Answers to these questions appear at www.watertechonline.com/certification-action-line.
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.
1. The modern automatic water softener is operated with ______________ cycles.
a) 1
b) 2
c) 3
d) 4
e) 5
2. Magnesium is held more strongly to a cation exchange resin site than is calcium.
a) True
b) False
3. As a downflow service flow proceeds through a water softener resin bed calcium, magnesium and sodium laden bands or layers form in the resin bed and move down toward the exit distributor.
a) True
b) False
4. Since strongly-acidic cation exchange resins exhibit distinct and consistent affinities for each different cation, such as Ca2+, Mg2+ and Na+, the different bands of calcium and magnesium exhausted resin will always form well defined, distinct and uniform layers whose boundaries and shape depend only on the amount of water hardness that has been exchanged at any point during a softener's service cycle.
a) True
b) False
5. Sodium leakage from strongly-acid cation exchange resin in the hydrogen form is influenced by:
a) percentage of total cations that are sodium
b) total dissolved solids (TDS) of the feedwater
c) alkalinity of the feedwater
d) all of the above
6. Weakly acidic (carboxylic) cation exchange resins can soften waters that because of high TDS are not possible or practical to soften with strongly acidic (sulfonic) cation exchange resins.
a) True
b) False
7. Larger swelling differences must be accommodated in weak acid cation (WAC) resins than in strongly acid cation (SAC) resins.
a) True
b) False
8. Silica is a (a) or (b) occurring anion in natural water supplies.
a) commonly
b) rarely
9. Silica in water is strongly ionized as the HSiO3– ion.
a) True
b) False
10. The majority of silica in water supplies can be removed by strongly basic anion (SBA) exchange resin.
a) True
b) False
