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Aluminum (Al+3) is an abundant metal in the Earth抯 surface, but its
solubilty in water is so low that it is seldom a concern in municipal or
industrial water systems. The majority of natural water contains from 0.1 ppm up
to 9.0 ppm of Aluminum, however the primary source of Aluminum in drinking water
comes from the use of aluminum sulfate (alum) as a coagulant in water treatment
plants. The total dietary exposure to aluminum salts averages around 20 mg/day.
Aluminum is on the US EPA抯 Secondary Drinking Water Standards list with
suggested levels of 0.05 - 0.2 mg/l; dependent on case-by-case circumstances.
Treatment
Aluminum can be removed from water by a cation exchanger but hydrochloric acid
or sulfuric acid must be used for regeneration to remove the aluminum from the
resin. While this is suitable for an industrial application it is not
recommended for domestic use unless it is in the form of a cation exchange tank.
Reverse Osmosis will reduce the aluminum content of drinking water by over 98%.
Distillation will reduce the aluminum content of water by over 99%.
Electrodialysis is also very effective in the reduction of aluminum.
