Is There Anything New in Desalination?

We have seen that the world is at least 70% covered in water. We have also seen that only about 9% of that water is what is called “potable” (that’s drinkable, pure water.)

We have also seen that converting dirty, salty ocean water to potability is expensive and requires great quantities of heat from one energy source or another, usually electricity.

One thing is certain – there is so much raw water available that a great number of researchers and water scientists are concentrating on the possibilities of developing greater quantities of potable water – at greatly reduced cost. And the good news? They are succeeding.

From the United States and Canada to China there are all sorts of experiments being made and developments tested for reliability and feasibility.

In Canada, for instance, two university graduates in Vancouver have developed a solar process for desalination of sea water that they claim can reduce electricity requirements by up to 80%. They further state that the process can cut the high cost of desalination in half.

The two have started a company, Saltworks Technologies Inc., that is building desalination plants using commercially available components, saving time and money,

Across the Pacific, a group of researchers from Tsinghua University in Bejing have announced that water desalination can be achieved without electric energy or high water pressure using a source of biodegradable organic matter or bacteria as the fuel.

Their claim has been published in the Environmental Science Technology journal in August, 2009. According to the paper the researchers modified a microbial fuel cell by placing two membranes between an anode and a cathode, creating a middle desalination chamber between the membranes. When electricity was produced by bacteria on the anode, ionic species in the middle chamber were transferred into the two electrode chambers, thereby desalinating the water in the middle chapmber.

If this sounds confusing, don’t be concerned. It really is. But if the process can be made to handle large quantities of water it will certainly be a major step in the right direction – clean water for more people.

Earlier we looked at the use of geothermal heat sources to desalinate water and that process continues to be tested around the Pacific coasts, particularly in California. At UCLA a mobile desalination test has proved successful and will be reported on here in the near future.

Meanwhile, we must all continue to be careful not to waste water at any time in any way.