Introduction

Amongst that of several other industries, the textile sector waste has received considerable attention in recent years, since it can generate large volumes of waste that, if not correctly treated before being disposed, can be a problem. For example effluents from the textile industry are extremely complex, since they contain a large variety of dyes, additives and derivatives that change seasonally, increasing the challenge to find effective, feasible treatments. Therefore treatments that are more efficient and economical than those currently available are required.

T-shirt manufacturing processes; From Field to Store

Field to Gin

Figure 1 Cotton ginningSpinner to Loom

Figure 2 Cotton Spinning

Wet processing

Figure 3 Wet processing

Cut and Sew

Figure 4 Manufacturing

At Your Door

Figure 5 Retail

Table 1 Health and Environmental Impacts in Spinning Industry

Process Chemicals used Impact of gaseous emissions

Impact of effluents Impact of solid wastes

Cotton Spinning

Opening Cotton dust(soil, particulates, bacteria, fungi, pesticides

Byssinosis (brown lung) diseuse, risk of chronic bronchitis

_____ _____

Spinning Noise (causes hearing problems)

Particulates _______ ________

Table 2 Health and Environmental Impacts in Fabric Formation Industry

Process Chemicals used Impact of gaseous emissions

Impact of effluents Impact of solid wastes

Sizing Natural starch, polyvinyl alcohol, carboxymethyl cellulose, oils,

waxe s, adhesives Urea, diethylene glycol, etc.

VOCs, methanol from PVA, is toxic at high levels, causing central nervous system damage and blindness Higly flamable, forms air pollutants

Washing residues cause high BOD and COD, metals (from size additives) causing disturbance of aquatic life

_______

Weaving Noise causes hearing disabling, particulates

Particulates cause respiration and hearing problems

_______ _______

Table 3 Health and Environmental Impacts in Finishing Industry

Process Chemicals used Impact of gaseous emissions

Impact of effluents Impact of solid wastes

Singeing Small amounts of exhaust gases, negligable impact

_______ _______ _______

Desizing - Enzymes or H2SO4 for starch, detergents and alkali for PVA and CMC

May cause bloating and Diarrhoea. Irritant to eyes and skin

High BOD or COD, high temperature, size impurities, lubricants, metals.

Residues of solvents

Scouring NaOH,Na2CO3, surfactants, chlorinated solvents

Non-ionic detergents may cause bloating and Diarrhoea, Irritant to eyes and skin.

High BOD and temperature, very high PH, fats, waxes, size residues, causing disturbance of aquatic life

_______

Bleaching -Hypochlorite -Hydrogen -peroxide

Chlorine gas released, causing severe irritation of respiratory tract and eyes tract and eyes

Low to moderate BOD, high pH and temperature

_______

-Acetic acid Toxic gases

Mercerization

NaOH, surfactants, acid, liquid ammonium

_______ Very high pH and dissolved solids, some BOD

_______

Contnd..

Dyeing - Dyestuffs

- Auxiliaries

- Reductants

- Oxidants

- Dye dust is a main source of pollution for breathing or skin

- Amonia is irritating to the skin, eyes nose, throat, and upper respiratory system. Basic dye is generally toxic (e.g. crystal violet)

- Potassium dichromate can cause dermatitis and ulceration, it is carcinogenic

- Exposure to dye dust through breathing or skin can result asthma, eczema, and severe allergic reactions.

- Heavy metals e.g. (Cu,Cr)

- Carcinogenic amines

- Toxic compounds, e.g. carriers

- H2S

- Corrosion,

- Irritant

- For wool dye, high BOD, possibly toxic, and pH low

Chemical residues can cause allergic reactions to skin or respiratory system.

Printing -Dyes(acids or alkalis), pigments, kerosene, binders, other additives

- Ammonia - Xylenes

- Formaldehyde causes intense irritation of eyes and nose, and headaches. It is carcinogenic

- Kerosene causes nausea, vomiting coughing, leading to respiratory paralysis

- Amonia vapour is severe irritant to eyes, causes vomiting, diarrhoea, sweating and coughing. High concentration can cause respiratory arrest.

- Heavy metals (toxic)

- Carcinogenic

- Irritants

- Fire hazard

- High BOD& COD depending on type of thickener

- Disturbance of aquatic life, eg. urea and phosphate

Chemical residues can be irritant and toxic.

