The diagram illustrates the way potable water is obtained from a river water with a 6-stage clearing process.
The treatment process involves of 6 different stages required for the producement of clean, consumable water. These stages are intake, screening, coagulation/flocculation, sedimentation, filtration and disinfection by order.
The procedure begins with an intake where water is taken from the river through a pipe and gets carried to pass through screens, big metal filters, to remove any unwanted objects such as leaves, twighs and rubbish during the screening stage. After screening, some chemicals responsible for destabilising tiny particles are added in coagulation/flocculation stage order to prevent any clumping that may result with large flocs.
Followed by coagulation, sedimentation helps the heavy flocs to settle at the bottom of a tank, helping the clear water from the surface to be collected easily while excess flocs are treated and disposed safely after this stage. At the next stage called ‘filtration’, the water passes through some layers of sand, gravel and and charcoal in order to remove last remaining small particles. During the last stage of the process, disinfection, water gets treated with chemicals such as chlorine or UV in order to kill any harmful microorganisms, setting an end to the process and obtaining clean potable water for public use.