Membrane
bioreactors (MBR) with submerged membrane modules have set
the standard for the next generation of biological wastewater
treatment plants as they offer two main advantages; a significantly
improved effluent quality and a substantially smaller footprint.
Besides the huge application in industrial wastewater treatment
there are many municipal applications where MBR technology
is being implemented. An example is the Bega Valley Sewerage
Program (BWSP) in Australia which includes state-of-the-art
MBR plants.
Bega
Valley is located on the southeastern coastline of New South
Wales (about 450 km south of Sydney). It includes the towns
of Cobargo, Wolumla, Kalaru and Candelo. The capacity of
the valley’s
wastewater treatment systems was stretched by urban growth and
by seasonal population increases during the holiday period. Some
unsewered villages in the valley were
at risk for environmental and public health issues caused by
discharge from septic tanks.
In
order to maintain Australia’s
Environment Protection Authority compliance and to enhance environmental
outcomes, the Bega Valley Shire Council developed the Bega Valley
Sewerage Program, which includes the installation of new pressurized
sewage collection systems coupled with MBR treatment plants in
the towns of Cobargo, Wolumla, Kalaru and Candelo. Each plant
has a footprint of approximately 20 x 15 meters. The Cobargo
MBR plant was commissioned in July 2006 and the remaining three
plants were commissioned in 2007.
The entire program is designed to keep capital and operating
costs at a minimum and to produce a very high quality effluent
for reuse. Reclaimed water from the MBR plants will be used
in an irrigation scheme on public facilities, replacing potable
water as the primary source. This paper describes the design
features of the four MBR plants as well as commissioning and
operating results; furthermore, it explains how this design
can be implemented in other rural areas around the world. |
