Page 410 - Industrial Wastewater Treatment, Recycling and Reuse

382 Industrial Wastewater Treatment, Recycling, and Reuse

Table 9.3 Specifications of Aqua EMBR membrane module
Parameters Figures and Description

Membrane type Flat polymeric membranes
Module dimensions 290 290 4500 mm (L W H)
Total membrane surface area 42 m 2
Operating mode Side stream (cross flow)
Material of construction FRP
Module mounting Vertical
Type of diffuser for air scouring Pipe diffuser

membrane cartridges are inserted into a housing to make a membrane
module. The membrane module has top and bottom end caps for recircula-
tion of sludge (MLSS). Recirculation occurs on the outside of the membrane
system. The product emerges from individual cartridges and is collected in a
common product header. The module is placed outside the bioreactor and
operated with the requisite velocity of air and MLSS. The velocity of MLSS
varies from 0.5 to 1.0 m/s and depends on the characteristics of the sludge
formed. Air is provided from the bottom end cap to scrub the membrane
surface. Aqua EMBR is most suitable for treatment of critical and various
industrial wastewaters because it is more robust and can be operated at high
velocity, which helps to sustain flux values, even with difficult-to-treat
industrial wastewater. Table 9.3 shows the specifications of the Aqua EMBR
membrane module. Overall, Aqua EMBR is an external MBR system with a
UF flat plate membrane with airlift arrangements. Thus it combines the
advantages of a flat plate member and external side stream MBR.

9.6.1.1 Design of Aqua EMBR System
The Aqua EMBR design has been tested on the laboratory scale for several
years to see consistency in membrane performance before testing it with
actual wastewater. Flat plate membranes are used in making the MBR mod-
ule, which is developed with PVDF as a base polymer (PVDF – Polyviny-
lidene difluoride). PVDF has outstanding oxidative, thermal, and hydrolytic
stability, as well as good mechanical and film-forming properties. The mem-
brane is supported by polypropylene fabric for better mechanical strength
and has been extensively tested to have uniformity in filterable pores. It is
tested separately for consistent pore distribution throughout the membrane.
A cross-sectional view of the membrane shows a finger-like structure
(Figure 9.6). A uniform and narrow pore size within the membrane surface