Process for cleaning wastewater and recirculating water in paper production, de-inking and bleaching of pulp
AssigneeBASF SE
InventorsFriedrich Linhart, Manfred Niessner, Martin Rübenacker, Claudia Nilz
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Abstract
Wastewaters and circulation waters in papermaking, in deinking and in pulp bleaching are treated by adsorption of water-soluble anionic compounds and compounds dispersed in water from the wastewaters and circulation waters over finely divided adsorbents which consist of insoluble, only slightly swellable polymers which contain polymerized vinylamine units, and these polymers are used as adsorbents for treating water circulations in papermaking and for treating paper machine wastewaters and wastewaters from the deinking process and from pulp bleaching.
Claims8
A process for treating waste waters and circulation waters in papermaking, in deinking and in pulp bleaching, comprising retaining insoluble impurities and absorbing water-soluble anionic compounds and compounds comprising phenolic resins and monobasic acids and anions thereof dispersed in water from the wastewaters and circulation waters over a finely divided absorbent, wherein the finely divided absorbent is an insoluble, only slightly swellable polymer which is prepared by copolymerizing
- (a) N-vinylcarboxamides of the formula
- wherein R and R1 are each H or C1-C6-alkyl, and
- (c) from 0.1 to 10% by weight, based on the monomer (a) of a compound containing at least two ethylenically unsaturated double bonds as a crosslinking agent, in the absence of oxygen and polymerization initiators to produce popcorn polymers, and eliminating the groups
- from at least 0.1% of the polymerized N-vinylcarboxamides of the formula I with the formation of vinylamine units of the formula
- wherein R1 is H or C1-C6-alkyl.
A process for treating waste waters and circulation waters in papermaking, in deinking and in pulp bleaching, comprising retaining insoluble impurities and absorbing water-soluble anionic compounds and compounds comprising phenolic resins and monobasic acids and anions thereof dispersed in water from the waste waters and circulation waters over a finely divided absorbent, wherein the finely divided absorbent is an insoluble, only slightly swellable polymer which is prepared by copolymerizing
- (a) N-vinylcarboxamides of the formula
- wherein R and R1 are each H or C1-C6-alkyl,
- (b) other monoethylenically unsaturated monomers copolymerizable with said N-vinylcarboxamides, and
- (c) from 0.1 to 10% by weight, based on the monomers (a) and (b), of a compound containing at least two ethylenically unsaturated double bonds as a crosslinking agent, in the absence of oxygen and polymerization initiators to produce popcorn polymers, and eliminating the groups
- from at least 0.1% of the polymerized N-vinylcarboxamides of the formula I with the formation of vinylamine units of the formula
- wherein R1 is H or C1-C6-alkyl.
Dependencies are inferred from the claim text.