In most cases, wastewater containing heavy metals is treated by adding chemicals to precipitate the metals and neutralize the resulting wastewater. This increases the salt content/salt load of the wastewater and leads to metal-containing sludge, which has to be separated and disposed of properly with additional effort for wastewater treatment. A scalable laboratory reactor based on the concept of electrochemical precipitation is being set up for the alternative treatment of process water and the recovery of heavy metals. The process works according to the principle of pH shift during water electrolysis towards an alkaline state at the cathode. This causes the precipitation of the heavy metals present as hydroxides. The pH value is lowered at the anode. After precipitation and separation of the metal hydroxides, both the catholyte and the anolyte are mixed again, which leads to complete neutralization of the treated water and guarantees that no chemicals need to be added. The aim of the NERA project is to develop an electrochemical wastewater treatment process on a continuous pilot scale with a volume flow of approx. 1^m3/h, in which the treatment takes place without the addition of chemicals. The aim is to reuse the treated water as raw water in the original process and thus reduce the water requirement by recycling the water.

Further information: https://www.projekt-nera.de/.