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7.1 Standard Operating Parameters
Standard Operation Mode
Standard Operating Parameters
Item
Requirement/Standard
Value
Note
Pretreatment
Filters or strainers (500
μm or less, or 200 μm
for seawater) used
Do not use slit screens as they let film-like substances
pass through but use perforated strainers.
Flow Rate
0.2 m
3
/hr
0 - 0.5m
3
/hr/module
Concentration of
Sodium
Hypochlorite
(NaClO) in
Backwash Water
1 - 5mg/L at module
inlet
Should be suppressed below 0.1mg/L in backwash
wastewater. (An amount larger than that consumed for
contaminants on the membrane needs to be added.)
However, since the membrane is clean for a while after
the start of use, add about 3mg/L of sodium
hypochlorite from the module inlet during this period.
Filtration Cycle
30min/cycle
(Filt AS/BW + FL)/cycle
20 - 60 min
AS/BW
Duration
1 min
Backwas
h flow
rate
3m
3
/hr/module
Backwash flow rate = 0.5 to 1.5 times the permeate flux
Minimum flow rate (m
3
/hr/ module)
UNA-600A
UNA-660A
UNA-620A
1.0
1.6
2.0
Flow rate limit for backwash: 8m3/hr
Dependent on operating parameters
Air flow
rate
5Nm
3
/hr/module
FL
30 sec.
30 - 60 sec.
Required
amount
23
~
45L/ module
UNA-600A
UNA-660A
UNA-620A
Required
amount (L)
23
30
45
FL flow
rate
1.5
~
6.0 m
3
/hr/ module
FL flow rate (m
3
/hr/ module)
FL duration
(sec)
UNA-600A
UNA-660A
UNA-620A
30
3.0
4.0
6.0
60
1.5
2.0
3.0
Temperature
< 40°C
pH Range
1 - 10
For the maximum concentrations of cleaning agents,
see Section 9.1.1 "Cleaning Agent Concentration".
Filtration
Simultaneous air scrubbing and reverse filtration (AS/BW)
Flushing (FL)