Membrane Cleaning
Periodic cleaning of the
membrane(s) can improve system
performance. In normal operation,
mineral scale, biological matter,
colloidal particles, and organic
substances can foul the membranes
WARNING: Cleaning chemicals are
dangerous and can cause injury and
damage to the environment. Read
and comply with all safety and
disposal precautions listed on the
Material Safety Data Sheets
(MSDS’s). It is the user’s
responsibility to comply with all
applicable federal, state, and local
regulations.
Crane Environmental manufactures
a complete line of membrane
cleaning stations that can be used to
clean membranes; however, if a
cleaning station is not available, the
membrane can be cleaned using the
EPRO system.
INORGANIC FOULANT CLEANING
Use an acid cleaning solution to
remove inorganic salts such as
CaCO
3
, CaSO
4
, BaSO
4
and metal
oxides (i.e., iron) from reverse
osmosis membranes. Do not use
sulfuric acid because it may cause
calcium sulfate to precipitate on the
membrane(s).
Acceptable cleaning solutions (all
compositions given by weight):
Crane Environmental Cleaning
Solution #3 (1 lb. per 15 gal. of
RO water).
A solution of 0.2% hydrochloric
acid (HCl),
A solution of 0.5% phosphoric
acid (H
3
PO
4
),
A solution of 0.2% sulfamic acid
(NH
2
SO
3
H), or
A solution of 1.0% sodium
hydrosulfite (Na
2
S
2
O4)
The solution will be most effective if
maintained at 95°F (35°C). The pH of
the solution should be around 2 - 3
pH.
ORGANIC FOULANT CLEANING
Use an alkaline cleaning solution to
remove silica, biofilms, and organics
from reverse osmosis membranes.
Acceptable cleaning solutions (all
composition given by weight):
Crane Environmental Cleaning
Solution #2 (8 oz. for every 15
gallons of RO water).
EPRO 150-8000 O&M MANUAL Rev.04/03 Page 27 of 55
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