Researchers in the US have built a prototype device which they say can generate electricity from waste water.
The team at Pennsylvania State University says the technology would simultaneously treat the water.
They suggest the process could be adopted in developing countries, providing clean water and power for homes.
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Instead of having a net drain, we have a net gain”
Professor Bruce LoganPennsylvania State University
Details are published in the journal Science.
Scientists in the Netherlands have for some years been exploring the idea of generating renewable power along the country’s coastline, where fresh water from rivers meets the salt water of the sea.
Using a process called reverse electrodialysis (RED), fresh water and seawater are placed in intermittent chambers separated by membranes, and an electrochemical charge is created.
A Norwegian company is developing a similar technology using saline and fresh water.
The Penn State team says RED technology is problematic because of the large number of membranes required, and because power plants have to be located by the sea.
They claim the number of membranes can be reduced and the power output boosted by combining the technology with what are called microbial fuel cells (MFCs). These use organic matter in solution to create an electric current – in this instance waste water.
The prototype technology also bypasses the need for salt water by using ammonium bicarbonate solution as a substitute, meaning the system could work in communities far from the sea.
The ammonium bicarbonate solution would be constantly recycled, using waste heat from local industry.
“If we treat waste water in just a microbial fuel cell, we don’t create much power and it takes a long time,” lead researcher Professor Bruce Logan told BBC News.
“In our process, we have the MFC part which is treating waste water and creating energy, and we have the RED stack which is just boosting that process, it’s making it happen more efficiently.”
He says the process could potentially be used anywhere, but could provide both clean water and power to communities in developing countries.
“The main application right now is in waste water treatment where you could effectively treat the water, but also gain some extra energy from waste heat.
“Instead of having a net drain, we have a net gain.”
Professor Logan and colleagues have previously reported on how the combination of microbial fuel cells and electrodialysis could generate hydrogen supplies.
mi opinion about this article is that the waste water generator is a very good idea, that have two objectives, clean water and make energy by the water.
i think that is a ambitiousness project because it isn’t 100 effective but is necessary for the countries that didn’t have a lot of ”clean” water and are located near the ocean. if they start this project now, in the future the develop countries that need water are going to have it. and the generator about the time is going to be perfectionated and sub develop countries that didn’t have a water fountain are going to have one and it help to me more clean world.
In my opinion, we have to find a way to deal with the contamination of water, it could be just reducing its use, or using this device, but the final objective is to help the preservation of drinking water in the world. The most interesting thing that this device gives us, is that it offers a way to clean water, and not contaminate in great quantities, or else, it would be worse to use this device, since the contamination and the destruction of the ecosystem that it would provoke, would we be worse than the contaminated water that it cleans. I hope that more inventions like these will be made, since they help the planet, but they aren’t extremely contaminant.
It is time to use another kind of energy. We always use nuclear, or with gas;but it harms our planet. Using energy such as wind or rivers is better, because someday, we will be out of gas and we will be in serius problems.
Im in favor of using new sources of producing energy because the problem of contamination it is getting bigger so we have to be happy of this.
This project is interesting because it talcks about this new experimente that it may has to be now. thats my opinion but no every people think the same thing becouse many people now are living in the business of petrolioum but it have to change because it can get over and water is a cycle that repeats every time. i think that this class of projects start running now because this is what can change our future with these new tecnologies.
I support every idea to help the planet, finding new sources of producig energy is a great change, other persons that are better economic positioned don’t really care about it because they are gaining money from other ways of producing energy, I don’t believe every of this persons are like this but is difficoult to prefer de change and the benefit of the others than the money that they are earning.
I agree with this project, because it could help not only devoloped countries. It can also help countries like here in Costa Rica maybe in a future. That is why I hope this project could be really recognized an approved by the people. The Penn State says RED, could be a problem because of all the large number of membranes required, but that it can be reduced, and with that you do not need to live close to the sea so that the project could work as it has to. This idea could help people from communities far from the sea by giving treated water and electricity, by using wasted water.