the Blominmki WWTP and RAVITA innovation Mari Heinonen Director of - - PowerPoint PPT Presentation

Case study: the Blominmäki WWTP and RAVITA innovation

Mari Heinonen Director of the wastewater services division Helsinki Region Environmental Services

Helsinki Region Environmental Services Authority

Water services

Helsinki Region Environmental Services Authority HSY

Waste management services High-quality drinking water for over a million inhabitants Environmental regional information

Energy from biogas Eco-compost from sludge Heat from wastewater Effective wastewater treatment for 1,4 MPE

Purely better, every day

Siuntio Kirkkonummi Espoo Kauniainen Vantaa Helsinki Tuusula Sipoo Kerava Järvenpää Pornainen Mäntsälä Sewer tunnel Pressure sewer Large pumping station Area with combined sewer system Sewer district boundary Outfall tunnel

• 1. Suomenoja wastewater

treatment plant 1962-2022

• 2. Viikinmäki wastewater

treatment plant 1994-…

• 3. Blominmäki wastewater

treatment plant and tunnels (under construction) 2022- …

• 4. Metsäpirtti composting field

for sludge 1 3 2 4

Metropolitan area sewer system

Facts:

Municipal wastewater treatment since 1910, AS process + biogas since 1932 2019: Two wastewater treatment plants New Blominmäki WWTP 2022 Combined sewer system in the centre

• f Helsinki, separate sewers elsewhere

Case story: New Blominmäki WWTP

5

Why Do We Need Increased Wastewater Treatment Performance and Capacity?

6

• Population growth

‒ Plant load values for 2040 = 1,5 x current load

• Increasingly strict treatment requirements by the authorities

‒ Environmental permissions have become tighter ‒ Design targets for effluent water: Phosphorus 0,2 mg/l , nitrogen reduction > 90 % , UV hygienization and bypass water treatment ‒ Prepared plans for other requirements (e.g. removal of micro pollutants)

• Protection targets of the Baltic Sea

‒ Loads from large point sources (e.g. WWTP) must be controlled and limited, even though the majority of load is coming from diffuse pollution

• Increasing nutrient (nitrogen) levels in influent wastewater

‒ Increased consumption of protein e.g. meat and dairy products

• Climate change adaption

‒ More runoffs to sewers, preparing for floods

Location options and selected position

7

Sewer tunnel Effluent tunnel Existing Suomenoja effluent tunnel Access tunnel for vehicles Western Metro Mikkelänkallio access tunnel Effluent tunnel shaft Inlet tunnel from northern main sewer

Overflow route from sewer to effluent tunnel Söderskog inlet tunnel Malminmäki access tunnel Friisilä access tunnel Finnoo access tunnel Inlet tunnel from southern main sewer Suomenoja effluent tunnel, leads to

• uter archipelago of Espoo

Suomenoja inverted siphons , buildings of current WWTP

Blominmäki wastewater treatment plant

Treatment Requirements and Targets

9

HSY’s Treatment Objective for Blominmäki Blominmäki WWTP Permit Values HELCOM Recommen- dation Existing Suomenoja WWTP Permit Values Phosphorus (Ptot) < 0.2 mg/l < 0.25 mg/l < 0.5 mg/l < 0.35 mg/l Phosphorus removal efficiency > 96% > 96% > 90% > 95% Nitrogen (Ntot) < 5 mg/l

• < 10 mg/l
• Nitrogen removal

efficiency > 90% > 80% > 70–80% > 70% Biochemical

• xygen demand

(BOD7) < 8 mg/l < 10 mg/l < 15 mg/l < 10 mg/l BOD7 removal efficiency > 96% > 95% > 90% > 95%

Blominmäki WWTP 2040: 150 000 m3/d 550 000 PE

10

UV OR THERMAL PROCESSING Option

Blominmäki wastewater treatment plant 150 000 m3/d

400 000 PE v. 2020 ➔ 550 000 PE v. 2040

1. Influent tank 2. Fine screen 3. Sand removal 4. Primary sedimentation 5. Aeration tanks 6. Secondary sedimentation tanks 7. Biological filters 8. Sludge thickening 9. Digestion reactors

• 10. Emergency exits
• 11. Reject water treatment
• 12. Exhaust pump
• 13. Administrative building
• 14. Storage/workshop
• 15. Sludge and biogas building
• 16. Sludge storage silos
• 17. Disc filters, approx. 20 µm
• 18. Gas storage tanks
• 19. Vehicle tunnels
• 20. Inlet and discharge sewer tunnels

