Dielectric barrier discharge plasma treatment for sustainable leather dyeing

Adapting green technologies to the leather industry plays a crucial role in environmental protection by reducing wastewater load, using fewer chemicals, minimizing waste, saving energy and water, reducing costs, and increasing productivity. Plasma treatment, accepted as a clean technology, is mostly used in textiles compared to limited studies in leather. Thus, this study will be the first in this respect. Crust leathers, treated with air and argon atmospheric plasma under the conditions of 130 W, 100 s, were dyed with acid and metal complex dyestuffs for 45 minutes at 20°C in different concentrations (1%–4%), and investigated in terms of dyeing properties, wastewater load, and the characterization of the leathers in terms of surface, mechanical and antimicrobial properties. The K/S results of 2% dyeing obtained after air and argon plasma treatment gave similar values with the untreated leathers dyed with a concentration of 4%. This result revealed that half amount of dyestuff is sufficient for the dyeing process to obtain the same dyeing characteristics with the maximum concentration of dyestuff (4%). In addition to improved dyeing efficacy, a reduction up to 35% in chemical oxygen demand value was achieved in addition to 2 and 3 mm inhibition zones without any negative effect to tensile and tear strength of leathers. Consequently, atmospheric plasma treatment is found to be effective and comprising as environment-friendly, and sustainable technique for the leather industry in terms of reduced dyestuff amount and wastewater load without altering the characteristics of the leathers.