Chemical finishing:

- Anticrease

- Flame proofing

- Softening

- CH2O

- Phosphorus

- Softeners

- Fluorinated chemicals

- Catalyst

- Formaldehyde

- Amonia

Intense irritation of eyes and nose and headaches. Carcinogenic. Causing vomiting, and coughing. High concentration can cause respiratory arrest.

- BOD and COD

- Carcinogenic

- Skin allergies

- Heavy metal toxicity

Chemical residues can be hazardous and toxic

(cont.) Health and Environmental Impacts In Finishing Industry

Process Chemicals used Impact of gaseous emissions

Impact of effluents

Impact of solid wastes

Antistaic

finishing

Surface- active substances Possibly skin allergies BOD,COD, additive residues

Resin residues may be skin allergy

Anti-felt finish

(for wool)

- Chlorine

- Polyamide

- Epich chlorohydrin resin

Chlorine vapour is hazardous, and can cause respiration problems

Large quantities of effluent with COD

_______

Moth and beetle protection

(for wool)

- Chlorinated sulphonamide derivatives

- Biphenyl ether

- Urea derivatives

- Pyrethroids

Pyrethroids may cause neuro toxic effects

COD Chemical residues may be hazardous

Hydrophilising - Polyamide

- Polyacrylic

- Silicon

VOCs, possibly skin allergies

Large quantities of effluent with COD

Chemical residues may be hazardous

Delustering - Phenol

- Turpentine

- Pine oil

- Glauber salt

- Barium chloride

-Resins containing formaldehyde

- Alkali sulphide

- Allergy inducing

- In some cases carcinogenic substances

COD, heavy metals

Chemical residues may be hazardous

Abrasion

resistant finish

- Silica gel

- Plastic resins

VOCs, causing irritation of respiratory system. Skin allergies

Large quantities of effluent with COD, toxicity

Chemical residues may be hazardous

Sanforizing - Urea formaldehyde

- Melamine formaldehyde

- Skin allergies

- Carcinogenic properties

- Wastewater, BOD

- Toxicity,

Resin residues may be carcinogenic

Table 4 Health and Environmental Impact in Garment Industry

Process Chemicals used Impact of gaseous

emissions

Impact of

effluents

Impact of

solid

wastes

Cutting fabrics No chemicals

Particulates

Little effect on respiratory system

_______ _______

Fusing the Fumes of interlining adhesive Slight effect of adhesive fumes _______ _______

interlining to fabric pieces

resin, and fabric finish on respiratory system (VOCs)

Sewing Particulates Negligable effect on respiratory system

_______ _______

Ironing Fumes from fabric Negligable effect on respiratory system

_______ _______

Table 5 Health and Environmental Impacts In Service Units

Process Chemicals used Impact of gaseous

emissions

Impact of

effluents

Impact of

solid wastes

Transportation - Vehicle exhausts, gasoline fumes

Gasoline fumes cause irritation of respiratory system

Oils reduce dissolved oxygen

_____

Boilers and

steam system

- Naphtha, coal, natural gas, oil fuel

Particulates, burning exhausts, cause irritation of respiratory system

Wastewater with precipitated salts reduces the dissolved oxygen

_____

Water treatment - H2So4 / Hcl and NaOH (for ion exchange)

- NaCl (water softening), trisodium phosphate (boiler water), chlorine or hypochlorite (for water disinfiction)

_____ _____ Chemical residues may be allergic.

Wastewater treatment.

- Alum or ferric salts, flocculant polymers, H2SO4 / HCl and NaOH / CaO,

- Nutrients (urea, phosphoric acid, ammonium phosphate)

VOCs from fabric chemicals, vapours and mists, may cause, irritation of respiratory system

_____ Wastewater sludge may cause skin irritation

From the Field

About a third of a pound of chemical pesticides and fertilizers go into each pound of conventionally-grown cotton.

