A scrubber utilizes a liquid to separate particulate or gaseous contaminants from gas. Separation is achieved through mass contact of the liquid and gas. For example boiler emissions to be controlled include fly ash and sulfur oxides. Incinerator emissions to be controlled include fly ash, sulfur oxides and hydrogen chloride. Low energy scrubbers are more efficient at gaseous removal than at particulate removal. A low energy scrubber utilizes a long liquid/gas contact time to promote mass transfer of gas. Scrubbers may be used as control devices on incinerators and boilers for fly ash collection. The plate, spray, venturi, and moving bed types have been successfully applied; however, their application has been limited. An electrostatic precipitator (ESP) is a device which removes particles from a gas stream. It accomplishes particle separation by the use of an electric field which:mparts a positive or negative charge to the particle, attracts the particle to an oppositely charged plate or tube, and removes the particle from the collection surface to a hopper by vibrating or rapping the collection surface.