Water Treatment and Purification

Raw water treatment is now confronted with new challenges. The pollution of the past has a direct impact today on the natural sources of water, surface waters and groundwater. Insufficiently treated process wastewater that is discharged into bodies of water results in long-term damage that then has to be tackled later on at great expense. The pollution of rivers, lakes and groundwater with pesticides, mineral oil residues or pharmaceuticals are examples of this.

In many cases the currently established processes and systems cannot do the job without adaptation and support from new, selective systems. Fraunhofer IGB has recognized this necessity and is working on the improvement of existing processes such as adsorption, filtration, flocculation/precipitation, homogenization and disinfection as well as on new approaches in process and unit operations. The use of oxidative and electrolytic processes for water treatment is one of our main fields of research. Together with industrial partners, new concepts and technologies are being developed at Fraunhofer IGB also to industrial scale. Water treatment and the circulation of process water can thus be carried out economically and sustainably.

Advantages

With oxidative and electrolytic processes, it is possible to oxidize dissolved contaminants or pollutants that are difficult to break down. In general, electrolytic and oxidative processes have the following advantages:

  • Complete mineralization of pollutants possible
  • Staff savings and increased reliability
  • No increase in salinity, which enables recirculation
  • No disinfection by-products – in particular no halogenated compounds
  • Less handling of hazardous chemical agents
  • Little or no sludge formed
  • Hygienic outflow water
  • Robust process – discharge criteria can be met reliably
  • Available quickly – standby operation possible
  • Suitable for varying quantities and qualities of wastewater

Applications

At present the focus is on industry-oriented studies of landfill leachate and textile effluents. The aim here is to meet the discharge criteria of the communal treatment plants in a cost-effective way. In other projects we have developed new technical solutions for UV treatment and anodic oxidation together with our industrial partners. These projects aim to make the solutions ready for market launch.

Electrophysical precipitation

Advanced Oxidation Processes (AOP)

Photolysis

Electro-oxidation and -reduction

Combination and integration of oxidative and electrolytic processes

Oxidative and adsorptive processes such as electrophysical precipitation can be combined, depending on the problems to be solved. By doing this, results can be achieved that exceed the sum of the results of the individual processes.

A further advantage of these processes is that they are suited to standby operation and can be switched on or off at any time. Integration into existing plants and automation including autonomous operation or remote control are feasible without any problems. Continuous online logging of organic carbon (TOC, total organic carbon) can be effected, enabling requirement- based and thus energy-optimized treatment.

Lubricants for wet machining of fiber reinforced plastics

Dust generated during milling of fibre reinforced plastic.
© Fraunhofer IGB

Dust generated during milling of fibre reinforced plastic.

Fiber‑reinforced plastics (FRP) are lightweight and have excellent stiffness, which is why they are increasingly used in the automotive and aerospace industries. The final processing steps e.g. milling and grinding produce dusts of hard glass or carbon fibers. The aim of the project is to use cooling liquids as lubricants to reduce tool wear and at the same time improve occupational safety and machine safety.

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