Certification Action Line features questions and answers typical of those appearing in Water Quality Association (WQA) certification examinations. Some answers may not satisfy everyone or every condition.

Match these three fluids characteristic in ultrafiltration with their commonly referenced terms:

1. Feed supply to the membrane a) Retention
2. Concentrate flow across the membrane b) Flux
3. Permeate flow through the membrane c) Solute

4. Spacing of the molecule separation in the structure of reverse osmosis and ultrafilter membranes is specifically designed to control the separation performance of that particular membrane.
a) True
b) False

5. A boundary of increased solute concentration at the incoming face of the RO or UF membrane _________ the rejection of contaminants.
a) increases
b) decreases

6. Velocity in feed flow can ____________ membrane performance.
a) enhance
b) decrease
c) both enhance and decrease

7. The test that compares the initial time in seconds to filter 500 milliliters to the time to filter 500 milliliters after 15 minutes of water flowing through a 0.45 micron cellulose triacetate filter is known as the:
a) membrane filter test
b) silt density index test
c) turbidity unit test
d) filtrate test

8. The SDI measures:
a) microbiological water quality
b) scale-forming tendencies of the water
c) colloidal matter in the water
d) precipitate foulants

9. Pressure and flow readings to depict or diagnose membrane system operation are generally taken to monitor:
a) Feedwater
b) Permeate
c) Concentrate
d) All of the above

10. Permeate water quality from ultrafiltration is more easily monitored than that from reverse osmosis.
a) True
b) False