Therefore, treatment pro-cesses that are reliable, cost efficient and effective in removing a
wide range of pollutants are required. One very promising technology
involves the utilization of membrane bioreactor (MBRs). There are
numerous successful pilot scale studies; some full scale units are in
use in various parts of the world. For instance, the fi rst large installa-tion was in the United States, with a full scale external membrane
MBR system for industrial wastewater treatment at the General Mo-tors Plant in Mansfield, Ohio in early 1990s [1] . In 1998, the fi rst
large scale internal membrane MBR system for the treatment of in-dustrial food ingredients wastewater was installed in North America
[2] . According to the global market for MBR, the growth rate is over
10% annually due to the ability of MBR which is amazingly effective
in removing the contaminants and in some cases, MBR is ideal for
wastewater reuse applications [3]. There are more than 2200 MBR in-stallations in operations or under construction worldwide and most
of them are for municipal wastewater treatment. In North America,
11% of the installation of MBR worldwide and Zenon are larger instal-lations as compared with Kubota and Mitsubishi. In Asian market for
MBR, especially Japan and South Korea, the small scale for domestic
wastewater is applied