NIRE-170-1-6
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4. Daily Inspection
The above section VII 2 lists operating parameters that should be monitored.
Daily
recording of the values associated with these parameters will be helpful in
determining the current condition of the MBR system. Operational data should be
analyzed daily to serve as a guide for preventative maintenance.
Take action to correct
any unfavorable operational trends before more serious conditions develop. In addition, it is
beneficial to inspect all system components for correct and smooth operation on a weekly
basis.
(1) Diffused air conditions
Check the air flow rate and blower discharge pressure of the air supply line to the MBR air
diffuser. Too low of an air flow rate can result in membrane clogging. Too high of an air flow
rate can result in element damage. Try and keep the air flow rate per module between
recommended ranges. If the recommended air flow rate cannot be achieved, stop filtration
and check the air supply piping for leaks, incorrect valve positions, blower inefficiency or
possible air line restrictions. In the case where multiple MBR modules are located in the
same tank check that diffused air is being evenly distributed between each MBR module. If
uneven air distribution is observed conduct an air diffuser cleaning as described in Section 2,
Chapter VIII.
If the scouring air flow rate drops or becomes extremely irregular or
if air supply is stopped, then immediately stop filtration to prevent
membrane clogging.
(2) Trans-membrane pressure
Check the trans-membrane pressure (TMP) frequently. When the TMP increases by 5 kPa
(50 mbar) at a constant filtrate flow rate, it is time to initiate a membrane element chemical
cleaning. A sudden increase in the trans-membrane pressure suggests that the membrane
surfaces are clogging. Clogging can be caused by abnormal diffused air distribution, too high
flux rate, too high MLSS concentration or deteriorating sludge properties. If TMP values are
increasing, check the MBR operating conditions and the biological condition of the sludge.
Take necessary actions to correct operating conditions and then perform a chemical cleaning
of the elements.
(3) Activated sludge characteristics
The activated sludge of the membrane bioreactor should be self-cohesive and free from odor.
CAUTION
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