As
part
of
the
Water
Institute's
WaterTalks
lecture
series, William
A.
Mitch,
Department
of
Civil
and
Environmental
Engineering,
Stanford
University,
Palo
Alto,
CA,
USA,
will
present:
Challenges
and
opportunities
for
moving
from
the
linear
to
the
circular
water
cycle.
This
event
will
be
offered
in
person
on
the
University
of
Waterloo
campus
in
DC
1302
from
11:30
a.m.
-
12:30
p.m.
As indicated by its name, “wastewater” has traditionally been considered a waste, with the development of safe methods for its disposal to surface waters being the primary focus of research. The increasing frequency of droughts in arid regions has necessitated the identification of novel water sources. Utilities have recognized that wastewater provides a local, reliable supply of water that can be more cost-effective than importing additional pristine water supplies or seawater desalination. In addition to water, utilities are increasingly viewing wastewater as a resource from which nutrients, energy, and even information could be recovered. In place of the “once-through” conventional model of wastewater treatment for disposal to surface waters, utilities are developing a circular model enabling recovery of these vital resources.
A key challenge has been the development of advanced treatment process trains that produce a quality of water of sufficient quality for potable reuse. This presentation summarizes some of the process trains used and the metrics developed to evaluate water quality. Conventional, linear wastewater systems expend significant energy to degrade nutrients prior to disposal to surface water, while significant energy is expended for the industrial production of nutrients for agriculture. This presentation will provide some discussion of efforts to recovery nutrients from wastewater, including how the treatment trains being developed to extract water for potable reuse can facilitate nutrient recovery. The aeration required to deliver the oxygen for aerobic wastewater treatment systems consumes significant amounts of energy. This presentation discusses novel treatment trains that rely on anaerobic bacteria. In addition to avoiding the energy expense associated with aeration, fermentation of the dissolved organics by anaerobic bacteria produces methane that can be harvested for energy production. The presentation ends with some of the key challenges associated with integrating the different treatment chains associated with these different objectives as well as challenges related to decentralized systems for the resource recovery from wastewater.
Speaker bio
The University of Waterloo is committed to achieving barrier-free accessibility for persons with disabilities who are visiting, studying or working at Waterloo. If you have questions concerning access or wish to request accommodations for this event, please contact Julie Grant (j26grant@uwaterloo.ca)