Final answer:
Floating fats, oils, and greases are removed during the primary treatment phase of water treatment.
Step-by-step explanation:
The removal of floating fats, oils, and greases occurs in the primary treatment phase of water treatment. In this phase, sewage is stored in a basin where solids settle to the bottom as sludge and lighter substances, including fats, oils, and greases, rise to the top. These layers are then removed, and the remaining liquid is sent to secondary treatment.
Preliminary treatment is the first stage in the process of wastewater treatment, and it focuses on the removal of large, easily removable solids and materials from the wastewater before it undergoes further treatment. This stage is crucial for protecting downstream processes and equipment in the treatment plant.
The removal of floating fats, oils, and greases (FOG) is an essential part of preliminary treatment. In this phase, physical processes such as screening and skimming are employed to eliminate larger debris, floating materials, and substances like FOG that can be separated easily.