Textile operations traditionally have a large environmental footprint, and new legislation is calling for reform. Novozymes enzymatic innovation
offers solutions that could have long-lasting impact.
China is one of the world’s largest textile producing countries, contributing a sizable portion of the estimated 9 million tons of knitwear manufactured globally every year. With the production of 1 ton of cotton knitwear consuming what corresponds to the daily water usage of 600–700 urban Chinese people, the Chinese government recently intervened in an attempt to improve this use of resources. As of 2011, new legislation caps the maximum water consumption by textile plants at 100 tons of fresh water per ton of cotton knitwear. A life cycle assessment (LCA) reveals that enzymes can help manufacturers to overcome this challenge.
Clear benefits of using enzymes
Chinese manufacturer Esquel has performed several trials incorporating Novozymes’ enzyme-based solution known as elemental textiles. In the LCA, for the concept in use Esquel reported savings of 30 m3 (or 30 tons) of water per ton of knitted fabric in just a single bleaching process when substituting enzymes for chemicals.
The LCA states similar results when switching the production of a dark-colored T-shirt from conventional to enzymatic processing. Only 2 m3 of water is used to produce the input of enzymes, but 100 m3 of water can be saved – of which 80 m3 is tap water. There are two main reasons for this. The first is that enzymes necessitate fewer rinses after each process compared to chemicals. The second reason is that enzymatic processing allows a greater combination of processes per bath, leading to dramatic decreases in water consumption and costs.
Smaller dosages + greater biodegradability = reduced toxicity
Enzymes degrade much more easily and rapidly than many of the chemicals used in textile mills. When water from textile production reaches the wastewater treatment plant, enzymes are deactivated into tiny pieces of protein and carbohydrate that function as food for beneficial microorganisms. From here they are degraded into harmless compounds.
The benefits of this process become even more apparent in the case of extreme weather, when some of the effluents from textile production could pass through the plant without being completely rinsed and go directly into waterways. In the case of chemically based operations, this exposes flora and fauna to surfactants. This is much less likely with enzymes.
In its enzyme-based trials Esquel achieved a substantial reduction in the consumption of both water and chemicals with toxic properties. Based on the trial’s LCA, calculations indicate that for every ton of blue navy knitwear produced, changing from chemicals to knitwear safeguards up to 2 million m3 of water against unacceptable toxicity.
In addition to their rapid biodegradation, enzymes also lower the toxicity levels of textile operations by requiring lower dosages thanks to their catalytic nature. Combined with their ability to substantially lower water use during operations, enzymes prove to be a powerful cocktail for improving how water is used in textile production.