Chitosan for Water Treatment

Chitosan is a natural biopolymer derived from chitin, commonly sourced from the shells of crustaceans like shrimp and crabs. It has gained popularity in water treatment due to its eco-friendly properties and effectiveness in removing contaminants. Chitosan’s positively charged molecules attract and bind to negatively charged impurities, making it effective in capturing suspended solids, heavy metals, dyes, and oils. It can also act as a natural coagulant and flocculant, helping to clarify water. Its biodegradability and non-toxic nature make it an appealing choice for sustainable and safe water purification methods.

• Low Viscosity (20–200 mPa·s): Suitable for flocculation and coagulation in water treatment, where rapid dispersion is needed.
• Medium Viscosity (200–800 mPa·s):Used for balancing ease of application and performance in adsorption and flocculation.
• High Viscosity (>800 mPa·s):Commonly applied in wastewater treatment for heavy metals or oil removal.

• Coagulation and Flocculation: Chitosan acts as a natural coagulant and flocculant, aiding in the aggregation of suspended particles. It helps clarify water by binding and settling out fine particles, turbidity, and organic matter, making it useful in drinking water and wastewater treatment.
• Heavy Metal Removal: The positively charged amine groups in chitosan effectively bind to negatively charged heavy metals such as lead, mercury, copper, and cadmium. This makes chitosan valuable for removing toxic metals from industrial wastewater.
• Dye and Colorant Removal: In textile and dyeing industries, chitosan is used to adsorb and remove colored dyes from wastewater due to its high affinity for many dye molecules, especially anionic dyes.
• Oil and Grease Removal: Chitosan is effective in capturing and removing oil and grease particles from wastewater, making it useful in industries where oily waste is common, such as food processing and petrochemical industries.
• Pathogen Control: Chitosan has antimicrobial properties that can inhibit the growth of bacteria, fungi, and viruses in water. This feature enhances water safety, especially in drinking water and aquaculture applications.
• Reduction of Phosphates and Nitrates: By binding with phosphates and nitrates, chitosan can help reduce nutrient levels in water bodies, mitigating algal blooms and eutrophication.