Patent ID: 7169309

Claim:
A process for removing heavy metals from waste water or for reducing the turbidity and the chemical oxygen demand (COD) of waste water or drinking water, and producing clarified, comprising the step of stirring said waste water or drinking water with a copolymeric polysaccharide formed from a main chain comprising similar or different anhydrohexose units and branches which comprise at least one neutral or anionic anhydropentose and/or anhydrohexose unit; said copolymeric polysaccharide comprising one or more units which carry(ies) an oxime function at least in a C2 carbon position located in an α position to an anomeric carbon and being capable of being obtained by implementing the following steps: a) bringing a polysaccharide into contact with an aqueous solution which comprises at least one oxidizing agent which oxidizes at least a hydroxyl function carried by the C2 carbon of one or more units of the polysaccharide to a ketone function; and b) bringing the polysaccharide obtained in step a) into contact with hydroxylamine, in order to transform the ketone function into an oxime function.