Culligan Aqua-Cleer Advanced Drinking Water Systems - Manual (Page 10)

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component of feed water will plug a membrane over time. Use of a softener will reduce
the fouling effect on a membrane. One way to detect too much hardness in the feed water
is the weight of a membrane installed for a period of time. A fouled membrane (dried)
will weigh significantly more than a new membrane. The increase in weight is a result of
precipitated hardness inside the membrane.
Iron
Iron is another common membrane foulant. There are a variety of types of iron, some
of which cannot be removed by an iron filter. Clear water iron can be removed more
effectively by a softener. Particulate iron can be removed more effectively by a 1 micron
filter. Organic-bound iron can be removed only by activated carbon or macroporous anion
resin. If there is enough iron to exceed the EPA secondary drinking water standard and
softening the water is not an option and the iron is soluble, then an iron filter is appropriate.
If none of these are an option then regular replacement of membranes will have to
be accepted.
Product Water Recovery
Product water recovery plays an important role in determining membrane and system
performance. Recovery refers to the amount of water produced in relation to the amount of
water sent to drain. The standard calculation is:
% Recovery = Product Water ÷ (Product Water + Waste Water) x 100
The Aqua-Cleer uses a flow control assembly to restrict the flow of waste water to the
drain. This restriction helps maintain pressure against the membrane. The sizing of the
flow control assembly determines the recovery rating of the system. The Aqua-Cleer is
manufactured with a recovery rating designed to be around 0% -40%. Depending on
temperature, pressure and tolerances the actual recovery value may be slightly different
for each system.
Installation
(con’t)