Modern Wastewater Treatment Essay

477 Words2 Pages
The world today is faced with a lot of different waste problems. One major problem is how to get rid of the waste safely so that it does not disrupted the environment or hurt people or animals. The major problem for the United States is waste water, the amount, and the cost of treatment and disposal. The United States treats over 1 billion tons of waste a year. How do we treat that much waste. One way it to send the waste water into a treatment plant ran by the state or county. The water contains solid particles, which mixed with the untreated water is called sludge. The sludge contains solid particles, like wood, dead animals, and trash that could cause problems later on, so they filter out all this stuff and send it to a land field.…show more content…
Each tank is divided into two sections. In the first, air is pumped through the water. As the organic matter starts to decay, it needs oxygen. The aeration stages supplies it with this oxygen. The bubbles lets grit settle out. The grit is pumped out of the tanks and taken to the landfills. The water then enters its stage of sedimentation. Here the Sludge settles out and is pumped out of the tanks. Some of the water is removed for a stepped called thickening and then the sludge is sent into large tanks called digesters. As the sludge settles to the bottom, the lighter materials float to the surface. This is called "scum" This can include anything from grease and oil, to plastics and soaps. Slow moving rakes remove the scum off the water surface. The scum is thickened and then pumped into the digesters along with the sludge. Also, many cities use filtration in sewage treatment. After the sludge is removed, the liquid sewage is ran through filters, usually sand, that removes all bacteria, reduces turbidity and color, and removes some of the odors, reduces iron, and removes any solid particles left. Another part of the waste water treatment is getting rid of the solid-waste material. The Solids are contained for 20 to 30 days in a large, heated and enclosed tank called a "digester." Here, Bacteria breaks down the material. This reduces the volume, odor, and destroys organisms that can cause disease. The product is then sent to
Open Document