October 2012
7-7
7.2
Water Purification
Operation, Maintenance, and User Education
For optimal water purification system efficiency, consider the following operation,
maintenance, and user education techniques:
••
Use water purification only when necessary and match the process to the actual
quality of water required.
••
For filtration processes, base backwash phases upon the pressure differential
across the filtration media. A pressure drop will indicate that the filter requires
backwashing.
••
For carbon filtration and deionization processes where regeneration occurs off
site, work with maintenance professionals to determine an optimal schedule for
removing and regenerating units. This can be determined based on incoming
water characteristics and the amount and quality of purified water required daily.
Deionization systems should require regeneration based on the volume of water
treated or conductivity.
••
For distillation systems, periodically clean the boiling chamber to remove accu-
mulated minerals. This will ensure efficient operation of the system.
••
For water softeners, work with a plumbing professional or the product manufac-
turer to account for and program regeneration based upon the incoming water
hardness and/or flow through the system. Monitor and adjust settings periodically.
Retrofit Options
Facilities might choose to install multiple water purification systems in sequence to
increase the effectiveness and efficiency of the water purification process. When one
of the later phases of treatment uses a membrane, at a minimum, it might be neces-
sary to install a pretreatment step to remove larger particles.
For filtration processes, consider installing pressure gauges, if not already installed.
Pressure gauges can be used to determine when to initiate a backwash phase.
Consider reusing water purification system reject water as an alternative onsite water
source where appropriate and feasible. See
Section 8: Onsite Alternative Water Sources
for more information.
Replacement Options
Prior to purchasing a new water purification system or replacing an old one, evalu-
ate the incoming water supply and assess the quality and quantity requirements of
the intended use for a period of time. This will help to determine the level of water
purification needed and the sizing of the system. Choose the least intensive treat-
ment needed to achieve the desired quality level and size the system correctly for the
intended use. Oversized systems can waste water and energy and lead to degraded
quality due to of long, inoperable periods.
