Tata Steel Europe manufactures special types of packaging steel with a process using the chromium-3 combined with formic acid. Both substances have to be removed from the wastewater before it is discharged to the surface water. Tata Steel Europe asked EnviroChemie to develop a process to remove the substances in such a way that no chromium-6 is formed in the wastewater.
EnviroChemie carried out various tests at its laboratory in Germany, to find the best possible process. This resulted in a combination of techniques. The chromium-3 had to be removed first, after which it was possible to continue breaking down the formic acid in the aerobic biological wastewater treatment plant.
The treatment process ultimately turned out to be physical-chemical process of detoxification, neutralization, and dehydration. The plant has been in operation since the end of March 2017. The chomium-3 concentration after the treatment is around 0.1 milligrams a litre, which is under the discharge limit.