Certification Action Line features questions and answers typical of those appearing in Water Quality Association (WQA) certification examinations. Some answers may not satisfy everyone of every condition.
1. The chemical structure of synthetic polystyrene-divinylbenzene ion exchange resins is best described as a:
2. The resin phase of macroporous resins has greater porosity than that of gelular resin.
3. Plastic molding is used to obtain the spherical shape of ion exchange resins.
4. Ion exchange resin beads are typically about the following diameter:
a) 0.1-0.05 millimeters
b) 1.0-0.5 millimeters
c) 2.0-1.0 millimeters
d) 5.0-4.0 millimeters
5. In resin manufacturing, the resin bead is heated with concentrated sulfuric acid to:
a) remove extraneous taste and odor compounds that could otherwise leach into service water
b) give the resin bead a curable hard shell
c) etch pores and surface area into the bead
d) add the ion exchange functional groups to the resin
6. The difference between strongly acidic cation (SAC) resin and weakly acidic cation (WAC) resin is that in the hydrogen form:
a) the SAC resin can split neutral salts (e.g., NaCl by exchanging H+ for Na+), while the WAC resin cannot
b) the SAC resin will withstand pH below 6, while the WAC resin will not
c) the SAC resin will exhibit a higher regeneration efficiency than the WAC resin
7. The difference between strongly basic anion (SBA) resins and weakly basic anion (WBA) resins is that:
a) the SBA resin can exchange strong mineral anions, while WBA resin cannot
b) the SBA resins will exhibit higher regeneration efficiency
c) the SBA resin can exchange alkalinity and silica anions, while the WBA resin cannot
8. The ion exchange reaction is driven further toward completion under _______ water flow conditions.
9. Pressure drop in an ion exchange water softener is usually greatest:
a) in the resin bed
b) at the resin interface with the distributor
10. Condensate polishing refers to:
a) smooth condenser walls
b) protection from sweat that forms on the outside of water conditioner tanks
c) removal of corrosion product in boiler waters