BIO-CEL® EASY | USER MANUAL
MANN+HUMMEL Water & Fluid Solutions | REVISION DATE: 09/06/2021
4Process Description
4.1
MECHANICAL PRE-TREATMENT OF WASTEWATER
The selection of an appropriate pre-treatment process is essential for the efficient operation of the downstream processes in any
wastewater treatment plant. For MBRs, the pre-treatment process is essential as certain materials may exacerbate fouling/ragging
or even cause damage to the membrane.
The fine screening is the most critical component in the MBR pre-treatment process. The fine screens must be selected, designed,
installed, operated, and maintained properly to ensure sufficient protection of membranes over the life of the membranes. It is
important to test and verify the performance of the fine screening system for both hydraulic performance and removal efficiency
to ensure they meet design specifications.
The fine screening requirements for the BIO-CEL®EASY are as follows:
•Minimum: screens with ≤2 mm (0.08 inches) round-hole openings.
•The screen design, installation, and operation must not allow overflow or bypass of unscreened wastewater to the MBR
system in any circumstances.
The screening requirements for industrial applications may be different from those for municipal applications depending on the
nature of solids in the wastewater and what needs to be removed prior to the membranes.
4.2
BIOLOGICAL PROCESSES
The most common biological configurations before the membrane filtration step are as follows:
In any biological configuration, the membranes should always filter mixed liquor from aerobic bioreactors. The mixed liquor is then
recirculated and returned from the membrane tank or from the aerobic tank back to the other zones depending on overall process
configurations. From the membrane point of view, however, the design considerations are always related to aerobic bioreactors.
The performance of systems using BIO-CEL EASY depends on the whole process including pre-treatment, biological treatment
process and mixed liquor quality. The mixed liquor filtered by the systems using BIO-CEL EASY must meet the quality
requirements listed in table 5. This list is intended for municipal wastewater treatment and additional criteria may be required for
other applications. The specific effluent quality requirements may also require additional mixed liquor qualities that are not listed
here. MANN+HUMMEL WFS should be consulted for specific cases.
A effective pre-treatment and biological treatment are the requirements for a well working filtration. In addition sludge filterability
testing may be used for monitoring the condition of sludge. Poor filterability may indicate high fouling potential and may lead to
low filtration performance. A detailed description of sludge filterability monitoring parameters is provided in Table 5.
Overview of biological configurations
