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
Bill
Mitch
is
a
Professor
in
the
Department
of
Civil
and
Environmental Engineering
at
Stanford
University.
His
research
focuses
on
environmental organic
chemistry,
with
particular
interests
in
contaminant
removal
within treatment
trains
for
the
potable
reuse
of
municipal
wastewater,
advanced oxidation
processes,
reactions
of
disinfectants,
and
seawater
photochemistry. He
obtained
a
BA
in
Archaeology
from
Harvard
University
and
MS
and
PhD degrees
in Civil
and
Environmental
Engineering
from
the
University
of California
at
Berkeley.
He
received
the
2004
Outstanding
Doctoral Dissertation
Award
from
the
Association
of
Environmental
Engineering
and Science
Professors
and
Parsons
Engineering,
and
a
NSF
Career
Award
in
2007. He
served
as
the
Chair
of
the
2017
Disinfection
Byproducts
Gordon
Conference. He
has
served
on
the
EPA’s
Scientific
Advisory
Panel’s
Drinking
Water Committee.
He
holds
a
PE license
in
California.