The Evolution of Water Filtration Systems and Their Uses
Although generally unseen and leaving the average consumer largely unaware of the surprisingly wide range of applications in which they feature, water filtration systems play an important role in many aspects of our daily lives. Unlike much of the other equipment in use today, however, various types of simple filtering device have been used for more than four millennia. In fact, archaeologists have discovered Sanskrit writings that outline the use of sand and charcoal for this purpose, although it would appear the aim, at that time, was to improve its taste rather than protect the health of those who drank it.
Around 1500 years later, it is believed that Hippocrates, the famed scientist and influential physician of ancient Greece, also developed one of the earliest water filtration systems when he used a cloth bag that eventually became known as a “Hippocratic sleeve” as the means to remove solid impurities from the water carried by Greek aqueducts. Even though this idea dates back to 500 BC, the same principle is still in use today. Now, filter bags made from more modern materials are widely used for a variety of purposes, such as keeping swimming pools free of suspended solids. Although his reasoning may have been based upon a mistaken premise with regard to the nature and origins of disease, Hippocrates correctly deduced that such filtration systems were necessary because clean water was essential to ensure the body’s health. As a result, others of that era set out to develop alternative ways in which to achieve this important cleansing. These included the use of macerated laurel and sacks of barley through which they passed rainwater and water drawn for from rivers and lakes as a means to remove the suspended solids.
The physicians of the time were still unaware of the existence of microscopic bacteria and the potential threat to one’s health that many of them can pose. Nevertheless, before passing the water through his primitive filtration system, Hippocrates first boiled it and then allowed it to cool before using it to lower the temperature of feverish patients. Following this early period of apparent enlightenment, further progress was impeded during the dark ages when religious leaders branded scientific experimentation as heresy and the next big breakthrough in this field came only in the early 19th century when, in 1827, the manufacturer of the world-famous fine English china brand John Doulton and his son developed the ceramic filter to create the first water filtration system with the ability to remove bacteria. Their invention came at a time when outbreaks of typhoid and cholera in the nation’s capital were frequent due to the heavy contamination of the Thames with raw sewage.
In the Doultons’ setup, an unglazed, porous bowl made of earth and clay served as the filter trapping any solids but allowing the cleared filtrate to pass through its tiny pores to be collected in a glazed, and therefore impermeable, bowl positioned beneath it. In response to a royal commission, they subsequently developed a stoneware filter mounted in a tall and decorative pottery container, complete with a tap. In 1835, their attractive and highly effective device became the first water filtration system to be offered for sale to the general public. With the development of the microscope and Pasteur’s work on bacteria came a greater understanding of the need for alternative ways to handle sewage and for methods to ensure the purity of drinking water. Treatment plants were eventually established and cities and larger towns in more-developed countries began building the infrastructure to deliver the potable water to individual homes where it could be drawn from a tap rather than a communal well. Today, not only do utility companies and municipal plants use various water filtration systems as part of the purification process but many industries are also required to purify their effluents prior to reusing them or discharging them into the environment.
Sand filters, bag filters, and various types of cartridge filters have since been joined by a newer and even more effective technique known as reverse osmosis (RO). Used in the home, in treatment plants, and even in the field, RO technology is so effective that it can even filter the dissolved solids from a solution and has become the preferred water filtration system for use in desalination plants. To find the best filter for your purpose, consult South Africa’s water treatment specialists – WaterIcon.