A gaseous stream treatment apparatus for reducing the content of total organic carbon and/or the content of other polluting compounds in the gaseous stream, the treatment apparatus comprising: - a plurality of treatment compartments, each of which is equipped with at least one adsorbent element suitable for adsorbing organic compounds that contribute to the total organic carbon and/or other polluting compounds; - an infeed opening for the gaseous stream to be treated; - a distribution chamber that is in communication with the infeed opening and onto which respective inlets of the treatment compartments open; - an outfeed opening for the gaseous stream treated; - a collection chamber that is in communication with the outfeed opening and onto which respective outlets of the treatment compartments open; - a regeneration system for regeneration of the adsorbent elements by means of desorption, wherein the regeneration system can adopt a plurality of configurations, each configuration corresponding to a regeneration condition of one or more respective treatment compartments, the regeneration system being suitable for feeding a purging fluid stream to the one or more respective treatment compartments to be regenerated, for discharging the purging fluid stream from said one or more respective treatment compartments to be regenerated, and for heating the at least one adsorbent element of said one or more respective treatment compartments to be regenerated; wherein, during use, at least one treatment compartment is in operating condition in which at least part of the gaseous stream to be treated flows through it and the regeneration system is operated in such a way that it adopts the plurality of configurations in sequence so as to cyclically switch each treatment compartment from the operating condition to the regeneration condition and vice versa; characterised in that each adsorbent element comprises adsorbent material that is a sheet or a portion of cloth with activated carbon or is a sheet or a portion of cloth with zeolite. - a plurality of treatment compartments, each of which is equipped with at least one adsorbent element suitable for adsorbing organic compounds that contribute to the total organic carbon and/or other polluting compounds; - an infeed opening for the gaseous stream to be treated; - a distribution chamber that is in communication with the infeed opening and onto which respective inlets of the treatment compartments open; - an outfeed opening for the gaseous stream treated; - a collection chamber that is in communication with the outfeed opening and onto which respective outlets of the treatment compartments open; - a regeneration system for regeneration of the adsorbent elements by means of desorption, wherein the regeneration system can adopt a plurality of configurations, each configuration corresponding to a regeneration condition of one or more respective treatment compartments, the regeneration system being suitable for feeding a purging fluid stream to the one or more respective treatment compartments to be regenerated, for discharging the purging fluid stream from said one or more respective treatment compartments to be regenerated, and for heating the at least one adsorbent element of said one or more respective treatment compartments to be regenerated; wherein, during use, at least one treatment compartment is in operating condition in which at least part of the gaseous stream to be treated flows through it and the regeneration system is operated in such a way that it adopts the plurality of configurations in sequence so as to cyclically switch each treatment compartment from the operating condition to the regeneration condition and vice versa; characterised in that each adsorbent element comprises adsorbent material that is a sheet or a portion of cloth with activated carbon or is a sheet or a portion of cloth with zeolite.