours needed in batch.
Amongst many chemical pollutants that cause environmental pollution, the presence of organic dyes in water resources can cause substantial health issues. Thus, owing to their mutagenicity and their adverse effects on human health, environment, and animals, they must be removed from industrial wastewater. In this study, UiO-66 metal–organic framework, as well as composite nanoparticles with carbonaceous materials such as MWCNTs-COOH and graphene oxide (GO) with different molar ratios (2.9 and 5.8 wt.%), were synthesized through solvothermal method since carbonaceous materials are an emerging material that demonstrates improvement in the properties of adsorbents. Then, the synthesized materials were utilized as a solid adsorbent for removing four different dyes including; anionic methyl red (MR), anionic methyl orange (MO), cationic methylene blue (MB), and cationic malachite green (MG) prepared from distilled water. The properties of prepared adsorbents were characterized via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Photoluminescence spectroscopy (PL), Brunauer–Emmett–Teller (BET), as well as surface area analyzer and energy dispersive spectroscopy (EDS-MAP). Further, the influences of various factors including initial concentrations of the dyes and adsorption process time on adsorption of dyes were investigated. Adsorption experiments indicated that synthesized adsorbents exhibited the highest adsorption efficiency towards MR and MO dyes. Moreover, the experimental adsorption results revealed that MWCNTs-UiO-66 nanocomposites could adsorb 98% of MR and MO as well as 72% of MB and 46% of MG. Furthermore, the kinetic and stability of the materials over time were investigated. To reach a clear picture, adsorption experiments demonstrated that the amount of dye uptake on adsorbents was enhanced by increasing the contact time as well as uptake of materials with time were stable for both cationic and anionic dyes. The MR, MO, and MB adsorption isotherms were fitted with the Langmuir and Freundlich models. The Langmuir showed the highest agreement in these dyes and MWCNTs-UiO-66 (2.9 and 5.8 wt.%) exhibited a maximum adsorption capacity of 105.26 mg/g for MR, while the MG isotherm was in line with the Langmuir model.
Coloring materials are classified as dyes and pigments. Dyes are soluble in their vehicle and make a solution; pigments are insoluble and result in a suspension. Dyes are used to impart color to textile, paints, cosmetics, food, and medicines. There are several ways to classify dyes based on the source of materials, the chemical structure, the nuclear structure, and industrial classification. One of the essential issues in applying dyes is safety, so there are many limitations and legislation on the use of dyes in different countries. Dyes and colorants showed several toxicities. Therefore, they need to be more studied, and if needed; their use should be limited or even banned.
Awareness of the harmful effects of chemical substances is gradually increasing and scientific investigations have time and again revealed the negative influences of the chemicals conventionally used. This has led to restricting the use of certain chemicals and dyes in textile wet treatments. Globally there has been an acceptance of this by branding agencies and retailers. Government organisations have also supported these restrictions, and curtailment in such chemical usage has now become the norm throughout the textile supply chain. This issue of Textile Progress reviews the chronological evolution of the restrictions leading to the concepts of RSL (Restricted Substances List) and MRSL (Manufacturing Restricted Substances List) now widely followed. The listing of harmful chemicals under Substances of Very High Concern (SVHC) is also discussed. The major chemicals or groups of chemicals facing restriction are dealt with in detail, covering their usage, hazards, sources, chemistry and possible substitutes (if any). Examples such as the alkyl phenols and alkyl phenol ethoxylates used for decades as detergents and wetting agents in preparatory processes, dyeing and printing were found to be potential hormone disruptors and very toxic to aquatic life, and substitutes have been put in place. Substances such as azo-amines, chlorophenols, formaldehyde, brominated flame retardants, heavy metals and fluorochemicals also have their share of adverse effects on human health and environment and need to be avoided. Studies have shown the presence of phthalates in routinely-used chemicals which can be traced back to the manufacturing process itself and other hazardous chemicals such as bisphenols, chloroparaffins, polycyclic aromatic hydrocarbons, quinoline, VOCs (Volatile Organic Compounds), biocides and UV absorbers have also figured in discussions. Comprehensive testing for the presence of the various restricted substances is essential but anomalies can arise.
