The main raw materials for iron salt-based wastewater treatment products are by-products from other production processes. The most commonly used by-product is iron sulphate, which is produced in large quantities during the pickling of steel and the production of titanium dioxide. These by-products are present in bivalent form.

Oxidation produces trivalent iron products, which are more effective in water treatment during coagulation.

In addition to the general applications described in the section metal salts in sewage treatment plants, iron salts are also used to bind sulphides (to avoid hydrogen sulphide in the digester gas).

Iron salt-based products that have been further developed by means of additives are also used to combat bulking sludge. Sewage treatment plants using the S::Select^® process have been able to show that these cost-intensive special products can be permanently avoided or their dosage significantly reduced.


« back