Developments in Nitrogen Removal by Reed Bed Treatment ......NO3- + organic carbon → NO2- → N2...
Transcript of Developments in Nitrogen Removal by Reed Bed Treatment ......NO3- + organic carbon → NO2- → N2...
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ARM Ltd
Developments in Nitrogen Removal
by
Reed Bed Treatment Systems
15 May 2013
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The Company
Agricultural Requisites and Mechanizations
1947 – 1990
Agricultural engineering,
buildings and composting
1990 – Present
Reed Beds
• 500+ constructed
• 75% for sewage
• 25% surface run off, leachate, process water
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Wetland Types
Passive Wetland Systems
• Horizontal Flow (SSF, SF)
• Vertical Flow (VF)
Intensive Wetlands • Forced Bed Aeration
• Fill and Drain TAYA System
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Wetland Mechanisms for TN removal
1. Primarily microbial through sequential microbially mediated
mineralisation of organic bound nitrogen (N) to N gas.
Ammonification (aerobic and anaerobic)
Urea/Amino acids + H2O →2NH3 + CO2
Nitrification (aerobic)
NH4+ + O2 → NO2- + O2 → NO3- + H2O +energy
Denitrification (anaerobic, anoxic)
NO3- + organic carbon → NO2- → N2 gas↑
All proceeding at various rates.
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Wetland Mechanisms for TN removal (cont)
2. Removal of N bound in solid material occurs through
filtration and settlement - Apparent
3. Plant and microbial biomass uptake – Apparent
4. Accretion in silts and litter
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Wetland Types
Passive Wetland Systems
• Horizontal Flow (SSF, SF)
• Vertical Flow (VF)
Intensive Wetlands • Forced Bed Aeration
• Fill and Drain TAYA System
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Horizontal Flow Reed Bed : Continuous flow
Passive Wetland Systems
Surface Flow
Sub Surface Flow
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Passive Wetland Systems
Horizontal Flow Systems
• Saturated
• Low Oxygen tensions
• Apparent Oxygen transfer rate is 7g/m2/d
• Suited to Denitrification (carbon source needed)
• Ammonification does occur
• Nitrification occurs but unreliably.
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Wetland Types
Passive Wetland Systems
• Horizontal Flow (SSF, SF)
• Vertical Flow (VF)
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Vertical Flow : Batch flow
Passive Wetland Configurations
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Passive Wetland Systems
Vertical Flow Systems
• Temporary saturation, re-aerated.
• Relatively higher, more coinsistent Oxygen tensions than HF.
• Apparent Oxygen transfer rate is 25g/m2/d.
• Suited to Ammonification and Nitrification.
• Denitrification is minimal.
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• Ammonification
Organic N to ammonia.
Can be achieved in Horizontal Flow and Vertical Flow Reed Beds.
• Nitrification
Ammonia oxidation to Nitrate.
which can be achieved in Vertical Flow Reed Bed.
• Denitrification
Nitrate reduction anoxic conditions to Nitrogen gas.
Which can be achieved in a Horizontal Flow Reed Bed.
• Combining Nitrification and Denitrification leads to perfect recycling by returning the
N2 to the atmosphere from whence it came.
Passive Combination: Vertical and horizontal
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• Oaklands Park is a Camphill Community dedicated to looking after
handicapped people.
• Full scale system for 65 pe hybrid system 2 sets of VF beds followed
by 2 sets of HF beds.
Passive Combination: Vertical and horizontal
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Inter-stage data (mg/l) for Oaklands Park averages of 47 samples over 2 years
Influent Stage1 Stage 2 Stage 3 Stage 4
VF VF HF HF
BOD 285 57 14 15 7
TSS 169 53 17 11 9
NH4N 50.5 29.2 14 15.4 11.1
Oxd.N 1.7 10.2 22.5 10 7.2
Nitrification Denitrification
Passive Combination: Vertical and horizontal
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• HF can denitrify effectively if we have a carbon source.
• VF can nitrify effectively at low ammonia levels (up to 50 - 100 mg/l – single
pass)
• Combination systems can achieve total N removal to secondary treatment
level.
• Rely on the diffusion of atmospheric oxygen into the effluent to ‘fuel’
microbial activity.
• Subject to vagaries of local weather.
• Have a relatively large land take.
• Work well if sized and designed properly.
