Aluminium is the most common metal in our anthroposphere and after oxygen and silica
even the most common element of the earth’s crust. Because of its big affinity to oxygen, aluminium
does not exist in elemental form in nature, but in different oxidized compounds.
In swimming pools, aluminium salts are used as flocculant for the water treatment.
For drinking water, the WHO recommends a guide value of 0.2 mg/l Al3+. In
accordance to the EU council guideline 98/83/EEC, the threshold value for drinking water is 0.2 mg/l
Al3+. In natural water, the concentration of aluminium compounds is even low,
but in waste water aluminium can appear in higher concentrations, e.g. at electroplating companies or
paper mills. Different national regulations tolerate 2 – 3 mg/l Al3+ in
effluents from various industries (metal, electroplating and printing industries).