Resource recovery from
wastewater through
advanced biorecycling
technologies
Society of Environmental Journalists
22nd Annual Meeting
Oct. 17-22, 2012
Lubbock, TX
Daniel Yeh, PhD, PE,
LEED AP
Associate Professor
Ana Lucia Prieto, PhD
Postdoctoral Researcher, Colorado School of Mines
Department of Civil and Environmental Engineering
University of South Florida, Tampa, FL, USA
Acknowledgement
• Craig Criddle (Stanford University)
– A constant source of knowledge and inspiration from whom I
have learned much about wastewater treatment and sustainable
water reuse via anaerobic processes
• Ana Lucia Prieto, PhD
– Postdoctoral Researcher, Colorado School of Mines
• Other Contributors:
–
–
–
–
Robert Bair, USF
Ivy Drexler, USF
Onur Ozcan, USF
Jim Mihelcic, USF
D. Yeh
- Piet Lens, UNESCO-IHE
- Harry Futselaar, Pentair
- Jeremy Guest, UIUC
FOX 13 video
• http://www.myfoxtampabay.com/story/186125
77/could-a-new-energy-source-start-righthere
D. Yeh
“Waste”
Water
For typical household wastewater (USA)
SS ~ 232 mg/L
BOD5 ~ 420 mg/L
COD ~ 849 mg/L
TOC ~ 184 mg/L
Nitrogen ~ 57 mg TKN/L
Phosphorous ~ 10 mg P/L
Soluble and particulate org. matter(
WERF onsite WW report)
D. Yeh
From 7 billion people, that
is a lot of potential
pollution, a lot of COD,
and a lot of potential
methane emission as
well as energy recovery
opportunities
The importance of technology for
clean water
UN World Water
Development Report 2
Conventional WWT in US
How do we clean our wastewater?
Trace
chemicals,
VOCs
Energy:
CO2
H2 S
CH4
Pumping
Mixing
Aeration
Disinfection
Heat for digester
Chem transportation
Clean Water
Chemicals:
Flocculation
Precipitation
Disinfection
Labor:
O&M
Unrecoverable
waste residuals
D. Yeh
Recovery of water
• Direct or indirect reuse for agriculture
• Potable water offset
• Sewer mining
•
•
•
•
•
•
•
Secondary treatment
Soil aquifer treatment (SAT)
Tertiary treatment
Membrane effluent filtration
MBR(+AOP)
MBR+RO (+AOP)
Need some sort of infrastructure for delivery of recovered water to
customers, depending on use
D. Yeh
How do we clean our wastewater?
Trace
chemicals,
CO2
VOCs
Energy:
H2 S
CH4
Pumping
Mixing
Aeration
Disinfection
Heat for digester
Chem transportation
Clean water
Chemicals:
Bioproducts
Flocculation
Precipitation
Disinfection
Labor:
Biosolids, Nutrients,
biopolymers
Unrecoverable
waste residuals
O&M
D. Yeh
A more sustainable approach
Recovery of nutrients
 Nitrogen, phosphorus, potassium
 Struvite and other precipitates
 Biosolids
 Bio-P phosphorus recovery
 Crop growth / Algae
 Liquid fertilizer
D. Yeh
How do we clean our wastewater?
Trace CO2
chemicals, H2S
VOCs
CH4
Energy
Energy
Clean water
Chemicals
Labor
Bioproducts
Biosolids, Nutrients,
biopolymers
Unrecoverable
waste residuals
D. Yeh
An even more sustainable approach
Wastewater as a
renewable resource
A paradigm shift is underway!
http://www.sustainlane.com/reviews/getting-the-most-fromhuman-waste/ICF8A2T14UAQ9HTV27Q8VLQXRTOI
Graphics: Jeremy Guest
D. Yeh
Energy potential in wastewater
Waste
Reservoirs
organic =
of energy
matter
View chemical oxygen demand (COD) as energy
potential, rather than pollution
The choices lie in how we recover this potential energy
Further, how sustainable are the choices?
D. Yeh
Can WWT be energy neutral?
• Can WWTP be energy neutral, or even energy
surplus to export energy to the grid?
0.3 kWh/m3 consumed for
WWT (Nouri et al 2007)
0.44 kWh/m3 potential from
waste organic matter (assume
harvesting 25% of max potential
at 1.74 kWh/m3)
D. Yeh
Excess energy
for export???
Example, small
(20,000 p.e.)
WWTP in Czech
Republic generate
AD biogas to heat
nearby homes
So, how do we extract
this energy from
wastewater?
D. Yeh
The Carbon Cycle
Aerobic – “with oxygen”
Anaerobic – “without oxygen”
D. Yeh
Energy states of carbon
all about biorecycling
Reduction (gaining e- )
Anaerobic
digestion
Fully
reduced
(-4)
Photo
synthesis
CH4
(CH2O)n
methane
Org C (biomass)
CO2
Fully
oxidized
Carbon dioxide
(+4)
Combustion, respiration
Oxidation (losing e- )
Methane
biomass
Carbon dioxide
Energy
rich
moderate
none
Redox state
-4
In between
+4
Typically 1-3 g OD/g
zero
D. Yeh
COD (energy)
4 g OD/g (180.4 Wh /g)
The anaerobic
MBR (AnMBR)
at Univ. South Florida
AD + UF membrane
D. Yeh
N, P recovery for reuse
(fertigation)
A
95% N
recovered
(cumulative)
B
93% P
recovered
(cumulative)
D. Yeh
Prieto et al, 2012
NEWgenerator TM
Potential to contribute on:
Sanitation
Water
Energy
Food
Health
Gender
Economics
Empowerment
D. Yeh
From Cormier 2010
Synergy of Algae and Wastewater
Requires
O2
Produces
CO2
Contains
Nutrients
Requires
Energy
D. Yeh
Produces
O2
Requires
CO2
Requires
Nutrients
Harnesses
Energy
Isolated Cultivation of Algal Resources
from Sewage (ICARUS)
D. Yeh
…perhaps in a not-too-distant future?
D. Yeh
Graphics: Ana Lucia Prieto
Thank you for your
attention.
Questions?
Prof. Daniel Yeh
dhyeh@usf.edu
USF Membrane Biotechnology Lab
http://mbr.eng.usf.edu/
D. Yeh
D. Yeh
Energy recovery from wastewater
Energy:
Pumping
Mixing
Aeration
Disinfection
Heat for digester
Chem transp.
Reduced WW
organic matter
• CH4 and H2 (anaerobic
digestion)
• Electricity and H2
(Microbial fuel cells)
•Biosolids for
combustion
•Also, algae biofuel
Electron donors
(energy reservoirs)
Figure from: Howard F. Curren WWTP post-aeration basin
(www.tampagov.net/dept_wastewater/information_resources/Advanced_Wastewater_Treatment_Plant)
D. Yeh