• Nitrate is a wide-spread contaminant of ground and surface water worldwide.
• The higher concentration of nitrate may be due to excessive use of fertilizers, pesticides and insecticides leaching from animal waste and nitrogen fertilizers 21.
• Urea is common type of fertilizer used in the agriculture due to its higher N content, high solubility
• The nitrate poses some unique problems to groundwater because it moves quickly through the soils with percolating water and it often indicates potential biological contamination

Excess Nitrate causes blue baby syndrome in infants - (Methaemoglobinemia)
Causes high infant mortality in rural India.

WHO / BIS limit - 45 ppm as Nitrate - 10 ppm as Nitrogen

• Excess Nitrate affects people
• In over 11 states like Punjab Haryana, Karnataka, UP etc. in India.
• Caused by indiscriminate use of nitrogenous fertilizers
• Improper disposal of sewage and industrial effluents.

High nitrate level in drinking water leads to infant methaemoglobinaemia (blue-baby syndrome), gastric cancer goiter, metabolic disorder, birth malformations, hypertension and livestock poisoning.

Elevated levels of methemoglobin in the blood are caused when the mechanisms that defend against oxidative stress within the red blood cell are overwhelmed and the oxygen carrying ferrous ion (Fe2+) of the heme group of the hemoglobin molecule is oxidized to the ferric state (Fe3+). This converts hemoglobin to methemoglobin, resulting in a reduced ability to release oxygen to tissues and thereby hypoxia. This can give the blood a bluish or chocolate-brown color.

CONVENTIONAL NITRATE REMOVAL METHODS

• Biological denitrification Nitrate is removed from water readily by denitrification, a bacterial respiration process which converts nitrate to harmless dinitrogen gas. Denitrification is carried out by numerous bacterial species found in soil and aquatic environments.



• Reverse osmosis An R.O. system uses a non-selective membrane to remove almost all dissolved contaminants from the water. When using R.O. to remove a dangerous contaminant such as nitrate.



• Eectrodialysis. Electrically driven process that uses a voltage potential to drive charged ions through a semi-permeable membrane, reducing the TDS in the source water (3). The process uses alternating, semi-permeable cation (positively charged ion) and anion (negatively charged ion) transfer membranes in a direct-current (DC) voltage potential field. The source water flows between the cation and anion membranes via flow spacers that are placed between the membranes



• Nitrate selective - Ion exchange process In ion exchange process charged with chloride where nitrate is exchanged by chloride. As more water passes over the resin, all the chloride is exchanged for nitrate. The resin is regenerated with sodium chloride solution. The regenerent can be properly disposed of in drain/sewage.

• INDION NSSR is a macroporous strongly basic anion resin which is tailor made to suit removal of nitrate ions from water for potable uses.
• The proper mix of physico - chemical properties gives ideal nitrate exchange kinetics to this resin making suitable for nitrate removal in the presence of sulphate ions.
• High concentration of nitrate in water is a potential hazard for two reasons.
• The nitrate ions form complexes with the blood and in the long run cause oxygen depletion affecting human life.
• The flow of nitrate bearing water through iron pipes can cause depletion of oxygen leading to corrosion.
• In view of these difficulties use of an Ion Exchange resin is the preferred process for nitrate removal.

• Sturdy
• Economical
• Does not require electricity
• Easy to operate
• Common salt (NaCl) required for recharge
• Ideal for rural applications
• Long life
• Flow of unit is 8-10 lpm
• Directly attached to hand pump

INDION –NSSR is a robust media with good mechanical strength and generally requires minimal pretreatment . However, the presence of high levels of suspended solids and biological organic matter may foul the media, resulting in the reduction in capacity and life time of media. Hence we recommend pretreatment with INDION NSSR for conversion of arsenite to arsenate and removal of iron and other organic matter.

Ion exchange resins require proper care at all times. The resin must never be allowed to become dry. Regularly open the plastic bags and check the condition of the resin when in storage. If not moist, add enough clean demineralised water and keep it in completely moist condition. Always keep the resin drum in the shade. Recommended storage temperature is between 20 C and 40 C.

Acid and alkali solutions are corrosive and should be handled in a manner that will prevent eye and skin contact. If any oxidizing agents are used, necessary safety precautions should be observed to avoid accidents and damage to the resin.