Various improvement strategies have been developed to enhance the visible light photocatalytic properties of materials. In these enhancement strategies, bismuth, a non-noble metal-based plasma metal, is deposited on the surface of the photocatalyst, which can improve the visible light response and photocatalytic performance of the photocatalyst. Herein, we constructed montmorillonite loaded BiOCl nanosheets with in situ reduced bismuth by one-step hydrothermal method. As for the results of TEM analysis, the in-situ reduced bismuth nanoparticles with diameters of 5–20 nm were evenly distributed on the surface of BiOCl nanosheets. Due to the surface plasmon resonance (SPR) effect of semi metallic bismuth nanoparticles on the BiOCl nanosheets, the light absorption range of the modified photocatalyst was expanded and its absorption band gap (Eg) was reduced from 3.16 eV (pure BiOCl) to 2.26 eV. Besides, the results of dark adsorption experiments confirmed that the montmorillonite supporter greatly enhanced the adsorption capacity of the modified photocatalyst for pollutants. Moreover, the radical species trapping tests revealed that •O2⁻ and h⁺ were the pivotal active agents in the pollutant degradation process. The visible light driven photocatalytic degradation rate of TCs and RhB by the modified photocatalyst was 3 and 4 times higher than that of pure BiOCl because of the synergistic effect of montmorillonite supporter and bismuth nanoparticles. The present work provides an innovative strategy for the great feasibility of fabricating low-cost clay and effective bismuth nanoparticles as a substitute for noble metal in environmental pollutants degradation.
A population-based case-control study was conducted in Los Angeles, California, which involved 1,514 incident cases of bladder cancer and an equal number of age-, sex- and ethnicity-matched controls. Information on personal use of hair dyes was obtained from 897 cases and their matched controls. After adjustment for cigarette smoking, a major risk factor for bladder cancer, women who used permanent hair dyes at least once a month experienced a 2.1-fold risk of bladder cancer relative to non-users (p for trend = 0.04). Risk increased to 3.3 (95% CI = 1.3–8.4) among regular (at least monthly) users of 15 or more years. Occupational exposure to hair dyes was associated with an increased risk of bladder cancer in this study. Subjects who worked for 10 or more years as hairdressers or barbers experienced a 5-fold (95% CI = 1.3–19.2) increase in risk compared to individuals not exposed. © 2001 Wiley-Liss, Inc.
Reduction of seven azo dyes (amaranth, Ponceau SX, Allura Red, Sunset Yellow, tartrazine, Orange II, and methyl orange) was carried out by cell suspensions of predominant intestinal anaerobes. It was optimal at pH 7.4 in 0.4 M phosphate buffer and inhibited by glucose. Flavin mononucleotide caused a marked enhancement of azo reduction by Bacteroides thetaiotaomicron. Other electron carriers, e.g., methyl viologen, benzyl viologen, phenosafranin, neutral red, crystal violet, flavin adenine dinucleotide, menadione, and Janus Green B can replace flavin mononucleotide. These data suggest that an extracellular shuttle is required for azo reduction.
We have evaluated the mutagenic activity of a series of diazo compounds derived from benzidine and its congeners o-tolidine, o-dianisidine and 3,3'-dichlorobenzidine as well as several monoazo compounds. The test system used was a modification of the standard Ames Salmonella assay in which FMN, hamster liver S9 and a preincubation step are used to facilitate azo reduction and detection of the resulting mutagenic aromatic amines. All of the benzidine and o-tolidine dyes tested were clearly mutagenic. The o-dianisidine dyes except for Direct Blue 218 were also mutagenic. Direct Blue 218 is a copper complex of the mutagenic o-dianisidine dye Direct Blue 15. Pigment Yellow 12, which is derived from 3,3'-dichlorobenzidine, could not be detected as mutagenic, presumably because of its lack of solubility in the test reaction mixture. Of the monoazo dyes tested, methyl orange was clearly mutagenic, while C.I. Acid Red 26 and Acid Dye (C.I. 16155; often referred to as Ponceau 3R) had marginal to weak mutagenic activity. Several commercial dye samples had greater mutagenic activity with the modified test protocol than did equimolar quantities of their mutagenic aromatic amine reduction products. Investigation of this phenomenon for Direct Black 38 and trypan blue showed that it was due to the presence of mutagenic impurities in these samples. The modified method used appears to be suitable for testing the mutagenicity of azo dyes, and it may also be useful for monitoring the presence of mutagenic or potentially carcinogenic impurities in otherwise nonmutagenic azo dyes.