Energy efficiency in Blominmäki WWTP

Biogas production c a.5,5 Mm3/year (65 % CH4). Biogas will be used in own power production like we do in Viikinmäki WWTP – 70 % electrical energy self-sufficiency in start up (Viikinmäki WWTP 95- 100 %)

• Gas engines (2 x 1,6 MW)

– Heat recovery from the electrical energy production

• ORC-process (170 kW)

– Utilizes the waste heat of gas engines’ exhaust gas and transfer it to electrical energy

• Water turbines (25 kW), in effluent water
• Solar Panels (400 kW), Panel fields on roofs and in the field
• All equipment are energy efficient and used will be optimized

– 100 % self-sufficiency in heat production:

• Several heat recovery points, 5400 m3 energy storage and heat pump.

Cost Budget

13

Cost Budjet M€

Plant Excavations 86 Influent and Effluent Tunnel Excavations 61 Influent arragements from Suomenoja 10 Construction 79 Machinery 54 HVAC 11 Instrumentation and Automation 7 Electrical Work 15 Design and Constuction Management 16 Reservations for Increase

• f Excavation Costs

15 Reservations for Other Unpredicted Costs 17 Total 371

EIB and NIB loans are the main instruments for the economy of the investment management

Design period 2009-2017 (2018-2021)

14

Aerial View (Planning Phase)

15

E18 Helsinki – Turku Motorway Helsinki – Turku Motorway E18

Underground Lay-Out

16 Digesters Thickening Discfiters UV hygienization Screening Grit removal Pre-sedimentation Aeration (Compressors) Secondary Sedimentation DN-filters Incoming chemicals Dried sludge Reservation for micropollutant removal Reservation for exhaust air treatment

17

3D design of Blominmäki

17

Ground Lay-Out

Construction period

19

Excavation period 2015-2018

• One construction contract with

former Lemminkäinen Ltd.

• Excavated volume
• ca. 1 000 000 m3
• Excavated rock has been and

will be utilized as blast stones and raw material for gravel and sand

Raising excavation

Container for underground safety purposes Deepening excavation

• f the digester

E x c a v a t i

• n

Construction period 2018-2022

• One main construction contract for

YIT Ltd.

• Project management contract

agreement with target budget

• Construction area ca. 100 000 m2

equal to 14 football fields

• Examples of construction materials:
• 85 000 m3 concrete
• 7,5 Mkg of reinforcement iron
• more than 40 km stainless steel

pipes

E x h a u s t A i r C h i m n e y

• 100 m high
• Slip casting method

D i g e s t e r s

Construction site at present

Innovation for recovering phosphorus

RAVITA

Phosphorus

• According to different sources virgin

phosphorus deposits will last for 40-100 years

• Most countries depend on imported P
• In Middle-Europe few WWTPs have demands

to recover P – Germany – Switzerland – Austria

• Recovery potential meets only large WWTP
• Cost of the recovered P is not competitive

Phosphorus recovery from water phase

Effluent wastewater Post- precipitations and separation Treated wastewater

WWTP

BIOSLUDGE

Precipitation chemical Acid

Chemical sludge Metal phosphate solution Recovery of Phoshorus Separation step Phosphoric acid

Dissolution step SURPLUS PHOSPHORIC ACID

Precipitation chemical recirculation Phosphoric acid recirculation End product 1

Heavy metals in RAVITA-sludge

500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 As Pb Ni

mg /kg Phosphorus Heavy metal

10,000 20,000 30,000 40,000 50,000 60,000 70,000 Cr Cu Zn

mg /kg Phosphorus Heavy metal

10 20 30 40 50 60 70 Cd Hg

mg /kg Phosphorus Heavy metal

■ RAVITA sludge ■ Viikinmäki WWTP sludge ■ Legislative limit

TECHNICAL steps

• RAVITA DEMO plant

– Increase of TRL (now 5 - 6) – Dissolution and separation of RAVITA sludge into the DEMO scale

• Energy and mass balances
• More analyses of the end product quality

– Hazardous substances and microplastics BUSINESS steps

• Ecosystem mining for potential partners

(out of the box) and clients

• End users ideas and comments needed to

complete the business concept

RAVITA Future steps

Puhtaasti parempaa arkea | En rent bättre vardag | Purely better, every day

Helsingin seudun ympäristöpalvelut -kuntayhtymä

Samkommunen Helsingforsregionens miljötjänster Helsinki Region Environmental Services Authority

Thank You!