Transcript Wastewater Treatment: MFCs

Dual
Green
Water
RoofsSystem
UV
Nano
Ultra
Micro
0.001μ
0.01μ
0.1μ
UV
Coarse
1.0μ
MicroFiltration
• Rooftop planted beds absorb rainwater
Create
a cycle
of reuse to diminish total water
– •Reduce
pollutants
in water
• Grey
water
treated
with microfiltration
demand;
minimize
– Decrease
stormwater
runoffadvanced drinking water
and
UV indisinfection
– Diminish
water
treatment systems
treatment
flow
• Decrease urban heat island effect by
• Reused
inproduced
toilets, landscaping,
other
• Grey
waterof
from showers,
washing
increasing
albedo
the urban landscape
outdoor dishwashers,
uses
machines,
cooking, etc.
• Reduce
air pollutants
• Increase energy efficiency of building
• Underground cisterns store grey water
• Lengthen lifespan of the roof
Wastewater Treatment: MFCs
Pretreatment
Clarifier
MFCs
• Pretreatment = physically remove
solids
• Microbial fuel cells (MFCs) replace
anoxic & aerobic reactors
• Anode
– Anaerobic bacteria in anode
– Wastewater feeds the bacteria
– Oxidize organic material  e- flow
to electrode
• Cathode
– O2, e-, & H+ combine  clean
water
– Power generated as current flows
• Clarifier or membrane separates and
returns biomass
Effluent
Anode
R
Air
Cathode
+
Anode
Wastewater
Based on design of Dr. Bruce Logan
-
i
Wastewater Treatment: MFCs
Pretreatment
MFCs
Clarifier
• Remove up to 80% of organic matter
• Self-sufficient wastewater treatment plant
• Likely there will be a surplus of energy
Three Power Projections for the City of Chicago
Based on Different Parameters of MFCs
Dr. Bruce Logan's goal of
1W/m2
434 MW
Naval Research Lab estimate
of 500W/m3
145 MW
Wastewater influent estimate
of 0.5 kJ/g COD
251 MW
Wastewater Treatment: Hydroponics
Pretreatment
MFCs
Clarifier
• UV disinfection prior to entering
• Plants grow suspended on nets with roots
directly in water
• Plant, invertebrate, and aerobic bacterial
communities perform nutrient uptake
• Located inside greenhouses for winter
operation near the head of each eco-boulevard
• Provides additional green space for city
• Produces valuable crops (vegetables, cut
flowers, etc.)
Wastewater Treatment: Wetlands
UV
Hydroponics
• Designed for worst-case scenario: 100-yr
• storm
Located
along
UrbanLab’s Eco-Boulevards
event
(1hr)
Constructed
surface
flow, benthic
•• Runoff
drains wetland,
directly to
wetlands
net*
• Water level in wetlands rise from baseline
• level
Polish(0.3m)
discharge
to 1 from
meterhydroponics
Benthic Net
Pedestrian
access provided
on raised
•• Decrease
concentration
of nutrients,
nature walkways
through 20 Eco-Boulevards
metals,
and particles
• Wetlands act as an environmental buffer
during storms
*Source: Ishida, et. al., “Microbial Ecology”, 2008, 56:140-152.”
Fuzhou, China
Combined
Sewer
Overflow
Map of
Chicago
After three decades, we’re still
DUMPING IN THE LAKE
By Michael Hawthorne, Tribune reporter4:19 p.m. CDT, March 19, 2011
• Billed as an engineering marvel and national model, Chicago's Deep Tunnel was
designed to protect Lake Michigan from sewage overflows and put an end to
the once-frequent practice of dumping human and industrial waste into local
rivers – 1970 - 2029.
• Nearly 4 decades after one of the nation's most expensive public works
projects (>$3.5B), billions of gallons of bacteria-laden sewage and storm runoff
still routinely pour into the Chicago River and suburban waterways during and
after storms
• Between 2007 and 2010, records show, the agency in charge of Deep Tunnel
dumped nearly 19 billion gallons of storm water teeming with disease-causing
and fish-killing waste into the Great Lake,
the source of drinking water for 7 million
people in Chicago and its suburbs. By
contrast, 12 billion gallons poured out
between 1985 and 2006.
http://www.chicagotribune.com/health/ct-met-0320-deep-tunnelproblems-20110319,0,1283119.story