25 percent of all pesticides used globally are put on cotton crops. Most cotton is irrigated, and the combination of chemical application (through pesticides and fertilizers) with irrigation is a direct conduit for toxic chemicals to circulate in groundwater worldwide [2]. Herbicides, and also the chemical defoliants which are sometimes used to aid mechanical cotton harvesting, add to the toll on both the environment and human health. These chemicals typically remain in the fabric after finishing, and are released during the lifetime of the garments. Exploitation of individual animals often goes hand in hand with intensive farming practices that also damage the environment as a whole [2].

Organic cotton is grown using methods and materials that have low impact on the environment with the organic production systems replenishing and maintaining soil fertility reducing of the use of synthetic pesticides, fertilizers and building a biologically diverse agricultural system.

Further, the aim of Global Organic Textile Standard is to define requirements to ensure organic status of textiles, from harvesting of the raw materials, through environmentally and socially responsible manufacturing up to labeling in order to provide a credible assurance to the end consumer [1].

To the gin

Ginning mills produce very fine dust that poses a significant breathing hazard to workers without proper ventilation and protective gear.

To the spinners

Figure 6 Spinning sequence

The noise level resulting from the machines used in the textile industry, especially from the dry processes, may violate the limit allowed by the law and cause hearing problems. The ring spinning machines, the open-end spinning machines, the winding machines etc. Work at very high speeds, thus exceed the allowed level of noise (90 decibels) and cause hearing troubles to the production workers.

The surrounding area is also affected by the fiber fuzz in case of facilities not using scavenging systems, and depending on ventilation through factory windows. This situation may have effect on the respiratory diseases of people living in the area [1].

Air emission control methods commonly installed at textile mills include cyclone separator, bag filters and wet scrubbers. Oil mist and volatile organic carbon are more difficult to control. Reductions can also be achieved by controlling the spinning oils. Proper air ducting and installation of mist eliminators

To the loom

Figure 7 Process flow

The noise level resulting from the machines used in the textile industry, especially from the dry processes, may violate the limit allowed by the law and cause hearing problems. The looms etc. Work at very high speeds, thus exceed the allowed level of noise (90 decibels) and cause hearing troubles to the production workers. The surrounding area is also affected by the fiber fuzz in case of facilities not using scavenging systems, and depending on ventilation through factory windows. This situation may have effect on the respiratory diseases of people living in the area.

Carding Drawframe Roving Ring Winding

Sizing Weaving

Reductions can be achieved by controlling the spinning oils. Proper air ducting and installation of mist eliminators [1].

Wet processing

Figure 8 Process flow

Here the fabric is treated with heat and chemicals to take on its final look and feel. In many textile mills, when chemicals are rinsed off fabric the polluted wastewater ends up in local rivers, which change color and composition according to the fashion of the season [3].

Starch wastes from desizing are the single greatest source of BOD at many mills. Consequently, substitutes with low BOD, such as CMC and PVA, have become useful to reduce BOD loadings on wastewater treatment systems. Harsh chemicals used in textile wet processes are being substituted with a number of enzymes [1].

Chlorine bleach is known to be extremely toxic to the environment and to consumers, yet chlorine-based chemicals are still often used to bleach fabrics. The bleaching method must be oxygen-based (hydrogen peroxide) and the wastewater is treated. In some mills, ozone, a very new technology, is used for bleaching. This technology relies on cool water (rather than having to maintain the fabric in a hot water bath for many hours) and the ozone breaks down into water and oxygen [2].

At the final stage of wet processing, fabric is "finished" in order to make it softer, cleaner, smoother or better able to take on coloring. To this end, the fabric is washed, scoured, bleached, rinsed and sometimes dipped in acid. All these finishing processes require the use of chemicals, heat and water, and produce contaminated wastewater are hazardous to human health and the environment [3].

Figure 9 Environmental impact

Further, Tons of these dyes are lost to effluents every year during the dyeing and finishing operations, due to the inefficiency of the dyeing process. Unfortunately, most of these dyes escape conventional wastewater treatment processes and persist in the environment as a result of their high stability to light, temperature, water, detergents, chemicals, soap and other parameters

Singeing Desizing Scouring Bleaching Mercerization Dyeing Finishing

such as bleach and perspiration. In addition, anti-microbial agents resistant to biological degradation are frequently used in the manufacture of textiles, particularly for natural fibers such as cotton. However, environmental legislation obliges industries to eliminate color from their dye-containing effluents, before disposal into water bodies

One of the most difficult tasks confronted by the wastewater treatment plants of textile industries is the removal of the color of these compounds. 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, reducing certainly improve the cost and quality of the effluent [4].

