Anionic Polyelectrolytes Synthesized in an Aromatic-Free-Oils Process for Application as Flocculants in Dairy-Industry-Effluent Treatment

The wastewater generated from many industries contains suspended and dissolved solids, including organic and inorganic particles, metals, and other impurities. Direct flocculation is regularly used to neutralize the charge of the colloidal particles and bridge the destabilized particles together to form flocs in a cost- and time-effective way. This work refers to the development of new anionic flocculants (co- and terpolymers) tailored to be used in dairy-effluent treatment, using a synthesis process in which new oil phases free of aromatics are applied. Regarding the terpolymers, anionic polyacrylamides were synthesized in the presence of three different hydrophobic monomers at different concentrations. Flocculation performance was evaluated using an effluent from dairy industry. Results show that the developed polyelectrolytes are very promising additives for the treatment of the mentioned effluent. For optimized conditions, 95% turbidity reduction, 44% chemical-oxygen-demand removal, and 57% total-solids removal were achieved with only 53 mg/L of flocculant.