Rolf Nilsson

Residual Aluminium Concentration in Drinking Water After Treatment with Aluminium or Iron Salts

In recent years a potential connection between human intake of aluminium and Alzheimer’s disease has drawn attention to the aluminium concentration in drinking water. In the present paper the aluminium concentration in drinking water from treatment plants using aluminium or ferric coagulants is compared with the solubility of aluminium hydroxide, reviewed from the literature. Aluminium hydroxide is least soluble at about pH 6.3. At lower pH, positively charged aluminium hydroxide complexes, and at higher pH, negatively charged aluminate ions are formed, and at these pH values, solubility is higher. Complexing agents increase the solubility.