AWE SPD2H, Руководство пользователя

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G01
SPD Owner’s Manual
12
Chemicals for Disinfection:
The recommended disinfectant to use is Renalin
TM
or Minncare
TM
, both
products of Renal Systems, Inc. HDC Medical makes a similar formula with the trade name
Peracidin
TM
. These are near identical formulations of a mixture of hydrogen peroxide and peracetic
acid.
Research has shown that a 36 minute exposure to a 1% Renalin
TM
solution will give a 6 log reduction in
bacteria level on an RO system. It is much faster and more effective than other chemical disinfectants.
Indeed it is considered to be a cold sterilant. A 1% Renalin
TM
solution can be left in contact with
otherwise clean membranes for 12 hours maximum without membrane damage.
Up to 2% formaldehyde solution can also be used for disinfection. However it must be left to soak a
much longer time and is slower to rinse out. Formaldehyde also causes a temporary flux (output) loss
that persists for hours.
Never use chlorine bleach on this RO system!
Chemical test strip kits are available for checking the concentration achieved and for testing for residual
disinfectant after rinsing.
Acid Clean First: . If the feed water supply contains any traces of oxidized iron or manganese, an acid
cleaning should be performed prior to disinfection with Minncare
TM
. This is necessary to prevent a
membrane chemical attack for which the iron acts as a catalyst.
Problem oxidized iron and manganese are typically evident by reddish brown (iron) or black
(manganese) particulates collected on the prefilter elements. Examination of the inside of fittings
downstream of the prefilter will indicate the extent of deposits to be expected on the membrane. If the
deposits are heavy, use of a finer 1 micron prefilter may be warranted.
Acid cleaning is done following a similar procedure as disinfection (Page 14) and is discussed further on
Page 22.
The volume of water contained in the RO membrane modules, piping, and disinfection tank is about 35
liters. So to attain a 1% Minncare
TM
concentration, some 350 ml of Renalin concentrate is required.
Normally formaldehyde comes as a 37% solution. So a 2% concentration would require almost 2 liters
of concentrate.
Disinfection Procedure Overview: To be effective, a proper level of disinfectant must be introduced to
all portions of the feed water path downstream of the prefilters and all portions of the product water
path. Note that to accomplish this, disinfectant flow must be forced into the reject and product pressure
regulators. When the flush valve is open, there is no flow through the reject regulator. When either the
product to tank valve, the product sample valve, or the product dump valve are opened, there is no
pressure to force the disinfectant through the product regulator valves. So these valves must be closed
part of the time to cause the disinfectant to enter the regulators.
The same concern occurs during rinsing. When water is flowing through the regulator valves, any
disinfectant is going back into the pump inlet rather than to drain. So the flow through the regulators
should be made after the majority of the disinfectant is already rinsed out.