Cheap drinking water from the salty seas

Afaster,better and cheaper desalination process enhanced by carbon nanotubes has been developed by New Jersey Institute of Technology professor Somenath Mitra.
The process creates a unique architecture for the membrane distillation process by using carbon nanotubes in the membrane pores.Conventional approaches to desalination are thermal distillation and reverse osmosis.
Unfortunately the current membrane distillation method is too expensive for use in countries and municipalities that need potable water, said Mitra.Generally only industry,where waste heat is freely available,uses this process.However,were hoping our new work will have far-reaching consequences bringing good,clean water to the people who need it.

WHAT IS MEMBRANE DISTILLATION


Membrane distillation is a water purification process in which heated salt water passes through a tube-like membrane,called a hollow fibre.Think of your intestines, said Mitra.Its designed in such a way that nutrition passes through but not the waste. Using a similar structure,membrane distillation allows only water vapour to pass through the walls of the hollow tube,but not the liquid.
When the system works,potable water emerges from the net flux of water vapour which moves from the warm to the cool side.At the same time,saline or salt water passes as body waste would through the fibre.
Membrane distillation offers several advantages.Its a clean,non-toxic technology and can be carried out at 60-90 degrees centigrade.This temperature is significantly lower than conventional distillation.
Together these benefits lead to a greener process which could make membrane distillation economically competitive with existing desalination technologies and we hope could provide potable water where it is most needed, said Mitra.


Somenath Mitra working in his lab