Constructed wetlands

for sustainable wastewater management

1st INTERNATIONAL SYMPOSIUM

“TOWARDS A NEW WATER MANAGEMENT MODEL”

5-9 August 2024 | Toluca

Prof Dr. Alexandros Stefanakis

Director, Laboratory of Environmental Engineering and Management,

School of Chemical and Environmental Engineering, Technical University of Crete, Greece

President, International Ecological Engineering Society, Switzerland

European Climate Pact Ambassador, European Commission, Belgium

Regional Coordinator for Africa & Middle East, Wetland Systems for Water Pollution Control, International Water Association

astefanakis@tuc.gr http://www.leem.tuc.gr

2019-today

School of Chemical and Environmental Engineering, Technical University of Crete, Greece

• Assistant Professor of Water and Wastewater Treatment Processes
• Director, Laboratory of Environmental Engineering & Management

2023-today

President

International Ecological Engineering Society, Switzerland

2021-today

European Climate Pact Ambassador

European Commission, Brussels, Belgium

2019-today

Regional Coordinator for Africa & Middle East

Specialist Group “Wetland Systems for Water Pollution Control”

International Water Association

Prof Dr Alexandros Stefanakis, Constructed Wetlands Expert

City of Chania, Island of Crete, Greece�

Technical University of Crete, Chania, Greece

Daedalus building wings

partner University of the

European University on Responsible Consumption and Production

• Established in the ‘70s
• In Top-3 most prestigious research institutions in Greece
• One of the two most active Universities in Greece with the highest number of research results
• School of Chemical and Environmental Engineering
• School of Production Engineering and Management
• School of Mineral Resources Engineering
• School of Electrical and Computer Engineering
• School of Architecture

Laboratory of Environmental Engineering and Management

Research topics and design services

• Water and wastewater treatment and reuse
• Nature-based solutions concepts
• Constructed Wetlands: design studies and research
• Physicochemical treatment processes
• Circular Economy and Sustainability
• Compost & Biochar production and application
• Quality characterization of water and wastewater
• Techno-economic studies

Established in 1992

Director: Prof. Alex Stefanakis since 2022

Indoor (250 m²) and outdoor (500 m²) facilities

www.leem.tuc.gr

8 International/EU- & 4 national projects

Collaborations & Funding bodies

• The IEES was founded in 1993,
• The idea: to bring together experts and conduct Ecological Engineering activities within an international society.

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https://iees.ch

International Ecological Engineering Society

An international network of Ecological Engineering enthusiasts

Ecological Engineering integrates ecological principles, processes and organisms with existing engineering practice to a holistic approach for a new circular problem solving.

An ecology-inspired approach to engineering

1993

1998

2007

2010

2023

Nature based solutions – Ecological Engineering

• biophilia & biophilic design : the innate human attraction to nature

→ increases the exposure and direct connection with nature → reduces stress, improves cognitive function and creativity

→ improves our well-being

• biomimicry: the process where we learn from, inspire by, and copy nature (nature-inspired innovation)

Nature-based solutions (NBS)

• concepts that bring nature into the human environment –ideas for urban design inspired and/or derived from nature
• harness the power of ecosystems and the sophistication of nature as infrastructure to provide natural services to benefit society and the environment

• introduced in the urban landscape to cope with challenges cities are facing.
• urban heat islands,
• flooding,
• treatment of waste- and runoff waters from different origins
• recovery potential of waste and water
• food provision
• positive symbiosis with other systems

• offer a range of ecosystem services beneficial for the environment - clean water production, nutrient recovery, heavy metals retention and recovery and a broad range of plant-based materials
• system’s perspective

Nature based solutions – Ecological Engineering

Nature based solutions for a circular city

• Foster NBS implementation towards circular urban water management.
• NBS to address urban circularity challenges for water resources in urban areas:
• Restoring and maintaining the water cycle
• Water and waste treatment, recovery, and reuse

Nature based solutions for a circular city and sustainable water management

• SDG 6: water and sanitation for all, covers the entire water cycle, including the management of water, wastewater and ecosystem resources.
• UN report 2017: over 80% of the wastewater worldwide is still discharged without adequate treatment.
• Still an open discussions about the approach, i.e., centralisation vs. decentralisation

Current scheme of water management in cities

Sustainable water management in cities integrating NBS

Wastewater treatment: established solutions

• Lagoons (passive or aerated)

- high area demands (10-15 m²/pe)

- old solution: no high treatment levels

- anaerobic processes, issues with mosquitoes, odours etc.

