1. Resource recovery from wastewater through advanced biorecycling technologies
Society of Environmental Journalists
22nd Annual Meeting
Oct , 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

2. 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 - Piet Lens, UNESCO-IHE
Ivy Drexler, USF - Harry Futselaar, Pentair
Onur Ozcan, USF - Jeremy Guest, UIUC
Jim Mihelcic, USF

3. FOX 13 video

4. “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)
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

5. The importance of technology for clean water
UN World Water Development Report 2

6. Conventional WWT in US

7. How do we clean our wastewater?
Trace chemicals,
VOCs
CO2
CH4
H2S
Energy:
Pumping
Mixing
Aeration
Disinfection
Heat for digester
Chem transportation
Chemicals:
Flocculation
Precipitation
Labor:
O&M
Clean Water
Unrecoverable waste residuals

8. 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

9. How do we clean our wastewater?
Trace chemicals,
VOCs
CO2
CH4
H2S
Energy:
Pumping
Mixing
Aeration
Disinfection
Heat for digester
Chem transportation
Chemicals:
Flocculation
Precipitation
Labor:
O&M
Clean water
Bioproducts
Biosolids, Nutrients, biopolymers
Energy?
Unrecoverable waste residuals
A more sustainable approach

10. Recovery of nutrients Nitrogen, phosphorus, potassium
Struvite and other precipitates
Biosolids
Bio-P phosphorus recovery
Crop growth / Algae
Liquid fertilizer

11. How do we clean our wastewater?
Clean water
Bioproducts
Biosolids, Nutrients, biopolymers
Unrecoverable waste residuals
Energy?
Trace chemicals,
VOCs
CO2
CH4
H2S
Energy
Energy
Chemicals
Labor
An even more sustainable approach

12. Wastewater as a renewable resource
A paradigm shift is underway!
Graphics: Jeremy Guest

13. Energy potential in wastewater
Waste organic = matter
Reservoirs of energy
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?

14. 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)
Excess energy for export???
0.44 kWh/m3 potential from waste organic matter (assume harvesting 25% of max potential at 1.74 kWh/m3)
Example, small (20,000 p.e.) WWTP in Czech Republic generate AD biogas to heat nearby homes

15. So, how do we extract this energy from wastewater?

16. The Carbon Cycle
Aerobic – “with oxygen”
Anaerobic – “without oxygen”

17. Energy states of carbon all about biorecycling
Reduction (gaining e- )
Anaerobic digestion
Photo
synthesis
CH4
(CH2O)n
CO2
Fully
oxidized
Fully
reduced
methane
Org C (biomass)
Carbon dioxide
(+4)
(-4)
Combustion, respiration
Oxidation (losing e- )
Methane
biomass
Carbon dioxide
Energy
rich
moderate
none
Redox state -4
In between +4
COD (energy)
4 g OD/g (180.4 Wh /g)
Typically 1-3 g OD/g
zero

18. The anaerobic MBR (AnMBR) at Univ. South Florida
AD + UF membrane

19. N, P recovery for reuse (fertigation)B
95% N recovered (cumulative)
93% P recovered (cumulative)
Prieto et al, 2012

20. NEWgenerator TM Potential to contribute on: Sanitation Water
Energy Food
Health Gender
Economics Empowerment

21. Synergy of Algae and Wastewater
From Cormier 2010
Produces O2
Requires O2
Produces CO2
Requires CO2
Contains Nutrients
Requires Nutrients
Algae naturally store its energy as lipids
Can be grown on wastewater
Does not infringe on cropland
Harnesses Energy
Requires Energy

22. Isolated Cultivation of Algal Resources from Sewage (ICARUS)

23. …perhaps in a not-too-distant future?
Graphics: Ana Lucia Prieto

24. Thank you for your attention. Questions?
Prof. Daniel Yeh
USF Membrane Biotechnology Lab

27. Energy recovery from wastewater
Electron donors (energy reservoirs)
Reduced WW organic matter
CH4 and H2 (anaerobic digestion)
Electricity and H2 (Microbial fuel cells)
Biosolids for combustion
Also, algae biofuel
Energy:
Pumping
Mixing
Aeration
Disinfection
Heat for digester
Chem transp.
Figure from: Howard F. Curren WWTP post-aeration basin (