Fieldtrip to the Sewage Treatment Plant!

Fieldtrip to the Sewage Treatment Plant

Class: Tuesday, November 5

Today we learned visited the Sewage Treatment Plant! We were given a tour of the plant and we learned the important role that bacteria plays in the breakdown of waste.

First, we talked about how the water is treated.  The BOD (biochemical oxygen demand) levels are low because the water is dilute.  Why is it dilute?  This is because of underground water coming into the system as well as the high levels of rainfall we experience in the town.  Also, the population density is much lower than in earlier times when the treatment plant was built.   This is why the treatment plant switches right into secondary treatment of water and waste.

 Also to combat the influx of clean water into the waste treatment system, streams have been redirected into the river.

This is the anaerobic generator.  The purpose of this is to grow bacteria, to burn the sludge created, and then to use the charred sludge as fertilizer.  

Different class levels of pathogens exist.  It is possible to use thermophiles (bacteria that thrive in the heat) to grow the right class of sludge.

 We also discussed how phosphorous is becoming a precious element - that one idea is to begin extracting phosphorous during treatment.

 Peracetic acid is a disinfectant that is currently being used at this treatment center.  It is cheaper and more effective.  Not only that, but it is good for the water and the environment.  Many treatment centers that use other harsh chemicals need biochemical teams to come in and test the waters to makes sure that the levels are safe.  However, when peracetic acid reaches the river, it dissolves.

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