DYES: ENVIRONMENTAL IMPACT AND REMEDIATION

• Guided by:• Prof.- G.S. Bramha• Prof.- Sri Lalitha• Prof.- Renu Rani

Presented by:Avinash Kr. Singh14STUHHME0224

OVERVIEW

• What is a dye?

• Types of dyes

• Impacts of dyes on environment

• Harmful effects of dyes

• Remediation measures

• Conclusion

What is a Dye?

• A natural or synthetic substance used to add a color to or change the color of something. Such substances with considerable coloring capacity are widely employed in the in the production of consumer products, including paints, textile, printing inks, pharmaceutical, food, cosmetics, plastics, photographic and paper industries.

Types of dyes

Types of dyes

1. Natural dyes

2. Synthetic dyes

3. Food dyes

4.Organic dyes

5.Other dyes like leather, laser

And also based on chemical classification With respect to the

number and production volumes, azo dyes are the largest

group of colorants, constituting 60-70% of all organic dyes

produced in the world.

Industrial Applications

• They have a wide range of applications in the textile, pharmaceutical and

cosmetic industries, and are also used in food, paper, leather and paints

industries

• At present, India contributes about 6% of the share in the global market with a

CAGR of more than 15% in the last decade.

• The dyeing process in various industries has garnered a lot of attention lately

because of the emerging concept of sustainability and eco-friendly variants.

1.Textile Industry:

• Till the midst of nineteenth century all the dyes used for textile products were

procured naturally

• The textile industry is accountable for using and producing 1.3 million tons of dyes

and pigments, most of which are made synthetically.

• The textile industry is one of the largest sectors globally and produces an

astonishing 60 billion kilograms of fabric annually, using up to 9 trillion gallons of

water.

2.Printing Ink:

• Heavy metals in the colorants used in printing industry has severe effects on the

environment.

• For example, titanium oxide, chromate, molybdenum, and iron are used as

pigments; titanium oxide is used for pearlescent pigments; and aluminum and

brass are used in metallic inks.

• Ink is a liquid or paste that contains

pigments or dyes and is used to color a

surface to produce an image, text, or

design. Ink is used for drawing or writing

with a pen, brush, or quill.

ENVIRONMENTAL IMPACTS Air pollution –

• Most processes performed in textile

mills produce atmospheric emissions.

Gaseous emissions have been identified

as the second greatest pollution

problem (after effluent quality) for the

textile industry.

• Speculation concerning the amounts and types of air pollutants emitted from

textile operations has been widespread but, generally, air emission data for

textile manufacturing operations are not readily available.

• Air pollution is the most difficult type of pollution to sample, test, and quantify

in an audit.

Water Pollution

• The wastewater from textile plants

is classified as the most polluting of

all the industrial sectors,

considering the volume generated

as well as the effluent composition

• In addition, the increased demand for textile products and the proportional

increase in their production, and the use of synthetic dyes have together

contributed to dye wastewater becoming one of the substantial sources of severe

pollution problems in current times.

• Dyes can remain in the environment for an extended period of time, because of

high thermal and photo stability to resist bio degradation..

HARMFUL EFFECTS OF DYES

o Dyes absorb and reflect sunlight in water. This diminishes photosynthetic activity

of algae and seriously influences the food chain.

o Many dyes and their breakdown products are carcinogenic, mutagenic and/or

toxic to life.

o Triple primary cancers involving skin, kidney, urinary bladder and liver of dye

workers have been reported.

o Textile dyes can cause allergies such as contact dermatitis and respiratory

diseases, allergic reaction in eyes, skin irritation, and irritation to mucous

membrane and the upper respiratory tract.

• Certain reactive dyes causes respiratory sensitization of workers who are

occupationally exposed to them.

• The presence of very small amounts of dyes in the water, seriously affects the quality

and transparency of water bodies such as lakes, rivers and others, damages the

aquatic environment.

• The highly toxic and mutagenic dyes decrease light penetration and photosynthetic

activity, causing oxygen deficiency and limiting downstream beneficial uses such as

recreation, drinking water and irrigation.

• Azo dyes have toxic effects, especially carcinogenic and mutagenic. They enter the

body by ingestion and are metabolized by intestinal microorganisms causing DNA

damage.

REMEDIATION MEASURES

o Enhance the existing effluent disposal treatment plants through Reverse

Osmosis (RO) and the resultant water can be used as fresh water for the

region

o Industries should switch over to Cleaner Production Technologies (CPT) by

using combination of soft flow machines, low salt dyes and membranes

filtration. This effectively reduces the water consumption by 50%.

o Use of activated carbon in the absorption of chemicals in waste from the

dye process, which has shown to greatly reduce some of the pollutants in

the waste.

o Dye fed silk worms' take silk farming to the next level:

Researchers have come up with a process wherein by adding a chemical dye to the

diet of the silkworms, cocoons are produced in bright; luminous hues. The process is

expected to eliminate the requirements of conservative dyeing such as huge volumes

of water. It would to result in restricting water and environmental pollution.

o Air Dyeing Technology is a dyeing process that uses air instead of water to dye garments, allowing companies to create garments with vivid designs and colors, without polluting the water and environment. • It uses 95 percent less water. • Emits 84 percent less Green House Gases

(GHG)• Requires 87 percent less energy

o Ultrasound-assisted textile dyeing: Ultrasound-assisted textile dyeing was first

reported by Sokolov and Tumansky in 1941.

The use of ultrasonic energy has been widely studied in terms of improving washing

fastness.Ultrasonic energy can clean or homogenize materials, accelerating both

physical and chemical reactions, and these qualities can be used to improve textile

processing methods.

CONCLUSION

• The Dyestuffs Manufacturers Association of India, popularly known as DMAI was set up in 1950, to promote and protect trade, commerce . The organization needs to promote environment concerns of this industry and the ways to manage it.

• An alternative to minimize the problems related to the treatment of textile effluents would be the development of more effective dye that can be fixed fiber with higher efficiency decreasing losses on tailings waters and reducing the amount of dye required in the dyeing process

• Moral outrage will not convince many leading manufacturers to change their ways; as long as companies do not pay a price for the land and water their suppliers poison, the excessive use and abuse of environmental parameters like air and water to dye products will continue.

THANKYOU