Water Filtration Solutions Through the Ages
In around 500 BC, almost 2 400 years before Pasteur eventually established the link between microscopic organisms and disease, the ancient Greek physician Hippocrates recognised the need for water filtration solutions. He recommended immersion in cold water for the treatment of feverish patients. Furthermore, based on the current theory of the four humours responsible for bodily health, he believed that to be fully effective, it should be clean and pure. His approach was to boil the ill-tasting and evil-smelling output from the city’s aqueducts and filter it through a cloth bag which later became known as a Hippocratic sleeve.
However, although the man responsible for the Hippocratic oath is also often cited as the originator of water filtration, his solution was not, in fact, the first. Some 1 500 years earlier, the ancient Egyptians were using porous clay pots for this purpose, while references in a Sanskrit text citing the use of gravel and sand as a filter medium also pre-date the Greek physician’s idea.
Interestingly, over the intervening centuries, each of these three early options has undergone various refinements and modifications, and has since become the basis for one of the more advanced types of filter media in use today. !827 saw the first significant advance in the evolution of water filtration systems. It was the work of an English father and son team named Doulton, perhaps better known for their quality bone china. In their revolutionary device, a porous ceramic pot positioned above a glazed ceramic pot filtered out bacteria and other solids while the lower vessel collected the clear filtrate.
This breakthrough came at a time when the Thames river was heavily contaminated with sewage and both typhoid and cholera were rife among the local population. The Doultons followed up with the world’s first carbon cartridge filter in 1862 while also developing water filtration systems using a new micro-porous ceramic known as diatomaceous earth.
As time has progressed society’s needs have changed. Some industries have presented us with new forms of contamination to deal with. Other sectors, such as pharmaceuticals, food and beverages and semiconductors, now require far higher standards of purity. To overcome these tough new challenges researchers have responded by developing two new media for use in water filtration systems – ion exchange resins and semi-permeable membranes. The former offers a means to remove selected cations and anions present in water, while the latter can retain both suspended and dissolved particles in the nano range using a process termed reverse osmosis.
For cost-effective and innovative water filtration systems, consult South Africa’s experts at WaterIcon.