NIRE-170-1-6
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(4)
Do not use seeding agents.
(5)
Do not use silicone-based anti-foaming agent which may cause choking of
membrane pores.
Prior to introduction of any seeding sludge into the membrane tank
pass all sludge through a 3 mm or less mesh screen device.
3. Actual Filtration Operation
After successfully seeding the sludge within the membrane tank, start the air supply to the
diffusers, start sludge circulation, activate the filtration process and the raw wastewater feed.
Pay particular attention to the following operational parameters:
(1)
The condition of the seeded activated sludge may not be optimal for membrane
filtration until such time the food to microorganism ratio (F/M) has been optimized.
To avoid fouling the membrane elements while the activated sludge is evolving,
operate the MBR well below the designed flux rate. This is especially important
until the activated sludge MLSS concentration approaches 7,000 mg/L.
Gradually
increase the flux rate as the condition of the activate sludge improves.
(2)
At the initial operation of suction pump, priming (filling the suction piping with
water) may be needed for proper pump suction and in that case avoid
pressurizing the filtrate side of "NHP210
Series” over 10kPa.
(3)
Sludge parameters such as MLSS and sludge filterability (see (11) in the page 39)
should be checked frequently to assess the actual sludge condition.
(4)
Check the air diffuser cleaning procedure and associated automated valves for
proper operation. Details for the procedure are given in the chapter VIII.
(5)
Once the filtrate water flow has stabilized, please measure and record the
trans-membrane pressure and the liquid temperature. Details for operation control
are given in the next chapter.
The air scour should be stopped when the filtration process is
suspended. There are two exceptions:
1) During the normal relaxation period.
2) When the activated sludge requires air for normal metabolic
processes. However, under these conditions the amount of air flow
directed to the diffuser should be reduced to just the amount
required to maintain sludge viability.
Avoid pressurizing the filtrate side of "NHP210 Series
” over 10kPa.
CAUTION
!
CAUTION
!
CAUTION
!