Sustainable extraction and utilization of chlorophyll from microalgae for eco-friendly wool dyeing

• Published in: Journal of cleaner production 2024-04, Vol.451, p.142009, Article 142009
• Main Authors: Jorge, Alexandre M.S., Pedroso, Pedro R.M., Pereira, Jorge F.B.
• Format: Article
• Language: English
• Subjects: Alcohol/salt; Aqueous biphasic systems; Chlorella vulgaris; Chlorophyll; cosmetics; cost effectiveness; dyeing; ethanol; Extraction; fabrics; industrial applications; Microalgae; sodium hydroxide; Textile dyeing; Wool
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2024.142009

Microalgae are promising and sustainable sources of diverse valuable compounds, including chlorophyll, a pigment widely used in food, feed, and cosmeceutical applications. Exploring its interesting green hue, recent investigations have delved into alternative industrial applications, such as textile dyeing, aiming to minimize reliance on non-sustainable synthetic dyes. To reduce the use of these environmentally harmful compounds in textile dyeing and establish cost-effective and eco-friendly approaches for chlorophyll extraction, this study investigates the use of chlorophyll extracted from Chlorella vulgaris NIVA CHL-108 for wool dyeing. Aqueous biphasic systems (ABS) composed of ethanol and sodium hydroxide were used for chlorophyll extraction, and the chlorophyll-concentrated phase was used for dyeing wool fibers. This sustainable integrated approach allowed complete chlorophyll recovery and enhanced performance for dyeing mordanted and unmordanted wool. The study achieved a remarkable chlorophyll uptake of 87% after two dyeing cycles using unmordanted wool, and a recovery of approximately 98% of copper ions present in the effluents of mordanted wool dyeing process. The study proposes two circular and integrated ABS-based platforms for chlorophyll extraction, concentration, and dyeing, also presenting the challenges impeding their industrial application and proposing strategies to overcome them. This work proves that alcohol/salt ABS-based platforms are simple, circular, and cost-efficient solutions for chlorophyll extraction and utilization in textile dyeing. [Display omitted] •Chlorophyll was effectively extracted from microalgae and applied in wool dyeing.•ABS fully extracted chlorophyll from microalgae, outperforming traditional solvents.•CuSO4-mordanted and unmordanted wool presented similar chlorophyll uptakes (≈70 %).•87 % of all chlorophyll was uptake by unmordanted wool in two dyeing cycles.•Two circular platforms for chlorophyll extraction and wool dyeing were proposed.