Urinary benzidine and conjugates have been used to assess the extent of occupational exposure to benzidine-based azo dyes. The aim of the present study was to investigate the presence of benzidine and its conjugates in the urine of workers exposed to benzidine-derived dyes. Urine samples were collected from 29 workers in three textile dyehouses, two tanneries, and two dyestuff quality control laboratories in West Yorkshire and Lancashire. In 200 samples, obtained over a period of 15 months and analysed by gas chromatography/mass spectrometry, no free benzidine or monoacetylbenzidine was detected. Nevertheless, after strong acid hydrolysis of urine samples taken on two separate occasions from textile dye weighers where the standard of hygiene appeared below average, trace amounts of benzidine were detected suggesting the excretion of a benzidine derived dye or a metabolite thereof.
Azo dyes represent the major class of dyestuffs. They are metabolised to the corresponding amines by liver enzymes and the intestinal microflora following incorporation by both experimental animals and humans. For safety evaluation of the dermal exposure of consumers to azo dyes from wearing coloured textiles, a possible cleavage of azo dyes by the skin microflora should be considered since, in contrast to many dyes, aromatic amines are easily absorbed by the skin. A method for measuring the ability of human skin flora to reduce azo dyes was established. In a standard experiment, 3x10(11) cells of a culture of Staphylococcus aureus were incubated in synthetic sweat (pH 6.8, final volume 20 mL) at 28 degrees C for 24 h with Direct Blue 14 (C.I. 23850, DB 14). The reaction products were extracted and analysed using HPLC. The reduction product o-tolidine (3,3'-dimethylbenzidine, OT) could indeed be detected showing that the strain used was able to metabolise DB 14 to the corresponding aromatic amine. In addition to OT, two further metabolites of DB 14 were detected. Using mass spectrometry they were identified as 3,3'-dimethyl-4-amino-4'-hydroxybiphenyl and 3, 3'-dimethyl-4-aminobiphenyl. The ability to cleave azo dyes seems to be widely distributed among human skin bacteria, as, under these in vitro conditions, bacteria isolated from healthy human skin and human skin bacteria from strain collections also exhibited azo reductase activity. Further studies are in progress in order to include additional azo dyes and coloured textiles. At the moment, the meaning of the results with regard to consumer health cannot be finally assessed.
A population-based case-control study was conducted in Los Angeles, California, which involved 1,514 incident cases of bladder cancer and an equal number of age-, sex- and ethnicity-matched controls. Information on personal use of hair dyes was obtained from 897 cases and their matched controls. After adjustment for cigarette smoking, a major risk factor for bladder cancer, women who used permanent hair dyes at least once a month experienced a 2.1-fold risk of bladder cancer relative to non-users (p for trend = 0.04). Risk increased to 3.3 (95% CI = 1.3-8.4) among regular (at least monthly) users of 15 or more years. Occupational exposure to hair dyes was associated with an increased risk of bladder cancer in this study. Subjects who worked for 10 or more years as hairdressers or barbers experienced a 5-fold (95% CI = 1.3-19.2) increase in risk compared to individuals not exposed.
Benzidine based azodyes are proven carcinogens, mutagens and have been linked to bladder cancer of human beings and laboratory animals. The textile and dyestuff manufacturing industry are the two major sources that released azodyes in their effluents. The dye, Direct blue contains two carcinogenic compounds namely benzidine (BZ), 4-amino biphenyl (4-ABP), while the dye Direct red has benzidine (BZ). Among 40 isolates of Pseudomonas fluorescens screened, one isolate designated as D41 was found to be capable of extensively degrading the dyes Direct blue and Direct red. Immobilized cells of P. fluorescens D41 efficiently degraded Direct red (82%) and Direct blue (71%) in the presence of glucose.
