Reverse Osmosis Systems Flashcards
7 cards from real CWS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Reverse Osmosis Systems flashcards as text
What is the typical recovery rate for a residential RO system?
Answer: 15-25%
Residential RO systems typically recover only 15-25% of feed water as permeate, wasting 75-85% as reject.
Which component in an RO system prevents backflow of treated water into the feed line?
Answer: Check valve
A check valve prevents back-siphonage of permeate back into the feed water supply.
What is the primary purpose of the flow restrictor in a residential RO system?
Answer: Maintain backpressure to create reject stream
The flow restrictor maintains sufficient backpressure on the reject side to force water through the membrane and produce a concentrate stream.
At what feedwater pressure do most residential RO membranes operate optimally?
Answer: 60-80 psi
Most residential RO membranes are rated for 60-80 psi operating pressure to achieve adequate permeate production.
Which type of RO membrane material is most commonly used in point-of-use drinking water systems?
Answer: Thin-film composite (TFC)
Thin-film composite (TFC) membranes dominate residential POU applications due to superior rejection rates and wider pH tolerance.
A customer's RO system is producing water very slowly. What is the MOST likely cause?
Answer: Storage tank fully pressurized with no room for water
A storage tank whose bladder has failed or that is pre-charged too high creates backpressure that shuts off permeate flow prematurely.
What does the term 'salt rejection rate' mean for an RO membrane?
Answer: Percentage of dissolved solids removed from permeate
Salt rejection rate is the percentage of total dissolved solids (or specific ions) removed from the feedwater, expressed as a percentage.