Process for treating waste water containing polyvinyl alcohol
AssigneeSando Iron Works Co., Ltd.
InventorsYoshikazu Sando, Hiroshi Ishidoshiro, Eiichi Nakano
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Abstract
A process for treating waste water containing polyvinyl alcohol (designated hereinafter as P.V.A.) comprising separation of the P.V.A. in the form of a compound with boric acid which is produced at pH 8 to 10 by a reaction with boric acid or borax added in the presence of an inorganic salt such as sodium sulfate, and using thus regenerated liquid repeatedly, and a process of utilizing waste containing P.V.A. for desizing textile.
Claims12
A process for treating waste water containing polyvinyl alcohol comprising reacting the polyvinyl alcohol in the waste water at a pH from 8 to 10 with a boron compound selected from the group consisting of boric acid and borax in the presence of an inorganic salt to produce a complex of the boron compound and the polyvinyl alcohol, and separating the complex therefrom.
A process for treating waste water containing polyvinyl alcohol by adding a boron compound selected from the group consisting of boric acid and borax and an inorganic salt to the water, heating the thus formed solution above 70.degree. C while the pH is from 4 to 7, adjusting the pH to 8 to 10 and then cooling the solution to room temperature to separate the polyvinyl alcohol in the form of a complex with the boron compound which is free from any salts and solid impurities in the waste water.
Dependencies are inferred from the claim text.