Page 165 - Facility Piping Systems Handbook for Industrial, Commercial, and Healthcare Facilities

CHAPTER 4

WATER TREATMENT AND
PURIFICATION

This chapter describes water treatment methods used to partially remove and replace vari-
ous impurities from a feedwater stream, water-conditioning additives used to neutralize
impurities and inhibit corrosion, and pure water systems used to remove all impurities from
the feedwater to a level at or below limits desired by the end user.
Information is presented on basic water chemistry, impurities found in water, water analy-
sis, and impurity measurement. Also discussed are general selection criteria for the removal
or reduction of specific impurities from water. Separate sections cover water-conditioning
systems for boiler feedwater, water-conditioning systems for cooling water, and the genera-
tion of purified water.
For purposes of discussion only, the term water treatment is intended to mean only
the removal and/or replacement of undesired impurities in feedwater with more desirable
impurities. The resultant water is not pure. Water conditioning is intended to mean the
addition of chemicals to water for the purposes of inhibiting corrosion and neutralizing
undesirable impurities. Pure water systems is intended to mean the production of water
pure enough for pharmaceutical and laboratory applications. The explanations and defini-
tions given are simplified ones.

CODES AND STANDARDS

There are many codes and standards that apply to various systems. These include:

1. Potable water treatment shall comply with the 1986 Safe Drinking Water Act and
Amendments.
2. Potable water treatment shall comply with EPA technologies describing contaminant
removal.
3. Pure water treatment shall comply with the following, depending on the purity of the
water desired:
a. CAP and ASTM reagent-grade water
b. USP standards for water purity
c. AAMI standards
d. NCCLS standards
e. SEMI and ASTM electronics-grade water standards (outside the scope of this
handbook)

4.1
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