Huels Aktiengesellschaft

Degussa-huels Aktiengesellschaft

Gerda Grund

John Kahsnitz

Uwe Tanger

Stefan Schmidt

Juergen Gruetzke

Peter Fast

A process for the removal of ethers and/or PAH's from water, such as contaminated groundwater, is provided that proceeds by initially separating off solid constituents and then adsorbing ethers and polycyclic aromatic hydrocarbons to an adsorber resin, then, as needed, desorbing the adsorbed compounds with steam and regenerating the adsorber resin with an acid, to provide purification of highly polluted groundwater to such a substantial extent that the groundwater can be added to flowing surface waters without problem, and, if desired, used as cooling water or, after further biological purification, as drinking water.

Process for removing ethers and/or polycyclic aromatic hydrocarbons from water containing them

Conventional regenerative adsorptive methods for the purification of waters of organic constituents are limited in their application, when owing to a low content of organic water constituents the loading of the adsorbers is so low that the condensed water vapor desorbate no longer has a tendency to form two phases, or when the organic components are readily water-soluble and thus, following desorption with water vapor, can be separated only with difficulty out of the condensed desorbate. The process of the invention improves the tendency toward phase separation by cycling back the aqueous phase of the desorbate onto a loaded adsorber prior to its desorption in order to increase the loading and reduce, through additional supply of external heat, the required amount of water vapor for desorption. The present process is particularly useful for purification of industrial process waters or ground water.

Processes for the purification of waters containing organic constituents

Polluted groundwater is purified by separating off solids and adsorbing dissolved organic compounds to an adsorber resin. The adsorbed organic compounds are desorbed using steam and the adsorber resin is regenerated using an acid and an oxygen-containing gas. The process makes it possible to separate aromatic and halogenated hydrocarbons off of heavily polluted groundwater to the extent that the groundwater can be added to flowing surface water without reservation. The purified water can, if appropriate, be used as cooling water, or after further biological purification, as drinking water.

Process for the purification of groundwater

The invention relates to a process for bleaching aqueous alkyl polyglycoside solutions using hydrogen peroxide, in a first step the actual bleaching being carried out at alkaline pHs in the presence of an inorganic additive (hydrogen peroxide decomposition inhibitor) and in a second step a specific decomposition of the unreacted hydrogen peroxide being performed by contact with transition metals or inorganic compounds thereof.

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Duelmen, Germany

Gerda Grund