Disclosed is an apparatus for reducing floating radioactive material in a containment building capable of reducing radioactive material in the event of a major accident in a containment building such as a nuclear power plant. A radioactive material reduction unit configured to reduce radioactive material in the air is provided upstream of a flow induction unit configured to induce an air flow through catalytic reaction with hydrogen in the air in the event of a major accident. The flow induction unit may have a replaceable modular form. The radioactive material reduction unit may include an adsorber module configured to remove gaseous radioactive material, such as iodine or an iodine compound. The adsorber module may have a replaceable modular form. In addition, the radioactive material reduction unit may further include an aerosol filter fixed to an inlet to remove particulate radioactive material.

A separation zone and a method of separating a mixed stream are described. The separation zone includes a tank and a stack having a gas outlet. A first baffle is positioned between the sides and defines a disulfide liquid compartment. The stack is positioned above the disulfide liquid compartment. A second baffle is positioned between the first baffle and the second side and defines an alkali compartment. The second baffle has a height less than the height of the first baffle. A third baffle is positioned between the first and second baffles. The bottom of the third baffle is at a height less than the height of the second baffle, and the top of the third baffle is at a height greater than the height of the first baffle.

A pre-treatment device capable of removing moisture from an exhaust gas containing moisture, carbon dioxide, and an acid gas before treatment in a carbon dioxide collection device, includes: a dehumidification tower capable of removing moisture from the exhaust gas; and a blower capable of sending the exhaust gas into the dehumidification tower. The dehumidification tower includes a moisture adsorbent capable of adsorbing moisture, an acid gas adsorbent capable of adsorbing an acid gas, and a dehumidification container filled with the moisture adsorbent and the acid gas adsorbent. The dehumidification container includes a first port into which the exhaust gas from the blower is able to flow and a second port from which a gas having passed through the moisture adsorbent and the acid gas adsorbent is able to flow out as a pretreated gas.

Systems and methods of direct air capture are described. Systems include a plurality of moving adsorber panels in a linear direction (or circular configuration) and one or more fans configured to move air across the adsorber panels; such adsorber panels may be oriented vertically or horizontally, relative to the ground. Systems may include an independent regeneration box that comprises a system of headers, ducts and valves configured to deliver and remove a plurality of gases to the regeneration box. The regeneration box contains multiple chambers such that steps such as oxygen removal and panel cooling may be performed independently from and simultaneously to thermal preheating and desorption of the CO.sub.2 on the panels. The desorption panels may be configured to achieve counter-current flow to the hot gases used for thermal preheating and desorption. A multi-stage heat pump may facilitate reuse of waste heat and decarbonization of the process heating requirements.