Nitrate is a compound that ...

Nitrate is a compound that is formed naturally when nitrogen combines with oxygen or ozone. Nitrogen is essential for all living things, but high levels of nitrate in drinking water can be dangerous to health, especially for infants and pregnant women. Nitrate contamination of ground water resources has increased in Asia, Europe, United States, and various other parts of the world. This trend has raised concern as nitrates cause methemoglobinemia and cancer. Several treatment processes can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation.

Safe & Economical Process

1. Biological denitrification exploits the ability of certain naturally-occurring bacteria to use nitrate for respiration under anoxic conditions (absence of oxygen). The overall process is the reduction of nitrate to nitrogen gas and proceeds as follows:

NO3 - → NO2 - → NO → N2O → N2

Denitrification can be achieved using both heterotrophic and autotrophic bacteria. In heterotrophic denitrification an organic carbon substrate, such as methanol, ethanol or acetic acid, is required as a food source for the bacteria. In autotrophic denitrification an inorganic energy source such as sulphur, reduced sulphur species (e.g. thiosulphate) or hydrogen is required; the carbon needed for bacterial growth is obtained from bicarbonate in the water.

1. Trickling filter followed by flash aeration may do the trick.
2. Algal turf scrubber.
3. Electrolytic reduction method