The aeration process is efficiently used to remove

Aeration bubbles air through water so that dissolved volatile organic compounds transfer into the air stream and are stripped out.

Persistent organic pollutants are only semi-volatile and resist this simple air stripping.

Metals are non-volatile and are removed instead by precipitation, coagulation or ion exchange.

Inorganic ions stay dissolved and need methods like membrane filtration or ion exchange, not aeration.

The efficiency of aeration rises with the compound's volatility and its low water solubility.

Air-stripping towers are a common aeration design for treating groundwater contaminated with such compounds.