Figure 1: Illustration of different ways that water can be reused and recycled.
however, provided a sound solution
and the people are now able to access
water through an installed water
treatment plant, he explains.
Braybrooke describes that during a
previous drought in Mossel Bay, while
a desalination plant was being built,
through reusing wastewater, Veolia
produced 5Mℓ/d of industrial water for
PetroSA in a very short period.
“We feel strongly that wastewater
is being underutilised, specifically in
major cities. We believe that to mitigate
the effects of the drought, one of the
fastest reactions is to go the water
reuse route.” The problem is, he points
out, that there is no one in government
prepared to take this subject on. “We
need someone in government to
endorse this method,” he urges.
“We believe that to
mitigate the effects of
the drought, one of the
fasted reactions is to go
the water reuse route.”
Chris Braybrooke – Veolia
Braybrooke highlights that there are
different models, including treating
the water and discharging it into the
distribution lines to users or, to treat
it and then feed it into a raw water
resource and treat it again. The problem
with the latter is that ‘double treating’
the water is a costlier process, which
will then be passed on to the consumer.
26
“The technologies are there and Veolia
is not the only company capable of
doing this,” he says.
The upside of this technology is
that it teaches people to be water-wise
and to cut back on consumption, he
says, while educating people that even
wastewater is a resource “and not just
something to be dumped”.
Water-wise
Braybrooke believes that public
participation is needed around
creating awareness of water reuse.
He also says that there needs to be a
balance between pushing industry to
be water conscious. “To achieve zero
liquid discharge in industrial plants
like Sasol and Mittal, for example, is
environmentally acceptable, but why
not add another step in the process and
provide potable water too?” In addition,
the equipment used to do this is not
high-energy dependent, he assures,
unlike desalination processes.
Water reuse could also significantly
benefit the agricultural sector, a major
water user. One example of modernising
plants is to replace the stone-based
biological reactors’ growth media with
lamella packing. In Walvis Bay, to boost
the town’s sewage treatment capacity,
Veolia has upgraded the local treatment
works. The project focused on replacing
the existing stone-media in the biofilter
to trickling filter technology. In this way,
the capacity has been doubled by using
the existing infrastructure.
“There are many boxes Veolia
can tick regarding the upgrading of
existing plants, and utilising the latest
Water Sewage & Effluent September/October 2017