The waste water that you flush down the drain may light up your home in the near future. A team of researchers from the Hyderabad-based Indian Institute of Chemical Technology (IICT) has developed a fuel cell capable of generating tiny amounts of electricity using industrial waste water as base.

“It is more of a proof of concept,” says P.N. Sarma, the IICT scientist, who led the research. The fuel cell that produced a few milli amperes of current practically involves no cost and uses locally available materials as electrodes. Besides, it employs a cocktail of bacteria commonly present in the soil to split hydrogen from organic compounds present in the waste water.

Such microbial fuel cells work on the principle that certain bacteria can convert organic matter into electricity. Though several groups have tried it in the past, nobody has so far reported a viable fuel cell that runs completely on waste water. The IICT researchers reported their work in a recent issue of the journal, Current Science.

“We all know that carbon present in organic wastes produces hydrocarbons such as methane on fermentation. What our scientists have done is stop this process mid-way, so that hydrogen ions can be generated instead,” IICT director J.S. Yadav told KnowHow.

Positively charged hydrogen ions thus produced will be trapped by a membrane and will be delivered to one of the electrodes, creating a flow of electric current. The entire chemical reaction takes place at room temperature. The scientists, however, have to maintain the pH value of the waste water at 5.5 for the optimal performance of the bacteria employed.

If the scientists are able to it scale up, the technique could be a boon for common effluent treatment plants, which process industrial waste for safer disposal. If integrated to waste treatment plants, fuel cells may be able to produce electricity at a relatively low cost and thus can partly contribute to their power requirement.

However, Venkata Mohan, another scientist associated with the work, thinks it would be a long way off and much more work is needed to reach that stage.