Textile industries are responsible for one of the major environmental pollution problems in the world, because they release undesirable dye effluents. Textile wastewater contains dyes mixed with various contaminants at a variety of ranges. Therefore, environmental legislation commonly obligates textile factories to treat these effluents before discharge into the receiving watercourses. The treatment efficiency of any pilot-scale study can be examined by feeding the system either with real textile effluents or with artificial wastewater having characteristics, which match typical textile factory discharges. This paper presents a critical review of the currently available literature regarding typical and real characteristics of the textile effluents, and also constituents including chemicals used for preparing simulated textile wastewater containing dye, as well as the treatments applied for treating the prepared effluents. This review collects the scattered information relating to artificial textile wastewater constituents and organises it to help researchers who are required to prepare synthetic wastewater.
Dear readers! Our articles talk about typical ways to solve the issue of renting industrial premises, but each case is unique.
If you want to know how to solve your particular problem, please contact the online consultant form on the right or call the numbers on the website. It is fast and free!
- Textile Dyes: Dyeing Process and Environmental Impact
- Celebrating 40 years of Trust & Quality work
- United Colours of Industry
- Textile dye wastewater characteristics and constituents of synthetic effluents: a critical review
- Chemical building blocks and useful products
- Unit of competency details
- Company profile
- Dyeing and printing
- SOLAR CELLS
SustainabilityVIDEO ON THE TOPIC: Dyeing Process
Of all dyes produced across the world, 11 per cent goes out as effluents. Each year, India produces 64, tonnes of dyes, 7, tonnes of which are directly discharged into the environment.
Enough to dye the river Sabarmati! While colours brighten our world, they are also ubiquitous and pervasive. We're not talking nature here, but products that are created by industry.
Like food colours, textile dyes, printing inks, pigments, acids, paints, even colours used in plastic. What goes into them? How are they manufactured? What is the monitoring mechanism? What are the procedures governing effluents? Can using them affect our health? What about the other end of the spectrum? What is the footprint we leave by using so many coloured products?
Does industrial discharge affect the drinking water sources of villages and towns far away? What are the regulations and how can they be enforced? Issues like this also need to be addressed, says kushal pal singh yadav. United Colours of Industry. Colours are inescapably embedded in everyday life. So it's critical to know, and to regulate , the way they operate.
Having said that, it's not easy to recognise the problems associated with their use. Adulteration in food colours, or allergic reactions to elements in fabric apart, consumers are unaware of problems caused by agents and vehicles of colour. But a look at the tailpipe in any industrial zone can cure that. Untreated and sometimes even treated effluents from these industries, released into rivers, lakes or through the drainage systems, seep into the groundwater and adjoining water bodies.
The cpcb puts their number at units. Only a third of these are in the organised sector, while the remaining come from the unregulated small-scale sector, which produces more than half of India's aggregate volumes. Most of these units are located in Gujarat more than 60 per cent of the total production and Maharashtra. In India, dyestuffs are consumed mainly by textile, paint and printing ink industries.
The textile industry consumes up to 80 per cent. Budget over quality The domestic textile industry looks for manageable costs rather than consistent quality. So the bulk of its demand for dyes is met by the small-scale sector, while the organised sector looks to exports or high-end producers. The small-scale sector's substantially lower investment in pollution control measures also makes it more economical.
We dye, they just buy Dye production in India is estimated to be around 60, tonnes, or about 6. There are around varieties of dyes and dye intermediates produced in India, mainly direct dyes, acid dyes, reactive dyes and pigments. Most of these dyes have not been evaluated for their impact on health and the environment. Yet, they are widely used by textiles, leather, paper, paints, plastics, printing and even in the food industry.
The largest producer of dyes in the world is Germany at 22 per cent, followed by the us at 18 per cent. However, a gradual shift is discernible in global dye production. The number of large-scale dyestuff manufacturers in the us has reduced drastically from 21 in to a mere ten in and the overall share of developed nations has also dropped from 65 per cent to 50 per cent.
Faced with spiralling labour and environment costs, developed countries are slowly disengaging themselves from the manufacture of dyestuffs setting up a dyeing plant in India, for instance, costs just a quarter of what it would to start up a similar plant in the West. Lack of enforcement and monitoring of regulations related to environment also make the industrialising countries in Asia a lucrative place to set up polluting industries. As China, South Korea, Taiwan and India become the new large producers, the extent of environmental and health problems are likely to shoot.
Thus, the South ends up paying the real ecological costs to produce dyes for the North. Indian dyestuffs are exported to the European Union, the us , Indonesia, Hong Kong, South Korea and Egypt, of which the us alone accounts for almost 20 per cent. World demand for dyes and organic pigments, forecast to increase over 5. Paints are big business The predominant use of paints is by industry automotive paint, high performance coating, powder coating and marine paint and architecture enamel, distemper, emulsion, exteriors and wood finishes.
Paints have market volumes of up to , tonnes, adding up to almost Rs 6, crore. The unorganised sector accounts for 45 per cent of this and comprises about 2, units that manufacture low technology paints for local use. Indian textile exports have risen from Rs crore in to Rs 34, crore in Of this, readymade garments constitute nearly 50 per cent of India's total textile exports and employ an estimated 35 million people directly.
