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Introduction to Textile Printing
Published in Asim Kumar Roy Choudhury, Principles of Textile Printing, 2023
By 1850, the empirical formula of an organic compound could be easily established, but the structure of these organic molecules remained a perplexing problem for organic chemists. Kekule’s most remarkable single contribution to organic chemistry was his paper, published in 1865, on the structure of benzene. The solution of the structure of benzene made an enormous impact on both organic chemistry and the dyestuff industry. The immediate impact of unrevealing chemical structures was the manufacture of two important natural dyes – alizarin and indigo – by chemical synthesis. Simultaneously, new classes of synthetic dyes were developed such as xanthenes, phenolthiazines and sulfur dyes. Meanwhile, significant progress had been made in azo dyes. Caro in 1875 discovered Chrysoidine, a dye used for many years, by diazotizing aniline and coupling the diazonium compound with m-phenylenediamine, the first azo dye for wool. Congo Red, made in 1884, was the first dye which had direct affinity for cellulose, and could be applied directly on cotton without using any mordant, while the natural coloring matters used in those days invariably required a mordant (Roy Choudhury, 2006).
Photocatalytic degradation of Congo red dye using Visible Light Active (VLA) carbon doped titanium dioxide nanocomposite and its kinetics
Published in Alka Mahajan, Parul Patel, Priyanka Sharma, Technologies for Sustainable Development, 2020
Jammula Koteswararao*, Madhu Gattumane Motappa, Venkatesham Vuppala, Nagaraju Kottam
The use of nanomaterials and nanomaterial composites for water treatment is relatively new area compared to other processes. Nanoparticles are promising as they exhibit unique properties such as, large surface area and the ease with which they can be attached onto the solid matrices for enhanced treatment in aqueous and gaseous streams (Sowmay et al., 2018). Congo red is a secondary diazo dye, soluble in water yielding red colloidal solution. Congo red and other bright dyes are commonly used in the manufacture of silk clothing. It is highly toxic to many organisms and is a potential carcinogen and hence absolutely essential for treatment (Konstantinou et al., 2004, Yang et al., 2010; Chen and Wang, 2014; Thomas et al, and Nair et al., 2016).
Graphene Oxide and Its Nanocomposite for Wastewater Treatment
Published in Dhiraj Sud, Anil Kumar Singla, Munish Kumar Gupta, Nanomaterials in Manufacturing Processes, 2023
Arshpreet Kaur, Harshita Bagdwal, Gagandeep Kaur, Dhiraj Sud
Congo red, a diazo anionic dye, is a sodium salt of benzidinediazo-bis-1-naphthylamine-4-sulfonic acid. The color of the dye shows the pH dependency as in basic medium, the red color of dye appears and turns into blue color when medium changes to acidic. Large volume discharges of Congo red dye that are elaborated with benzidine into a water body constitute a health risk to human bodies and aquatic lives.
Removal of Malachite Green using carbonized material derived from disposable facemasks: optimization of removal process through Box–Behnken design
Published in Environmental Technology, 2023
Subramanian Srinivasan, R.S. Kaarmukhilnilavan, Kumarasamy Murugesan
Textile, food, pharmaceutical, paper printing, leather and cosmetic sectors are the main sources of dyes [3–5]. The majority of dyes are discharged into the environment due to the inefficacy of dye molecules for complete attachment to materials [6,7]. It is very complicated to degrade dye by nature, and their presence in water bodies pollutes natural environment and causes health problems [8]. The presence of trace amount of hazardous dyes in water causes a significant environmental impact. For example, Malachite Green (MG) a cationic dye used in textile and aquaculture as a fungicide and Congo Red (CR), a diazo anionic dye used in textile dyeing (Figure 1a and b). MG is a toxic dye utilised not only for product coloration in the textile, paper, rubber and leather sectors [9] but also as an antiprotozoan, fungicide in fisheries. However, referral studies had revealed that MG is toxic (at 0.05 mg/L) to freshwater species in both acute and chronic exposure. Similarly, Congo red is another anionic azo dye mainly used in textile industries for staining silk and cotton cloths. It is also used as a staining agent in biological laboratories to visualize cells. Studies have proven that these dyes can produce serious carcinogenic and toxic effects in mammalian cells and organs such as kidney, lung, spleen and skin [10,11]. Moreover, these synthetic dyes deteriorate the water quality. Hence, for the health and environmental concerns, the removal of dyestuffs from coloured effluent is a primary process in textile wastewater treatment processes [12].
Capability of potato peel powder (PPP) for the adsorption of hazardous anionic Congo dye
Published in Journal of Dispersion Science and Technology, 2022
One of the most polluting industries on the earth is the textile industry. According to the World Bank, textile treatment and dyeing account for around 20% of all global industrial water pollution. It is well established that dumping dyes into bodies of water reduces sunlight penetration, increases biological and chemical oxygen consumption, inhibits photosynthesis, and limits plant development.[2] Dye-containing effluent is commonly generated during dyeing and printing procedures. These dyes are used to color industrial end products including cloth, paper, and other materials. Congo red is the adsorbate that is to be removed from water. It’s a type of azo dye. It gives red colored solution in the aqueous phase at pH > 5 and the color changes to blue at more acidic pH. Its chemical formula is C32H22N6Na2O6S2. The molecular weight of Congo red is 696.665 mol/g, λmax = 496 nm (Figure 1).
Production of cellulase by Novosphingobium sp. Cm1 and its potential application in lignocellulosic waste hydrolysis
Published in Preparative Biochemistry & Biotechnology, 2022
Kongkana Goswami, Hari Prasanna DekaBoruah, Ratul Saikia
To isolate cellulolytic bacterial strains, 180 soil samples have been gathered from the rainforest area of Dehing-Patkai wildlife sanctuary, Assam, India. For this, 114 bacterial strains were isolated and primarily examined on CMC-agar plates as CMC induces a higher level of cellulase production. Further, Congo red test was performed as a secondary screening method to identify the best cellulase producer amongst the isolates. Congo red binds to the non hydrolyzed cellulose only and helps to identify the hydrolyzed cellulose that forms a halo zone around the bacterial colonies.[25] Several studies reported this method to identify the best cellulase producing strains based on their hydrolytic zone. In the present study, 14 isolates showed cellulolytic zone on CMC agar plates. A positive control LCB-66 (Bacillus oceanisediminis: KY631533) was considered for the study as Bacillus oceanisediminias has already been reported for its cellulolytic potential.[26] The bacterial strain C2, followed by Cm1 showed the maximum ratio of a clear zone when compared to the other 12 isolates (Table 1).