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11.6.2
Chemical cleaning
Chemical cleaning dissolves biological clogging (fouling) and mineral deposits (such as lime) trapped
inside of the hollow fibres. Chemical cleaning is done only if the flow is extremely reduced.
Intensive chemical cleaning of the membrane cartridge may be done in two ways:
In-Situ, directly in the bio reactor
External in a separate cleaning container
The main differences of the two cleaning possibilities are:
In-Situ cleaning
External cleaning
Cleaning time
1 hrs
12 - 24 hrs.
Cleaning result
(grey water application)
Depends on the state of the
membrane
up to 1.5 l/min
Independents of the state of the
membrane up to 2.0 l/min
Required accessories
Bracket and connection hose
separate cleaning container,
container size depends on the number of
membranes on the Membrane Station
11.6.2.1 In-Situ cleaning in the bioreactor
Description:
The Membrane Station remains in the bio reactor. For each membrane 2 litres of cleaning fluid are
poured into the back flush tank. With an automatic cleaning process controlled by the control unit the
membranes are cleaned for one hour. After the flushing with clear water the cleaning process is finished.
Note:
Throughout the chemical cleaning cycle the growth bodies can remain in the tank, the amount of
chlorine used does not affect the bacteria on the growth media, it removes only the biological
accumulations in the membrane. However, it is important that the amount of chlorine used shall not be
higher than directed.
