The New “Microbial Desalination Cell” to Purify Seawater

When’s the last time you heard about bacteria making water more drinkable? This time around that’s precisely what we are going to tell you.

Who and what?

Bruce Logan, an electrical engineer at Pennsylvania State University in University Park and his colleagues at Tsinghua University in Beijing, China have devised a new microbial desalination cell that removes 90% of the salt from a seawater-like solution.

How?

They have adapted a technique called electrodialysis for this purpose, in which electricity draws ions from salt water through semi-permeable membranes into two chambers – negatively charged chlorine ions into one and positively charged sodium ions into another – leaving the water salt-free.

So where do the microbes come in to play…

You might wonder? Logan’s team replaced an external source of electricity with a microbial fuel cell, which transforms bacteria into batteries! When the bacteria metabolize nutrients – acetate in this case – they generate protons and electrons. The researchers then used these positive and negative charges to drive desalination by electrodialysis.

If you’re next question is why bother…

Here’s the reason: Microbial desalination could offer big advantages over the methods currently used to purify seawater, which require enormous pressure to operate, and gobble up huge amounts of energy!

via: NewScientist