Erosion of metallic electrodes by sputtering is undesirable in electrostatic precipitators and must be avoided. This work reports the operational variables promoting sputtering, the applied voltage (-8.5 to -13.0 kV) and the air velocity (3.3 to 9.9 cm s(-1)), during the collection of NiO and KCl particles with a dry, wire-plate electrostatic precipitator, using electro-fluid dynamics analysis to evaluate the influence of the ionic flux on the sputtering. For the conditions evaluated in this work, the exclusive removal of NiO particles occurred at velocities of 9.9 cm s(-1) (at applied voltages from -8.5 to -10.0 kV) and 3.3 cm s(-1) (at -8.5 kV). Other operational conditions favored sputtering, causing the release of nanoparticles (median sizes of 10-25 nm) from the device. The parameters of the particle size distribution were related to the natural logarithm of the electro-fluid dynamics parameters, with coefficients of determination of 0.98 and 0.95 for the median size of the particles and the geometric standard deviation, respectively. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.