Technologies for Sustainable
Wastewater Treatment
Nitrogen Removal from Sludge Dewatering Liquor
March 20, 2012 WATERCON 2012 2
Primary
Settler
Primary Sludge
(30 lbs. N)
Waste Activated Sludge
(140 lbs. N)
For every 1 mil. gal. of water treated:
330 lbs. N
March 20, 2012 WATERCON 2012 3
Anaerobic digestion
Primary
Settler
Sludge
Thickener
Anaerobic
Digester
Sludge
Dewatering Cake
N = 300 to 1,000 mg/L
~10% of influent load
4
Anaerobic digestion + imported sludge
Primary
Settler
Sludge
Thickener
Anaerobic
Digester
Sludge
Dewatering Cake
N x 2 N x 3 N x 1
March 20, 2012 WATERCON 2012 4
5
Anaerobic digestion + solids pretreatment
Primary
Settler
Sludge
Thickener
Anaerobic
Digester
Sludge
Dewatering Cake
N = 1,500 to 3,000 mg/L
March 20, 2012 WATERCON 2012 5
Reject Water Handling Alternatives
• Do Nothing
• Export
• Attenuate
• Treat
– Integrated treatment
– Separate treatment
March 20, 2012 WATERCON 2012 6
Do Nothing
WAS
RAS
Reject
Water
March 20, 2012 WATERCON 2012 7
Boulder 75th Street Wastewater Treatment Facility
Source: Fevig, et al, “Centrate Equalization – What You Don’t Control Can Hurt You”
WEFTEC 2011.
Export
• Regional districts w/ multiple plants
• To less sensitive watersheds
• To underloaded facility with capacity to handle additional solids
• New York City
Attenuation
• Flow equalization
• Continuous operation
• Stand-alone or incorporated with treatment
Source: Brown and Caldwell (1979) Equalization of flow in Wastewater Treatment.
Report prepared for the US EPA, EPA-600/2-79-096.
Don’t Reject the Idea of Treating Reject Water*
*Janus, H.M., and vanderRoest, H.F. (1997). Don't reject the idea of treating reject water. Wat.
Sci. Tech. 35 (10)27-34.
• Highly Concentrated - Small tank volumes
• Warm – Short SRT’s
• Bioaugmentation - Stable off-line source to boost main-stream SRT
March 20, 2012 WATERCON 2012 12
Integrated Treatment – in-line
RAS f 1 - f
March 20, 2012 WATERCON 2012 13
Integrated Treatment – off-line
Nitrate to Headworks
March 20, 2012 WATERCON 2012 14
Integrated Treatment: in-line
Full-scale facility Capacity
(mgd) Process Drivers
NYC 26th Ward WPCP
85 AT-3 Effluent Total Nitrogen, centralized solids handling (bioaugmentation)
Los Angeles Valencia WRP
15 - Effluent Total Nitrogen, centralized
solids handling
Appleton, WI WWTP
15.7 BAR Effluent Ammonia (bioaugmentation)
Inland Empire Carbon Canyon
9.5 Carbon Canyon TIN bubble permit
Lincoln, NE WTF
24 Prenitrification Effluent Ammonia (bioaugmentation)
March 20, 2012 WATERCON 2012 15
Lincoln, NE Theresa St. WWTF
Source: Sova, R. et al, WEFTEC 2008. March 20, 2012 WATERCON 2012 16
Lincoln, NE Theresa St. WWTF
March 20, 2012 WATERCON 2012 17
Solution: Prenitrification of Filtrate
• Alkalinity from RAS
• Increased temperature – + 20% growth rate
• Enriched source of nitrifiers to increase effective SRT in main-stream
• Up to 82% removal demonstrated at 10% to 100% RAS (HRT = 10.5 to 3.2 hours)
March 20, 2012 WATERCON 2012 18
Integrated treatment: off-line
Full-scale Facility Capacity
(mgd) Process Drivers
Phoenix 91st Ave. Multi-Cities WWTP
230 Activated Sludge (flow-through)
Digester Upgrade, Effluent Total Nitrogen, odor
control
Winnipeg, Canada North End WPCC
53 SBR Centralized solids handling, Effluent Ammonia & Total
Nitrogen (Bioaug./cold)
Dallas Southside WWTP
110 Activated Sludge (flow-through)
Centralized solids handling
Richmond, VA WWTP
80 In-Nitri Effluent Total Nitrogen (Bioaug./storm-cold)
Muncie, IN WPCF
24 Activated Sludge (flow-through)
Effluent Ammonia
March 20, 2012 WATERCON 2012 19
Phoenix 91st Ave. Multi-Cities WWTP
• Upgrade to multi-phase digestion
– 1,300 mg NH3-N/L (27% of PE)
• 10 mg / L Total N effluent permit limit.
