Wiki Page, Community Fluoridation: Module 3 - Overview of Water Treatment Part 2

Wiki Page
2017-07-18T12:57:56-06:00

In this part of the Module, the following components of the water treatment process that are going to be covered are shown below. The components that are not covered in this part are shaded.

Filtration

The filtration media in a rapid sand filter consist of two layers of different-sized sand.

Multi-media filters typically include a layer of crushed coal (anthracite) atop two or more layers of different-sized sand. Regardless of the number of media layers.

The largest particles are always at the top, grading downward to the smallest particles. This allows the whole depth of the filter bed to catch suspended particles.

The largest types of media grains have the lowest densities. This way, after all the grains have been agitated in the backwashing process, they settle again into the desired layers, largest media on top.

The layers of filtration media rest atop one or more layers of gravel, at the bottom of which is a network of perforated pipes.

This underdrain system supports the filtration media, collects filtered water and distributes backwash water evenly during the backwash cycle.

Treatment Process Illustration.

Disinfection

Public water supply systems are vulnerable to a variety of organisms that can cause diseases such as amoebic dysentery, typhoid fever, cholera, giardiasis, and cryptosporidiosis.

Most of these organisms are sensitive to disinfection, so disinfection is considered the single most important treatment step in the production of safe, potable water.

Chlorine is most often used as a disinfectants.

Treatment Process Illustration.

VIDEO 2 FILTRATION DISINFECTION FINISHED WATER-Final from Enos C Inniss on Vimeo.

Now, it's time for a quiz! Click next at the bottom for Module 3 - Quiz 2.