Nitrate Removal from Drinking Water by Membrane Processes

Drinking water, also known as potable water is the water that is safe to drink. In 2015, 89% of people had access to suitable drinking water. 1.8 billion People still use an unsafe drinking water source. Nitrate (NO3-) is a colorless, odorless and tasteless substance which is very soluble in water and is the most oxidized form of nitrogen found in drinking water. Excess amounts of nitrate in water resources not only can cause Eutrophication which changes color and taste of the drinking water resources but also can cause a potentially fatal blood disorder in infants called blue-baby syndrome. The U.S. Environmental Protection Agency (EPA) has set the Maximum Contaminant Level of nitrate as nitrogen (NO3-N) at 10 mg/L for the safety of drinking water. Physical and chemical membrane processes for nitrate removal are (1) ion exchange, (2) reverse osmosis, (3) electrodialysis and (4) nanofiltration. Although these processes are capable of removing nitrate in drinking water supplies with varying degrees of efficiency, all of them have some advantages and disadvantages which are discussed in this paper.

Keywords:

Nitrate removal , Drinking water , Ion exchange , Reverse osmosis , Electrodialysis , Nanofiltration