▎ 摘　　要

NOVELTY - Filtration apparatus comprises a support substrate, and a graphene oxide film provided on the support substrate, where the graphene oxide film including graphene oxide sheets, where each of the graphene oxide sheets covalently coupled to a chemical spacer (120), each of the graphene oxide sheets is not covalently crosslinked to other graphene oxide sheets form graphene oxide sheets, the graphene oxide film has a lignin rejection rate of 50% with a black liquor feed containing 10 wt.% total dissolved solids at a temperature of 50℃ and a pressure of 200 psi. USE - Filtration apparatus used for processing black liquor feed. ADVANTAGE - The filtration apparatus improves flux and/or rejection rate of the graphene oxide film as compared to a rough support substrate. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a filtration apparatus. 100Graphene oxide film 110Graphene oxide sheets 120Chemical spacers