Without the modern water purification process we as a race would be susceptible to far more endemics and illnesses. The fact that we have such a dedicated water purification system is testament to the modern world we live in. Its development has allowed civilisations to grow while today it provides us with cheap and clean drinking water. The process however is not made up of one component however; it is a multi stage practice that utilises a number of different water purification methods. It is hoped that this article, a study into the different purifying methods, will give the reader a greater appreciation of what goes into their glass of tap water.
The first stage is a rather basic wire mesh that sits at the opening of the inlet to purification plant. The purpose of this mesh is to prevent large pieces of debris such as trees and dead fish from passing into the plant. Ultimately this is the first step in a process that supplies a crystal clear, life giving and thirst quenching liquid.
Purification methods do differ however for the different applications it is to be used for. Some plants purify water for the chemical, industrial and medical industries and hence this water has, in some cases, got be purer than the water we drink. Each of these plants has a method of processing the water so that it meets the demands of whatever scientific or medical application it is needed for. In some cases this process may take twice as long as regular treatment due to the exacting nature of some industrial and scientific uses.
In some scientific applications it is vital that for the water to be suitable all minerals and salts must be removed. This differs from tap water in the way that minerals are left in for health reasons. These reason some sciences require them to be removed is that they can interfere with the results of experiments and testing. The ways in which these minerals and salts are removed range from chemical disinfectants to UV lights and distillation. All work towards producing the most pure sample of water possible.
Public water purification is not as exacting but equally important. The process normally starts out at a lake or reservoir where the mesh removes the largest debris. The mesh and filters that carry out this process get smaller further through the process to produce water that is free from visible debris on entry to the plant. These filters however have to be cleaned regularly to free any extraordinarily large debris items.
The next stage involves adding chemicals and especially chlorine to the water in order to neutralise the liquid so it reaches a neutral pH level. It is only after the water is pH neutral that it is sent through for disinfection. This is when flocculation occurs, another process of filtering and adding chemical agents that removes items from the sample and bacteria.
One of the most important methods of purification is in fact one of the most simple. This is sedimentation and in lay man's terms this simply means letting the water sit until all of the particles settle to the bottom. The clear water is then pumped into another sedimentation tank and is repeated a number of times to ensure any particles are completely removed. After this chlorine is once again added to prevent any bacterial growth on the transit from plant to tap.
Amazingly this is the process that gives us the most important liquid in life. Naturally this has been in extremely simplified terms and does not delve into the more complex procedures involved. Even so, it is an amazing process that all should understand so they further appreciate the work that goes into giving them drinking water.
Science expert Thomas Pretty looks into the water purification process and how it supplies us with the source of life.