WC138 SeptOct 2024 - Flipbook - Page 17
But with eDNA analysis, you can get a much faster and
more accurate look at all the species present. Hallam and Ziels
have identified which species are present when foaming occurs
and which are present when there is nitrogen and phosphorus
removal, building a knowledge base for technicians to make the
overall microbial community stronger.
The speed and ease of use of eDNA also means that water
plant staff can be proactive, finding out if there’s a problematic
community forming and taking preventative measures before
foaming gets out of hand. This could include spraying small
amounts of foam with chlorine. “We discovered, however, that
the spray does not work for all foam-making bacteria,” said
Ziels, “and that there are also chlorine-resistant bacteria present
in plants that consume different compounds and physically live
in different niches.”
Seeing the system
A water or wastewater treatment plant is a complex mix of
bacterial communities that changes at each treatment stage,
explained Ziels. There have been estimates
from around the world that there could be
up to a billion species in a water plant.
“The best approach is to look at wastewater treatment
“Some bacteria die right away, some
grow, some just float through and do not
environments as what they are: engineered ecosystems.”
affect anything, some cause problems,” said
Ziels. “Some species depend on other sets of
organisms to thrive, and others are independent.” Time of year is also a factor. During the winter for exCurrent and future work
ample, plants might see proliferation in foam-causing organisms
Hallam and Ziels are very pleased to have a proof of concept
or a loss in nitrogen-degrading organisms.
complete for the use of eDNA in water plants for the treatment
As Hallam explained, the best approach is to look at wasteof BFB and more.
water treatment environments as what they are: engineered
“The reporting has wrapped up and now we will continue
ecosystems. “All the species present in a bacterial community
to build on what we’ve developed,” said Ziels. “The Genome
play a role in how these systems function, and how communities
BC project has enabled us to create the basic platform and now
shift affects the treatment process,” he said. “There are many
we need to determine the best way it can be adopted by plant
species and types of species, and that’s where eDNA shines. It
operators. From the outset, our aim was to create open source,
allows not just an initial look at a population, but we can take
low-cost protocols that any municipality can adopt, even those
DNA snapshots across time to track how the populations change
with fewer resources.” The scientists are also transitioning the
and test different treatment protocols and changes in a plant that
eDNA sampling tool to an affordable handheld device that costs
improve the treatment process.”
about $1,300.
In terms of how it might work at different plants, samples
Starting the research
taken at large plants such as those in Metro Vancouver could
Before they could look at BFB and other issues in depth, Hallam
be analyzed at on-site labs with the purchase of DNA analysis
and Ziels first needed to develop a reliable testing framework. To
equipment. Samples taken at smaller plants in Canada without
do so, they honed the required sampling and processing techlabs could also be processed onsite or sent away to testing facilities.
niques at the two wastewater treatment plants in Kelowna, B.C.
“The key is standardization,” said Hallam. “Municipalities could
(Note that these plants, which have different configuration and
also talk to their service partners that do a lot of sampling and
treatment protocols, were also a great research opportunity in
monitoring about how this new data collection can be integrated.”
that one had better nitrogen removal than the other. Hallam and
Hallam and Ziels are also very excited about opportunities to
Ziels were able to determine the different bacterial communities
develop a more holistic approach to wastewater treatment across
that were present and some of the reasons why these species were
a region, province or even the entire country.
thriving.)
“There are various ways that data could be aggregated and
Once the testing framework was in place, Hallam and Ziels
compared and monitored at different scales,” said Hallam. “This
discovered the different species that cause bulking and foaming
is similar to what is done in epidemiology, where everyone learns
— and over time, determined whether the organism causing
from what has happened in one or a few situations. It’s like
current foaming was the same one that had caused it in the past.
self-driving cars where they are all learning together. We can also
With this kind of information, plant managers apply what they
use the data for modelling. In addition, it will someday enable
previously learned to achieve similar or better success in the presus to better design water and wastewater plants because we will
ent. They can also share their insights about mitigation strategies
have a solid underlying understanding of plant microbe populawith colleagues at other plants.
tions and how they act. There are exciting times ahead.”
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