Resumen

CONTRERAS-ANDRADE, I. et al. Synthesis of flocculants based on responsive polymers and its use in solids removal from river water and wastewater. Rev. Mex. Ing. Quím [online]. 2015, vol.14, n.2, pp.415-427. ISSN 1665-2738.

Flocculants based on responsive polymers were synthesized by means of free radical polymerization in aqueous environment at 25 °C. Poly(N-isopropylacrylamide) (PNIPAAm), statistical copolymers from NIPAAm and either acrylamide (AAm) or acrylic acid (AAc), and a copolymer composed of the three different monomers were prepared. These materials were characterized by Dynamic Light Scattering (DLS), Fourier Transform Infrared Spectroscopy (FT-IR) and Thermogravimetric Analysis (TGA). The polymer diameters in water were in the range from 22 to 42 nm. Copolymers containing acid units exhibit a sharp T/pH-responsive behavior. Polymeric flocculants were evaluated in the turbidity removal from high-turbidity river water and wastewater (urban and agricultural). Temperature and time of flocculation, as well as composition and dosage of polymer were tested. The most effective temperature and time of flocculation were found to be 40 °C and 15-25 min, respectively. Polymer dosage of 0.1 mg mL^-1 is sufficient for a high percentage of turbidity removal (~80%). At 1 mg mL^-1 of flocculant, turbidity removal from 23.9 to 99.2% depending on the polymer composition and water quality were reached.

Palabras llave : water treatment; flocculation; turbidity removal; responsive polymers; PNIPAAm.

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