Water pollution caused by the release of dyeing and printing liquids

The textile industry is one of India’s most important industrial sectors, generating significant revenue and employment. At the same time, it has a negative influence on the environment since it produces extremely hazardous wastewater during the wet processing of fabrics in dye factories. Textile production (including cotton cultivation) requires about 93 billion cubic metres of water each year, according to the Ellen MacArthur Foundation, accounting for 4% of worldwide freshwater extraction. India’s textile industry is the country’s second largest industry in terms of job opportunities, with over 35 million people employed.

Dyes, salts, and a variety of other organic and inorganic substances are commonly found in the wastewater. If wastewater is released into the environment untreated, it contaminates nearby soil and water bodies, causing significant harm to plants, animals, and humans. There have been numerous media reports exposing the extent of pollution in rivers around textile clusters, with entire stretches of river becoming red or blue due to untreated colours in the water. Every year, a large number of health problems are recorded in India as a result of drinking dirty water. Textiles, on the other hand, are one of the most water-intensive industries, with wet processing procedures such as dyeing taking anywhere from 60 to 150 litres of water per kilo of yarn.

Every year, India experiences unequal rainfall distribution, resulting in floods and droughts in different parts of the country. This puts the sustainability of water-intensive industries like textiles in jeopardy. As a result, it is the responsibility of all stakeholders, particularly entrepreneurs and mill owners, to ensure that industries operate responsibly and aim to use water efficiently while avoiding pollution by adhering to government regulations such as those set by the Central/State Pollution Control Board (s).

Let’s have a look at some of the water conservation techniques:

Industrial wastewater reuse is a viable option

Industrial wastewater treatment and reuse (recycling), as well as the use of treated municipal water, are proven solutions that can help industry preserve water while also reducing pollution. A textile wastewater treatment system typically consists of primary, secondary, and tertiary treatment units that remove contaminants from wastewater to the level set by state and federal regulatory agencies. Although standard treatment technologies effectively remove organic pollutants, inorganic salts remain in the treated wastewater, necessitating the adoption of high-end technology to remove them and make the water fit for reuse in industry. The Zero Liquid Discharge (ZLD) technique is a cost-effective but ineffective solution.

Sustainability of ZLD systems

Zero Liquid Discharge is an engineering approach in which wastewater is treated in several stages, primary, secondary, Reverse Osmosis (RO), and thermal evaporation systems, before being recovered for reuse as pure water and other useful resources, with no wastewater discharge from the industry. In general, some major criteria such as water cost, (ii) water shortage, (iii) regulations, and (iv) wastewater input characteristics determine the necessity and viability of ZLD. From wastewater, a ZLD-based textile treatment facility can recover 95-98 percent pure water by volume and 80-90 percent salts by weight. In the context of resource scarcity, this makes it a highly desired technology. India is the world’s largest exporter of yarn, with a 25 percent share of the global yarn export market and a 12 percent part of global yarn and textile fibre output. India has the most loom capacity, accounting for 61 percent of global loomage. With a growth rate of 23 percent in 2013, it has become the world’s third largest textile and apparel exporter (after China and the UK). Several factors influence the final equipment and process flow selection, including the volume of wastewater, the types of salts present, the colours/dyes present, and so on.

Support and regulations from the government for the construction of wastewater treatment plants

The federal government, as well as state governments, have a number of programmes and incentives in place to encourage industry to implement water conservation and pollution control measures. The Integrated Processing Development Scheme (IPDS) assists Micro Small Medium Enterprises (MSME) textile wet processing units in constructing common treatment facilities, providing critical financial assistance to these businesses that often lack the resources to set up their own treatment facilities. Occasionally, the government must impose restrictions to nudge industries toward environmental sustainability. The Tamil Nadu Pollution Control Board (TNPCB) regulated textile processing units in Tirupur to utilise Zero Liquid Discharge (ZLD) System based effluent treatment plants to treat and reuse wastewater in the dyeing process due to the harmful effects of textile wastewater on the environment. The deteriorating water situation in Tamil Nadu, which has been experiencing low rainfall for many years, prompted this legislation.

Some state governments and municipalities have devised a system in which municipal sewage water is purified to an industrial standard and then distributed to clusters in the municipality’s proximity. Surat, Gujarat, is a good example of this.

Water stewardship - collaborative effort

While business and government are the primary participants in water conservation and pollution prevention on a wide scale, all stakeholders must contribute to the fight against a global water catastrophe. Consumers can have a significant impact on private-sector decision-making. Consumer demand for sustainable products, i.e., products made with less water, energy, pollution, etc. and with no social injustice, will encourage brands and manufacturers to embrace excellent supply chain practises.
Water stewardship is a comprehensive approach that emphasises the significance of collaboration among all parties involved. Individual stakeholders cannot properly manage water because it is a key resource. The private sector (business), government agencies, consumers, and even farmers must work together to effectively distribute resources and responsibilities. This strategy will ensure that future generations will not be robbed of this valuable resource.

Published On: July 20th, 2021 / Categories: Water Recycle /