• Robust
Passive Wetland Configurations
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Wetland Types
Passive Wetland Systems
• Horizontal Flow (HF)
• Vertical Flow (VF)
Intensive Wetlands • Forced Bed AerationTM
• Fill and Drain TAYA System
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Passive
Natural Systems
Active
Mechanical
Treatment
Systems
Area Requirements MOST LEAST
LEAST MOST Energy and O&M Needs
Water Treatment: Natural vs Mechanical
Intensive Treatment Systems
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Wetland Types
Intensive Wetlands • Forced Bed AerationTM
• Fill and Drain TAYA System
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Forced Bed Aeration™
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Forced Bed AerationTM
• A new technology for enhancing reed bed performance.
• Tried and tested in the USA.
• FBATM compliments existing reed bed technology.
• Increases treatment capacity of reed beds by up to 15 times.
• Adds flexibility to counter variability in loads.
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Forced Bed Aeration™
• Reduces variability in performance (counters climatic issues).
• Reduced area required (lowers capital costs).
• No constraints on bed dimensions or aspect ratio.
• 1 to 2m deep.
• Can be retrofitted into existing wetlands.
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Standard and Forced Reed Beds 02 transfer rates
Series1 0
20
40
60
80
100
120
140
160
Horizontal Flow 5g/m2/d
Vertical Flow 17-25 g/m2/d
Forced Bed Aeration up to 160 g/m2/d
Typical Oxygen Transfer Rates ForDifferent Reed Bed Systems
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Passive & Mechanical Systems Power Costs
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
kW
h /
m³
of
wast
ew
ate
r
Active Systems Passive Systems
FBA
Systems
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Wolseley Area: 72m2
Flow 0.54 - 7 m3/d
HRT: 3 – 37 days
Aeration 10 hrs
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Wolseley Bridge Ammonia Removal
14 hrs aeration
90% 98.9%
10 hrs aeration
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Balhall Area: 151m2 +31m2
Flow 5 m3/d
Aeration 18 hrs
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Balhall WwTW: Single Bed, Passive, VF system
207
86
55
26 35
26
0
50
100
150
200
250
BOD SS NH4
Balhall Passive Performance Spot Sample Averages
Suspended Solids, BOD, Ammonia
Influent Effluent
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Balhall WwTW: Two bed, Aerated, VF system
460.6
26.1 11.6
144.3
51.4
21.2
90.1
13.5 1.8
0.0
50.0
100.0
150.0
200.0
250.0
300.0
350.0
400.0
450.0
500.0
Settled Reed Bed 1 Out Reed Bed 2 Out
Balhall FBATM Performance Spot Sample Averages
Suspended Solids, BOD, Ammonia
BOD Suspended Solids Ammonia
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0
50
100
150
200
250
300
350
400
450
500
Sep-99 Sep-00 Sep-01 Sep-02 Sep-03 Sep-04
TAN
Concentr
ati
on [
mg/L]
Influent Effluent
New Pretreatment System and
Forced Bed Aeration ™ System
Iron fouling
No Aeration Startup
Jones County Landfill: Total Ammonia (TAN)
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Eichten Cheese CBOD Removal
0
1000
2000
3000
4000
5000
6000
7000
8000
Mar-9
8
Mar-9
9
Apr-9
9
Apr-9
9
Jun-9
9
Jul-9
9
Sep-9
9
Dec-9
9
Mar-0
0
Jun-0
0
Sep-0
0
Dec-0
0
Mar-0
1
Jun-0
1
Sep-0
1
Dec-0
1
Mar-0
2
Jun-0
2
Sep-0
2
Dec-0
2
Mar-0
3
Jun-0
3
Sep-0
3
Dec-0
3
Mar-0
4
Jun-0
4
Jun-0
5
CB
OD
5 (
mg
/L)
Eichten Cheese CBOD Removal
In Out
Intermitten
t Aeration
Forced Bed Aeration TM
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Buffalo Niagara International Airport Glycol removal from surface water
1.7 Ha, removing 4,500 kg/day
Heathrow trials
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Buffalo Airport De-icing Fluid Treatment
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Buffalo Niagara International Airport
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Intensive Wetland Systems
Forced Bed Aeration (FBATM)
• Increases Oxygen availability significantly.
• Increases wetland nitrification capacity 10 fold.
• More consistent performance, especially with beds in series.
• Reduced area requirements, can go deeper also.
• Denitrification options under investigation.