Wet processing, dyeing and printing of textiles in India is mostly done in the decentralised sector. Most of these units buy their inputs from local markets and therefore lack detailed information about eco-standards and possible substitutes, technical know-how and financial resources to invest in pollution control measures.
About 80 per cent more than 51, tonnes of all dyestuff produced in India is used by textiles alone. With its needs for dyeing and printing, the textile sector is probably the worst offender when it comes to releasing coloured effluent discharge and Ludhiana, Panipat, Pali, Bichchri, Patancheru, Jetpur, Ahmedabad, Surat and Tirupur are some of the country's most polluted zones.
As a result, textile manufacturers have faced the most protests from local people who they affect and a fair amount of litigation as well. Though in the last decade, some change has been forced, mainly under pressure from court rulings and local people's movements, several problems still plague this sector. Leather that weathers India has about 3, tanneries with a total processing capacity of , tonnes of hides and skins per year.
About 35 large firms are reported to account for 60 per cent of India's leather exports. In India, tanneries process sheep, goatskin, cow and buffalo hides, using both vegetable and chrome tanning.
The highest concentration of tanneries in India is along the banks of the Ganga river in North India and around the Palar river system in Tamil Nadu. Most tanneries in India use old technologies and production methods. Even in large tanneries, the technology used is inefficient. This is largely responsible for the wasteful use of water and chemicals, high load of effluent pollutants and low productivity.
A study of India's tanning industry, carried out on behalf of the Union ministry of science and technology, found that the chemical consumption in Indian tanneries is about 25 to 30 per cent higher than international norms. So a tannery that needs only tonnes of colour ends up using tonnes. The extra 30 tonnes goes out as waste and contaminates the soil and the water around the tannery. However, export demands for higher standards may fuel some changes in environmental standards.
This was followed by a German ban on the import of leather and textiles treated with a number of azo dyes in The use of benzidene and arylamines in dye formulations has also been banned in Germany since Coloured paper is obtained by dyeing the paper stock or the paper surface size press, paper coating.
Additionally, fixing agents and other additives are used to improve dye fixation and to obtain better dyeing results. Both inorganic and organic pigments for instance, azo and phthalocyanine types and carbon black are used for paper dyeing.
Colour impacts the environment when it is released into water. Paper mills, which experience several changes of tints or shades each day, have to get their water circuits cleaned every now and then. Discharge of coloured pulping effluents in water inhibits photosynthetic activity of aquatic biota by reducing the penetration of sunlight, besides direct toxic effects on biota.
The colour compounds also collect metal ions and may import contamination by heavy metals. India's large-scale pulp and paper sector discharged more than tonnes of dyes as unused dyes each year between and Black chemistry.
Ruled out. Sanganer, a small industrial town near Jaipur, is famous for hand block printed fabrics. But for its residents, dyeing units are a serious problem. Says Purshottam Singh: "Sometimes the supplied water is red and at other times bluish. How can we drink this? Sanganer's problem is typical of areas where industrial units operate freely. Colour in water is a pointer to contaminants ranging from dissolved organic material, high levels of disinfectants and excess of its by-products and inorganic contaminants like metals.
The average hazard limit varies from five to 30 colour units, but colour can be objectionable even at 15 units. What you see, what you get? The limits for colour in potable water are based on visual or "aesthetic" parameters. Given a choice between visibly coloured water and a colourless source that may be more unsafe, people tend to opt for the latter.
Colour is also determined by a visual comparison with a standard solution see box: Gauging colour in water. New drinking water standards prescribed by the Bureau of Indian Standards is set colour standards at five colour units as the desirable limit and 25 colour units as permissible limit in the absence of alternate source. The us Environmental Protection Agency usepa lays down 15 colour units as the secondary standard for drinking water in the us.
These standards are non-enforceable guidelines regulating contaminants that may cause skin or tooth discoloration or aesthetic effects such as taste, odour, or colour in drinking water. States, however, may adopt them as enforceable. On the other hand, the Drinking Water Inspectorate of England and Wales has prescribed the colour standard for water supply at 20 colour units.
Unlike India and the us, these standards are not only prescribed but are enforceable in the uk. No fix on industrial discharge Colour standards for industrial discharge vary. Countries like Mauritius have set up standards for colour discharged from dye manufacturing, textile dyeing and paint units. In India, however, the Central Pollution Control Board cpcb does not stipulate any standard for colour in the wastewater discharged from industries, except relating to dyes and dye intermediates.
It just recommends that, "All efforts should be made to remove colour and unpleasant odour as far as practicable.
Of all dyes produced across the world, 11 per cent goes out as effluents. Each year, India produces 64, tonnes of dyes, 7, tonnes of which are directly discharged into the environment. Enough to dye the river Sabarmati! While colours brighten our world, they are also ubiquitous and pervasive. We're not talking nature here, but products that are created by industry. Like food colours, textile dyes, printing inks, pigments, acids, paints, even colours used in plastic.