• H2S emission limit at property line
March 20, 2012 WATERCON 2012 20
91st Ave. Multi-Cities Centrate Treatment Facility
Source: Husband, J. et al, Water Science & Technology, vol. 61 n. 5, 2010 March 20, 2012 WATERCON 2012 21
Solution: nitrify centrate to reduce recycle ammonia load
March 20, 2012 WATERCON 2012 22
91st Avenue Multi-Cities WWTP
Raw Vs. Pri Effl Ammonia (mg/L)
20
24
28
32
36
40
2005 2006 2007 2008 2009
Raw Ammonia (mg/L) Primary Effluent Ammonia (mg/L)
H: 91 Monthly Averages.xls
CTF on-line 03/24/08
Source: Husband, J. et al, Water Science & Technology, vol. 61 n. 5, 2010 March 20, 2012 WATERCON 2012 23
Solution: Discharge to headworks to oxidize sulfides
March 20, 2012 WATERCON 2012 24
0
5
10
15
20
25
30
35
40
45
Ga
seo
us
H2S
, p
pm
Time
Centrate Treatment Off
Average H2S - 12 ppm
Maximum H2S - 32 ppm
Centrate Treatment On
Average H2S - 6 ppm
Maximum H2S - 21 ppm
Source: Husband, J. et al, Water Science & Technology, vol. 61 n. 5, 2010
Separate Treatment
Full-scale Facility Capacity
(mgd) Process Drivers
NYC Ward’s Island 230 SHARON Total Nitrogen TMDL (Long Island
Sound), centralized solids handling
HRSD York River Treatment Plant
15 DEMON Total Nitrogen TMDL
(Chesapeake Bay)
ASA, Alexandria, VA 54 DEMON Total Nitrogen TMDL
(Chesapeake Bay)
NYC 26th Ward 85 ARP NYCDEP Nitrogen Control Plan
(Jamaica Bay), centralized solids handling
March 20, 2012 WATERCON 2012 25
1 mole Ammonia
(NH3 / NH4+)
1 mole Nitrite
(NO2-)
1 mole Nitrate
(NO3-)
1 mole Nitrite
(NO2-)
1/2 mole Nitrogen gas
(N2)
75% O2
25% O2 40% Carbon
60% Carbon
Nitrification /
Denitrification
Aerobic Anoxic
March 20, 2012 WATERCON 2012 26
1 mole Ammonia
(NH3 / NH4+)
1 mole Nitrite
(NO2-)
1 mole Nitrate
(NO3-)
1 mole Nitrite
(NO2-)
1/2 mole Nitrogen gas
(N2)
75% O2
25% O2 40% Carbon
60% Carbon
Nitritation /
Denitritation
Aerobic Anoxic
March 20, 2012 WATERCON 2012 27
Nitrogen removal over nitrite
• Temperature
• D.O.
• pH
March 20, 2012 WATERCON 2012 28
Nitritation-Denitritation
• Continuous / no sludge retention (SHARON®) - 13 facilities
• SBR (B.A.B.E. ®, STRASS) – 2 facilities
• North America – 1 SHARON® (NYC)
March 20, 2012 WATERCON 2012 29
SHARON® configurations
Complete Mix
Plug Flow
Concentric
MeOH
March 20, 2012 WATERCON 2012 30
WWTP Zwolle (NL) SHARON® reactors
• 200,000 p.e.
• 160,000 gpd / 900 lbs. N / day
• 2 reactors -238,000 gal. / 119,000 gal.
Source: Mulder, J.W., Duin, J., et al, “Full-scale experience with the SHARON process through
the eyes of the operators”, WEFTEC 2006. March 20, 2012 WATERCON 2012 31
SHARON® operation
Source: Mulder, J.W., Duin, J., et al, “Full-scale experience with the SHARON process through
the eyes of the operators”, WEFTEC 2006. March 20, 2012 WATERCON 2012 32
1 mole Ammonia
(NH3 / NH4+)
1 mole Nitrite
(NO2-)
1 mole Nitrate
(NO3-)
1 mole Nitrite
(NO2-)
1/2 mole Nitrogen gas
(N2)
75% O2
25% O2 40% Carbon
60% Carbon
Aerobic Anoxic
Deammonification
Anaerobic March 20, 2012 WATERCON 2012 33
Deammonification
• SBR (DEMON®) 11 facilities
• MBBR 2 facilities
• Upflow granulation 7 facilities
• North America – 2 (under construction)
March 20, 2012 WATERCON 2012 34
Alexandria Sanitation Authority AWTF
Source: Johnson, T, et al, A Universal SBR Design Concept for Sidestream Nitrogen
Removal, North Carolina AWWA-WEA 2010 Annual Conference.
WWTP Strass, Austria
Source: Bernhard Wett, Water Science & Technology, Vol. 56 No. 7, 2007. March 20, 2012 WATERCON 2012 36
DEMON® Operation
Source: Bernhard Wett, Water Science & Technology, Vol. 56 No. 7, 2007. March 20, 2012 WATERCON 2012 37
DEMON® energy
Source: Bernhard Wett, Water Science & Technology, Vol. 56 No. 7, 2007. March 20, 2012 WATERCON 2012 38
March 20, 2012 WATERCON 2012 39
Ammonia Stripping
• Air stripping – 8 facilities
• Steam stripping – 1 facility
• Vacuum distillation (ARP) – 1 (under construction)
ARP
Courtesy of ThermoEnergy Corporation
March 20, 2012 WATERCON 2012 40
Costs
Process Capital Cost
N removed (lbs./day)
SHARON - NYC $71.5 million 10,000
Integrated Treatment - Winnipeg
$25 million 3,000
ARP - NYC $27 million 6,600
March 20, 2012 WATERCON 2012 41
March 20, 2012 WATERCON 2012 42
Robert Smith, P.E., BCEE, Ph.D. [email protected]