what+is+Wastewater+Treatment

===Before approaching in more detail how this process is helping save our world, and as a result human kind it's important to examine just what exactly waste water treatment is. sewagesystems have existed for centuries now but until early 1900's waste water treatment has exploded and improved substantially. As a result better healthier reusable water is available to our communities. The process in illustration form is as follows: ===

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===A picture is said to be worth a thousand words but in case this diagram is confusing here is an explanation of the process. Preliminary treatment screens out coarse solids such as rocks and sand and gravel which are normally sent to landfill. Wastewater is screened down to smaller particles. The screened wastewater then continues on. Primary treatment screens wastewater, and performs some rudimentary treatment to remove crude solids and skim off grease, oil and fat. Wastewater sits in settling tanks, which are designed to hold the wastewater for several hours. During that time, most of the heavy solids fall to the bottom of the tank, where they become a thick slurry known as primary sludge. (From personal experience this stage is disturbing to look at)The material that floats is also skimmed from the surface of the tanks. Both the primary sludge and skimmed material are typically pumped or trucked to a solids treatment processing plant. Secondary (or biological) treatment removes dissolved oxygen-demanding organic substances by using bacteria to convert degradable organic matter into bacterial cells. The wastewater is then clarified by separating treated liquid from grown bacterial cells using gravity. Bacteria and sludge is then either processed onsite or sent to a separate solids treatment facility. (At our Mass Maritime school the waste water plant processes on site.) === ===Tertiary treatment further treats effluent to remove nitrogen, phosphorus, fine suspended particles and microbes, and to kill or disable disease-causing organisms and viruses. Upon conclusion of this step the water can be reclaimed and re used, saving water and helping our planet. ===