Electrostatic precipitators (ESPs) can achieve high collection efficiencies. However, their application for nanoparticle removal has not been widely discussed, largely because the charging mechanism is affected by the small diameter of these particles. Therefore, this work evaluated the influence of the discharge electrode parameters such as number (1-4), diameter (0.3 and 0.4 mm) and spacing (6.5 and 12 cm) on the electric characteristics of a wire plate ESP and the nanoparticle collection efficiency (5.94-224.7 nm). A greater number of wires and a smaller wire diameter improved particle collection almost three-fold but under some operating conditions was reduced by the shielding effect. On the other hand, the wire spacing had a small influence on the particle collection. The highest collection efficiency (99.99%) was achieved using 4 discharge wires and wire diameter of 0.4 mm, although similar collection efficiencies were achieved with the configuration of 2 wires and wire diameter of 0.3 mm. (C) 2020 Elsevier B.V. All rights reserved.