Is an Effective Recovery of Heavy Metals from Industrial Effluents Feasible?

Usual methods for wastewater purification produce metal bearing remnants. These are deposited in landfills and the included metals are lost by dissipation. Exemplarily, we estimated the re-source potential of the neutralisation sludges. Referring to a low estimated annual volume of 50,000 tons, the loss sums up to 2,000 tons for Cu and 5,300 tons for Ni on macro-economic scale. We developed a new method for effective recovery of heavy metals (> 99.9 %) while preserving efficient purification of wastewater. Our treatment procedure provides recycling or even upcycling of the recovered zero-valent phases or diverse metal oxides. Moreover, this method leads to a drastic decrease of the precipitate volume compared to the usual neutralization treatment of wastewater. It combines ecological benefit and economic advantages with regard to both, business and macro economy. Additionally to the recovery of metals as secondary raw materials, our method contributes to save costs of transport and disposal (av. 100-200 €/t). The introduction of a new urban mining technology needs also an analysis of the stock and dynamics of waste flows. Due to applied statistical nomenclature systematics, the suitability of official statistical reports for urban mining purposes is only limited. As a first approach, we used the official monitoring data for wastewater treatment to derive maps showing potential sources for secondary raw materials.