March 2, 2010
Asahi Kasei Chemicals Corp.

New Microza™ submerged membrane module for high-turbidity feed water
- Up to 30% higher flux than with previous modules -
Asahi Kasei Chemicals has launched a new high-flux submerged membrane module, the Microza™ UHS-620A, to further expand sales in regions with high-turbidity feed water, most notably in Asia, and in new applications including recovery of backwash water from sand filters.

With the addition of this new submerged membrane module to its Microza™ product lineup centered on pressurized membrane modules, Asahi Kasei Chemicals is aiming to achieve the world's leading share of the market for separation membranes for water treatment applications.
  Separation membranes for water treatment are produced in two basic module configurations - pressurized membrane modules compatible with low-turbidity feed water, and submerged membrane modules compatible with high-turbidity feed water. Adoption of membrane filtration systems has been most prevalent in low-turbidity applications. With its Microza™ pressurized membrane modules for use with relatively clear feed water used at over 600 waterworks facilities worldwide, Asahi Kasei Chemicals is one of the world's top-tier suppliers.

While filtration systems based on submerged membrane modules are suitable for use with high-turbidity feed water, they have generally been less economical than conventional water treatment systems based on coagulation, sedimentation, and sand filtration. Asahi Kasei Chemicals launched its first submerged membrane module in 2005 and, although adoption has been limited, sales have steadily grown with proven superiority over competing products in many aspects of performance.

The high bonding network structure of the polyvinylidene fluoride (PVDF) hollow-fiber membrane was modified to endow the new submerged membrane module with high flux for greater economy in installation and operation. The new module is thus well suited for use in regions of Asia which have high-turbidity feed water and in new applications such as recovery of backwash water from sand filters, enabling increased share in growing markets and facilitating a further expansion of the market for membrane filtration systems.
Features of Microza™ UHS-620A high-flux submerged membrane module
  • Excellent stability in filtration of feed water with high-turbidity or with wide variation in turbidity.
  • A 20-30% increase in flux compared to our previous product together with pore size reduction to 0.08 µm, by modifying the high bonding network structure of the PVDF hollow-fiber membrane.
  • Small space requirement - roughly half that of our pressurized membrane units - enabled by proprietary design for modules with high packing density and space-efficient rack configuration.
  • Greater tolerance to high turbidity enables reduced frequency and volume of wastewater disposal from backwashing, for a higher rate of feed water utilization and lower disposal costs (95-99% recovery rate, 4-5% higher than with our pressurized membrane modules).
Sales outlook
  Marketing of the new module will focus on waterworks facilities in Asia where adoption of membrane-filtration systems was limited due to the high turbidity of feed water, and on new applications such as recovery of backwash water from sand filters. Orders for the new module have been received at facilities in China, and work is advancing toward adoption at several large water-treatment facilities with capacity exceeding 10,000 m3/day in Korea and other Asian countries.
Reference information
Pressurized and submerged membrane modules:
  Features of pressurized membrane modules include excellent flux with low-turbidity feed water and ease of handling. Submerged membrane modules provide excellent stability in filtration of feed water with high turbidity and highly variable water quality, and feature smaller installation space requirement than pressurized membrane modules.
Pressurized membrane modules   Submerged membrane modules
Pressurized membrane modules   Submerged membrane modules
Recent notable orders received for Microza™ submerged membrane modules:
Country Capacity
Start-up Use
Japan 1,400 2007 Industrial water treatment
China 10,350 2007 Gray water recovery
Japan 4,000 2008 Industrial wastewater treatment
China 10,800 2008 Industrial wastewater recovery
China 16,300 2009 Industrial wastewater recovery
Sri Lanka 6,500 2009 Drinking water
Korea 2,500 2009 Industrial water treatment
China 20,000 2010 Municipal wastewater recovery
China 7,200 2010 Gray water recovery*
China 6,500 2010 Industrial wastewater recovery*
  * UHS-620A modules.


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