Removal of NO by nonthermal plasma, combined with in situ absorption, was experimentally investigated with a wire-in-tube pulsed-corona reactor. High pulse voltage was applied to the wire of the reactor and the tube was grounded. For the reactor combined with in situ absorption, the grounding electrode was covered by a Ca(OH)(2) layer as the sorbent for in situ capture of the NO oxidation products. It was found that NO removal was much higher by the reactor combined with in situ absorption than by the reactor without Ca(OH)(2) sorbent and, meanwhile, the outlet NO2 concentration from the reactor was also suppressed to less than 10 ppm. It was indicated that in situ absorption of the NO2 by Ca(OH)(2) was responsible for the promotion of NO removal. The existence of O-2 and water vapor in the gas stream is beneficial for NO oxidation, therefore resulting in the significant increase of NO removal. (C) 2004 American Institute of Chemical Engineers.