• Mechanical systems (MBR, activated sludge)

- high costs, especially for operation

- high energy consumption / use of chemicals

- general lack of awareness for its limited lifetime

- need for re-investment after 5-10 years

- OPEX usually not considered

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New solutions are needed!

• Sustainable solutions for wastewater management
• Circular water economy: treated effluent reuse, no waste generation

Constructed Wetlands:

The Green solution in the water and wastewater sector

Modern ecological engineering solutions

Constructed Wetlands for wastewater treatment

designed to mimic the functions of natural wetlands BUT under

controlled conditions

+ cost effective / reduced capital costs

+ green and sustainable

An alternative approach than conventional/mechanical technologies

Naturally occurring pollutant removal processes

• water
• substrate media (e.g., soil, gravel)
• plants
• microorganisms
• atmosphere (sun, soil, air) for pollutants removal

• natural responses (e.g., gravitational flow and sedimentation)
• natural components (e.g., plants, gravel, biological organisms)

Services of wetland technology

• Wastewater treatment
• Sludge dewatering and stabilization
• Flood control / runoff treatment
• Habitat creation

Modern ecological engineering solutions

Constructed Wetlands processes

Stefanakis et al., 2014. Vertical Flow Constructed Wetlands. Elsevier Publishing

Source: Orbicon, ARM

Aerated Wetland

Horizontal subsurface flow Constructed Wetland

Vertical flow Constructed Wetland

Surface flow Constructed Wetland

Floating Treatment Wetland

Modern ecological engineering solutions

Constructed Wetlands types and designs

Data from the continuous monitoring of the wetlands 🡪 development of an advanced design approach: the PkC* model. The required wetland area is calculated using the following equation:

A = the surface area of the bed (m²),

Qi = influent flow rate (m³/d)

C_i = inlet concentration (mg/L),

C_o = outlet concentration (mg/L),

C* = background concentration (mg/L)

P = apparent number of tanks‐in‐series (TIS) (-)

h = wetland water depth (m)

k_A = modified first‐order areal rate coefficient (1/d),

k_V = modified first‐order volumetric rate coefficient (1/d)

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• more accurate designs
• considers the rate coefficients
• temperature correction

Modern ecological engineering solutions

Constructed Wetlands design advances

Modern ecological engineering solutions

Constructed Wetlands within a resource-oriented, circular economy paradigm

Modern ecological engineering solutions

Constructed Wetlands within a resource-oriented, circular economy paradigm

Constructed Wetland (CW) systems design today focuses on new goals:

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Water reuse

• Greywater treatment for local reuse and recreational purposes
• Rainwater (including first flush) treatment and storage,
• Treatment of persistent organics in low concentrations for water reuse,
• Reduction of pathogens to acceptable levels as part of a multi-barrier approach,
• Polishing of secondary treated wastewaters, as long as these still exist, for reuse

Nutrient recovery

• CWs as pre-treatment for fertigation
• Biomass production from secondary sludge, digestate or primary sludge.

Energy production

• Anaerobic reactor (biogas) + CW as polishing stage;
• CWs as biomass production plots
• Greywater collection and heat recovery
• CW for grey water treatment

Ecosystem services

• Multi-purpose CWs for rainwater storage, recreation and wetland ecosystems (sustainable urban drainage concepts)
• Re-adaptation of ornamental green areas in terms of ecosystem services (green roofs, green walls, indoor green areas, parks, permaculture productive areas) comprising organic food pro-duction in integrated habitats

Constructed Wetlands:

Examples and case studies

Municipal wastewater treatment and reuse (Oman)

Planting

1 month after planting

No separate sludge handling!

Compliance with effluent Std B

TSS<10 mg/L ΒΟD5<5 mg/L TN <25 mg/L

• Inflow from trucks
• 120 m³/day (600 pe)

Stefanakis, 2020. Water journal, doi:10.3390/w12061665

• Entirely gravity flow
• No electricity at site

oasis in the desert!

