How to remove nitrates in drinking water
Distillation (WaterStillar): Eliminates nitrates. Completely
Reverse osmosis: A quality membrane will reduce nitrate by 80-90%
Ion exchange (with chloride ions): A fully regenerated ion exchanger “removes” nitrates by replacing it with chlorine ions through anion exchange.
Activated carbon? – No effect
Boiling of water? – No effect whatsoever on nitrate.
What is nitrate?
Nitrates are inorganic compounds of nitrogen and oxygen that occur naturally and synthetically in the environment. Nitrates occur in the earth’s atmosphere, in the soil and in water. They are easily biodegradable and readily soluble in water. Nitrates are produced by decomposition of plants, animal waste and as an agricultural by-product.
Rainwater, flooding, and soil erosion can all cause nitrates to leak into groundwater.
Nitrogen is one of the most important nutrients for the growth of plants and crops. Nitrogen is one of the building blocks of the chlorophyll molecule, which enables plants to produce food for themselves through the process of photosynthesis. Fertilizers for lawns, gardens, flowers, and crops all use nitrates to provide that natural energy to plants so they can thrive and stay healthy.
When these fertilizers are carried into streams and lakes by floods or rains, the nitrate content in the groundwater increases.
Different safe limits of nitrate
Across the world different levels of nitrate are considered safe in drinking water by authorities:
EU: 50 mg/liter
US (EPA): 10 mg/liter
Science and research shows considerably lower levels for safe water than the authorities has set out:
International Journal of Cancer: 3,87 mg/liter
EWG: 0,14 mg/liter
Denmark: Prenatal exposure to nitrate from drinking water (2021)
A study of 898,206 births in Denmark during 1991-2011 by linking of home addresses of mothers with nitrate data in drinking water showed evidence that infant weight and length decreased with the higher levels of nitrate.
Read the full study here.
Denmark: Nitrate and colon cancer (2018)
Individual nitrate exposure was calculated for 2.7 million adults based on drinking water quality analyses at public waterworks and private wells between 1978 and 2011 in Denmark. They found statistically significant increased risks at drinking water levels above 3.87 mg/L, well below the current drinking water standard of 50 mg/L.
Read the study here: Link to International Journal of Cancer
USA: EWG (2019)
The nonprofit environmental grooup EWG has made a study for nitrate levels in the US and finds that 1,4 mg/l is a maximum.
Spain and Italy (2016)
Overall, effects of nitrate exposure differed by exposure source (water, vegetables and animal dietary sources). A positive association is suggested between CRC risk and long-term exposure to nitrate in drinking water at levels below the European regulatory limit, particularly among subjects with other risk factors. Dietary nitrate from animal sources increased rectal cancer risk, but high intake from vegetables seems to decrease it. Further research is required to confirm these findings.
Read the study here.