Azo colorants can be divided in bioavailable, soluble azodyes and in non-bioavailable, non-soluble azo pigments. Bioavailable azodyes are cleaved reductively in the human organism under liberation of the aromatic amines used as diazo component for synthesis of the dye. Since epidemiological studies point to an enhanced incidence of tumors of the urinary bladder in painters, working histories of painters in Germany (before 1960) have been examined. Up to the 1950ies it was usual for painters to mix and prepare their painting materials themselves, with the possibility of inhalation exposure to the dust of colorants. Also, case histories revealed the particular possibility of direct skin contact. For wall painting, also in former times mineral pigments were used. Soluble azo dyes, including those based on benzidine, were used in materials for the surface treatment of woods. Differences between the former work profile of painters and the current practice are evident. Hence, it is important to relate bladder cancer cases of painters to the former work conditions.
The continued use of permanent hair colors utilizing oxidative dyes cannot be recommended until more evidence on their safety is found. The consumer should be aware that these dyes do not have the approval of the Food and Drug Administration, while certain of the temporary hair dyes do have FDA approval. The evidence against hair dyes that is now appearing serves to give additonal caution to the user of textile dyes. Substances used for cosmetic or food purposes have always had more extensive testing than substances used for fabrics or paints. Oxidative hair dyes have been used and studied for almost 100 years. Textile dyes have not received nearly this amount of study, and should be used with the care necessary of chemicals with unknown physiological effects. Both the craft-dyer and industrial textile dyer are not always aware of the chemical dye class being used, and therefore cannot know the potential risk involved in the use of a particular dye. For this reason, each of the major dye classes is discussed separately in this paper along with a brief desciption of typical dyeing procedures and fabrics dyed, to assist in better identification. (73 references).
It has been known for many years that the etiology of bladder cancer is associated with the exposure to (some) aromatic amines. However, the carcinogenic potential of azo dyes based on carcinogenic aromatic amines has been controversially discussed. A large number of investigations has demonstrated that humans and other mammals as well possess the capability of reducing azo dyes to the initial aromatic amines. Some recent investigations suggest that bladder cancer in humans can be directly attributed to exposure to benzidine-based dyes. According to the large application in many industries and occupations benzidine-based dyes may significantly contribute to the pathogenesis of occupational bladder cancer.
A series of bisazobiphenyl dyes derived from benzidine, 3-3′-dimethylbenzidine or 3,3′-dimethoxybenzidine were studied in the dog and rat. The dyes, which are commercially useful in the textile and leather industries, possess potential for metabolism to the carcinogenic aromatic amines, benzidine, 3,3′-dimethylbenzidine and 3,3′-dimethoxybenzidine via metabolic reduction of the azo bonds. Dyes were administered orally and the urine analyzed for benzidine, 3,3′-dimethyl- or 3,3′-dimethoxybenzidine using a specific gas chromatographic assay. The identity of the chromatographic peaks was confirmed by gas chromatography-mass spectrometry. Dogs treated acutely (100 mg/kg) with benzidine derived dyes excreted substantial quantities of benzidine (166–1675 μg) in urine (0–48 hr). No benzidine was detected in urine prior to treatment. Benzidine present in dog urine following dye administration exceeded by at least ninefold the benzidine present as impurity in the administered dyes and was comparable to that excreted in urine when pure benzidine was fed (100 mg/kg). Rats chronically dosed (100 mg/kg/day) with benzidine-based dyes excreted N-acetylbenzidine (3–54 μg/day) and traces of benzidine in urine. Bisazobiphenyl dyes derived from 3,3′-dimethylbenzidine and 3,3′-dimethoxybenzidine were metabolized to 3,3′-dimethyl- and 3,3′-dimethoxybenzidine, respectively, in both the dog and rat. The N-acetyl derivatives of 3,3′-dimethyl- and 3,3′-dimethoxybenzidine were identified in urine from rats treated with dyes derived from 3,3′-dimethyl- and 3,3′-dimethoxybenzidine, respectively. Results from this study indicate that the metabolic conversion of bisazobiphenyl dyes, derived from benzidine and 3,3′-dimethyl- and 3,3′-dimethoxybenzidine, to carcinogenic aromatic amines is a general phenomenon and therefore with few exceptions should be anticipated for each member of this class of chemicals.
