NOVELTY - A treatment apparatus comprises a planar dielectric barrier discharge (DBD) type non-thermal plasma (NTP) generation cell assemblies (6) with a gas flow path (7). Each cell has several catalytically-active DBD electrodes, catalytically active parts and dielectrics to develop NTP fields to create reactive oxygen species, hydroxyl species and other highly ionized molecules and atomic species, to cause oxidation and/or reduction of volatile organic compounds, halogenated volatile organic compounds and fine organic particulate contaminants in air streams, for decomposition in environment.    USE - For treatment of volatile organic compounds (VOCs) or halogenated volatile organic compounds (HVOCs), some of which can be odorous, and/or organic fine particulate contaminants in gas emissions (claimed) and commercial and/or industrial air to be released into the environment; useful for treating other hydrocarbon compounds such as chlorine and fluorine in the gas/air emissions.    ADVANTAGE - The apparatus decomposes volatile organic compounds, halogenated volatile organic compounds and fine organic particulate contaminants in the air streams, to simpler, non-pollutant, non-odorous compounds that can be subsequently released into the environment. In the apparatus, the ignition concentration is not required to fully oxidize and reduce the gas, the NTP is able to fully oxidize and reduce the gas to be treated regardless of the hydrocarbon level.    DETAILED DESCRIPTION - A treatment apparatus comprises a planar dielectric barrier discharge (DBD) type non-thermal plasma (NTP) generation cell assemblies (6) having a gas flow path (7). Each cell has several alternately arranged electrically-hot electrodes and ground electrodes, in the gas flow path so that the gas flows through an air space between the electrodes; a dielectric material separating the electrodes; a gas inlet (2) leading to the gas flow path through the cells; a gas outlet for discharging gas that has passed through the cells; and a catalytically active mesh at the outlet for passage of gas. All electrodes are made of catalytically active materials or coated with a catalytically active material. The dielectric material prevents occurrence of a direct arc between the electrodes with an alternating voltage potential difference in operation, so that the (DBD) develops an (NTP) field when sufficient power is applied, so that a range of reactive oxygen species (ROS), hydroxyl species, molecular and atomic species all in various states of low, medium and highly ionized states-Reactive Species (RS), with the dielectric barriers, possibly coated with a catalytically active material.    DESCRIPTION OF DRAWING(S) - The figure shows a dielectric barrier discharge (DBD) cabinet containing DBD cells, high voltage transformer and a gas flow path.    gas stream (1)    gas inlet (2)    adjusting damper (4)    straightening vanes (5)    dielectric barrier discharge cells (6)    gas flow path (7)    high voltage transformer (10)    dielectric barrier discharge cabinet (11)    cabinet door (19)    baffles (20)    ceramic platform (23)    vent. (22)