3. Water treatment with chitosan

Chitosan's polyelectrolyte and chelating properties make it a good candidate for environmental applications in wastewater and sludge treatment (table 3 ). Although known since the late 1970s, this application has only really taken off in the last twenty years. Chitosan is currently considered to be a product of the future in this field, which should also encourage its industrial production. This application is mainly based on the polycationic nature of the biopolymer and its solubility in acidic media.