Method of treating pulp bleaching effluents
AssigneeEKA Aktiebolag
InventorInge G. Mansson
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Abstract
A method for cleaning effluents from bleaching plants which use ultrafiltration for cleaning, preferably after the first extraction stage, by dividing the ultrafiltration into two stages, and between them inserting an alkali treatment stage. The high molecular chlorine compounds are thereby split into innocuous sodium chloride in the permeate from the second ultrafiltration stage, which can be returned to the extraction stage so that with the alkali excess after the splitting, it can cover all or part of its alkali requirement.
Claims9
A method of cleaning effluents from pulp bleaching plants, containing high molecular weight organic chlorine compounds, comprising ultrafiltering the effluent to produce a permeate and a concentrate containing high molecular weight chlorine compounds, contacting the concentrate with alkali to split a portion of the high molecular weight chlorine compounds in the concentrate into phenols and alkali chloride, and again ultrafiltering the alkali-treated material.
Dependencies are inferred from the claim text.