Wednesday, February 23, 2011

Uranium from sea water: Bhabha Atomic Research Centre develops special membrane to extract uranium

By Syed Akbar
Visakhapatnam, Feb 22: Bhabha Atomic Research Centre has developed a specialised membrane that could extract uranium from seawater much faster than the conventional methods, boosting uranium mining from the Deep.
Seawater is estimated to contain as much as 4.6 billion tons of uranium and the nuclear fuel obtained from the oceans could help feed nuclear reactors once the conventional uranium reserves of 5.5 million tons are exhausted. With a vast coastline, India can extract large resources of sea uranium to meet its uranium demand.
Laboratory studies in Barc have shown that the new membrane called PEGMP has increased the overall efficacy for uranium uptake from seawater. This is far superior to the conventional membrane called PAO. Since it has been proved that the uranium obtained from the seawater can be used in uranium reactors for power generation, nuclear scientists hope that the Barc’s new membrane combined with nanotechnology will make seawater uranium mining highly economical.
According to Dr Ashok K Pandey or radiochemistry division of Barc, “PEGMP membrane offers several advantages over widely used PAO membrane for uranium recovery from seawater. An attempt was made in our lab to carry out comparative evaluation of PEGMP-membrane with PAO-membrane for uranium sorption under seawater condition. The studies indicated potential applications of the PEGMP-membrane in uranium preconcentration from seawater and other natural aquifers for uranium quantification as well as its recovery,” he said.
Dr Ashok is presenting a technical paper at the ongoing five-day 10th biennial symposium on nuclear and radiochemistry (Nucor – 2011) in the port city of Visakhapatnam. “The presence of uranium in the dissolved state makes its recovery from seawater possible. The uniform concentration of uranium throughout the sea indicates existence of a dynamic equilibrium between dissolved uranium and insoluble sedimentary uranium. Therefore, the recovery of uranium from seawater may lead to dissolution of uranium present in the seabed,” he pointed out.
However, the economical recovery of uranium is a challenge in view of the chemical and bio-aggressive nature of seawater. Stating that the scientific challenge is the development of the sorbents that are selective towards uranium and can withstand hostile bio-chemical marine environment over a prolonged period, he said efforts are on in making the recovered uranium cost competitive. Enormous volume of water has to be processed for 
recovery of one ton of uranium.
Barc’s new membrane technology is also superior to other conventional processes involving solvent extraction, ion exchange, reverse osmosis and ultra filtration.

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