Carcinogenicity studies on three purified diarylide pigments and one contaminated with 3,3′-dichlorobenzidine (DCB) were conducted in mice and rats at concentrations of 0.1, 0.3 and 0.9% in the feed. The studies were terminated after 104 weeks of treatment. Both mice and rats tolerated the different pigments up to a dietary level of 0.9%, receiving an equivalent of 715 and 230 g/kg/year, respectively. No adverse effects were exerted on growth, food intake, health condition, survival, or the histological appearance of a wide range of tissues, even when DCB was added to the pigment at a concentration of 20 ppm. In mice and rats of both sexes there was no indication of a significant correlation between treatment and tumour incidence. Based on the results, it is likely that diarylide yellow pigments were not absorbed after oral ingestion and it is unlikely that they underwent a metabolic splitting to DCB or 3,3′-dimethylbenzidine (DMB) either in mice or in rats. This fact was confirmed by an additional study in rabbits after single oral treatment at a dose level of 50 mg/kg.
Analysis of the lifetime occupation histories of 1030 patients with bladder tumours compared to control groups showed two
patterns of industrial hazard. The classic pattern showed risk from all periods of exposure and the development of tumours
at a lower age. Chemical dyeworkers, and possibly textile dyers and cutters and hairdressers, showed this pattern. A long-term
pattern, present among weavers, tailors, tailor's pressers and possibly among cooks, electricians and some engineering workers
showed risk after long periods of exposure only. The reality of the risks was supported by the larger proportion of bladder
patients (53 per cent compared to 35 per cent) who had only one occupation and by comparison with census data.
The azo reductase activity of a cell-free extract of Fusobacterium sp. 2 is characterized using trypan blue as a substrate. Either chemical reduction of this dye with sodium hydrosulfite or reduction by the cell-free extract produces a mutagenic product, o-tolidine. The o-tolidine is mutagenic in the Ames Salmonella/mammalian-microsome mutagenicity test when activated by a rat liver S9 preparation.
3-3'dichlorobenzidine (DCB) was shown to be absent from the urine of rats, rabbits and monkeys to which were given orally 20 and 400 μg/kg of C.I. Pigment Yellow 13, an insoluble yellow pigment derived from DCB. The study was made by means of thin layer chromatography on samples of 50 ml urine collected over 48 hours. The analysis, which has a sensitivity of 0,05 μg, did not reveal presence of DCB in the urine of the three species under study, neither before nor after enzymatic and acid hydrolysis of the samples.
A recent study of relationships between occupation and cancer at Roswell Memorial Institute, Buffalo, New York, identified significantly high risks of bladder among men and women with a history of employment in plants manufacturing leather and leather products. Among males, the relative risk increased with duration of employment and remained elevated after adjustment for smoking habits. Among male leatherworkers, significantly increased risks were seen for cancers of the buccal cavity and pharynx and larynx that could not be explained by differences in smoking habits. Malignant lymphomas were also associated with elevated risks among men and women who had worked in the leather industry. Review of processes and agents found in leather manufacture reveals several areas with exposure to potentially carcinogenic materials, including azo and other synthetic dyes that have induced cancer in laboratory animals. Further studies of person employed in the leathermaking and fabrication industries seem advisable to characterize the nature of exposure-response relationships.
Rhesus monkeys were fed azo dyes derived from benzidine (a known human bladder carcinogen). The urinary excretion of free benzidine was assayed and compared to the amount excreted when benzidine itself was fed. A substantial amount of the dye fed was converted to free benzidine. Results indicate that the simple precaution in the use of only azo dyes manufactured from noncarcinogenic aromatic amines, e.g., aniline, for all consumer products appears prudent. The knowledge that the aromatic amines 2 naphthylamine, benzidine, and 4 aminobiphenyl are carcinogenic has led to precautions and legislative restriction on their manufacture, while azo dyes derived from them have not received the same consideration, even though it has been known for some time that man and other mammals can metabolically reduce such dyes to free aromatic amines.
Under study was the urine from 22 workers being in long-term contact with direct azo dyes (direct black 3, direct diazo black, direct pure blue, direct light fast KU). Benzidine was found in the urine of 8 workers and dianisidine--in 3. Consequently, there occurs metabolic decomposition of the dyes concerned to free blastomogenic agents.
In a case-control study, 403 male patients with a diagnosis of "bladder tumor" and (as controls) 426 patients suffering from prostate disease were investigated. The results of this study indicate that past employment as a painter was associated with an excess risk of bladder tumor. The relative risk of bladder tumor estimated for painters was 2.76. The possible role of benzidine-based azodyes (or azodyes based on substituted benzidines) as a carcinogenic risk factor for painters is discussed.
