Comparative Study Between New Polyacrylamide Based Copolymer Poly(AM-4VP) and a Cationic Commercial Flocculant: Application in Turbidity Removal on Semi-Industrial Pilot

In the present work, adiabatic copolymerization allowed us to synthesize two poly(AM-4VP) (s) copolymers with various macromolecular weights as determined by viscosity measurement. The H-1-NMR was used for copolymer's structure verification. UV-Visible was also used to determine the percentages of acrylamide (AM) and 4-vinylpyridine (4VP) monomers in each copolymer. Synthesized copolymers were tested in the aim to eliminate turbidity from bentonite suspension. A first study was realized on a conventional jar-test in order to determine the optimum parameters, such as time and the speed of stirring of different flocculants, during the flocculation process. Optimized parameters were then used on a semi-industrial pilot of coagulation/flocculation. Flocculation efficiency of the synthesized copolymers was compared with a commercial cationic flocculant FO4910 obtained from Sigma-Aldrich (France). The effect of macromolecular weight and 4VP amounts were also studied. The flocculation experiments results showed that a good turbidity removal superior to 80% was recorded using low copolymers concentrations of < 5 mg/L.