Background The core activity of the leather industry has expanded in recent years following the availability of a wider range of dyeing products from dyestuff manufacturers. An estimated 2.3 million tonnes/yr of dyestuff are produced globally. This dyestuff is often chemically complex and heterogeneous in nature, which can present environmental hazard risks. Dyeing effluents released into wastewater may contain up to 50% of the dye used to set dye baths. Therefore, commercial dyes can constitute a significant source of heavy pollution. Elimination of contaminants from the leather industry’s dyeing effluents is thus an important environmental objective. The challenge is especially pertinent in Italy and Spain, the EU's two largest leather industries, which produce some 235 000 tonnes/yr of leather goods. Objectives The BioNaD project’s main objective focuses on demonstrating the economic and environmental performance of innovative dyes for the leather industry. These so-called 'naturalised dyes' provide an alternative to conventional methods (that commonly rely on acid dyes). The project will also test bacteria-based degradation processes on dye effluent wastewater, enabling it to be recycled of water and thus reducing water consumption. Specific project actions will demonstrate: The synthetic chemical design of dyes in compliance with EU REACH Regulation (CE) No. 1907/2006; The use of lactose from waste milk serum to generate naturalised dyes; The use of naturalised dyes with a higher purity than commercial acid dyes; The avoidance of chemical additives in the dyeing processes; and The use of eco-friendly Escherichia Coli biodegradation technology, to achieve the purification of dye-containing effluents in aerobic conditions without the generation of toxic metabolism by-products; Expected results: The project expects to achieve the following results: Total elimination of chemical additives as dispersing agents and surfactants from the synthesis output of dyes; A 100% increase in the purity of naturalised dyes in comparison with commercial dyes; An 80-100% reduction in the release of lactose from waste milk serum into the environment; A 70-100% reduction in pollutants in dyeing wastewater;A 70-100% increase in the biodegradability of dyeing wastewater; Recycling of 100% of bacteria biomass for further wastewater purification; A 20% increase in penetration of naturalised dyes into leather; A 20% increase in efficacy for dyeing homogeneity; A 10-15% increase in bath exhaustion; A 15-20% improvement in the quality of dyed leather using finishing protocols; A 50% improvement in the purification of dyeing effluents using E. Coli bacteria; A 40-50% reduction of the COD and BOD of dyeing wastewater;Recycling of 70-80% of purified wastewater (e.g. for further dyeing); A 40-50% reduction in water consumption; and A 20-30% reduction in energy consumption.