New methods of nitrate removal from water

Nitrate contamination in groundwater resources originates mainly from the e xcessive use of fertilisers and uncontrolled land discharges of treated was tewater. This can cause potential health hazards to infants and pregnant wo men, thus limiting the direct use of the groundwater resources for the huma n consumption in several parts of the world, including India. The conventio nal processes used to eliminate nitrate from water are ion exchange, revers e osmosis and electro-dialysis. The utility of these processes has been lim ited due to their expensive operation and subsequent disposal problem of th e generated nitrate waste brine. This paper presents a comprehensive accoun t of the methods/techniques used for the removal of nitrate ion from water during the last 10 years with special reference to the biological denitrifi cation and fate of the metals in decontamination processes. (C) 2001 Elsevi er Science Ltd. All rights reserved.