wastewater treatment in the netherlands developments ...€¦ · 2 october 2019 challenge the...
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2 October 2019
Challenge the future
DelftUniversity ofTechnology
Wastewater treatment in the Netherlands Developments, Trends & InnovationsProf.dr.ir. Jules van Lier / [email protected]
2ND Malaysia-Netherlands Water
Dialogue 2019
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High quality effluents:• Extensive C removal • Extensive N & P removal• Effluents for discharge• Minimizing combined sewer overflows
Wastewater treatment in the Netherlands: pollution prevention!
Cost-effective guaranteed provisions:• Cost-effective management• Full cost recovery by public taxes
(polluter pays)• ≈ 100% households connected• Guaranteed urban drainage
Contributing to cyclic economy:• Effluents for Reuse?• Resources from sewage?
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Biological process
Screen Gritremoval
Primarysettling Selector
Anaerobictank
Anoxictank
Aerobictank Final
clarifier
Influent Effluent
Return sludge Secondaryor Waste sludge
Optional postTreatment
Primarysludge
ThickenerSludge
DigesterBiogas
DewateringRejection water
treatment
Sludge treatment
WWTP Harnaschpolder - Delft
Removes:‘C’: BOD < 20 mg/l‘N’: < 10 mg/l‘P’: < 1 mg/l
Current standard
Basic WWTP process: activated sludge & biological nutrient removal (BNR)
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Current challenges of Sewage Treatment Plants (STPs) in NL:
- More stringent discharge criteria (EWFD):- N: 10-15 → 5-7 → 2.2 mg/L- P: 1-2 → 0.35 → 0.1 mg/L
- Energy efficiency / less fossil fuel consumption- Recovery of resources- Reduction green house gas emissions (CH4, N2O, etc.)- Less/no (?) micro-pollutants in effluent- No (antibiotic) resistant bacteria / pathogens in effluent- Etc.
Current and upcoming effluent restrictions set the boundary conditions for new developments (like resource recovery)
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Aeration tank
Bar screen
Sandtrap
Sedim.Tank
Sedim.Tank
Sludge treatment
INFLUENT
EFFLUENT
• Sludge • digestion
Thickeners
less energy for nitrification!
air / energy
N2
Anammox CHP
Conventional STP with Anammox in sludge reject water line:
NH4+ + NO2
- → N2 + 2H2O(3 x less energy)
Enhanced N/P removal?
Micro pollutants?
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‘mainstream’ Anammox
Bar screen
Sandtrap
Sedim.Tank
Sedim.Tank
Sludge treatment
INFLUENTEFFLUENT
• Sludge • digestion
Thickeners
air / energy
N2
Anammox CHP
Poly electrolytes + FeCL3: Enhanced COD & P-removal
A stage
aeration
A-B system with Anammox as B stage
Pilot reactor STP Dokhaven, Rotterdam
Results so far:Below 15oC problems with process stability
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More efficient WWTP: NEREDA
TUD-RHDHV: First full scale May 2012
Advantages: 35-45% reduction energy consumption! 75% reduction space requirement! Decreased investment and operational costs Highly efficient for BOD, N, P Bio-polymers of excess sludge mass: potential
resource
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influent
screening grit chamber
sludge drying bedreuse
effluentU A S B
biogas use
watersludgebiogas
- Pond / Lagoon- Trickling filter- Activated sludge- Wetland- RBC- etc.
At temperatures > 20oC: Anaerobic sewage treatment!
Post treatment
Residual BOD, N / P?
COD/BOD -removal
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Rio Claro STP
Piracicaba STPFull-Scale Experiences in Brazil
Sao Paulo, Brasil
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Nova Odessa – SP, BrasilCapacity: 50.000 inhabitants
Combined anaerobic-aerobic treatment in single reactor: BIOPAQ®UBOX REACTOR
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‘
RAW SEWAGE
AIR
FLARE
TREATEDEFFLUENT
ANAEROBIC
BIOGAS WITHOUT
H2S
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AEROBIC
3
2
4
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1. INFLUENT DISTRIBUTION
2. 3-PHASE SEPARATOR
3. AERATION SYSTEM
4. HIGH-RATE SETTLER
5. BIOGAS SCRUBBER
BIOPAQ®UBOX REACTORWorking principle
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Resource Recovery from Waste Water?!“Green Deal” Water Authorities – Ministry:
Bound N(NH4
+)
Phosphate
Bio-Plastics
Energy
Proteins / biopolymers
Fibres
Water
??
MetalsSulphur
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Resource Recovery from Waste Water?!
Energy
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AEROBIC
Heat loss
Sludge, 30-60 kg
Effluent,2-10 kg COD
Influent +
Aeration(100 kWh)
Activated sludge: Energy Recovery via Sludge Digestion!
Energy recovery via sludge digestion
1 kg sludge ≈ 1.5 kg COD≈ 5.7* kWhtheor
45 kg sludge ≈ 255 kWhtheor
≈ only 30-50% ? biodegradable
1 kg COD (organic matter)≅ 13.8 MJ (hhv)≅ 3.8* kWhtheor
Note: conversion efficiency: - biogas motor: 30-35%- CHP: 40%- SOFC: 80-85%
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Enhancing Energy Recovery via Digestion??• More efficient energy conversion techniques: CHP/SOFC
• Green gas production: gas-grid injection / automotive?
