A new procedure for recovering heavy met

The treatment of heavy metal containing industrial wastewater is commonly associated with the generation of significant amounts of hydroxide sludge, leading to inefficient recovery of valuable non-ferrous metals. This study aims to develop novel procedures for the treatment of wastewater containing heavy metals like Cu, Ni, Zn, Mn, Pb, Sn, Pd, and Ag, reaching concentrations of up to 25 g/l. We employed a modified ferrite process with a specific iron-to-metal ratio of 2/1, resulting in the production of a mixture of heavy metal ferrites, oxides, or zero-valent metals without the formation of undesirable hydroxide by-products. Additionally, a new treatment method termed Lt-delafossite, with an iron-to-metal ratio of 1/1, was investigated. Application of these methods to five different rinsing waters from the electroplating industry demonstrated a recovery rate exceeding 99.9%. Calculating based on a model volume of 1000 liters of wastewater with weekly exchanges revealed that approximately 1 ton of metals is lost annually due to dissipation. This approach not only enhances metal recovery but also significantly reduces waste volumes, thereby minimizing transport and disposal costs associated with neutralization sludge.