Today

Reuse irrigation field

Municipal wastewater treatment and reuse (Oman)

1st-stage VFCW

2nd-stage VFCW

Municipal wastewater treatment and reuse (Oman)

2-stages Vertical Flow CW

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Design modifications for irrigation standards

• Effluent complied with Standard A (reuse in irrigation)
• Effluent nitrate < 11.3 mg/L
• Removal rates: total suspended solids (99.6%), BOD (98.7%), COD (97.8%), ammonia nitrogen (99.5%), total phosphorus (97.2%), pathogens (99.9%)

Municipal wastewater treatment and reuse (Oman)

• Aerated CW: State-of-the-art in wetland technology
• Oxygen transfer is the main sizing limitation for conventional wetlands (degradation processes for organic matter and nitrogen are aerobic)
• Air pumped into gravel bed: enhances the treatment efficiency and reduces land area requirement, providing higher effluent quality

Petersfield WWTP

20,000 pe

4750 m³/day

→1250 m³/day to AVFCW

Municipal wastewater treatment and reuse (England)

Effluent fulfils the legal criteria for environmental discharge and reuse, without a final disinfection step.

The superior efficiency of aerated CW in microbiological contamination removal compared to passive systems is demonstrated for the first time.

Municipal wastewater treatment and reuse (England)

Constructed Wetlands: how much area is needed

0.5-3 m²/pe (depending on design, type, climate…)

[lagoons > 7 m²/pe

activated sludge: 0.2-0.5 m²/pe]

passive CW: 6-7%

aerated CW: 10-15%

of the energy demand of a traditional activated sludge plant

16.5 m³/day

Effluent from 150 pe

Total area demand: 2.2 m²/pe

mixed effluent: hotel, restaurant, brewery

Mixed effluent: domestic & industrial wastewater (Czech Republic)

Mixed effluent: domestic & industrial wastewater (Czech Republic)

Irrigation with treated effluent & well water

tomatoes (Solanum lycopersicum L.)

potatoes (Solanum tuberosum)

lettuces (Lactuca sativa L.)

irrigation field of 50 m2

E. coli: 15-47 CFU/mL (outflow)

Intestinal enterococci: 1.6 CFU/mL (outflow)

Total Coliform: 73 CFU/mL (outflow)

Mixed effluent: domestic & industrial wastewater (Czech Republic)

Tomatoes

First year: similar production, total harvested yield > 4% higher in the WW field.

Second year: harvested yield > 133% in the WW field, average weight > 31.6% higher

Higher crop yield when irrigated with treated effluent

Potatoes

total yield of biomass > 4 times higher in the WW field

average weight > 76% higher in the WW field

Lettuces

lettuce yield > 104% higher yield in the WW field

average plant weight > 107% in the WW field

Industrial wastewater: glass manufacturing industry (Iran)

Safety Glass Khorasan (SGK): Glass manufacturing industry, Mashhad, Iran

Freshwater consumption (30 m³/day)

Wastewater

(10 m³/day)

Collection tank

CO₂

$

Glass industry

$

PREVIOUS EFFLUENT MANAGEMENT STRATEGY

WWTP

Solution needed to

• Reduce overall wastewater management costs
• Reduce freshwater consumption

⮊ Constructed Wetland

1^st step

pilot-scale unit for performance investigation, design verification and operation parameters optimization

2^nd step

upscaling, full-scale unit construction

Before

pilot

After

Gholipour et al, 2020. Chemosphere journal

Industrial wastewater: glass manufacturing industry (Iran)

NEW EFFLUENT MANAGEMENT STRATEGY

Wastewater (10 m³/day)

Constructed Wetland

Glass industry

🡫35%

Effluent recycling

• Freshwater consumption: reduced 35%
• Cost savings >20,000 USD/year
• Eliminated CO2 emissions from wastewater management

Freshwater consumption (20 m³/day)

Industrial wastewater: glass manufacturing industry (Iran)

Municipal wastewater treatment and reuse - large scale (Saudi Arabia)