• Looking for an AD digestate trial.
• Power consumption.
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Wetland Types
Intensive Wetlands • Forced Bed AerationTM
• Fill and Drain TAYA System
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TAYA Treatment System
• Developed from reciprocating wetland technology.
• Engineered to maximise the efficiency of the
microbial biomass through nutrient management
and effective natural aeration.
• Proprietary open channel bottom pumping design,
maximises the use of gravity during operation, to
minimize power consumption, maintenance and
operational costs.
• Complete mix is achieved and thus maximum
dilution.
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The design of the wetland incorporates the filling and draining
of subsurface flow basins.
Minimum Head
• Pumping from the bottom
• Open Channel arrangement
Feed arrangement
• Max dilution
• Complete mix
TAYA Treatment System
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TAYA Treatment System
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TAYA Effluent TAYA Influent Anaerobic Ponds Influent mg/l
20 500 12,000 CBOD
30 250 15,000 TSS
40 - 100 900 900 -1,300 NH4
300 300 300 Flow
(m3/d)
Lahav Kibbutz : Summary Operational Data
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Lahav Kibbutz Piggery: Operational Data
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Lahav Kibbutz Piggery: Operational Data
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1/2/10 2/21/10 4/12/10 6/1/10 7/21/10 9/9/10 10/29/10 12/18/10 2/6/11 3/28/11 5/17/11 7/6/11 8/25/11
Value (ppm) Lahav - TN Removal
Influent
Effluent
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TAYA Treatment System
TAYA System
• Effective natural aeration.
• Flexibility through process control.
• Nitrification/Ammanox and denitrification.
• No sludge production.
• Small footprint even compared to FBATM.
• AD digestate systems being installed in Italy this year.
• Need a climate trial in the UK.
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Helmholtz Centre for
Environmental Research (UFZ)
Three research campuses Leipzig, Halle, Magdeburg 1,000 employees 180 post-grads and post-docs
Additional partners
… and massive support from many colleagues, friends, and family
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Fo
to:
Künze
lman
n/U
FZ
Septic Tank
(primary treatment)
Unsaturated vertical flow filters
Saturated vertical
flow with aeration
Horizontal flow Fill and
Drain
1m deep +
aeration
0.25m deep 0.5m deep
1-3mm Sand
periodic resting
1-3mm Sand, no
resting
4-8mm gravel,
no resting
8-16mm
gravel,
no resting
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Comparative Ammonia Removal
NH4-N
0
10
20
30
40
50
60
0 1 2 3 4 5 6
nHRT (days)
Co
nce
ntr
ati
on
(m
g/L
)
HF 1.0m Aerated + plants
HF 1.0m Aerated - plants
HF 0.25m + plants
HF 0.25m - plants
HF 0.5m + plants
HF 0.5m - plants
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Comparative Nitrate Generation
NO3-N
0
5
10
15
20
25
30
0 1 2 3 4 5 6
nHRT (days)
Co
nce
ntr
ati
on
(m
g/L
)
HF 1.0m Aerated + plants
HF 1.0m Aerated - plants
HF 0.25m + plants
HF 0.25m - plants
HF 0.5m + plants
HF 0.5m - plants
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Comparative Total N removal
Total N
0
10
20
30
40
50
60
70
80
0 1 2 3 4 5 6
nHRT (days)
Co
nc
en
tra
tio
n (
mg
/L)
HF 1.0m Aerated + plants
HF 1.0m Aerated - plants
HF 0.25m + plants
HF 0.25m - plants
HF 0.5m + plants
HF 0.5m - plants
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Total N removal summary
0
1
2
3
4
5
6
Unplanted Planted Unplanted Planted Unplanted Planted Unplanted
Horizontal Flow Aerated HF Vertical Flow FaD
System Design
TN
Ma
ss
Re
mo
va
l R
ate
(g/m
2.d
ay)
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Summary
• Passive Reed Bed/Constructed wetland systems can effectively
reduce total N levels when used in combination demonstrating
the principle of total N reduction in wetlands.
• Intensive systems through increased oxygen transfer rates can
achieve higher removal rates more consistently.
• FBATM systems show significant potential for AD digestate
treatment, though not yet proven, but looking for trials…
• The TAYA systems has already demonstrated high level
nitrification and denitrification and the first commercial AD
digestate treatment installations are being installed this year
in Italy. We are looking for UK climate trials …
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Thank you