The base for coagulants is salts of either aluminium or iron, two of the most common elements in the earth’s crust (8.1% and 5.1%. respectively).

Coagulants are produced either directly from ore extracted from the earth's crust or mainly via side streams from other industrial processes.  Only when there is no access to such side streams, then the aluminium and iron salts are produced from virgin raw materials. 

The salts must be in a water soluble form either as a sulphate or as chloride. This means that either sulphuric acid or hydrochloric acid are the other main raw materials used to leach aluminium and iron from the ore.

The acids being used to dissolve the aluminium and iron are not generated on purpose but are products of different industrial processes.

The  total production of coagulants can be seen as a recycling process resulting in useful products helping to sustainably protect the environment.

Coagulants used for sewage treatment are therefore very often attributed with a double positive effect concerning their impact on the environment.  The production of most coagulants consumes a negligible amount of energy.