Occupational bladder cancer due to aniline dye intermediates such as beta-naphthylamine and benzidine has long been known; benzidine congeners (o-tolidine and o-dianisidine) are highly suspect. Among 400 men from the Amalgamated Clothing and Textile Workers Union (ACTWU) Dyers locals in New York and New Jersey screened over a 4-year period, two cases of bladder cancer were detected. (Microscopic hematuria, not cytological evaluation, prompted further investigation.) Before a 1984 ACTWU screening program in North Carolina, three workers from the same plant self-reported bladder cancers. Another member, with inconclusive screening results, was diagnosed 2 years later. For these six cases, the mean age at detection was 56.5 years (age range, 38 to 79 years), a decade earlier than age at diagnosis of nonoccupational bladder cancer in men. The average latency from onset of exposure to diagnosis was 23.3 years. These cancers provide evidence to support the initiation of screening programs for high-risk workers. To overcome the emotional and economic disincentives faced by potential victims of occupational bladder cancer, training programs are needed. Worker involvement is required, through trade union representation where possible, to assure reliable training and the equitable distribution of screening and treatment costs.
The kinetics of total DNA adducts were compared in the liver, bladder epithelium and small intestinal epithelium of rats and mice following a single oral dose (100 mg/kg) of 3,3'-dichlorobenzidine [( 14C]DCB). Peak DNA binding (expressed as pmol DCB bound/mg DNA) in rat tissues was 153.5, 144.8 and 36.9 in the intestine, bladder and liver, respectively, whereas in mouse tissues, the binding was 72.5, 58.2 and 55.8, respectively. In either species, the half-life of the DNA adducts in the liver (13.5 and 13.8 days in rats and mice, respectively) was comparable to that in the bladder epithelium (14.8 and 12.7 days in rats and mice, respectively) but longer than that in the intestinal epithelium (5.9 and 4.7 days in rats and mice, respectively). Peak total DCB binding in hepatic but not intestinal or bladder epithelial DNA correlated positively with total urinary DCB metabolites. In vitro, mouse hepatic S9 was 57% more active in catalyzing the formation of DNA-binding derivatives of DCB, in parallel with the higher in in vivo maximum hepatic DNA binding in mice than in rats. Thus, a single oral dose of DCB in rats and mice leads to extensive binding of the chemical to tissue DNA, with the rate of removal of the adducts not differing between target and non-target tissues.
In the following review, available data on the metabolism, biological reactivity, mutagenicity, and carcinogenicity of 3,3'-dichlorobenzidine (DCB) are discussed and compared to those of other benzidines and carcinogenic arylamines
Urine samples of workers in a small-scale unit manufacturing Direct Black 38 were analyzed by high-pressure liquid chromatography for the presence of benzidine and mono and diacetyl benzidine. Acetylated metabolites were found in all the urine samples, and benzidine was found in all except two. Two workers excreted very high levels of benzidine and its metabolites in their urine. This study highlights the potential risk of bladder cancer in such units of developing countries where manufacture of benzidine-based dyes is yet to be regulated.
The role of the rat intestinal flora in the azo reduction of some benzidine-based dyes was studied in vitro and in vivo. The formation of benzidine was measured after anaerobic incubation of direct black 38, direct blue 6 and direct brown 95 in the presence of caecal bacteria in vitro. Benzidine was absorbed from the intestinal tract much better than the parent compounds. Oral administration of direct black 38 or direct brown 95 to Wistar rats results in the urinary excretion of mutagens. After oral administration of these dyes to germ-free Wistar rats no mutagenicity was observed in urine. The present results show that after oral administration, reduction by the intestinal flora should be considered as the first essential step in the biotoxification of benzidine-based dyes.
