Water Treatment

Nitrate Removal

Since nitrates are very soluble and do not bind to soils, they have a high potential to migrate into groundwater. For short-term, excessive levels of nitrate in drinking water has caused serious illness and sometimes death. The serious illness in infants is due to the conversion of nitrate to nitrite by the body, which can interfere with the oxygen-carrying capacity of the child’s blood. This can be an acute condition in which health deteriorates rapidly over a period of days. Symptoms include shortness of breath and blueness of the skin. The presence of nitrite in the digestive tract of infants can lead to a disease called methemoglobinemia or infant cyanosis. This condition is also known as “blue baby syndrome” because of the bluish coloring of mucous membranes in infants.

PuriTech has built up a long experience in nitrate removal from drinking water, with more than 60 installations including the largest unit ever made in Europe. A lot of municipalities use PuriTech IONIX technology to reduce the nitrate level at the beginning of drinking water production process.

Nitrate selective exchange resins are now available to run even more efficient. They have a higher selectivity for nitrate over sulphate. The volume of the brine is largely dependent on the raw water quality and the configuration of the system. In PuriTech's ION-IX system this brine consumption and waste production is extremely low (the lowest possible compared to any other technology). 
The ION-IX system can be broken up into 4 distinctive zones with all zones operating continuously. Generally there are 20 vessels in total of which at any one time, 14 are in the adsorption zone, 1 is in displacement, 3 are in regeneration and 2 are in strip wash. Although the number of columns contained within each zone does not alter, as the multi-port valve process disc changes position, each vessel will effectively move along one position in the process cycle. Therefore, by rotating the valve internals at regular calculated intervals as described, each vessel will go through the entire adsorption zone, then into displacement, through regeneration and finally through the strip wash zone prior to its return to adsorption.

Following adsorption, the resin is backwashed, regenerated and washed. It must be noted that all zones are part of the continuous automatic process, this is carried out without interruption to the nitrate adsorption process.

Depending on the nitrate concentration in the feed water and on the feed water flow rate to the ION-IX multi-port valve, the cycle time will increase or decrease thereby optimising the nitrate loading within the adsorption zone. The cycle time of the ION-IX multi-port valve will be set once the feed nitrate levels and site flow rate is known. 

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