An Investigation of the Factors Affecting the Removal of Fulvic Acid From Water by Aluminum and Polymers

Abstract

The effect of five operating variables on the removal of fulvic acid from water by means of aluminum and polymers was studied. These variables were the pH, the calcium concentration in the water, and the polymer dosage, molar mass and degree of hydrolysis. The study followed a 25−1 resolution V fractional factorial experimental design. Based on a statistical analysis, the most significant effects were the pH, the calcium concentration, the polymer molar mass and the interaction of pH with calcium concentration. A calcium concentration of 40 mg/L, a pH of 7 and a polymer with a molar mass of 5 to 6 million were found to be most effective based on fulvic acid removal by filtration. The effect of calcium was larger at pH 8 than at pH 7. The type of polymer did not have any significant effect.