Water is one of nature’s great wonders why, due to its structure and stability, It is the universal solvent, so it is essential for life. But it also remains Death bearer for many children in Third World countries. For example, 95% of the almost two million deaths caused by diarrhea each year could be avoided by drinking potable water. This situation is a contradiction because the technology to ‘clean’ the germ water has been optimized for a long time and is not expensive, The problem is that to implement it, infrastructure is required that not all countries are capable of building and maintaining.
The management of the integral water cycle includes several physical and chemical processes. In one of them, the filtration, a kind of large colanders and sand filters are used to retain most of the solid matter that carries water. In the flocculation the precipitation of solid substances is induced to drag the smallest particles that have managed to escape to the mechanical filters. The following water purification process is used active carbon, like that of cigarette filters, to trap dissolved harmful substances. Once the water has been ‘cleaned’ of undesirable substances, both solid and in solution, we must kill the bugs that can transmit diseases. This is achieved using ultraviolet radiation or adding to the water biocidal substances such as ozone or chlorine. This last method is the most efficient and economical, so it is the most used.
Pure chlorine, which exists as a gaseous molecule formed by two atoms, Cl2, has a great tendency to capture electrons to form chloride, 2Cl-, which is how we usually find it in nature; That is the case when it forms sodium chloride, better known as common salt, NaCl. The great reactivity of the small Cl2 molecule made it have a deadly debut in History: it was the first substance used as war gas when it was launched on Ypres during World War I, causing more than 5,000 casualties in the French army, many of whom suffered a heinous death. But if instead of using pure gas it is added to the water in small quantities, Chlorine kills all bacteria and viruses that cause disease and death, being harmless to humans. Taking into account its great reactivity, it is clear that the amounts of chlorine that is added to the water must be calculated very precisely, and also that all storage and transport systems need to be kept clean and disinfected.
It is difficult for First World inhabitants to appreciate all that is worth the privilege of obtaining clean and germ-free water every time we turn on the tap. First World women and girls we are especially lucky because if we were born in many of the Third World countries, In addition to addressing the risks of drinking non-potable water, we would be forced to dedicate a large part of our life and our energy to transport water from the sources and wells to the villages. More than three million children and 14 million women have to walk for more than 30 minutes to get water, often twice a day. On average they travel about six kilometers, barefoot or in rubber sandals, usually carrying a child and carrying others by the hand. On the way back they also have to carry 20 liter bottles on their heads, which causes them all kinds of back injuries.
On February 11 the International Day of Women and Girls in Science was celebrated, Since its creation by the UN in 2015, it is helping to change the perception of the role of women in science. This year I want to take advantage of the celebration of this event to remind girls that not only will they not be able to aspire to be scientists, but they will lose part of their lives because they don’t have access to one of the greatest achievements of science: provide that wonder of nature that is water free of health risks. Since we are still able to achieve that immense achievement, the women and men of the First World must work so that all the inhabitants of the Earth can enjoy it.