Indian-American teen finds cheap way to make saltwater potable

Chaitanya Karamchedu, an Indian-American student from Portland, Oregon, has found a cheaper and easier method to turn salt water into potable fresh water. His research has caught the attention of major technology firms and research institutions.

Chaitanya, a senior at the Jesuit High School, used hydrogel based desalination technique using saponified starch grafted polyacrylamide's hydrophilic properties to harvest fresh water.

The process does not require any thermal and electrical energy and filtered water has comparable conductivity of 306.32 µS/cm which is comparable to the conductivity of distilled water at 200 µS/cm.

The process has negligible pre-treatment and post-treatment cost, which makes it suitable for small scale plants, especially for those who do not have the means to set up desalination plants.

While testing the mass and conductivity of the treated water, it was found that the water had a total dissolved solids concentration of 513 mg/L which is well within WHO standard at <600 mg/L, compared to 35,000 mg/L for seawater.

Detailed analysis of the water constituents showed that water contained 25.8 mg/L of sodium and 36 mg/L of chloride. Normal sea water contains 10,500 mg/L sodium and 19,000 mg/L chloride concentration. The relevant EPA secondary concentration levels (aesthetic standards) for sodium is 20 mg/L and for chloride is 250 mg/L. The process yielded over 70 per cent of fresh water and also produced a commercially useful fertilizer, CaSO4, as a byproduct.

"1 in 8 people do not have access to clean water, it's a crying issue that needs to be addressed," said Karamchedu, who is determined to make his experiment a success.

"The best access for water is the sea, so 70 per cent of the planet is covered in water and almost all of that is the ocean, but the problem is that's salt water," said Karamchedu.

Isolating potable water from the ocean in a cost effective way is a problem that has stumped scientists for years and Karamchedu had figured it out, on his own, in a high school lab.

"Scientists looked at desalination, but it's all still inaccessible to places and it would cost too much to implement on a large scale," Karamchedu said.

"The real genesis of the idea was realising that sea water is not fully saturated with salt," he was quoted as saying.

By experimenting with a highly absorbent polymer, the teen discovered a cost effective way to remove salt from ocean water and turn it into fresh water.

"Its not bonding with water molecules, its bonding to the salt," said Karamchedu.
 
"People have been looking at the problem from one view point, how do we break those bonds between salt and the water? Chai came in and thought about it from a completely different angle," said Jesuit High School Biology Teacher Dr Lara Shamieh.

"People were concentrated on that 10 per cent of water that is bonded to the salt in the sea and no one looked at the 90 per cent that was free. Chai just looked at it and said if 10 per cent is bonded and 90 per cent is free, then why are we so focused on this 10 per cent, lets ignore it and focus on the 90," Shamieh said.

It is a breakthrough that is estimated to impact millions of lives if ever implemented on a mass scale.

"What this is compared to current techniques, is that its cheap and accessible to everyone, everyone can use it," said Shamieh.

Scientists across the country are taking note. He won a $10,000 award from the US Agency for International Global Development at Intels International Science Fair and second place at MITs TechCon Conference where he won more money to continue his research.