The MBR Book: Principles and Applications of Membrane

200 The MBR Book
BC-400 respectively. The company’s literature indicates a very wide range of airflow
rates (0.15–1 m 3 /h airflow m 2 membrane, depending on module size) and TMP values
(0.03–0.3 bar) without providing a target flux rate.
There are also a number of other German MBR products developed for niche
applications (ZEK, 2004). These include that developed by A3 (Abfall-Abwasser-
Anlagentechnik GmbH). A3 provide an FS membrane and have had a textile wastewater
treatment reference site since 2000. A3 also appear to have interests in
the ship industry, a market sector for which MBRs provide a key candidate technology
for wastewater treatment and, ultimately, recycling. Another company, ATB
Umwelttechnologien GmbH – also in the North Rhine-Westphalian region – have
produced a single house-scale MBR, sized for 4–16 population equivalent (p.e.). This
product also appears to be based on FS membranes, and would appear to be similar
in concept to the more established BusseMF system. This technology, originally commercialised
in 1997, comprises a two-stage sedimentation � FS MBR process,
apparently employing Kubota membranes, and is available for 4 and 8 p.e. As of
December 2005 there are over 200 such units installed in Germany alone, with perhaps
another 30 installed across Europe.
Finally, worthy of a mention is the earliest commercially established anaerobic
MBR. The anaerobic digester ultrafiltration (ADUF) process is based on sidestream
treatment and was commercialised in the early 1990s in South Africa following successful
demonstration based on 0.05–3.0 m 3 reactors. The process is used to treat
industrial wastewaters with high COD concentrations (3.5–37 kg/m 3 ), achieving
removals generally �90% depending on the biodegradability of the organic matter.
A 3 m long, 12 mm diameter MT PES UF module, the membrane pore size typically
being 0.10 �m, is employed with flow paths of over 60 m (i.e. �20 modules). MLSS
levels of 10–50 g/L are used, coupled with high crossflow velocities to maintain
fluxes above 50 LMH. As with aerobic processes, the permeate produced is of a
consistently high quality with regard to particulate material, bacteria and viruses.
Whilst this process achieved some technical success and was licensed to Bioscan in
Denmark in the mid-1990s, it has not achieved the commercial success of the
Figure 4.47 The Microdyn-Nadir module