• Better operation existing sludge digesters (mixing / feeding)
• Pre-treatment of excess sludge (Pressure, Temp., OH-, enzymes, etc.: more CH4 per ton sludge! (e.g. Cambi, Sustec, etc.)
• Energy from residue: pyrolysis, gasification, sludge drying
• More “energy” to sludge digesters
Increase primary sludge production
External sludge: co-digestion?
Others?
- Total NL sewage sludge: 1,500,000 ton excess sludge/y (22-23% dry weight)- Incineration costs: up to 500 € / ton DS (≈ 175-200 x 106 €/y)
Dried sludge (90% DS): 10-16 MJ/kg (lignite: 10-20; petrol: 40)
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Anaerobic WW Treatment at Industry: Energy factory!
Energy recovered:17 ton COD x 0.85 (eff) x 3.8 MWh* x 0.9 lhv x 40% CHP eff. = 20 MWh-e/day ≈ 0.8 MW powerplant
No energy consumption: Assuming ≈ 1 kWh-e/kg CODremoved in activated sludgeSaved: 17 ton COD x 0.85 (eff.) = 15 MWh-e/day
Total energy benefit: 22 + 15 = 37 MWh-e/day≅ 3300 €/d (with 0.09 €/kWh), or 1.200.000 €/year
Energy content 1 ton COD ≈ 13.8 GJ ≈ 3.8 MWh
Coal powered electricity plant: 0.86 ton CO2/MWh-e
Total CO2 emission reduction: 19 (renewable fuel)/0.33 + 39 (prevented) = 96
ton CO2 /day≅ 380 €/day (with 20 €/ton CO2), or 140.000 €/year
Reducing the carbon footprint:
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Empty Fruit Bunch Solar Thermochemical Reactor:Gasification (syngas) / enhanced conversion
Palm Oil Waste to Fuel! PhD Candidate: Saqr Al-Muraisy
Palm Oil Mill Effluent
POME:
EFB
AnCMBR Reactor: high quality effluent
biogas
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Resources from Wastewater Treatment PlantsPhosphate
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P removal? ↔ P Recovery!!Formation of MAP (struvite)
MgOaq + NH4+ + PO4
- MgNH4PO4 . 6H2O [MAP]
Slow release fertiliser
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P recovery via struvite precipitation from AD sludge reject water
Struvite…Mg NH4.PO4.6H2O
Problem becomes a resource!
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P recovery in Amsterdam STP
STPAmsterdam
Value of this struvite??
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Resources from Wastewater Treatment Plants
Bound N(NH4
+)
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Ammonium: energy-based nutrient So far: NH4
+ merely destructed (at expense of fossil energy): - Nitrification/denitrification: 53 MJ/kg-N- Anammox: 16-18 MJ/kg-N- Theoretically available energy in NH3: 16 MJ/kg-N
Recovery of the nutrient NH4+?
Growing interest for N recovery from concentrated N-streams- Direct reuse: manure - Stripping and recovery as (NH4)NO3? (NH4)2SO4?- Pre-cursor for proteins?- Ferti-irrigation: use of treated sewage in irrigated agriculture
NH3 / NH4+ a scarce resource?
Recovery sustainable?
Ammonium production (Haber Bosch): 1910: ≈ 100 MJ/kg N2019: ≈ 25-30 MJ/kg N
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NH3 Fuel
Electrons
N2 + H2O
NH3 cracking
H2 oxidation
O2 reduction
O2 depleted
air
Air
O2- migration
ElectrolyteAnode Cathode
Electrical energy production
Thermal energy production
Energy content of ammonia*:• 4.8 kWh/kg-NH3* Gibbs Free Energy of ammonia oxidation at T = 750 °C
Performance SOFC:• Operational temperature: 650 – 850 °C• Electrical efficiency: 50%• Thermal efficiency: 35 – 45%
Fuel requirements:• Gaseous• 10% NH3 (90% water)• No oxidants (H2S, Cl2, O2)• No siloxanes
Solid Oxide Fuel Cell: Energy Recovery from NH3
(SOFC)
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Resources from Wastewater Treatment Plants
Water
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• Treated sewage is a reliable water source (≈ constant quality)• Potential water source for agriculture, industry, households (?)• With adequate treatment of concentrate: concomitant
accomplishment of current and future effluent (FWD) criteria
WWTP Emmen
DOWTerneuzen
Use of Treated Sewage
Industry examples, The Netherlands
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Industrial AnMBR for Water Reclamation
MF / UF RO
Coupling AnMBR to RO:high-rate water reclamation / minimized biofouling
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Memthane® + ROFull scale plants – Dairies (South Africa)
• 2 Memthane® + RO plants • Currently preparing at start-up and
commissioning• Design COD = 9,000 mg L-1
• TSS = 2700 mg L-1
• FOG up to 1,850 mg L-1
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Resources from Wastewater Treatment Plants
Bound N(NH4
+)
Phosphate
Bio-Plastics
Energy
Proteins / biopolymersFibres
Water
??
MetalsSulfur
Check sustainability…!!
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Thanks for your attention!
Questions??
Acknowledgement:colleagues, students, cooperating companies!