• Red Sea Project: one of three giga-projects in the tourism sector [28,000km²]
• Archipelago at the Western coast of Saudi Arabia
• 200 km coastline and more than 90 islands: undeveloped
• more than 90 pristine islands, never been disturbed by man

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• New airport, marina, numerous leisure and lifestyle facilities
• Supporting logistics and utilities 75km roads

• daily wastewater volume: 16.000 m³/day
• Estimated population > 80,000 people
• Largest CW project in the world for municipal wastewater
• 13.5 hectares of treatment wetlands
• 1.5 million reed plants (Phragmites, Typha, Arundo and Cyperus)
• treated sewage effluent reused for irrigation in landscaping

Municipal wastewater treatment and reuse - large scale (Saudi Arabia)

• daily wastewater volume to be treated: 16.000 m³/day
• Estimated population > 70,000 people
• 13.5 hectares of constructed wetlands

Municipal wastewater treatment and reuse - large scale (Saudi Arabia)

Municipal sludge dewatering in Constructed Wetlands

• Sludge = 0.5-2% v/v of inflow wastewater

BUT

• Sludge management ~ 50% of total operating costs of a WWTP

• Sustainable dewatering and stabilization of sludge using Sludge Treatment Wetlands
• Production of compost and biochar using dry sludge and reeds as biomass

Municipal sludge dewatering in Constructed Wetlands (Germany)

• Ecological solution for sludge dewatering
• No need for regular sludge removal/disposal
• Sludge loadings continue for 8-12 years without emptying the beds

Fresh sludge applied on the surface

Residual sludge removal from the bed – compost type, use as fertilizer (facility in Germany)

Municipal sludge dewatering in Constructed Wetlands (Oman)

5-Star Resort, Six Senses Zighy Bay, Dibba

• onsite conventional MBR, 300 m³/day
• daily sludge production up to 5 m³/day
• sludge handling was an issue
• transportation at a distance of >30 km
• eco-tourism and sustainability promoted

Municipal sludge dewatering in Constructed Wetlands (Oman)

• sludge treatment rate built in 2010
• Well integrated into the natural landscaping
• No chemicals used for the dewatering process
• Energy is used only for sludge pumping
• No smells escape to the atmosphere

Municipal sludge dewatering in Constructed Wetlands (Saudi Arabia)

• The Line was developed for around 9 million inhabitants
• Footprint of 34 km².
• Inhabitants will have access to all facilities by walking and a high-speed rail with 20-minute transit.
• The project was designed with a model where residents can reach the facilities they need by walking for 5 minutes.

• Constructed Wetlands is the selected technology for key segments of the project
• Sludge Treatment Wetland project ongoing: largest STW in the world
• Design completed, tender is out for construction

• Sludge Treatment Wetlands: 150 m m³/day

area of 2 hectares

• Constructed wetlands for wastewater treatment as zero-liquid discharge systems: 600 m³/day
• 6 hectares in total

Municipal sludge dewatering in Constructed Wetlands (Saudi Arabia)

Effluent & raw wastewater treatment (Mexico)

• effluent from the Cerro de la Estrella Wastewater Treatment Plant (Cerro WWTP),
• meet the Mexico Water Quality Limits for Human Consumption (NOM-127-SSA1-2017).
• produce effluent quality that can be reused as a potable supply for Mexico City
• First testing and demonstrating system
• daily flow: 100 L/s or 8,640 m³/d

Two parallel lines

• first stage Vertical flow CW followed by a Surface flow CW
• first stage of an Aerated Vertical flow CW followed by a Surface flow CW

first-stage VFCW: 9500 m².

• passive VFCW treatment train: 4000 m³/day (partially saturation 80cm)
• aerated VFCW: 4650 m³/day.

