你见过无水的生态厕所吗?

Loowatt is the name of this simple toilet. It doesn't rely on a system of water for sanitation, saving an increasingly scarce and vital resource. Nor does it rely on liquid chemical solutions to break down the waste and mask smells.

Various types of waterless toilets are in production around the world, and most of them use biodigesters, but the Loowatt team say theirs has some important differences.

The light aluminum base is covered in a strong polymer film. Once the solid and liquid waste has fallen inside the toilet bowl a lever on the side is pumped up and down. This seals the waste in its own pouch.

Each roll of film lasts for around eight days. When it's full the top of the toilet is lifted away and the waste is sealed into the base. The lid automatically slides shut.

This prevents any odor being released into the immediate environment. It can be scaled up to provide communities with sanitation and can also provide the added bonus of bio-gas. The waste in the tank is deprived of oxygen. This allows microbes to break it down to methane, carbon dioxide and other gases and people can use that gas as clean energy.

Loowatt founder and inventor Virginia Gardiner says one of the most important points about the system is that it doesn't require people to be in contact with the waste.

"The biodegradable film, plus the human waste solve the transport problem which is always an issue in waterless toilet systems, because they keep the toilet hygienic, they keep the user experience hygienic and then the packaging combined with the human waste goes into the anaerobic digester and produces methane and the packaging adds to the gas production. So what you've got is a system where there's actually incentive to treat the waste this way and you can produce an economy around waste treatment."

The charity WaterAid runs many of its own projects to ensure there is enough water to go round, especially in some developing countries where it's scarce and lack of sanitation can result in death, disease and famine.

Technical manager Eric Harvey says most western sanitation systems rely on a complex system of tunnels and pipes to transport waste. But the worst part of the process is that vast quantities of water are squandered in the process of removing our waste.

"These new solutions that are coming about are encouraging in the sense that they are trying to reduce those human contact points, they are trying to turn human waste into a viable economic product, however they're in their infancy and we need to be working a lot more on the management systems around those particular technologies to make them a viable solution."

Harvey says that a single solution isn't going to provide an answer for the whole world.

"We have lots of these small scale pilots underway. I think the trick is how do we get a commitment from governments, from donors, from utilities to really see this to scale. To take the big step and say right we are going to do this in the city, we are going to expand it to an entire range of settlements within the city."

Gardiner began the Loowatt as a university degree project. Her task was to develop a waterless system that would work in the city and also turn human waste into a usable commodity.

For CRI, I am Li Dong.