Paper mill wastewater treatment using flocculating agents

The primary concern of this study is to determine the most effective type of polymeric flocculant in terms of its treating ability on paper mill wastewaters. The polymeric flocculants evaluated were classified into three groups according to their ionic natures, namely -- cationic, anionic and nonionic, all of which have high molecular weights, and low to medium charge densities. Alum was used as the primary coagulant for destabilization purposes and the polyelectrolytes were added to enhance the agglomeration process. Cylinder tests were performed to determine the alum dosage and jar tests were conducted to ascertain the most effective polymeric flocculant among the various samples available. This selection was based on their effect on the pH, turbidity, solids content and supernate color. Based on the analysis of experimental results, it was concluded that the high molecular weight, medium charge density, cationic polymeric flocculant was the most effective in the chemical treatment of paper mill wastewaters