Each VFCW in both treatment trains is followed by a SFCW system of 7500 m²

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Effluent & raw wastewater treatment (Mexico)

Effluent & raw wastewater treatment (Mexico)

Effluent & raw wastewater treatment (Mexico)

Master plan

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Wetland systems 100 hectares

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~80.000 m³/d

Effluent & raw wastewater treatment (Mexico)

Master plan

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Wetland systems 100 hectares

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~80.000 m³/d

Effluent & raw wastewater treatment (Mexico)

Master plan

Wetland systems 100 hectares

~80.000 m³/d

Effluent & raw wastewater treatment (Mexico)

before

after

Mine drainage treatment (Brazil)

polymetallic mine and concentrate processing facility: proven reserves of Zn, Pb, Cu, Ag, Au

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Process water: approx. 1.500 m³/h,

Stormwater wetlands: rain-driven systems

5 wetland systems: total flow > 100,000 m³/d

1. Ore beneficiation process (Fe, Cu, talc, Zn)
2. Mine drainage (Al, F, Pb, Pb and Mn)
3. Stormwater / waste heap runoff
4. waste tailings

main elements that usually exceed the maximum concentration permitted by federal legislation: SO₄^2-, F^-, Al₃⁺, As, Ba, Ca²⁺, Cd²⁺, Cr²⁺, Cu²⁺, Fe, K⁺, Pb²⁺, Mg²⁺, Mn⁴⁺, and Zn²⁺.

Mine drainage treatment (Brazil)

161,852m²

16 hectares

29,336 m²

2.9 hectares

Mine drainage treatment (Brazil)

Mine drainage treatment (Brazil)

Mine drainage treatment (Brazil)

Mine drainage treatment (Brazil)

Groundwater remediation (Germany)

Leuna, Germany: Industrial mega-site history

• 1916 Ammonia synthesis
• 1923 Methanol high pressure plant
• 1927 Coal hydrogenation
• 1938 Benzene distillation
• 1942 Synthetic tensides
• 1951 Crude oil manufacturing
• 1965 Petrochemical complex in WT II
• 1990 Reconstruction of the chemical industry
• 2005 About 100 companies – 10,000 employees

during WWII: (approx. 80,000 bombs)

Large-scale soil and groundwater contamination

Leuna, Germany: Industrial mega-site history

> 200 mill. m³ contaminated groundwater

The legacy… scale 10 km x 10 km x 80 m

Average:

Benzene = 20,000 µg/L

MTBE = 3,000 µg/L

Ammonium = 45 mg/L

Groundwater remediation (Germany)

Organic compounds in a single groundwater sample!

Groundwater remediation (Germany)

Solution (?) – established technology (hi-tech)

Groundwater remediation (Germany)

Solution – Innovative technologies (eco-tech): First phase: experimental facility

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2002: Isolation and identification of MTBE- degraders

2007: Construction of the research site Leuna

2011: Construction of the technical pilot module

2014: Full scale implementation

Groundwater remediation (Germany)

M D V V

MITTELDEUTSCHE

VERMÖGENSVERWALTUNGS-

GESELLSCHAFT MBH

Groundwater remediation (Germany)

Official opening day June 2014

Cost savings in 5 years ~ 2 million €

Research investment 1.5 mil €

Groundwater remediation (Germany)

Effluent polishing and restoration (Saudi Arabia)

• Polishing of combined effluent from Industrial Wastewater Treatment Plant (IWTP) and Sewage Treatment Plant (SWTP) of total capacity 215,000 m³/day

SWTP ≈ 127,000 m3/d

IWTP ≈ 85,000 m3/d

• SWTP and IWTP: do not meet Discharge Standards (Coastal or Irrigation)
• Treated Water Reuse
• Part of the effluent is already reused
• Irrigation of parks, golf course, horse track.
• About 20,000-30,000 m3/d for cooling tower.
• Higher than Irrigation Discharge Standard: BOD < 10 mg/L, NH₃-N < 3mg/L, TSS < 10mg/L

Effluent polishing and restoration (Saudi Arabia)

Effluent polishing and restoration (Saudi Arabia)

Effluent polishing and restoration (Saudi Arabia)

Oil Field Produced Water:

• Contains oil and hydrocarbons
• Brackish to saline
• Large quantities produced every day
• Water management often imposes a bottle-neck on oil production rates

Nimr oilfield, Sultanate of Oman

• Traditional disposal = deep-well injection (>1.5km depth)

🡪 energy and OPEX intensive

• aquifer contamination risk

TDS = 7,000 ppm

Oil in Water = 280-450 ppm

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Deep Well Disposal

environmentally undesirable

operationally energy intensive

Goal: To replace deep disposal wells with a reliable, environmentally-sound alternative

Oily produced water treatment and reuse (Oman)

~65% of produced water generated at the Nimr Oilfield (275,000 m³/day) is treated in this facility (half of the daily water consumption in Oman’s capital)!

