Wewage Treatment

At a sewage treatment center they sometimes use three steps to filter and clean the waste water.

Primary Treatment: Primary treatment is when all of the sewage is put in large tanks and allowed to settle. this separates each individual material. the sludge sinks to the bottom and is sent to a separate sludge treatment area and the grease and oil is scraped off the top. the treatable liquid id then sent to the next stage.

Secondary treatment: in the secondary treatment, aerobic and biological processes are used. there are two types of secondary treatment. fixed film treatment is when a fixed biomass is grown and the sewage passes over it. suspended growth is when the biomass i suspended within the sewage. these processes remove BOD or biochemical oxygen demand.

Tertiary Treatment: this is the last and most rare form of sewage treatment. it uses bacteria to denitrify nitrates in the water producing nitrogen gas which id then released into the atmosphere. the major purpose is to remove nitrogen and phosphates

Hopefully after all this you can drink some of it!