Lesson 3 - Water SAQ
This lesson allows you to test yourself on the material covered in the Water lesson and determine the level to which you have met the learning outcomes.
Suggested Response - Q3
** Why would you recommend having a system comprising WAC, SAC, WBA, and SBA versus one comprising only SAC and SBA? If you did not have sufficient funds for four separate ion exchangers, is there another option you would recommend?
Response:
The system that consists of WAC, SAC, WBA, and SBA has some clear benefits:
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Having a WAC before the SAC allows for temporary hardness, calcium (Ca2+) and magnesium (Mg2+) ions bound to bicarbonate (HCO3-) to be removed. CO2 can be vented off after this and the SAC can then be left to deal with the other cations.
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The same goes for having a WBA before an SBA – it allows for the anions of strong acids to be removed first and then the SBA only has to focus on silicates.
- Thus, by having a WAC and a WBA the load on the SAC and SBA is reduced.
Since the SAC and SBA option does not have these advantages, it should be clear that having a WAC, SAC, WBA, and SBA system is the better solution.
If you did not have sufficient funds for four separate ion exchangers, you could employ a mixed bed reactor(s). This option means that there are two types of resin in the reactor. It is important to note that the reactor would have to be regenerated twice, as each resin will require different treatment. You also would not be able to replace only one of the resins, as some mixing invariably occurs.