Agriculture and food processing industries generate a large amount of organic waste that still contains colouring pigments. Their sustainable use in dyeing textiles will expectedly solve the problem of their disposal. Some studies involving the use of agro and industrial waste have been documented in this chapter to provide a guideline for further research. Information on some selected wastes that have been used in dyeing of textiles by several authors have been listed, their composition and production details highlighted and their use is explained systematically. The documented studies have been placed in the form of case studies to highlight the different approaches of the authors for explaining the effectiveness of such wastes as a source for textile colourants. As reported in some studies, the extracted dye from the waste doubled up as a mordant itself. Most studies also indicate good dyeability with appreciable fastness with respect to the textiles dyed with such wastes. Some wastes have also reportedly rendered antibacterial and sun/light protective properties to the dyed fabric.
Part of the book: Chemistry and Technology of Natural and Synthetic Dyes and Pigments
Colouration of textiles as well as food products with natural colorants is an interesting subject with respect to the growing eco-concern among the consumers. Several colorants are available in nature for textile colouration and are renewable, biodegradable, and eco-friendly. Being safe for human consumption, they can serve the dual purpose of also coloring food. Several such natural dyes are available. This review chapter deals with the chemistry, extraction, application, and colorimetric analysis of colorants derived from turmeric (root), annatto (seeds), and cochineal (insect) for use on both textiles and food products.
Part of the book: Colorimetry