This research focuses on the removal of nitrite by ultrasound-dispersed nanoscale zerovalent iron (NZVI) particles. The factors affecting the removal of nitrite, namely, the length of ultrasonication time, the dosage of NZVI, the initial nitrite concentration, the temperature, and the solution pH, were investigated. Kinetics studies revealed that the denitrification process is a pseudo-first-order reaction with respect to the concentration of nitrite under the given experimental conditions. The derived activation energy of NZVI-based nitrite reduction is 31.44 kJ.mol(-1).