Sanitation is one of the biggest problem India is facing due to the lack of toilets and poor hygiene practices. Prime minister Narendra Modi started a nation wide “Clean India” program, which has recieved support not only within India and also from public and private agencies out India. In a latest addition to this support, Belgian newspaper Falanders today has reported that how researchers at Ghent University (UGent) have come up with a simple technique that could help solve the sewage treatment problem.
India’s problem involves poor health and deaths caused by bacteria, viruses and other pathogens in sewage circulating in the environment. The government has a large-scale programme to build community toilets, but often there are no sewers to which they can be connected.
“So the water goes into a septic tank, and then from the septic tank it overflows and still ends up in the environment,” explains Korneel Rabaey, head of UGent’s department of biochemical and microbial technology. “In larger cities like Mumbai they have treatment plants, but in all the slums and villages, that’s not possible.”
One solution would be to treat the wastewater with chemicals, but these are expensive to make, transport and store. So Rabaey and his colleagues proposed making the chemicals on the spot.
Wastewater contains salts, and the chloride in these salts can be turned into chlorine by applying electricity. The chlorine, a disinfectant chemical, then kills any pathogens present. After mopping up any residual chlorine, the water is safe to be released.
From the toilet to the garden
The chemistry is simple enough, but the challenge has been to make robust units that can be mass-produced and easily installed and maintained. “We have to make it so that the guy who comes to clean the toilets can also clean the treatment system,” explains Rabaey.
The electricity can come from the grid, or solar panels if necessary, although this adds to costs. At the moment the plant runs at 600 watts, roughly the equivalent of 10 light bulbs. “For a toilet for 100 people, that’s an acceptable cost,” Rabaey says.
After testing the system on a household toilet, the researchers are now working with a community toilet, combining electrochemical treatment with a natural filter of earth and pebbles that cleans the water further.
This water is currently used on lawns around the installation, but the next step is to use it to irrigate vegetable gardens. The fact that the treatment does not remove nitrogen compounds from the water means that it is still useful as a fertiliser.
“We are not making drinking water,” Rabaey notes. “We’re making water safer for the environment.”
(Story reproduced from Flanders Today)