Fill in the blanks.

Examine Poster #1: Wastewater

What is another reason for cleaning wastewater, besides disposing of dangerous pathogens and chemicals that threaten humans and wildlife?

Follow instructions for step 2/Examine Poster #2: Screening

What was trapped in your model?

Why is this step needed?

Where are the screenings taken in real life (and where in the classroom)?

Follow instructions for step 3/Examine Poster #3: Grit Removal

Why is this step needed?

Follow instructions for step 4/Examine Poster #4: Primary Settling

What is being removed from your wastewater now?

What is sludge and what happens to it?

Follow instructions for step 5/Examine Poster #5: Biological Treatment

Note: The “tiny organisms” are types of bacteria, especially nitrifying bacteria.

What types of dissolved nutrients are being removed? Where did they originate?

What would happen if these nutrients were not removed? (use info from class, not just the poster)

What are we using to represent the nitrifying bacteria?

Follow instructions for step 6/Examine Poster #6: Secondary Settling

What is secondary sludge?

Where does the secondary sludge go?

Follow instructions for step 7/Examine Poster #7: Disinfection

What waste is still present in the water when it enters this chamber?

What is disinfection and why is it necessary?

Examine Poster 8: Discharge

Discuss some of the environmental problems that could occur in the stream if these treatment steps were not carried out. Remember, even in developed countries, often raw sewage is directly released into waterways, both legally and illegally, by accident and on purpose.

Briefly describe the environment in the video.

What kind of primary treatment happens before the water reaches the wetland?

What happens after the primary treatment?

What step in traditional secondary treatment does this replace?

What are some ecological and economic incentives to using wetland to treat wastewater?