OPM BWT PERMAQ® Pico Rev. 2.0 EN
Glossary
EN
59
Glossary
Antiscalant (AS)
A product for the pre-treatment of feed water
for hardness stabilisation. The addition of an
antiscalant to the feed water causes the com-
plexation of hardness elements, which can pre-
vent accumulations on the concentrate side of
the RO module.
Antiscalant dosing system
Hardness stabilisation can usually be achieved
only by incorporating an antiscalant dosing
system.
Concentrate
Waste water containing the salts and minerals
that have been removed from the permeate.
Electrical conductivity
The electrical conductivity provides informa-
tion about the proportion of dissolved salts in
the permeate. This value is mainly determined
by the salt retention rate of the membrane
used and the drinking water quality. The smal-
ler the value (µS/cm) measured for the electric
conductivity of the water, the lower the salt
concentration. With typical drinking water, a
permeate conductivity between 5 and 30
µS/
cm can be achieved.
Feed water
The water to be desalinated that is initially fed
into the reverse osmosis unit. It is usually
softened drinking water (softened water).
Full-fit concept
The full-fit design of the BWT PERMAQ® re-
verse osmosis units with minimal dead volume
more or less rules out any contamination.
High rejection (HR)
RO membrane with increased salt retention.
Installation and operating manual
Manual for installing and operating the device.
NaOH dosing
Dosage of sodium hydroxide (NaOH) for adjust-
ing the pH value, for example, so that CO2 can
be converted into carbonate form and retained
by the reverse osmosis unit.
Offline operation
The permeate produced during offline opera-
tion is temporarily stored in a permeate tank
and is delivered to the consumer via a booster
pump. The permeate tank is monitored with a
level contact (NO).
Permeate
“Purified water” that has largely been desalin-
ated by reverse osmosis. The most important
quality parameter is the electrical conductivity
in μS/cm.
Permeate yield (WCF)
The permeate yield (water conversion factor,
WCF) is the ratio between the quantity of puri-
fied water produced (permeate) and the
quantity of feed water required to do so
(softened water).
Raw water
Raw water is water before water treatment. It
must be pre-treated (usually softening) before
it can be used in the reverse osmosis unit.
RO module
Wound membrane module that separates the
raw water flow to be desalinated into perme-
ate and concentrate.
RO, reverse omosis
Membrane separation process for the sub-
stances dissolved in the water, which is used
to desalinate softened water. The salt concen-
trate that forms on the raw water side is
drained off as waste water (concentrate). The
water that has flown through the membrane
(permeate) is low in salt. The retention rate for
the dissolved salt is usually 95 to 99 %.
Silt density index (SDI)
SDI is a measurement for the colloidal impurity
of raw water. The measurement system is a fil-
tration process which determines the blocking
tendency, measured over a period of 15
minutes.
Softening
Process for exchanging hardeners in the water
(calcium and magnesium ions) with sodium
ions with the aid of ion exchange resin.
