Environmental Aspects in Textile Industry: Ecological Hazards and Remedial Measures

Introduction

Indian textile industry is a unique combination of growth, development and export performance. This identity is now been checked and challenged. Where is the problem? The concern is because of the anthropogenic sources of pollution. Green parties today insisting upon the manufacturing, processing and disposal of textile products as per environmental norms. The commercial decision in global business now depends on how much conscious we are in protecting our environment. So, there is a wake-up call for the textile industry.

What we are doing to harm our environment? Which are the areas causing destruction to our biosphere? What should we do to remain in the competition? Will our business exist? These are the questions to be investigated and the motivating factor for this study.

Eco Degradation in Textile Industry

Textile industry contributes 30% of India’s export. It produces over 400 million meters of cloth and around 1000 million kg of yarn per annum. The textile sector is labour intensive and nearly a million workers are associated in various unit operations of about 700 mills. There exist a number of important environmental benchmarks, associated with the key environmental issues. Because of the nature of the industry, many of these are directed towards wet processing which tends to be the most obviously polluting sub-sector.

Textile wet processing activity contributes about 70% of pollution in the textile industry. It is estimated that there are around 12,500 textile processing units wherein the requirement of water ranges from 10 litres with an average of 100 litres per kg [1]. Right from cotton cultivation and manufacture of fibres, spinning, weaving, processing and finishing, more than 14,000 dyes and chemicals are used and a significant quantity of these goes in the solid, liquid and air wastes, thereby impart pollution of air, land and surface water.

Towards the end of the 20^th century, the world has become more environmentally conscious and thus the green textile concept is emerged to facilitate eco-management in the textile arena. Different unit operations, which contribute to eco-degradation, are described and analysed in this chapter.

Noise Pollution

Noise is one of the most pervasive environmental problems. There is no doubt that it has an adverse effect on human beings and their surroundings.

The ISO defines noise intensity level [2] as:

L = 20 log₁₀ (P / P₀) = 10 log₁₀ (I / I₀)

where P and P₀ are the sound pressures of the noise present at a place and the reference sound pressure at 1000 Hz at the threshold of hearing which is given by 20 micro Pascals. I is the sound intensity level being measured and I₀ is the reference sound intensity at 1000 Hz at the threshold of hearing and is given by 10^-12­ w/m².

The relationship between sound pressure, sound intensity and intensity level (dB) are given in the literature [3]. In industry, increased mechanization results in increased noise levels. Operation of textile machines carries a high risk of hearing loss. The evaluation of textile worker’s noise-induced hearing loss was reported elsewhere in the literature [4].

Noise Levels in Textile Machinery

Noise Levels in Yarn Production

Because of high spindle speeds reached on new machines (ring spindles up to 20000 rpm, rotor up to 110000 rpm) spinning mills can generally be assumed to generate a great deal of noise. Noise levels of 70 to 100 dB are commonly recorded in workrooms.

Noise Levels in Weaving and Knitting

Although considerable progress has been made in the weaving sector over the last 20 years, the whole area of noise nuisance and, closely associated with it, vibration coming from looms, cause major problems.

Noise levels of 100 to 120 dB must be expected in weaving rooms, according to the design, type, fitting, erection and number of looms used, fabric structure, building type and size etc. The vibration transmitted from the running looms to the building can, under certain circumstances, cause a nuisance to the local population and damage to nearby buildings, and to avoid these special vibration absorbers are now provided.

However, the permissible limit set up at 90 dB by Federal Standards of the USA for a maximum exposure duration of 8 hours per day. Typical values of the noise level in textile machines are shown in Table I.

Noise Level Remedial Measures

Noise level can be lowered by the use of noise control enclosures, absorbers, silencers and baffles and by the use of personal protective equipment (PPE), such as earmuffs. Where technical methods are insufficient, noise exposure may be reduced by the use of hearing protection and by administrative controls such as limiting the time spent in a noisy environment and scheduling noisy operation outside normal shifts or at a distant location. Even though noise-reducing measures may have been incorporated in the design of the machinery, the greater output may generate higher noise levels. For instance, every doubling of the speed of rotary machines the noise emission rises by about 7 dB, warp knitting machines by 12 dB and in fans by around 18 to 24 dB.

Noise pollution is a problem that has unsatisfactorily been tackled so far. Though noise-absorbing sheets are used to cover the inner walls of loom shed, still more appropriate means need to be devised. In modern shuttle less looms because of better engineering designs of the machines the noise level is lesser. But those shuttle-less looms are costly.