Resource recovery from wastewater through advanced biorecycling technologies

Ana Lucia Prieto, PhD

Postdoctoral Researcher, Colorado School of Mines

Department of Civil and Environmental Engineering University of South Florida, Tampa, FL, USA

Society of Environmental Journalists22nd Annual MeetingOct. 17-22, 2012Lubbock, TX

Daniel Yeh, PhD, PE, LEED AP

Associate Professor

D. Yeh

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

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FOX 13 video

• http://www.myfoxtampabay.com/story/18612577/could-a-new-energy-source-start-right-here

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For typical household wastewater (USA)For typical household wastewater (USA)

SS ~ 232 mg/LSS ~ 232 mg/L

BODBOD55 ~ 420 mg/L ~ 420 mg/L

COD ~ 849 mg/LCOD ~ 849 mg/L

TOC ~ 184 mg/LTOC ~ 184 mg/L

Nitrogen ~ 57 mg TKN/LNitrogen ~ 57 mg TKN/L

Phosphorous ~ 10 mg P/LPhosphorous ~ 10 mg P/L

Soluble and particulate org. matter(Soluble and particulate org. matter(

WERF onsite WW report)WERF onsite WW report)

““Waste” Waste” WaterWater

From 7 billion people, that From 7 billion people, that is a lot of potential is a lot of potential pollution, a lot of COD, pollution, a lot of COD, and a lot of potential and a lot of potential methane emission as methane emission as well as energy recovery well as energy recovery opportunitiesopportunities

The importance of technology for clean water

UN World Water Development Report 2

Conventional WWT in US

D. Yeh

How do we clean our wastewater?

Energy:PumpingMixingAerationDisinfectionHeat for digester Chem

transportation

Chemicals:FlocculationPrecipitationDisinfection

Labor:O&M

Clean Water

Unrecoverable waste

residuals

Trace chemicals,

VOCs

CO2CH4

H2S

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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?

Energy:PumpingMixingAerationDisinfectionHeat for digester Chem

transportation

Chemicals:FlocculationPrecipitationDisinfection

Labor:O&M

Clean water

BioproductsBiosolids, Nutrients,

biopolymers

Unrecoverable waste

residuals

Energy?

Trace chemicals,

VOCs

CO2CH4

H2S

A more sustainable approach

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Recovery of nutrientsRecovery of nutrients

Nitrogen, phosphorus, potassium

Struvite and other precipitates Biosolids

Bio-P phosphorus recovery

Crop growth / Algae Liquid fertilizer

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How do we clean our wastewater?

Energy

Chemicals

Labor

Clean water

BioproductsBiosolids, Nutrients,

biopolymers

Unrecoverable waste

residuals

Energy?

Trace chemicals

,

VOCs

CO2

CH4

H2S

Energy

An even more sustainable approach

D. Yeh

Wastewater as a renewable resource

A paradigm shift is underway!

http://www.sustainlane.com/reviews/getting-the-most-from-human-waste/ICF8A2T14UAQ9HTV27Q8VLQXRTOI

Graphics: Jeremy Guest

D. Yeh

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?

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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)

Excess energy for export???

Example, small (20,000 p.e.) WWTP in Czech Republic generate AD biogas to heat nearby homes

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So, how do we extract this energy from

wastewater?

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The Carbon Cycle

Aerobic – “with oxygen”

Anaerobic – “without oxygen”

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Energy states of carbonall about biorecycling

CH4 (CH2O)n CO2methane Org C (biomass) Carbon dioxide

Combustion, respirationCombustion, respiration

(-4)

Anaerobic digestionAnaerobic digestion

PhotosynthesisPhotosynthesis

Fullyreduced

Fullyoxidized

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

Oxidation (losing e- )

Reduction (gaining e- )

(+4)

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The anaerobic The anaerobic MBR (AnMBR)MBR (AnMBR)

at Univ. South Floridaat Univ. South Florida

AD + UF membrane

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N, P recovery for reuse (fertigation)

A

B

93% P recovered (cumulative)

95% N recovered (cumulative)

Prieto et al, 2012

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NEWgenerator TM

Potential to contribute on:Sanitation WaterEnergy FoodHealth GenderEconomics Empowerment

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Synergy of Algae and Wastewater

Requires Requires NutrientsNutrients

Requires Requires COCO22

Requires Requires OO22

Requires Requires EnergyEnergy

From Cormier 2010

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Isolated Cultivation of Algal Resources from Sewage (ICARUS)

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…perhaps in a not-too-distant future?

Graphics: Ana Lucia Prieto

Thank you for your attention. Questions?

Prof. Daniel Yehdhyeh@usf.edu

USF Membrane Biotechnology Labhttp://mbr.eng.usf.edu/

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D. Yeh

D. Yeh

Energy recovery from wastewater

Figure from: Howard F. Curren WWTP post-aeration basin (www.tampagov.net/dept_wastewater/information_resources/Advanced_Wastewater_Treatment_Plant)

Energy:PumpingMixingAerationDisinfectionHeat 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)