▎ 摘　　要

NOVELTY - Manufacture of membrane involves forming suspension (S1) comprising water and graphene oxide, mixing a base into the suspension (S1) to form suspension (S2), vacuum filtering the suspension (S2) on a membrane support to form a membrane, and conditioning the membrane under a pressure of 10 bar or more until the flux of the membrane is less than 5% per hour. USE - Manufacture of membrane used in system for purifying black liquor (all claimed). ADVANTAGE - The method produces membrane having improved stability for a stable flux under variety of operating conditions. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) membrane, which comprises porous substrate, two or more graphene oxide sheets arranged on the porous substrate and comprising graphene oxide flakes containing planar graphene structure with oxygen moieties, and an intercalating agent arranged between the two or more graphene oxide sheets. The intercalating agent interacts with graphene oxide sheet, and provides non-covalent stabilization of the two or more graphene oxide sheets; (2) method of purifying black liquor, which involves feeding black liquor feedstock comprising 1-50 wt.% solids and water to the membrane under a transmembrane pressure of 10-50 bar, producing a permeate stream comprising one or more purified products which have passed through the membrane, and obtaining a retentate stream comprising one or more rejected components which have not passed through the membrane; and (3) system (100). DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the system for purifying water from liquor streams. System (100) Membrane unit (110) Feed line (120) Permeate line (130) Retentate line (140)