Water is life, but it cannot be taken as it is. Nowadays we all buy water from the shops, a real kind of evolution where water is bought from the counter. We do not drink our tap water; we drink filtered water. So what has changed, from taking water from rivers and lakes to fetching it from the store? Water filtration was initially about improving taste since the link between water and disease had not been discovered. When waterborne diseases became an issue, there was a paradigm shift to water purification to rid water of harmful microbes. With the advancement of technology, people are now drinking water that is 98% pure.
Ancient writings from India and Greece dating to 2000 BC contain evidence of individual water treatment methods. The writings show that even then, people knew that heating water was a mode of purification. They were also aware that filtration using gravel and sand, boil and straining would work. The issue then was improving the taste of water. There were no chemical contaminants or knowledge of microbes.
The Egyptians initially discovered the principle of coagulation after 1500 BC. There were pictures found on the tomb walls of Ramses II and Amenophis II showing the use of alum for settlement of suspended particles. Later on, Hippocrates revealed to the world the healing power that water possessed. He came up with the act of sieving water and even made the first filter bag that was supposed to trap the sediments responsible for odours or bad water taste. The period between 300-200 BC saw Archimedes invented the Romans building aqueducts and the water screw.
The Dark Ages
There was a time when there were no innovations or experiments in water supply, hence such methods that existed were less sophisticated. This period is what is referred to as the dark ages. When the Roman Empire came down, the aqueducts went down with them after being destroyed by their enemies. The way forward on water treatment was therefore not known. In 1627 showed positive insights when Sir Francis Bacon initiated seawater desalination. He was trying to rid seawater of salt particles. Unfortunately, he did not succeed, but still he is the trailblazer of such experiments by scientists.
In the 1670s, there seems to be light at the end of the dark tunnel when Antonie van Leeuwenhoek builds a microscope that makes it possible to study the particles in water. In 1676, Van Leeuwenhoek observed microorganisms in water for the first time.
The 1700s saw the first domestic filters being used. The materials were charcoal, wool, and sponge. Robert Thom designed the first municipal water treatment plant, which was then built in Scotland. A horse and cart distributed the water while the water underwent slow sand filtration. Water pipes were then installed three years later after a suggestion that everyone should be able to access clean water. In 1854, there was a discovery that cholera was a waterborne disease. It was also discovered that its outbreak was not so severe in areas where there were sand filters installed. John Snow, a British scientist, found that the water pump had been contaminated by water from the sewer, thus the outbreak. He used chlorine for purification and forged water disinfection. The conclusion was that the taste and smell of water were not enough to determine its safety. Governments then started installing water filters in the municipal. There was also chlorination.
The Americans started constructing large sand filters in the 1890s, and it was a great success. They used rapid sand filtration and made use of powerful steam to clean the filter. Waterborne diseases started becoming less common.
The use of chlorine to treat water did not last long as it was associated with respiratory disease, hence the search for other forms of water disinfectants. In 1902, coagulation and disinfection were achieved simultaneously by mixing calcium hypochlorite and ferric chloride in the water supply. In 1903, water was softened in a process known as desalination where cations are removed. Read more about water softeners and their processes are unifiedwater.com.
The French used ozone as a water disinfectant in 1906. From 1914 onwards, there were standards put in place to ensure that all drinking water was safe for the public. The US Clean Water Act was passed in 1972 and 1974; the Safe Drinking Water Act appeared. The aim was to ensure safe drinking water for all. From this period, concerns have shifted from water-borne diseases to manufactured water diseases due to irresponsibility for instance industrial water contamination.
Today scientists do not focus on the purification of water but that of the by-products. Water pipes are corroded, and this exposes water to lead. Lead is linked to cancer. Therefore, as you enjoy your bottle of water, you see how the journey of getting it to you was quite a trip downstream.
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