O/w emulsions that have become unusable, for example water-miscible coolant emulsions or rolling emulsions resulting from the mechanical processing of metallic and non-metallic materials contain oils and greases emulsified in water.

The main part is water and the rest are mostly organic chemicals that give the emulsion the necessary effect and stability – but also the resulting high COD (chemical oxygen demand). These o/w emulsions have to be disposed of with great effort and high costs. The water produced after a common chemical-physical demulsification must be additionally after-treated to remove residual oil, heavy metals and other pollutants.

For this purpose, a second step is necessary and in addition to the oil, the resulting thin sludge must also be disposed of here.

is a very economical and environmentally friendly solution.

The used water-miscible coolant emulsion is treated with our special de-emulsifier DKS-30-10 and in combination with our heavy metal precipitant. The latter eliminates not only heavy metals such as copper and zinc far below the prescribed limits, but also residues of other undesirable pollutants.

The resulting insoluble oil droplets with the adsorbed heavy metal flakes and other pollutants form the floatation oil. The split water is completely de-oiled and clarified at the same time. After the natural or a technical flotation the resulting clearwater and the flotation oil are separated from each other.

Only this floatation oil is then sent for controlled disposal.

The oil- and heavy metal-free clear water with a residual hydrocarbon content of < 20 mg/L (limit value in Germany), but usually well below 10 mg/L and a further lowered COD can be used directly industrially for simple applications or, for example after osmosis or evaporation, for many other sustainable applications.

It is in our opinion more economical and environmentally friendly if the clear water is first fed into a classic industrial biology to reach the COD of 1500 mg/L specified by the authorities in Germany and then disposed of in a municipal sewage treatment plant.

A strictly controlled, but then very low-dose disposal of the clear water separated after flotation directly into a municipal sewage treatment plant is also possible if the competent authority has checked and approved this.

In order to implement this 1-step process, no complex plant technology is required. The treatment can be carried out, for example, very easily in a simple IBC container with an agitator or in an existing flotation plant on the operating side.