An environmental control system includes an air conditioning subsystem; a mix manifold downstream of the air conditioning subsystem and upstream of an environment to be conditioned; and a contaminant removal subsystem downstream of the environment to be conditioned. The contaminant removal subsystem includes a first gas-liquid contactor-separator. The first gas-liquid contactor-separator includes a first packed, stationary bed that provides a heat/mass transfer surface for contact between a contaminated air from the environment and a liquid absorbent.