Chitosan is a non-toxic, biodegradable product derived from chitin by deacetylation in the presence of alkali. It is the second most considerable polysaccharide, after cellulose and regarded as a cellulose derivative. The new permanent property is anti-microbial and film-forming, which makes chitosan promising regarding Nano treatment of textiles. Chitosan got many promising qualities such as biodegradability, non-toxicity, and anti-microbial, and can, therefore, used developing anti-microbial textile finish.
Furthermore, it works on many different types of textile fabrics such as cotton, silk, and synthetic filter fabrics. The surface treatment process is few, such as exposes impregnated fabrics to UV lights (lamp). Chitosan used in pre-treatment as well as after-treatment of fabrics, used in combination with direct dyes, increase the colour strength more than reactive dyes. Textile dyeing is one of the most environmentally unfriendly industrial processes because they produce coloured wastewaters that are heavily polluted (chemicals, dyes).
Equally important, the textile dye coloured with high values of pH scale, salts, heavy metals, mineral oils, and surfactants. Chitosan in coloured dying has proven to be more favourable in wastewater treatment due to its environment-friendly characteristic. Chitosan is a renewable source and is commercially available from the shellfish industry.