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Closing Water, Nutrient and Energy

cycles

Starting in wastewater treatment systems…

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Wastewater in The Netherlands• Production almost 2 billion m3 clean effluent per year• Originating from industry and approximately 7.2 million

households• Treated in 350 WWTP’s• Electricity use of 0.37 kWh/m3 treated wastewater

(but heating of water 60 Mjprimair/m3) • 15-20% of imported phosphate rock ends up in wastewater

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Wastewater treatment focus;changes in the past 60 years

Removal of Organics

Removal of organics, Nitrogen and phosphate

MultifunctionalArea use

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Is this enough?• Water Framework Directive (WFD-EU)• Changing focus to more “sustainable” wastewater treatment:

• Grey water, black water and rainwater treatment;• Less energy use + energy recovery;• Wastewater as source

Possibilities & limits of the activated sludge

processSTOWA 2007

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5

Drinking water purification

N P

P

NProduct formaton

Changes in the next (60) jaar?

E&Q

Wasteprocessing

Nutrient re

covery

Newsanitation

Sewer management

(waste)(water)chain

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Demand driven research?!Commitments of the waterboards:

• Water Framework Directive EU• Good ecological status surface water (Nutrients, Micro Pollutants,

metals, EDC’s, pharmaceuticals etc.)• Reduction energy consumption

• 2% / year (2005-2020: 30%)• Climate agreement with the National Government, March 2010

• 40% sustainable energy production in 2020• 30% reduction GHG 1990 en 2020• 100% sustainable purchase

• Green deal, October 2011• 12 Energy factories + 5 Phosphorus recovery plants

• Covenant Phosphorus Cycle, October 2011

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Themes for the coming years

Water reuse

Nutrientrecovery

Energy recovery

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Roadmap 2030 – “sources-factory”

Water

EnergyNutrients

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Water reuseWater

EnergyNutrients

Water

EnergyNutrients

Water

EnergyNutrients

Important characteristics for WWTP configuration

• Physical removal of COD

• Biological removal of N

• Biological and chemical/physical removal of P

• Biological processes based on activated sludge

and attached growth (membrane, sand filters,

activated carbon).

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Projects• Irrigation in greenhouses

• Pilot at Harnaschpolder with filtration methods;

• Sewermining

• Production of high quality process water from sewer, preferably energy neutral

• Anaerobic Membranes

• uncoupling HRT and SRT, resulting in high quality nutrient rich, pathogen free effluent;

• Fouling, shear and costs

Water

Energy

Water

Energy

WaterWater

Water

EnergyNutrients

Water

EnergyNutrients

Water

EnergyNutrients

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Nutrient recoveryProduct recovery

Important characteristics for WWTP configuration

• Separate nutrients and COD

• Concentrate nutrients (precipitation)

• Recover other products or produce products (bioplastics, other polymers, fine sieve

material, algea?, duckweed?)

EnergyNutrients

EnergyNutrients

Water

EnergyNutrients

Water

EnergyNutrients

Water

EnergyNutrients

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Chances for decentralized treatmentor different wastewater collection

Feaces; 35%

Urine; 47%Grijs water

18%Grey water

Urine; 85%

Feaces; 11,6%

Grijs water 3,4%

NitrogenGrey water

Phosphate

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Energy production or Energy-factory

Important characteristics for WWTP configuration

• Separation of COD instead of aerobic degradation (optimization biogas production and energy consumption at

aeration)

• Energy: economic removal of N, P and residual COD (anammox)

• Maximal recovery of sludge caloric content

Chances for heat recovery in the sewer

Water

EnergyNutrients

Water

EnergyNutrients

Water

EnergyNutrients

14 www.energiefabriek.com

• Realisation• Research/development

• Marketing

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Research topics formulated by the waterboards

treatmentconcept (11)Separation solids and waterSeparation C and N treatmentRejectionwater treatmentSmall WWTP’sLow energy technologies

Sludge treatment (5)Optimalisation digestionprocesAlternatives digestionCo-digestionFinal sludge treatment

Energyconversion, -supply (7)Energy conversionEnergie supply Heat from watercycle

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Role of Anammox in the E-factory

Sewage “Sewage treatment with Anammox”

Kartal et al., 2010 - Science

Based on: Lower COD for N-removal (denitrification) more COD for biogas production

Rejection Water“Anammox brings WWTP closer to energy

autarky due to increased biogas production and reduced aeration energy for N-removal”

Siegrist et al., 2008

Revival of the A/B system: Lower COD for N-removal (Anammox in the B-stage) more COD for biogas production

(Biomass production in A-stage)

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Anammox technology at low temperatures(Paques, TUD, RUN, WSHD, STOWA)

Main concern:Competition ammonium and nitrite oxidizing

bacteria and Anammox at pilot (and full scale) conditions

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Combining old and new goalsAerobic granular sludge technology: Excellent settling properties sludge Granules without carrier material High biomass concentrations Extensive nutrient removal

Low area requirement Simple single-tank concept Sustainable (energy and additives) Low costs

Activated sludge

Aerobic Granules

Water

EnergyNutrients

Water

EnergyNutrients

Water

EnergyNutrientsProducts

???!

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Example of technology development

Successful cooperation needed,In this Nereda Case:University (TUD), Industry (DHV) and Government (waterboards, stowa, stw, EU)

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Questions?