Phase 1

Dec 2010

45,000 m ³/day

Phase 2

Sep 2012

95,000 m ³/day

Phase 2 exp.

Jan 2015

115,000 m ³/day

Phase 3

May 2019

175,000 m ³/day

Oily produced water treatment and reuse (Oman)

Constructed Wetlands

490 hectares

(4.9 million m²)

Evaporation ponds & salt-works

780 hectares

(7.8 million m²)

treatment capacity:

175,000 m³/day

Oily produced water treatment and reuse (Oman)

Constructed Wetlands

490 hectares

(4.9 million m²)

Evaporation ponds & salt-works

780 hectares

(7.8 million m²)

treatment capacity:

175,000 m³/day

Oily produced water treatment and reuse (Oman)

Constructed Wetlands

490 hectares

(4.9 million m²)

Evaporation ponds & salt-works

780 hectares

(7.8 million m²)

treatment capacity:

175,000 m³/day

1200 football fields

Oily produced water treatment and reuse (Oman)

Treatment of 175,000 m³/d produced water

Crude oil

Produced Water from PDO

> 85% oil recovery

> 400 bbl/day oil

Reuse

Oily produced water treatment and reuse (Oman)

Phragmites Typha Schoenoplectus Cyperus Juncus

Oily produced water treatment and reuse (Oman)

From this…

(Wetland inflow)

Total Petroleum Hydrocarbons < 0.5 ppm (99% removal)

More than 85% of the oil is recovered at the front-end using hydrocyclones and skimmers

INFLOW

- OiW : on the average close to 350 mg/L

- TDS close to 7,000 mg/L

- low nutrients concentration

- BOD5 always very low (around <50 mg/L)

- COD/BOD ratio in the wetland system: 8-10

Oily produced water treatment and reuse (Oman)

Carbon Footprint and Energy Efficiency

• After 10 years of operation, approximately 1.275 million ton CO2 emissions have been saved ~ emissions from 25,000 cars over a 10-year period
• Energy savings > 99%
• Greenhouse gas emissions: 99% reduction
• Reduced operational costs by 99%

Oily produced water treatment and reuse (Oman)

Solar farm

Market value

↓CO2

↓CO2

Water conservation

Closing materials cycle

↓CO2

Aquaculture

Constructed Wetlands

Treated effluent

Biosaline agriculture

Desalination

Date palms

Fodder

Reeds biomass

Operations

Compost

Biogas

R&D

R&D

R&D

R&D

R&D

Offset of emissions 🡪

R&D

DWD

- biofuel

- wood

R&D

Hydroponics 🡪 fodder

Applying the circular water economy

Oily produced water treatment and reuse (Oman)

Reuse in agriculture

2015 – 2019: 4 years research project

• 220,000 m² irrigation field
• different water salinities and irrigation methods
• >15 different crops and trees (fodder grass, cotton varieties, biofuels, coal biomass, wood biomass)

Next generation hydroponic grow unit tested to provide a daily supply of fresh fodder (barley)

Oily produced water treatment and reuse (Oman)

2015 – 2019: 4 years research project

220,000 m² irrigation field

different water salinities and irrigation methods

• Textile
• 2 tons cotton lint / ha – similar to yield measured in USA and Australia
• Estimated market value of 1.7 USD/kg – Count 30/1 Ne for knitting or weaving
• Firewood
• Bulk density still low after 2 years
• Kuwaiti tree below European Pellets Standard EN 14961-1
• Cosmetics
• Jojoba growth is under monitoring since 1.5 years
• 4-5 years before harvesting seeds and analysis of wax quality
• Bio-fuel

🡪 Salicornia, Ricinus communis under monitoring

Oily produced water treatment and reuse (Oman)

Oily produced water treatment and reuse (Oman)

“Aviation is one of the fastest growing sources of greenhouse gas emissions”

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“The industry has promised carbon neutral growth by 2050 – to be met by biofuels”

Industry Aim:

By 2025 - 5 million tonnes of biofuel

By 2050 - 285 million tonnes (50% of the world’s aviation fuel needs)

285 million tons = 3 x current biofuel world production!

