Samantha O’Hara & Naiara Fonseca€¦ · The Nutrient Challenge: Phosphorus Removal Reed Beds...
Transcript of Samantha O’Hara & Naiara Fonseca€¦ · The Nutrient Challenge: Phosphorus Removal Reed Beds...
The Nutrient Challenge: Phosphorus Removal Reed Beds
Creating better results together
Samantha O’Hara & Naiara Fonseca
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What is the Nutrient Challenge?
Increased Nutrient Use
Into Water Bodies
Eutrophication Dead Fish
European Union
This is not acceptable
EU Directives
Decreased Nutrient Use
Into Water Bodies
Less Nutrient in Water Bodies
Happy Fish!
Where are we now?
Watercourse
Agriculture
Detergents
Sewage Effluent
“Inland and coastal waters to reach ‘good water status’ by 2015” Water Framework Directive
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What does this mean?
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P leads to “low status”
Reduce P to the
environment
Catchment Challenge
P Removal Treatment
Tightened phosphorus
consents
Large Works
Small Works
The Challenge: Unmanned Rural
Sites
Shock Loading
Large Diurnal
Variation
Difficult Access
Low Operator Presence
No Potable Water Supply
Small Scale
Power Supply
Sensitive Receptors
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The Solution: Chemical Dosing?
• Dosing metal salts to precipitate
phosphorus from effluent
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Assets
SludgeChemicals
But….
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Shock Loading
Large Diurnal
Variation
Difficult Access
Low Operator Presence
No Potable Water Supply
Small Scale Power Supply
Sensitive Receptors
Unwanted chemical reactions
Need Tight Control
Tankering&
DeliveriesControl &
Mechanical parts
Safety showers & eye washes
May need power
upgrade
Pollution Potential
The Solution: P Removal Reed
Beds
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Reed bed = Constructed Wetlands
What are P removal reed beds?
Supporting media
Reeds
HF
VFGravel
traditionally SS removal
Reactive material
with high P affinity
Basic Oxygen Furnace (BOF) steel slag
Compound Typical composition (%)(*)
CaO 40-45
Fe2O3 25-30
SiO2 10-13
MgO 5-6
(*) Dunster, A. (2001) Building Research Establishment (BRE) Information Paper 18/01 – Blastfurnace slag and steel slag: their use as aggregates, London: CRC Ltd.
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Hhhh
Hhhhhh
Hhh
ggggg
What are P removal reed beds?
Gravel traditionally SS removal
Reactive material
with high P affinity
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Large Diurnal
Variation
Shock Loading
Difficult Access
Low Operator Presence
No Potable Water Supply
Small Scale Power Supply
Sensitive Receptors
So… Benefits?
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Unwanted chemical reactions
Need Tight Control
Tankering&
DeliveriesControl &
Mechanical parts
Safety showers & eye washes
May need power
upgrade
Pollution Potential
No Chemicals
Passive Technology
No Tankering
or Deliveries Few
mechanical parts
No Need for Potable
WaterLow Energy
Creates a new
habitat
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How do we prove they work?
Demonstration scale trials
Effect of particle size
Potential way of
increasing P removal
Potential roll-out to full scale
Successful full scale
trials - 74% TP removal
Commercially available BOF
slag size employed
Lab scale trials
0.75 mm 1.75 mm 5.09 mm 7.60 mm 10.04 mm
How do we prove they work?
5 fully saturated columns
Synthetic P solution
[TP] 5 mg/L
5 fractions
HF reed bed
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How do we prove they work?
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Inlet and effluent [TP]
Fraction (mm) [TP]eff (mg/L) % removal
0.75<0.08 >97
1.75
5.09
<1 80-857.60
10.04
Increased surface
area More CaOreleased, more P
removed
Hydraulically not viable
Applicable to full scale
0
1
2
3
4
5
0 5 10 15 20 25 30 35 40 45 50 55 60
[TP
] (m
g/L)
Time (days)
Inlet
Col0.75
Col1.75
Col5.09
Col7.60
Col10.04
CaPO4
Likely P consent
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pH<9 consent
How do we prove they work?
Acidification solutions
0
1
2
3
4
5
6
7
8
9
10
11
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0 5 10 15 20 25 30 35 40 45 50 55 60
pH
(-)
Time (days)
Inlet
Col0.75
Col1.75
Col5.09
Col7.60
Col10.04
pH ~ 11
8.5<pH<9.5
Not acid addition
To be monitored for 2 years, starting November 2014
Demonstration scale trials
Humus tank effluent
Dilution
86 m3 86 m3 86 m3
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How will it fit with AMP6 strategy?
83Sites with
tightened P
consents
49Site for P
Removal
Reed Beds
Outcomes
• Lowest TOTEX solution• Low carbon footprint• Attenuate loadings from flooding & drought• Re-use of the steel slag waste • Potential P recovery
1Site for 3 Pilot
P Removal
Beds
Approximate Figures : To Be Confirmed with Final Issue from EA
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Lowest TOTEX Solution
Step change in Innovation
No Chemical
No Tankering
Lower Energy
Lower Manpower
Lower Maintenance
Lower CAPEX
Media Regeneration
CAPEX
OPEX
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AMP7 & Beyond
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(1) Cordell et al. (2009) The story of phosphorus: Global food security and food for thought, Global Environmental Change, 19, 292-305(2) Press release, European Commission (2014) http://europa.eu/rapid/press-release_IP-14-599_en.htm(3) The Environmentalist, July 2014, p.4, Institute of Environmental Management and Assessment (IEMA )
Proposal for P as waste
stream in theEC wasterecycling
scheme (3)
P RECOVERY AND REUSE
Fertilizer price
Phosphaterock in EC
Critical RawMaterials
List(2)
(1)
Once saturated
what do we do?
P Recovery
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Dispose to Landfill
Cost of Transport
Landfill Tax
Lowest on Waste
Hierarchy
Reuse as fertiliser
Waste Regulations
?
Market?
Potential Value?
Summary
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Increased Nutrient Use
Into Water Bodies
Eutrophication Dead Fish
European Union
This is not acceptable
EU Directives
Less Nutrient in Water Bodies
Happy Fish!
Acknowledgements
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Special Thanks to:
Questions?