Waste Water Treatment

Physical/Chemical Treatment of Industrial Waste Water

Eisenmann develops and builds made-to-measure plants for the physical/chemical treatment of industrial waste water. These include:

  • Decontamination/oxidation
  • Precipitation, flocculation, sedimentation
  • Flotation

We provide planning, design and installation services for physical/chemical treatment plants, turnkey solutions, and BOT models in line with your specific needs.


Industrial waste water is frequently contaminated with inorganic substances (above all cyanide, chromate, arsenic and nitrite.) To remove them from the effluent a variety of decontamination methods can be employed.

Eisenmann uses the patented Fentox® process for this purpose. This oxidizes toxic organic compounds with a solution of hydrogen peroxide and a ferrous iron catalyst (Fenton’s reagent). This method is not only advantageous from an engineering point of view, it also requires less hydrogen peroxide. Our UV Fentox® method is suitable for very high COD loads. With this method, less Fe(II) is required and the sludge quantity can be significantly reduced.

Precipitation, Flocculation, Sedimentation

Precipitation, followed by flocculation and sedimentation, is a long-established and proven physical/chemical process for treating industrial waste water. It is mainly employed for the removal of heavy metals, fluorides and phosphates.

During the precipitation stage, neutralizers (acid/lye) and special precipitation agents are added, and insoluble compounds are formed at specific pH values. Precipitation is followed by flocculation aided by flocculants. This enables the effective removal of harmful substances from the waste water. The sludge produced in the previous process steps is separated from the waste water by means of sedimentation.


Flotation is used to treat industrial waste water that contains substances that tend to float to the surface. These include paint, oils, grease and carbohydrates. Flotation is facilitated by the addition of chemical agents and the injection of air (dissolved air flotation). The dirt particles adhere to the air bubbles and rise with them to the surface, where the floating matter can be skimmed off. The sludge produced by flotation is further dewatered in dewatering containers, chamber filter presses or decanters.