NIRE-170-1-6
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following: level control devices, level control circuits, filtrate pump VFD controls, activated
sludge feed control valve, membrane flux rate. Take corrective action as necessary.
(9) Sludge viscosity
It is recommended that the sludge be no higher than 100 mPa.s (measured by B-type
viscometer) or 250 mPa.s (measured by C-type viscometer). If the sludge viscosity is too
high, check MBR operating conditions and biological conditions, such as F/M ratio, and take
necessary corrective actions.
(10)
Sludge filterability
Paper filtration method is a simple and reliable method to determine the filtration properties
of the sludge. See the method described in the attached document. Toray recommends
conducting paper filtration test and measurement of TOC and/or turbidity of filtered water
routinely. In the case an abrupt decrease in filterability is recorded and/or increase in
TOC/turbidity, check the operating and biological conditions, and take appropriate action
based on those findings.
(11) Pretreatment system
In addition to
the operating parameters for the “NHP210 Series”, check the status of the
pretreatment systems (particularly the screening device) frequently. At regular intervals
remove any accumulated trash that may accumulate on the screening device.
