In the metal processing industry, the wastewater produced is usually treated by adding acid, alkali, precipitation chemicals and flocculants before it is discharged into the receiving water. This addition of chemicals leads to a significant increase in the salt load of the water, which is why process water recovery is not economical. Innovative solutions in line with the German sustainability strategy adopted by the federal government are needed to realize resource- and climate-friendly water use by 2030.
In the joint project NERA, the project participants are developing a new wastewater treatment process to tap wastewater partial flows from the metal processing industry as a valuable source of raw materials and process water. In the sense of an improved circular economy, the recovery of wastewater ingredients and process water is to be as free as possible of chemical consumption, free of residues and at the same time climate neutral. The new wastewater treatment process is based on an innovative reactor system for the electrochemical precipitation and recovery of phosphate and heavy metals such as manganese, nickel, zinc and chromium. This process is being tested at the VW plant in Braunschweig.