Water is one of the most essential substance required for living, it is the life blood of every creature living on earth. Although the three fourth of the planet is covered with water still very less water can be taken into use. With the increase of population, water resources are getting short to meet the requirements of people. Because of this, we strive to save every drop of water from getting waste. We render pure and fit water for variety of uses.
The Primary Treatment Process
Wastewater which is to be treated and enter the treatment plant contains items like rocks, food and even dead animals. If they are removed, they can create problem in the treatment process later. Most of the materials removed are sent for landfill.
To move sewage from your house to the treatment plant, most of the wastewater system uses force of gravity. Therefore these treatment plants are placed on low ground, often near to a river into which treated water is released. The waste-water needs to be pumped up to the aeration tanks, if the plant is built above the ground level. From this place, gravity moves the wastewater by treatment procedure.
Shaking up the sewage and exposing it to air, is the first step which a treatment facility do. This results in dissolving some of the gases like hydrogen sulfide that tastes bad & smells bad to get released from water. The wastewater enters in several parallel and long concrete tanks. Each of these tanks is segregated into two sections. First section receives pumped up air through the water. When organic matter decays, oxygen is used. The process of aeration refills the oxygen. Through water bubbling oxygen keeps the organic substance suspended forcing other grit to settle out. Pumped up grit is taken for landfill.
4. Removing sludge
Wastewater then enters the sedimentation tanks or second section where, the sludge (the organic portion of the sewage) is removed from the wastewater and is driven out of the tanks. Some water is removed during thickening and then the organic waste is processed in big tanks called digesters.
5. Removing scum:
Lighter materials float up on the surface as the sludge settles down to the bottom. These materials include plastics, grease, oils and soap. Slow moving rakes float materials off from the surface of the treatment several cities also use filtration. After the removal of solids, the liquid sewage through a substance is filtered, usually sand, through gravity. Through this method almost all the bacteria are removed, it reduces color & turbidity, and amount of iron, removes odor, and removes most of the solid particles from the water. Water is filtered using carbon particles to remove organic particles. This method is taken into use in homes also.
6. Killing bacteria:
At last, the wastewater flows down into a ‘chlorine contact’ tank, here chlorine is added in it to kill bacteria. This can create health risk, which is done in swimming pools. Chlorine is eliminated after the bacteria are killed, and sometime it needs to be neutralized by adding other chemicals. This helps in protecting fish and other aquatic animals, which can be affected even by a small pinch of chlorine. The treated water is then released into ocean or a local river.
Another thing attached with the treatment of wastewater is removing the solid waste from it. These solids are placed in heated, large and enclosed tanks known as digesters. Here, bacteria break down all these materials, reducing odors, volumes, by getting rid of organisms which cause diseases. Finished products are then sent to landfills and sometimes are used as fertilizer.