Polyelectrolyte titration using PCD-03 pH and PCD-T3 is a very good means of studying and optimizing the dosage of PAC.
Problem Description Poly aluminium salts are used as flocculants in many different processes, eg water treatment, paper industry, leather production. PAC consists of aluminium containing clusters with a high surface charge. The chemical properties are strongly influenced by the quality of the product and the pH of the process in which PAC is used.
The surface charge of PAC decreases considerably with rising pH by formation of aluminium hydroxide with a negligible positive charge. The quality of the PAC is of decisive influence on how fast it is transformed into the hydroxide. When the pH exceeds 8, the hydroxide turns into the anionic aluminate.
The decreasing surface charge of PAC with rising pH is represented by the decreasing consumption of titrant (0,001 N PES-Na).