METHOD OF TREATMENT OF FAT-CONTAINING SEWAGE Russian patent published in 2002 - IPC

FIELD: sewage treatment, ecology. SUBSTANCE: invention relates to a method of treatment of fat-containing sewage, for example, margarine, mayonnaise manufactory. Before filtration fat-containing sewage are subjected for a preliminary purification by three-step scheme. At the first stage discharges are separated for three layers by flotation being a median layer overemulsified with fat substances is fed to the second stage where separation for two layers is performed. The upper layer containing fat substances is fed to the manufacture and a lower layer overemulsified with fat substances is fed to the third stage from that water is fed to ultra-nanofiltration where separation for two flows is carried out. One flow containing a concentrate of fat substances is recovered to the first stage of flotation and permeate is recovered to the manufacture. EFFECT: improved method of treatment. 1 tbl, 1 ex