Homework Filtration

Name: Date:

Homework Filtration

Instructions: Answer the questions inline below. Save the document with your last name in the file name. Submit the assignment through WebCT. See the instructions on the course website (www.agls.uidaho.edu/asm320).

1. List the 5 mechanisms by which particles are removed in a filter.

2. Which of the 5 mechanisms above refers to the particle being trapped because it is larger than the pore space?

3. Why is activated carbon used in filters?

4. Why is diatomaceous earth used in filters?

5. When might you decide to use a larger particle size in your filter media?

6. When might you decide to use a smaller sized particle in your filter media?

7. Why does a water plant always have more 4 or more filter units?

8. What must one do if the filter becomes clogged with particles?

9. How do you know if a filter needs to be backwashed?

10. What problems can develop if backwash rates are too high?

11. What problems can develop if backwash rates are too low?

12. What do you do with backwash water?

13. Why are particle counters used?

14. What is the difference between a turbidimeter and a particle counter?