A cohort of 703 male and 677 female hairdressers born from 1880 onwards, who started to run salons in Geneva between 1900 and 1964 was followed-up to the end of 1982. Cause-specific mortality was analysed from 1942 to 1982 and a significant excess mortality from bladder cancer (observed deaths = 10, expected deaths = 3.9) was found among males. Cancer incidence recorded for the years 1970 to 1980 showed a significant increase among males for all neoplasms (O = 65, E = 51.4), cancer of the buccal cavity and pharynx (O = 6, E = 2.5), cancer of the prostate (O = 12, E = 6.1), and bladder cancer (O = 11, E = 5.3). Among female hairdressers no significant increase in mortality or in cancer incidence was found. Mean age at diagnosis of the 18 deaths and/or incident cases from bladder cancer found among the male hairdressers was 68.6 years (range 51-88) and mean latency period since first exposure was 52.2 years (range 24-73). Occupational history was obtained for most of the 18 cases and of 54 controls randomly selected from the cohort. Little evidence was found of a causal relationship between exposure to hair dyes and the excess risk for bladder cancer among the male hairdressers. It is a suggestion that this excess might be related to some colouring agent(s) in brilliantines which were widely used in men's hairdressing salons in Geneva until about 1950.
The yellow transparent O and K pigments are not mutagenic in the Ames and sister chromatid exchange tests. In chronic experiments with CC//5//7 white female mice and noninbred rats these substances showed marked carcinogenicity.
Metabolism experiments were conducted with rats dosed with nine azo dyes based on dimethyl-, dimethoxy-, or dichlorobenzidine
to determine whether the free amine congeners, their monoecetyl or diacetyl metabolites, or alkaline hydrolyzsble conjugates
were excreted in the urine. After preliminary tests of the dyes, 2-mg doses were administered to each animal and urine samples
were collected at intervals up to 96 hours. EC/GC procedures were based on the analysis of heptafluorobutyryl derivatives
of the free amine congener moleties or their monoacetyl metabolites. Peak levels of metabolites were excreted either 0–12
or 12–24 hours after administration and, in seven of nine instances, no metabolites persisted in the urine after 48 hours.
Minimum detectable levels of all metabolites were 12 ppb or less. All nine dyes were shown to be converted to measurable levels
of their benzidlne-congener-based metabolites in rats.
The fate of two water-insoluble (WI) dichlorobenzidine-based pigments, chlorodiane blue (CDB) and pigment yellow 12 (PY12), and of their sulfonated water-soluble (WS) analogs was studied in male Fischer 344 rats. Water-soluble analogs of chlorodiane blue and pigment yellow 12 were synthesized in order to study the effect of water solubility on the absorption and metabolism of dichlorobenzidine-based pigments. [14C]WI-CBD, [14C]WI-PY12, and the water-soluble analogs [14C]WS-CDB and [14C]WS-PY12 were administered by gastric intubation or dermal application at doses of 1.24-2.65 mumol/kg. Neither [14C]WI-CDB nor [14C]WI-[Y12 could be detected in any tissue at time points up to 1 d. The entire dose was accounted for in the feces after oral administration, and at the application site after dermal administration. Water-insoluble CDB is a component of a photoconductor (Weaver, 1981). Approximately 4.1% of [14C]CDB was observed and located primarily in the urine and liver after oral administration, but no detectable amount was absorbed after dermal application. Metabolites of [14C]WS-CDB identified in the urine were 3,3'-dichlorobenzidine diacetate, 3.3'-dichlorobenzidine and its glucuronide conjugate, and 3,3'-dichlorobenzidine monacetate and its glucuronide conjugate. Only 0.02% of [14C]WS-PY12 was absorbed after oral administration. Thus, some degree of water solubility was prerequisite for even a small amount of absorption or metabolism in vivo.
The ability of rat liver microsomes from phenobarbitone pretreated animals to reduce the azo groups of amaranth, sunset yellow, congo red, trypan blue, chloramine sky blue FF and direct black 38 was measured spectrophotometrically in vitro. The dyes amaranth and sunset yellow acted as positive controls. Of the dyes derived from benzidine or its congeners, only direct black 38 was reduced to an appreciable extent; the rate of reduction was 10% of that for amaranth. The dyes were tested for mutagenicity in the Salmonella/microsome assay, the only active compound being direct black 38. Mutagenicity of this dye may be due in part to the mutagen 1,2,4-triaminobenzene. Mutagenic activity and azo-reduction of direct black 38 was independent of the presence of oxygen. The results presented suggest that mammalian liver may play only a minor or negligible role in the azo-reduction of dyes derived from benzidine or its congeners.
