A successful removal of pollutants like chromate, nitrate or chlorinated compounds has been proved by using zerovalent iron particles. The production of this kind of particles has increased recently and their properties change significantly depending on the supplier chosen. Batch experiments were run with 5 types of zerovalent iron particles to test and characterize them by making them react with nitrate. Erlenmeyers filled with 100 ml of deionized water, 2ml of nitrate 3 g of iron particles and different volumes of HCl were followed by taking samples during several hours. Nitrate, nitrite, ammonium, chlorine and potassium were analyzed by ion chromatography. The results showed a first order reaction for all the irons. After one day no trace of nitrate was found for all the irons when 800 μL of acid were added. For higher volumes of HCl the reactions were incomplete. The faster iron was iron called “J”, with complete reduction of nitrate in 5 h.