Certain rocks in the earth contain radioactive elements, and these are known as NORM, i.e. Natural Occurring Radioactive Materials. When drinking water comes in contact with these rocks, the radioactive elements react with it and form, for example, radioactive iodine. If rocks containing radioactive elements come in contact with river flow, then the water becomes impure because of the radioactive elements present.
The elements that may present in these rocks are:
- Radium and its products
- Uranium and its products
- Thorium and its products
- Strontium and its products
- Radioactive Iodine-131
However, the nuclear disasters like the nuclear plant damage that recently happened in Japan may also be the cause of radioactive impurity in drinking water. Radioactive iodine escapes from the damaged plant in the form of gas. The gas mixes into the atmosphere, and when rain occurs, it settles in the water supply.
It is estimated that the U.S. generates 260,000 metric tons of TENORM ("Technology Enhanced" NORM) every year. This is in addition to 600 metric tons generated by per utility. The radioactive iodine and strontium are very dangerous for your health, and it may cause certain diseases. Because of this, radioactive iodine and strontium removal from water is very important.
The processes that can remove the drinking water radioactive iodine and like radium and strontium from drinking water are given below.