Six azodyes derived from benzidine, o-tolidine or o-dianisidine were separately administered orally by gavage to rats. Urine was collected over a 24 h period. Following dichloromethane extraction, urines were analysed by h.p.l.c. for the presence of the respective parent amine and its N-acetylated and N,N'-diacetylated derivatives. After alkaline hydrolysis, urines were analysed for the amines resulting from the cleavage of N-conjugates. All six dyes, direct black 38, direct brown 95, direct blue 6, Congo red, trypan blue and Chicago sky blue were found to be reduced, N-acetylated and N-conjugated. However, no N,N'-diacetylated metabolites were detected. After administration of the same dyes via injection into the hepatic portal vein, bile was collected over a 3 h period by cannulation of the bile duct. Urine was withdrawn from the bladder by syringe at the end of the three hours. Both body fluids were analysed for reduction products which were found only in the case of direct black 38, direct brown 95 and direct blue 6. Of the six dyes examined only the three direct dyes were mutagenic to S. typhimurium strains TA98 and TA1538 in the absence of flavin mononucleotide. The same three dyes were also substrates for rat liver microsomal azoreductase enzymes whereas Congo red, trypan blue and Chicago sky blue were shown to be inactive in a previous publication. The possible relationship between these results and the potent carcinogenicity exhibited by direct black 38, direct blue 6 and direct brown 95 is discussed.
Urine samples from 36 workers exposed to dichlorobenzidine (DCB)-derived pigments and 12 controls were screened for aromatic amines by a nonspecific colorimetric method and then further analyzed by GC/MS specifically for DCB and monoacetyldichlorobenzidine. Of the samples screened for aromatic amines, six (17%) of the exposed population and one (7%) of the control population registered positive (1.0 part per billion [ppb] or greater). One of the positive samples (5.6 ppb) reflected medication, and the remainder (1.1 to 1.8 ppb) were due to high urinary background. The specific analyses were negative (less than 0.2 ppb) for DCB or monoacetyldichlorobenzidine in all samples.
The metabolism of a benzidine-based dye, Direct Black 38, a 3,3'-dimethylbenzidine-based dye, Direct Red 2 and a 3,3'-dimethoxybenzidine-based dye, Direct Blue 15 has been studied both in pure cultures of anaerobic bacteria and in bacterial suspensions derived from the intestinal contents of the rat. All of the pure cultures and the rat intestinal bacteria were able to reduce the azo linkages of Direct Black 38, Direct Red 2 and Direct Blue 15 with the subsequent formation of benzidine, 3,3'-dimethylbenzidine and 3,3'-dimethoxybenzidine, respectively. The metabolites of Direct Black 38, Direct Red 2 and Direct Blue 15 were isolated and identified by gas chromatography/mass spectrometry and had similar chromatographic and mass spectral properties with those of authentic standards. Results from this study indicate that in vitro anaerobic incubations of rat intestinal microorganisms were able to reduce and cleave the azo bonds of dyes derived from benzidine, 3,3'-dimethylbenzidine and 3,3'-dimethoxybenzidine to form potentially carcinogenic aromatic amines.
Impurities of aromatic amines in the azo dye and pigment, Direct Black 38 and Pigment Yellow 12, and in vitro stability of the dye were determined. These factors can affect the results of studies designed to ascertain whether the two
compounds are metabolized to potential carcinogens in hamsters. Procedures for removing impurities from the two compounds
are also presented. Electron-capture gas chromatography of the heptafluorobutyryl derivatives of the impurities and degradation
products was used to satisfy all the analytical requirements of the experiments. Major impurities found in Direct Black 38
were benzidine, 4-aminobiphenyl and 2,4-diaminoazobenzene; whereas, only 3,3′-dichlorobenzidine was found in Pigment Yellow
12. Stability studies of the purified dye conducted in water and in urine from hamsters and humans indicated that the dye
would not degrade under the conditions used for collecting and assaying samples from a metabolism experiment. However, within
48 hours at 25 and 37.5°C. the dye did degrade to known carcinogens in both hamster and human urine. Such degradation not
only points out the need for proper storage of samples from metabolism studies but suggests that industrial effluents containing
the dye should be properly treated before release into the environment.