Simple recipe for safe drinking water

American scientists discovered that, in order to have cleaner and safer drinking water, we need to add the following 'additives': salt, lemon and sunlight.

In many developing countries, water supplies are primarily infected with viruses and bacteria. In fact, the United Nations estimates that about 1/6 of the world's people do not have access to enough clean water to drink.

Pour water into clear plastic bottles and put them in sunlight for about 6 hours can kill disease-causing organisms. This is a simple, inexpensive but always effective way.

However, there is one obstacle: water must be sufficient in order for the sun rays to penetrate, while most of the water supply on Earth is muddy due to clay in the river or pond bottom. , lake.

According to NPR, Joshua Pierce, associate professor of engineering and materials science at Michigan Technical University, and colleagues discovered, by adding a little salt to the turbid water, they could causing clay particles to stick together and settle to the bottom, making enough water to use the method of sunlight purification.

The team also found that adding salt was most effective for clay called bentonite but not very good for other clays. However, when they put some bentonite clay and salt into the water containing other clay, the effect will be maximized.

Few ordinary people know about the method of disinfecting it but it is quite close to wine producers, because bentonite is often used to purify products of poor purity.

Drinking water with a salty taste is not so pleasant, but Mr. Pierce said that compared to health risks caused by pathogens in dirty water, the taste and health benefits of adding a little salt to the water is not difficult thing to overcome.

If you don't like salt water, there is still another solution: add a little lemon to the water. A group of researchers at the Johns Hopkins Bloomberg School of Public Health said that adding lemon juice to water before putting it in the sun could eliminate harmful bacteria, such as E. coli, quickly. Significantly more than just using sun light purification.

Kellogg Schwab, director of Johns Hopkins University's Global Water Program and a member of the research team, explains that a chemical called psoralen in lemon and other vegetables and fruits is found to be able to digest. kill pathogens in the blood. So they decided to experiment with water.

Mr. Schwab and Alexander Harding, a medical student, tested it, if you squeeze half a lemon into a 2-liter bottle of water, it will reduce the time of water disinfection under sunlight from 6 hours to 30 minutes.

However, this method is still not perfect. Although very effective in eliminating E. coli, lemon juice seems harmless to diarrhea-causing viruses like norovirus. Therefore, Mr. Schwab's advice to you is: If in doubt, let the water have more lemon juice in the sun.