Abstract: The invention relates to the use of macroporous weakly-basic anion exchangers, charged with palladium or platinum and based on crosslinked polystyrene, as catalysts for the removal of oxygen from aqueous media by catalytic reduction, a process for the preparation of these catalyst resins, and new macroporous weakly-basic anion exchangers, charged with palladium or platinum and based on crosslinked polystyrene, in which the amino groups are primary or secondary amino groups.

Abstract: The invention relate to a process for reducing the wash water required by weakly basic anion exchangers containing primary and/or secondary amino groups when fed with water containing carbon dioxide; in accordance with the process the exhausted, weakly basic anion exchangers are treated with dilute aqueous mineral acids before being regenerated.

Abstract: The invention relates to a new process for the preparation of strongly acid cation exchangers loaded with catalytically active metals by loading the cation exchangers with a solution of a salt of the catalytically active metal and reducing the cation exchangers loaded with metal ions, according to which the loading of the cation exchangers is carried out at temperatures from 50.degree. to 120.degree. C. and formic acid is used as the reducing agent; the invention also relates to the catalyst resins which can be obtained by the process.

Abstract: Method for rendering visible the line of separation between cation exchangers and anion exchangers in mixed-bed filters, in which method an amount of a cation exchanger (anion exchanger) sufficient to form a visible line is added to the cation exchangers and anion exchangers constituting the mixed-bed, the added ion exchanger clearly differing optically from the cation exchanger and anion exchanger used to build up the mixed-bed and having a density 0.01-0.05 g/ml lower (higher) than that of the mixed-bed cation exchanger (mixed-bed anion exchanger), and the resin beads of which predominantly having the same particle sizes as the finest (coarsest) screen fraction of the mixed-bed cation exchanger (mixed-bed anion exchanger).

Abstract: Upward-flow process for treating liquids in ion exchange filters containing cation exchangers and anion exchangers in separate layers arranged one on top of the other, in which the cation and anion exchangers are separated from one another by a resin layer which does not participate in the ion exchange, the anion exchanger is regenerated externally and the cation exchanger, which remains in the filter, is regenerated in the counter-current and the anion exchanger is removed from and recycled to the filter without whirling up the separating layer and cation exchanger layer. The invention furthermore relates to a new counter-current ion exchange filter for carrying out the process.

Abstract: The invention concerns a counter-current adsorption filter for the treatment of liquids, with different adsorbents which require different regenerating agents, in which loading of the different adsorbents is effected in a stream of liquid flowing upwards and regeneration of the different loaded adsorbents with the different regenerating agents is effected in a stream of liquid flowing downwards, the inside of which filter is subdivided, by horizontal devices which are permeable to liquid, into a number of chambers corresponding to the number of different adsorbents to be used; in which the adsorbents which are regenerated with different regenerating agents are present in adjacent chambers; the chambers - with the exception of the topmost chamber of the filter - are equipped with a liquid drainage system which is located below the device which is permeable to liquid and forms the upper boundary of the chamber, and which is embedded in a layer of inert material; and in which the individual chambers are filled w

Abstract: The invention relates to a process for internal regeneration of mixed bed filters in which, after the exhausted ion exchanger mass has been separated into the two components and these have been regenerated and washed out, the exchanger layer in the region of the cation exchanger/anion exchanger interface is selectively removed from the mixed bed filter, the cation exchanger remaining in the filter is mixed with the anion exchanger remaining in the filter for the new loading stage, the ion exchanger mass removed from the filter is added again, when the work cycle has ended, to the exhausted ion exchanger mass before or during the separation into cation exchanger and anion exchanger, and, after the separation, the loading stage is started again with the regeneration of the cation exchanger and anion exchanger; and also to a mixed bed filter for carrying out the process.

Abstract: The invention concerns a counter-current adsorption filter for the treatment of liquids, with different adsorbents which require different regenerating agents, in which loading of the different adsorbents is effected in a stream of liquid flowing upwards and regeneration of the different loaded adsorbents with the different regenerating agents is effected in a stream of liquid flowing downwards, the inside of which filter is subdivided, by horizontal devices which are permeable to liquid, into a number of chambers corresponding to the number of different adsorbents to be used; in which the adsorbents which are regenerated with different regenerating agents are present in adjacent chambers; the chambers--with the exception of the topmost chamber of the filter--are equipped with a liquid drainage system which is located below the device which is permeable to liquid and forms the upper boundary of the chamber, and which is embedded in a layer of inert material; and in which the individual chambers are filled wit