Carpet Industry Cleaning Up Its Act
ALAN BEST explains recent moves by the carpet industry to clean up its act:
Carpet manufacturing has always relied heavily on large quantities of water and, as with most textile products, the mills were mostly built on rivers during the industrial revolution which began in around 1760. The rivers provided power as well as process water and an easy way to discharge waste.
Regulation of this waste and concern for the welfare of the workforce and the populace generally were a fairly late development, from the last quarter of the 20th century. Over the years the industry has relied on various raw materials and additives which have been replaced or withdrawn due to concerns about their potential toxicity, including stain repellents and fire retardants.
The industry, of course, relies on dyes and dyeing processes which have been significantly improved through advances such as solution dyeing. This is a one-stage combined spinning and dyeing process which uses no water and gives excellent results. More traditional disperse dyeing methods have improved and less water and energy are now required. Dyes supplied by leading brands are becoming less toxic and advanced treatment of dye effluent involving microbial and organic treatments are being introduced to replace chemical treatments.
Most, but not all, countries now require the treatment of dye effluent before discharge into rivers. The process normally involves the separation of water from the dye sludge, but some of the water, which still contains some potentially toxic dyes, may then be discharged into rivers. The sludge presents an ongoing disposal problem.
One development in yarn dyeing is airflow technology where flowing air largely replaces water in the process, resulting in low wastewater levels and reduced energy consumption.
The carpet industry has actively sought safer alternatives when raw materials or additives have proven harmful in terms of health or environmental toxicity. However we need to select alternatives in terms of their whole of life impacts, from the source of the raw materials used to make them, to their effects during the life of the carpet and following disposal at the end of the carpet’s life.
One illustration of this is the use of Aluminium Trihydrate (ATH) as a fire retardant to replace the potentially toxic brominated flame retardants. ATH is itself relatively benign, but the raw material from which it is manufactured is Alumina, a bi product of a highly caustic red mud.
In 2010 the Ajka alumina waste pond in Hungary collapsed, releasing 1 million cu m of caustic sludge flooding 40sq km and causing several deaths. All life in the adjacent Marcal River was extinguished and the pollution affected large parts of the Danube River.
Thus when considering a product’s environmental impacts and water toxicity the bi products from mining the raw materials to make it must be included through lifecycle assessment methodologies as none of these impacts tend to appear on product safety data sheets.
Most conventionally constructed carpet presents a potential, if indirect, threat to drinking water at the end of its life due to the need to dispose of it at landfill sites. According to Carpet Recycling UK around 400,000 tonnes are sent to landfill each year and this comprises 15% of all civic site waste.
The threat is from water percolating through landfills and dumps (leachate) and picking up chemicals, bacteria and toxic materials and carrying them into the water table. Although the carpet itself contains few toxins, it is a bulky constituent of the landfill and one which will allow water to flow through it with relative ease.
In the UK an average rainfall of around 100cm leads to around 5m litres per acre passing through the waste. This water then finds its way to surface aquifers which is the permeable rock that stores groundwater and allows it to flow readily into a well or borehole.
A study has shown that around 0.1 to 0.4% of water in surface aquifers may be polluted from landfill and dump sources. Well managed landfill sites are designed to deal with this threat and also to tap into methane gas for use as an energy source.
However, this is not the norm globally and a rethink of landfill policies and practices is part of the UN initiative. Practices that have gone on for hundreds of years are now being challenged and are slowly changing. Major players are now engaged in cleaning up textiles’ act globally. It is to be hoped the carpet industry can work jointly on common issues and follow the lead of the ZDHC group.
This article has been reproduced from the Contract Flooring Journal. You can find them at www.contractflooringjournal.co.uk. .