What started as just a highschool science experiment has turned Indian American student Chaitanya Karamchedu’s has potential to revolutionize the need to turn salt water into pure drinkable fresh water. The project’s commercially viable fortunes have made many firms queue for it already.
Chaitanya from Portland, Oregon in the US, is a senior student at Jesuit High School is aware of the massive water crisis awaiting the humanity. “One in eight people do not have access to clean water… The best access for water is the sea, so 70% of the planet is covered in water and almost all of that is the ocean, but the problem is that’s salt water,” he told KPTV in an interview.
There is no dearth of research to desalination of sea water but the process involved an expensive infrastructure. The answer was for a cost effective way and Karamchedu has hit upon the idea more scientifically than expected.
“Sea water is not fully saturated with salt,” he explains about his method. While the research hitherto focused on 10% of water that’s bonded to the salt in the sea, Chaitanya addressed the problem experimenting on 90% of the water that is free from salt bond.
Using a highly absorbent polymer, Chaitanya was able to discover a cheaper method effective way to remove salt from ocean water and turn it into fresh water.
“Chaitanya thought about it from a completely different angle,” said Jesuit High School Biology Teacher Dr. Lara Shamieh. “What this is compared to current techniques, is that it’s cheap and accessible to everyone, everyone can use it,” she said.
Using superabsorbent hydrophilic polymers, with no external energy, under room temperature and pressure Chaitanya was able to produce drinkable water which stands WHO standards for potable water. Based on saponified starch-grafted-polyacrylamide’s hydrophilic properties, he was able to create a hydrogel to separate freshwater from seawater, then separated hydrogel from the brine, dewatered the gel resulting in aqueous sulfuric acid and then recovered fresh water from the aqueous solution.
The use of hydrophilic polymers to desalinate water required no thermal or electrical energy and the extracted water was comparable to fresh water with an average conductivity of 306.32 µS/cm, comparable to the conductivity of 200 µS/cm for the reference distilled water used.
It involves virtually no cost for pre-treatment and post-treatment and it is amenable for small scale use as well. Mass and conductivity analysis showed that the extracted water had a total dissolved solids concentration of 513 mg/L, well within WHO standard at <600 mg/L, compared to 35,000 mg/L for seawater.
The sodium concentration was 25.8 mg/L, compared to 10,500 mg/L for seawater and that of chloride was 36 mg/L, compared to 19,000 mg/L for seawater. 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% of fresh water and also produced a commercially useful fertilizer, CaSO4, as a byproduct.
Chaitanya Karamchedu has already hit headlines when he won a $10,000 award from the US Agency for International Global Development at Intel’s International Science Fair. MIT’s TechCon Conference provided him funds to continue his research.
Chaitnya was also named one of 300 Regeneron Science Talent Search Semifinalists, one of the prestigious competitions in the country for high school seniors.