An environmental control system includes an air conditioning subsystem and a contaminant removal subsystem downstream of the environment to be conditioned. The contaminant removal subsystem includes: a first gas-liquid contactor-separator; a second gas-liquid contactor-separator; and a dehumidifier disposed either upstream of the first gas-liquid contactor-separator or downstream of the second gas-liquid contactor-separator.

An environmental control system includes an air conditioning subsystem and a contaminant removal subsystem downstream of the environment to be conditioned. The contaminant removal subsystem includes a first gas-liquid contactor-separator, a second gas-liquid contactor-separator, and a third gas-liquid contactor-separator. One of the first, the second, and the third gas-liquid contactor-separators is configured to receive used absorbent liquid having at least a first contaminant and discharge at least a first contaminant for recovery and reuse. Another of the first, the second and the third gas-liquid contactor-separators is configured to receive used absorbent liquid having at least a second contaminant and discharge at least the second contaminant for recovery and reuse

An environmental control system (ECS) includes an air conditioning pack that receives outside air; a regenerative treatment subsystem, wherein the treatment subsystem includes a treatment bed configured to cycle between an adsorption phase and a desorption phase; and a fan that receives recirculated air from the environment and moves the recirculated air to a mixing manifold.

An Environmental Control System includes sensors, an air purification subsystem, and a controller in communication with the sensors and air purification subsystem. The sensors detect contaminants in outside air supplied through engine and APU bleeds or other air sources including ground supplies and electric compressors, contaminants in recirculated air, particulates in outside air, carbon dioxide in recirculated air, temperature in an environment, and pressure in an environment. These sensed parameters are compared against thresholds. Based on the comparisons, changes to the outside air and/or recirculated air are made.

An air purification system includes a photocatalyst on a support disposed to contact airflow through an airflow channel passing across or through the support; an ultraviolet light emitting diode (UV-LED) disposed to emit ultraviolet light onto the photocatalyst, the UV-LED operated at a less than one hundred percent duty cycle, the duty cycle determined at least in part as a function of a desired minimum volatile organic compound conversion rate of air flowing through the airflow channel and a desired maximum by-product concentration of air flowing through an outlet of the airflow channel.

A compact lightweight air filtration system is disclosed. The air filtration system includes a hydrophobic particulate/coalescing filter and a cleanable ozone converter housed in a housing with an inlet and an outlet. Air flowing from the inlet to the outlet passes through the particulate/coalescing filter element and then the cleanable ozone converter to remove particulates, aerosols, liquids, and ozone. The air filtration system may comprise a fuel tank inerting system (FTIS) filter assembly. The FTIS filter assembly may include a binderless media (no binder) suitable for use in high temperatures. The FTIS filter assembly includes a catalytic converter configured to adsorb one or more VOCs, such as Toluene, Propylene Glycol (C.sub.3H.sub.8O.sub.2), Pentanoic Acid, Butane (C.sub.4H.sub.10), Formaldehyde (CH.sub.2O), and Carbon Dioxide (CO.sub.2).

A compact lightweight air filtration system is disclosed. The air filtration system includes a hydrophobic particulate/coalescing filter and a cleanable ozone converter housed in a housing with an inlet and an outlet. Air flowing from the inlet to the outlet passes through the particulate/coalescing filter element and then the cleanable ozone converter to remove particulates, aerosols, liquids, and ozone. The air filtration system may comprise a fuel tank inerting system (FTIS) filter assembly. The FTIS filter assembly may include a binderless media (no binder) suitable for use in high temperatures. The FTIS filter assembly includes a catalytic converter configured to adsorb one or more VOCs.