A hybrid wet electrostatic precipitator for collecting sub-micron and nano-particulate material. The collector can be made up of three concentric tubes or pipes with an internally formed gas path communicating between an inlet and an outlet. A first collector and discharging zone can be provided in the gas path to create a corona discharge to charge particles and to collect particulate. A second collector can be formed by a porous wall which can act as a filtration device. A third collector can be formed by two or more of the concentric circular tubes, one porous and one solid, with a zone of uniform electric field between them. The porous tube can be either the inner tube or the middle tube. A liquid pool can be placed between the first and third collectors to provide chemical treatment of the gas flow or simply filtration as the gas passes through. A high-tension voltage supply can be used to supply a discharge voltage capable of generating a corona discharge into the flow in the first zone. The corona discharge can cause the fine particulate to become charged and to be captured on the collecting electrode in a zone of uniform field. A second (or the same) high-tension voltage supply can create the uniform electric field.