EOF Eassy Part 2

Step 1

Raw sewage enters the treatment facility

Preliminary treatment

remove large particles using

bar screen: screen out dirt (1 inch grid)

grit tank - let grit settle

primary treatment

primary clarifier - slowly flow through large tanks, because it is nearly motionless fat and oil float to the top and organic matter settles

secondary treatment

aeration basin, secondary clarifiers, and filiering and disinfection

(Ozone and UV radiation

Tertiary treatment

trickling filter system - water percolate through bed of rocks with bacteria and detritus

Final Effluent

typically has lower organic and nutrient content than many bodies of water BOD you want to be low

what are the left over solids called and what is the process for them

Sludge → cake→ sold to farmers (fertilizer)

septic system

on site treatment

order of steps

1)raw sewage enters

2) preliminary treatment

3) primary treatment

4) secondary treatment

5) tertiary treatment