Abstract: A gas and liquid contacting apparatus, illuminated, with circulation, and a method, are disclosed. To remove a trace component from a mixture of gases, for example to remove carbon dioxide from air, the inefficiency of attempting to dissolve all of the gas mixture followed by desorption of the non target components is overcome by injecting small bubbles (5) into a liquid filled chamber (1) which is inclined at an angle and has an abrupt change in cross section (2) & (3). The target component diffuses out of the small bubbles. The small bubbles, substantially relieved of the target component, are collected in a gas trap (4) created by the inclination and dimension change of the chamber. Large bubbles (8) escaping from the gas trap via an upper riser (9) to a reservoir (10) assist with the circulation of the contents of the system. A return tube (11) connecting the reservoir to the bottom end of the chamber completes the circuit.