Wastewater Treatment
Design Challenge
Item |
Cost per Item ($) |
Quantity Needed |
Cost Subtotal |
Plastic soda bottle (any size) |
0.05 |
|
|
Tubing |
1.50/m |
|
|
Straight connector for tubing |
1.80 |
|
|
T connector for tubing |
1.00 |
|
|
Duct tape |
0.15/m |
|
|
Stopper |
0.15 |
|
|
Screen – 10 cm2 |
0.75 |
|
|
Gravel – 100 g |
0.50 |
|
|
Sand – 100 g |
0.75 |
|
|
Aerator |
3.00 |
|
|
Bucket |
2.00 |
|
|
Activated charcoal – 10 g |
1.00 |
|
|
Alum – 10 g |
0.75 |
|
|
Source of microbes* – 10 g |
0.25 |
|
|
Coffee filter |
0.10 |
|
|
Duckweed or other aquatic plants (free if collected by students) |
1.00 |
|
|
Other: |
|
|
|
TOTAL COST |
$ |
*
In activated sludge treatment
systems, sewage sludge is added back into the system as a rich source of
microbes capable of digesting organic matter. Sludge is not an option for
classroom projects because it contains disease-causing organisms, but a wide
range of microbes can be found in samples of compost, soil, or sediment from a
pond or stream.
Cost Analysis Instructions
· Under Quantity Needed, enter the # of pieces or estimated length of each item you plan to use.
· Multiply the numbers in column 2 by column 3 to obtain the subtotal for each item.
· Sum the subtotals in column 4 to determine the total cost of your design.
Other Materials: If approved by your teacher, you may use materials other than those listed above, with prices based on those listed in commercial catalogs.