Wastewater treatment

The wastewater is put into a storage tank for several hours. This is referred to as sedimentation and during this time the solids will sink to the bottom and the greases will float to the top. After all particles have gathered at the top and bottom they are scraped away. This waste is referred to as "sludge". The remaining water is then sent to the next step in the process know as the secondary treatment.
             The secondary treatment is a biological treatment in which the dissolved organic matter is removed. There are three methods to doing this, the fixed film system, the suspended film system and the lagoon system. Either of these processes takes microorganisms and adds them to the wastewater. The microorganisms absorb organic matter from the waste as their food.
             The final treatment centers on the removal of disease-causing organisms from the wastewater. This is accomplished by disinfecting the water by adding chlorine or by using ultraviolet light. Sometimes, however, high levels of chlorine may be harmful to aquatic life. To offset this, treatment systems often add a chlorine-neutralizing chemical to the treated water before discharge. Occasionally, an advanced treatment is necessary to remove nutrients from the water. To do this, most treatment plants add chemicals sometime during the treatment process to help settle out or strip out phosphorus or nitrogen. This is the complete process and expectantly after completion, the water should meet all government requirements. Although water can never actually be put back to its natural form, this process does an immaculate job of returning water to a sanitized state.
             As mentioned before, all the waste removed from the water is referred to as sludge. These sludges usually are very potent and have an extremely bad odor and require its own treatment before disposal. Untreated sludge is made up of about 97 percent water, thus the main goal in sludge treatment is to remove a majority of the water, remove the odor, kill disease causing bacteria and decompose some of the organic matter.