FLOCCULATING AGENTS BASED ON CATIONIC AGAROSE.

H. PRADO; M. C. MATULEWICZ; P. BONELLI; A. L. CUKIERMAN

Rosario, Argentina

Workshop; 1st Argentinian Workshop in Environmental Science / Taller Argentino en Ciencia Mediambiental; 2009

Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario

The adsorption of polymers onto colloidal particles can cause changes in their colloidal stability leading to improved flocculation. Although cationic polyelectrolyte flocculants are widely based on polyaacrilamide derivatives, concerns regarding biodegradability and high cost have encouraged research towards natural polymers. In that sense, we synthesized novel cationic agaroses with different degrees of substitution (DS) and their tested performance in destabilization of kaolin dispersions. The cationic agaroses were prepared by the reaction of agarose in alkaline aqueous solution with 3-chloro-2-hydroxypropyltrimethylamonium chloride. In order to obtain agaroses with different DS and to find the best reaction conditions. The reaction products were characterized by different techniques, FTIR, 1H NMR, HPSEC-MALLS. Products with DS between 0.04 and 0.77 were obtained. As opposed to natural agarose these products did not forms gels. The flocculation behaviour of cationic agaroses was tested by turbidimetry. Best results were obtained with the modiffied agarose  presenting DS=0.19 with a concentration of 2-4 mg of flocculant per g of kaolin. Cationized agarose constitutes a natural polymer with potential application in flocculation of aqueous suspensions