▎ 摘　　要

NOVELTY - Filtration apparatus comprises: a support substrate; and a graphene oxide membrane (100) disposed on the support substrate, where the graphene oxide membrane comprises many graphene oxide sheets (110), each of the graphene oxide sheets coupled to an adjacent graphene oxide sheet via a chemical linker (120), the graphene oxide membrane has a flux of at least about 2.5x10-4 gallons per square foot per day per psi (GFD/psi) with 1 wt.% lactose solution at room temperature, and the graphene oxide membrane has magnesium sulfate rejection rate of at least 50% with 0.1 wt.% magnesium sulfate solution. The support substrate is microporous polymer substrate. USE - The apparatus is useful for processing black liquor (claimed). ADVANTAGE - The apparatus utilizes graphene oxide membranes having tunable permeability, rejection rate, flux, less cost, high chemical stability, strong hydrophilicity and compatibility with variety of environments. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for processing black liquor, where the black liquor comprises lignin, sodium sulfate, sodium carbonate, sodium hydrosulfide, sodium thiosulfate and/or sodium hydroxide. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the graphene oxide membrane of the filtration apparatus. Graphene oxide membrane (100) Many graphene oxide sheets (110) Many chemical linkers (120) First end (122) Second end (124)