Revolutionary water purification: This is how we save Saxony's waters!

Revolutionary water purification: This is how we save Saxony's waters!

The TU Bergakademie Freiberg is working on a promising process for cleaning water contaminated with pollutants, which was developed as part of the MindMontan project. This innovative water treatment process has proven to be efficient in a pilot plant that has been in operation since July 2024. The aim of the project is to clean contaminated leachate in the Freiberg mining area, which is heavily contaminated with metals such as aluminum, cadmium, zinc and manganese. TU Freiberg reports that the necessary measures must be taken in good time before the legally required deadline for compliance with the EU Water Framework Directive by 2027.

The results of the research project show that the process is not only cost-effective, but can also be easily integrated into existing renovation landscapes. Over 1,300 kilometers of streams and rivers in Saxony do not achieve the required good ecological and chemical status due to metal pollution. The catchment areas of the Freiberger and Zwickauer Mulde are particularly affected. IDW reports that There is an urgent need for sustainable solutions to minimize the environmental impact of mining.

Innovative treatment methods

The water purification process consists of several treatment stages. First, the pH value of the leachate, which is around 4.9, is raised using a limestone filter. This leads to the precipitation of aluminum hydroxide. The treatment then takes place in a bioreactor filled with a special biomix of limestone, wood chips, straw and compost. This helps in the formation of metal sulfides.

The final treatment stage includes a plant basin that acts as a natural wastewater treatment plant to filter additional pollutants and suspended solids. The entire project is funded by the Federal Ministry of Research, Technology and Space in the program “WE! – Change through innovation in the region” and is expected to make a significant contribution to fulfilling the EU Water Framework Directive.

Regulatory background and challenges

The EU Water Framework Directive plays a central role in environmental protection and sets a legal framework for keeping water bodies clean. The European Parliament emphasizes that Member States are obliged to draw up management plans and programs of measures to achieve good ecological status. The directive protects inland surface waters, transitional waters, coastal waters and groundwater.

The EU is increasingly faced with challenges such as extreme weather events that threaten water resources. It is therefore essential to promote innovative approaches such as the one developed by TU Freiberg in order to sustainably protect and manage European waters.