METHOD AND SYSTEM FOR REDUCING PHOSPHORUS IN EFFLUENT OR FILTRATE

摘要

The invention relates to a method for reducing phosphorus in effluent or filtrate from a process which comprises a stage in which green liquor dregs are filtered using a green liquor dregs filter and at least one stage in which conditions are acidic, wherein the method comprises the steps of: a) obtaining an effluent or filtrate from a stage in which conditions are acidic; b) adjusting pH of at least a portion of the ef- fluent or filtrate to alkaline with an alkaline agent; c) allowing phosphorus to be precipitated in form of a phosphate salt; d) separating the precipitate to produce purified effluent or filtrate and a sludge comprising the precipitate; and e) filtering the sludge comprising the precipitate obtainable from step d) using the green liquor dregs filter.