There is no facility dedicated to production of biofuels for the aviation industry.

A man-made valuable habitat for migratory and resident birds and other wildlife

> 130 different bird species in and around the wetland cells and ponds have been identified

🡪 a new, attractive island refuge in the desert for birds migrating between Asia and Africa

Cooling effect on the surrounding environment regulating the microclimate

• positive effect of the constructed wetland system on its surrounding environment.
• temperature reduction of up to 10°C for the points inside the CW system and the wetland edge

Oily produced water treatment and reuse (Oman)

Conclusions – key message!

• Constructed wetlands is an established green technology of ecological engineering that still produces innovation
• Wetland technology proven for a wide range of wastewaters
• Proof of scale exists (even at largest scale)
• Cost effective and sustainable solution
• Wide range of environmental benefits
• Serves excellently the circular water economy

reuse in agriculture / recycling in the industry / environmental restoration

GRACIAS POR SU ATENCIÓN

Asst. Prof. Dr. Alexandros Stefanakis

Technical University of Crete, Greece

International Ecological Engineering Society

astefanakis@tuc.gr

www.leem.tuc.gr

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Manifesto of Ecological Engineering

https://iees.ch/our-manifesto

Going circular: Ecological Engineering in 2023+

Manifesto of Ecological Engineering

https://iees.ch/our-manifesto

• fundamentally change the way we think, the way we make decisions.
• multi-dimensional, complex and interrelated problems
• systems thinking towards new holistic engineering solutions at all scales
• ecology-inspired approach to engineering provides answers
• value of nature as part, not only of solutions, but also of the design process
• EE integrates ecological principles, processes, organisms with the existing engineering practice, forming a new, holistic approach for problem-solving
• EE reshapes engineering solutions, to design out waste, restore the ecological functions and eliminate the unwanted impact of all processes and interventions
• Circularity in problem-solving, re-establishing cycles of materials
• nature as an inspiration, using ecosystem services and renewable resources.
• we work with nature for the benefit of society and the environment
• people and civil society: an integral part of this new problem-solving approach

Topic title, font size 36

Constructed wetlands vs conventional technologies

1. Case study (KSA): lagoons remediation

Raw wastewater design flow rate:

MBR: 1000 m³/day,

CW: 1300 m³/day

MBR: re-investment after ~10 years (end of membranes lifetime)

CWs: lifetime prolonged up to 20 years

CW: 31% lower Capital Investment than MBR

Influent BOD 200 ppm

Lagoon sludge treatment: CW = included,

MBR = not included

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Topic title, font size 36

Constructed wetlands vs conventional technologies

1. Case study (KSA): lagoons remediation

CW: 31% lower Capital Investment and

41% lower Operational Costs

Topic title, font size 36

Constructed wetlands vs conventional technologies

2. Case study (USA): manufacturing Industry (1500 m³/d)

CW: 31% lower Capital Investment and

90% lower Operational Costs

Topic title, font size 36

Constructed wetlands concept for Iraq: Al-Afra village

1st Stage Vertical Flow Constructed Wetland (with sludge mineralization)

1200 m²

Chlorination tank

2nd Stage Horizontal Subsurface Flow Constructed Wetland

1100 m²

Treated Effluent reuse

Gravity flow

800 pe

160 m³/day

Topic title, font size 36

Potential for Constructed wetlands in Iraq

• Working with WFP to identify first locations for the implementation of Constructed Wetlands
• Visit to Iraq in March. Site visits to more than 10 locations from the south to the north

Topic title, font size 36

Potential for Constructed wetlands in Iraq

Diyala

• One of the candidate locations
• Constructed wetland will be designed for municipal wastewater treatment within a plot pf the Water and Sewage Department
• The existing pump station will be used

Topic title, font size 36

Potential for Constructed wetlands in Iraq

Al-Afra Village/ Al-Dhelimia

• Candidate location
• Constructed wetland will be designed for municipal wastewater treatment within a plot pf the Water and Sewage Department