Secondary treatment

What is the first step in the water treatment process?

• coagulation

• filtration and removal of debris, sand, grit, etc.

• flocs

• concentation

What is the first step in the water treatment process?

• coagulation

• filtration and removal of debris, sand, grit, etc.

• flocs

• concentation

What word means the solid particles that have settled out during the sedimentation process.

• sediment
• solubility
• settlement
• solidifying

Preliminary treatment

• prevents toxic chemicals.

• removes large objects.

• is unnecessary.

• is useless.

Which substance is used in a sewage treatment system to kill harmful bacteria?

• ammonia

• chlorine

• sand

• soap

What is the purpose of using ultraviolet light on the water?

• To bleach it out
• To "sterilize" any bacteria 
• To remove chlorine
• To kill viruses

What is the role of bacteria in the water purification process?

• digested organic matter
• add chlorine
• nothing, we don't want them in there
• add nutrients to the sludge

What was the name of the brown wastewater solution in the aeration tank?

• sludge
• effluent
• mixed liquor
• sewage

What gas must be maintained at precise levels in the aeration tank?

• CO₂
• O₂
• H₂
• CO

What is the first step of preliminary wastewater treatment, which removes large items such as plastic wrappers and sticks?

• screening - employs the use of a "bar screen"

• sedimentation

• aeration

• disinfection