▎ 摘　　要

NOVELTY - The application model claims a multi-stage separation filtering device for removing acid by graphene oxide, comprising a storage tank and a discharging tank, a double-stage filtering device is set between the storage tank and the discharging tank. The application-stage separation filtering device for graphene oxide removing acid provided by the invention uses the nano-filtration membrane as the main washing device, and can recycle most of the high-concentration sulphuric acid for production and recycling in the initial washing period, and the device only needs to deionized water, without introducing other impurities, the whole washing process belongs to continuous operation, the operation is simple and efficient. The device is in full closed state, no acidic gas discharge, after finishing production, only need to deionized water the cleaning device. when back washing, it greatly reduces the damage of the back washing liquid to the first-level nanofiltration membrane and the second-level nanofiltration membrane, prolongs the use life of the first-level nanofiltration membrane and the second-level nanofiltration membrane.