Some of the chemicals, including dyes and pigments, are toxic or can lower the dissolved oxygen content of receiving waters, threaten aquatic life and damage general water quality downstream. Formaldehydes are used in wrinkle-free, non iron finishings but also as a fixing agent for cotton. (10) It is an irritant to the skin and also a hormone disrupter.

The main aim is to safeguard human health and environment through the better and earlier identification of the properties of chemical substances and to promote the use of alternative methods for the assessment of the hazardous properties of substances.

Raw material uses should be zero residues.

Rigid procedures, requiring the use of only specific chemicals and specific methods should be converted into flexible ones to facilitate substitution of non-eco friendly chemicals by their safe counterparts from time to time.

Green Technology or Clean Technology should be practiced.

Product (GNP) of a nation should be increased by substantially reducing the quantities of inputs.

Eco friendly index of product must include its shelf life period and extend of eco friendliness of degradation products.

Eco friendly machinery and processes should be used.

Solvent processing is an example of a new process technology. It involves the use of a non-aqueous solvent such as perchloroethylene to scour and dye fabric. Because the solvent has a high vapor pressure (compared to water), it is possible to vaporize it more easily and recover it for reuse. It has not, however,

Supercritical CO2 is one of the most popular fluids currently used in manufacturing processes. It is non toxic, non hazardous and low cost and environment friendly. Moreover, by reducing the pressure at the end of the process, dye and CO2 can be recycled.

Standard reactive dyeing procedures require high levels of water, salt and alkali, which lead to very large volumes of effluent. Specialty Chemical Group introduced more environmentally

friendly method of fabric pre treatment that lead to complete elimination of salt and alkali, lower water volumes and reduced process times. Thus several green chemistry reductions (waste, energy, raw materials) are achieved.

The latest textile processing equipment offer lower water and chemical usage. For example, pressure dye machines use dyestuff more efficiently, reduce water requirements and reduce the level of toxic dye carriers required in atmospheric dyeing.

To the Garment Factory

 About 12 to 15 percent of the fabric will end up as scraps on the cutting room floor, depending on how the pattern is laid out.

To the Clothing Company and the Store

The finished t-shirt makes its way from the garment factory to a brand name clothing company. The use phase, meaning the phase when the garment finally reaches the consumer, is a phase with a high impact on the environment. The way we wash, dry and care for our clothes decides how high these impacts are. Most environmental impact comes from laundering and not from growing, processing and producing of the fabric or disposing of it at the end of its life.

“..the major part of environmental impact in the lifecycle of a blouse arises from the consumer use phase..”, “as much as 82 per cent of energy use, 66 per cent of solid waste, over half of the emissions to air and large quantities of waterborne effluents are amassed during washing and drying."  

The use phase if followed by the end of life phase of a garment in which it is disposed of and not used any longer [7].  Old clothes that we throw away take up precious space in landfill sites, which is filling up rapidly [5].

Recycling: Textiles that have been discarded by consumers, retailers or charitable organizations, which have undergone a discriminating process of sorting, grading and separation into waste-free products suitable for reuse [6].

References

1. Http://www.ptj.com.pk/Web-2009/10-09/Muhammad-Ayaz.htm 2. Http://www.oecotextiles.com/PDF/textile_industry_hazards.pdf

3. Http://www.nrdc.org/living/stuff/t-shirt-life-story.asp

Cutting Sewing Washing Drying Ironing Folding Packing

4. Http://www.intechopen.com/books/eco-friendly-textile-dyeing-and-finishing/textile- dyes-dyeing-process-and-environmental-impact

5. Http://www.fibre2fashion.com/industry-article/textile-industry-articles/impact-of- textiles-and-clothing-industry-on-environment/impact-of-textiles-and-clothing-industry-on-environment2.asp

6. Http://www.fibre2fashion.com/industry-article/textile-industry-articles/impact-of- textiles-and-clothing-industry-on-environment/impact-of-textiles-and-clothing-industry-on-environment5.asp

7. http://make-do-and-mend.org/overconsumption_of_clothes__2.html