Contamination of ground waters with nitrogen compounds originates mainly from the excessive use of fertilizers and uncontrolled discharges of treated wastewater. This can cause potential health hazards to infants and pregnant women, thus limiting the direct use of the groundwater resources for the human consumption in several parts of the world, including Republic of Moldova. The conventional processes used to eliminate nitrogen compounds from water are ion exchange, reverse osmosis and electro-dialysis. The utility of these processes has been limited due to their expensive operation and subsequent disposal problem of the generated waste brine. This paper presents a comprehensive account of the methods/techniques used for the removal of nitrite ion from water.