Textile Dyes: Dyeing Process and Environmental Impact
It offers excellent dyeing results at highest productivity and reproducibility rates. With a packing diameter of mm and packing height of mm, the basic machine is designed to cover standard production capacities up to 37 liters. With the user- friendly control software reproducible and constant dyeing results can be achieved. Aiming for a high reproducibility as well as for a reduction of the operating costs and the environmental impact, dyes and chemicals can be precisely adapted. Thies machines are manufactured to comply with pressure vessel codes and safety regulations of the operating sites, e.
Celebrating 40 years of Trust & Quality work
Unit descriptor. This unit covers the skills and knowledge associated with selecting, developing and testing dyes, chemical and auxiliaries and developing a dye specification and recipe for the production of textiles. Application of the Unit. This unit applies to selecting and testing dyes and developing dye formula and specifications used in the dyeing of textiles.
Eco-Friendly Textile Dyeing and Finishing. Dyes may be defined as substances that, when applied to a substrate provide color by a process that alters, at least temporarily, any crystal structure of the colored substances [ 1 , 2 ]. Such substances with considerable coloring capacity are widely employed in the textile, pharmaceutical, food, cosmetics, plastics, photographic and paper industries [ 3 , 4 ]. The dyes can adhere to compatible surfaces by solution, by forming covalent bond or complexes with salts or metals, by physical adsorption or by mechanical retention [ 1 , 2 ]. Dyes are classified according to their application and chemical structure, and are composed of a group of atoms known as chromophores, responsible for the dye color. These chromophore-containing centers are based on diverse functional groups, such as azo, anthraquinone, methine, nitro, arilmethane, carbonyl and others. In addition, electrons withdrawing or donating substituents so as to generate or intensify the color of the chromophores are denominated as auxochromes. The most common auxochromes are amine, carboxyl, sulfonate and hydroxyl [ 5 - 7 ]. It is estimated that over 10, different dyes and pigments are used industrially and over 7 x 10 5 tons of synthetic dyes are annually produced worldwide [ 3 , 8 , 9 ]. Textile materials can be dyed using batch, continuous or semi-continuous processes.
United Colours of Industry
Natural Science Vol. Color is the main attraction of any fabric. No matter how excellent its constitution, if unsuitably colored it is bound to be a failure as a commercial fabric.
JCIL stands for the same values that it did forty years back — clean ethical practice, continuous innovation, technological upgrades, consistent learning and selfless environmental concerns, backed by adequate action and a customer centric approach. In addition to standard products, we are also equipped to offer disperse dyes, auxiliaries and tailor made reactive dyes. Our commitment to research drives us to enhance our products, process and application methods. We are engaged in the development of processes to reduce the environmental impact by offering solutions that minimize water and energy consumption. We have a carbon management strategy that ensures a reduced footprint for ourselves and our customers. The award JCIL as a company, has always invested in forward oriented sustainable innovation. Received extra ordinary response from Visitors from across various domains like Architects, Interiors, Developers and Dealers Created by Netlink.
Textile dye wastewater characteristics and constituents of synthetic effluents: a critical review
Colorants are used in many industries - to colour clothes, paints, plastics, photographs, prints, and ceramics. Colorants are also now being used in novel applications and are termed functional high technology as they are not just included in the product for aesthetic reasons but for specific purposes, for example in surgery. Colorants can be either dyes or pigments. Dyes are soluble coloured organic compounds that are usually applied to textiles from a solution in water. They are designed to bond strongly to the polymer molecules that make up the textile fibre.
Chemical building blocks and useful products
Solaronix is developing a new generation of photovoltaic panels based on Dye Solar Cell technology. Our models offer unprecedented possibilities in terms of customization and integration. The main goal of Solaronix has always been to bring innovative solutions to solar energy in the form of new applications, reduced costs, or easier fabrication. In that quest our efforts are directed towards the development of easy-to-manufacture photovoltaic solar cells using ubiquitous industrial equipment and readily available components. Our vertical expertise in photovoltaics comprises: materials , surface treatments, assembly techniques, testing equipment , and performance assessment. This portfolio of competences allows us to develop innovative solar cell prototypes that can be further produced on our pilot line and integrated into application test cases. Solaronix has been a pioneer of Dye Solar Cell technology since its inception. We believe this type of solar cell demonstrates unmatched features that open solar technology to a host of innovative applications.
Unit of competency details
We have by far the broadest product range on the market, covering almost all fibers and quality specifications. DyStar Textile Services DTS supports brands, retailers and their industry partners with fast and innovative global solutions to create sustainable fashion. Color Solutions International CSI is a leading service provider in color communication for brands and retailers.
These metrics are regularly updated to reflect usage leading up to the last few days. Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.
Dyeing and printing
This class also includes units mainly engaged in manufacturing chlorine, sodium hydroxide and other alkali using electrochemical processes. Primary activities Acid, inorganic, manufacturing n. Alkaline salt manufacturing n.
Dyeing is the application of dyes or pigments on textile materials such as fibers , yarns , and fabrics with the goal of achieving color with desired color fastness. Dyeing is normally done in a special solution containing dyes and particular chemical material. Dye molecules are fixed to the fibre by absorption, diffusion, or bonding with temperature and time being key controlling factors.