An aircraft contaminant removal system includes one or more membrane separators configured to absorb a contaminant from a cabin air stream into a liquid sorbent, desorb the contaminant from the liquid sorbent, discharge the contaminant in a contaminant stream, and return clean air back to the cabin. In some examples, the contaminant removal system includes a membrane scrubber-separator and a membrane stripper-separator, while in other examples, the contaminant removal system may include a single membrane separator configured to operate in a scrubbing mode and a stripping mode. The contaminant removal system may include a humidity management system configured to maintain a humidity of the clean air stream or water concentration of the liquid sorbent using one or more water sources of the aircraft or a thermal management system configured to maintain a temperature of the liquid sorbent using one or more heat exchangers fluidically coupled to an aircraft air stream.