Tackling emissions in the textiles industry

Textiles are only one thread of a fabric called TULAC, which stands for “Textiles, Upholstery, Leather, Apparel, and Carpets” - a sector combined by the European Law Makers. Before delving into the regulations affecting TULAC companies, let’s look at the main emissions generated by this sector. 

COD

Chemical oxygen demand (COD) includes a series of substances in wastewater which can be removed via oxidation. These include solvents and processing chemicals, e.g. for curing, which can be strictly regulated by Persistent Organic Pollutants (POPs), and many other pollutants. If not removed from textile process wastewater, COD can harm marine wildlife. In addition to this, COD could also disrupt bacteria in wastewater treatment biofilters.

Phenols

Phenols are organic substances which are found in a huge range of products, including textiles and dyes. Their concentrations in wastewater must be reduced to very low levels to protect human and animal health.

AOX

Adsorbable organic halides (AOX) are components containing chlorine, bromine, or iodine that are used in textile processing (e.g., bleaching, dyeing, finishing). Most AOX are chlorinated, including dichloromethane (DCM), trichloromethane (chloroform), chlorophenols, chlorobenzene, etc. Some AOX components are not biodegradable. Among these are POPs such as polychlorinated biphenyls (PCBs) and dioxins.

Per- and polyfluoroalkyl substances (PFAS)

The TULAC industry accounts for a third of all PFAS used (mostly PTFE membranes in outdoor clothing). Although there are no set emission limits yet on PFAS, TULAC businesses could future proof their activities against upcoming restrictions. 

Microplastics

As the name suggests, microplastics are small in particle size (between 1 μm to 5 mm) fragments of plastic. Recent studies showed that microplastics are released across the whole TULAC value chain. Moreover, some research highlighted that current wastewater treatments are not able to capture microplastics.

VOC

Volatile organic compounds (VOCs) are hydrocarbons that evaporate at low temperatures and may be found in the exhaust air of production processes. Some of the most common VOC include solvents, BTEX (benzene, toluene, ethylbenzene and xylenes), siloxanes and terpenes. With regards to textile manufacturing, VOC could arise from a series of processes such as dyeing, finishing, printing, and fixing.

H₂S

Even at low concentrations, hydrogen sulphide’s rotten egg smell causes odour nuisances. When using sulphur-based compounds, textile dyeing can give rise to H2S emission as a by-product.

Wet Scrubbing

Relying on a chemical process called absorption, wet scrubbing has been widely used for treating emissions across different sectors, including TULAC. However, scrubbing units are prone to corrosion and clogging, thus requiring regular maintenance. This obviously translates into higher operation costs. In addition to this, scrubbers can be less efficient when very low VOC emission levels are targeted. Accordingly, a polishing step (e.g., activated carbon filtration) is often needed downstream.

Membrane Separation

Membranes can selectively capture some compounds out of a liquid phase. A typical application of membranes in the TULAC industry is color removal from wastewater. On the other hand, membranes can easily get clogged or fouled. Therefore, plant operators have to integrate their purification system with an upstream pre-treatment such as an activated carbon filter to prevent membrane fouling.

Activated Carbon Filtration

Activated carbon is recommended by the EU as one of the best available techiques (BAT) to treat emissions generated by textile manufacturing. Thanks to its tunable porous structure, activated carbon can adsorb a wide range of pollutants. Combining activated carbon with mobile filters, DESOTEC has fulfilled the purification needs of several TULAC businesses. Some of these real-world applications are outlined in the section below. 

It’s no longer sustainable to design textile production without thinking about recycling. In line with the new EU circular economy act, recycling will be playing a key role also in the TULAC industry. Although the market is still in its infancy, DESOTEC’s purification solutions are ready to remove pollutants from recycling facilities’ emissions.

Similar to post-consumer plastics, recycled textiles often contain residual dyes, microplastics, and chemical additives that can contaminate the process solvent and reduce the recycled material’s quality. Process liquids generated during mechanical or chemical recycling often require advanced purification technologies to remove these impurities. 

In this article, we explain how DESOTEC’s mobile activated carbon filtration provides recyclers with an efficient and sustainable way to remove contaminants from wastewater, process effluents and product streams. This not only improves the quality of recycled materials but also ensures compliance with environmental regulations, supporting a cleaner and more circular textile value chain.