In Bangladesh, huge amount of prawn shell are wasted although it can be used in different promising sectors. One of the main components of prawn shell is chitin. The most useful derivatives of chitin is chitosan which is chemically defined as a copolymer of two residues: 2-acetamido-2-deoxy-β-D-glucopyranose and 2-amino-2-deoxy-β glucopyranose. Chitosan is being used in many traditional and potential applications like in water and beverages clarification and purification, wound dressings, drug delivery, contact lens, bandages, cholesterol reducing agent, cosmetic and personal care etc. Here some the modern applications of chitosan are mentioned:
1. In the wastewater treatment as coagulant and substitute to other chemical flocculants
2. In the food industry as thickening, gelling, emulsifying, and whipping agents.
3. In wound dressing .
4. In agriculture as plant growth promoters
5. Removal of harmful metal ions
6. Treatment of industrial wastes
7. Decolorization of dye house water
8. In cosmetics as moisturizing agent and in hair care
9.In retention of flavors
10. As a fining agent in beverages
11. As a food preservative
12. As fat trappers
13. In inhibition of infection of bacteriophages