A method and apparatus electrically charges particulates that need to be removed from a moving air stream. Various methods of corona charging of particulates are used in the fields of electrostatic precipitation of dust, printers and copying machines. This invention is preferably specifically aimed at improving the separation and collection of particulates from dust, mist or vapor generating devices. In another embodiment, a grid electrostatic precipitator, in combination with a corona pre-charger, is used to remove diesel exhaust.