Hundreds of millions of membrane fibres in Ontario, but who’s counting?
By Brian Sahely, M.A.Sc., P.Eng.
The development of backwashable
low pressure,
hollow core fibre technology
has resulted in membrane
filtration becoming costeffective
for implementation in
water treatment plants (WTPs) in
Ontario since 1998. By the end of
2006, 37 low pressure membrane
filtration plants with a combined
capacity of 409 ML/D will be
installed in Ontario. This equates
to hundreds of millions of membrane
fibres, but who’s counting?
These data are reflected in
Figures 1 and 2, respectively,
which show the cumulative number
and capacity of membrane
water treatment plants each year
since 1998. Membrane plants that
are anticipated to be commissioned
in 2006 are also included in
these figures, which show the
cumulative capacity of membrane
plants expected to more than double
between 2005 and 2006 alone.
By 2006, 73% of the membrane
plants commissioned will have been
designed with capacities less than 10
ML/D, while 49% of the plants commissioned
will have been designed for
capacities less than 3.78 ML/D.
Examples include new facilities in
South Chatham-Kent WTP with
USFilter/Memcor membranes (Figure
3), Petrolia WTP with Pall membranes
(Figure 4) and Port Hope WTP with
Zenon membranes (Figure 5).
So why is the number of membrane
WTPs on the rise in municipalities in
Ontario? A primary factor is that
membranes with nominal pore size of
less than or equal to 0.1 µm pore size are available and proven. This pore size
is less than the size of Giardia cysts
and Cryptosporidium oocysts, resulting
in high log removal credits of these
protozoa using membrane filtration.
This gives municipalities confidence
that membrane technology will meet
current and future regulations, which
are continuously becoming more and
more stringent. With the development
of the membrane integrity test (MIT),
municipalities are also becoming more
confident that the safety of the membrane
system is measurable.
The required number of membrane
modules/elements/cartridges can be
installed now to meet current water
demand, with the ancillary equipment
installed now to meet future water demand at a marginal increase in
capital cost. As additional water
production is needed, either the
membrane flux rates can be
increased upon agreement with the
membrane supplier or additional
membrane modules/elements/cartridges
can be installed without the
need for a general contractor.
The small footprint of membranes
can minimize building costs
and in some cases can allow an
existing water treatment plant to be
retrofitted with membrane technology
to increase water production.
The improved manufacturing of
the membranes and improved
design of the overall system framework
have resulted in a decrease in
the capital and operating costs of
membrane water treatment plants.
This has resulted in the purchase of
large volumes of membranes, which
in effect has resulted in a decrease
in membrane costs.
Figure 3 - USFilter/Memcor CMF M10V Membranes
Figure 4 - Pall Microza USV-6203 Membranes
Figure 5 - Zenon ZeeWeed® 1000 Membranes
All of the above factors will continue
to increase the implementation of
membrane technology in Ontario, with
the cumulative capacity of membrane
water treatment plants in Ontario
expected to double the 2006 capacity
by 2007 and more than triple or possibly
quadruple the 2006 capacity before
2010.
The author would like to thank
USFilter/Memcor, Pall (Canada) Ltd.
and Zenon Environmental Inc. for providing
data for this article.
Brian Sahely is with KMK
Consultants Ltd.,Brampton, Ontario.
Contact: brians@kmk.ca
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