MAINSTREAM DEAMMONIFICATION

Transcription

1 MAINSTREAM DEAMMONIFICATION Mark W. Miller 2015 VWEA Education Seminar April 30 th, 2015 Charles Bott HRSD, Sudhir Murthy DC Water, Bernhard Wett ARA Consult GmbH

2 Outline Conventional BNR to Mainstream Deammonification Mainstream Deammonification Strategies Anammox Retention Maximize AOB Growth Rates NOB Out-selection AVN (Ammonia versus NOx-N) Control AIZ Demonstration Study DC Water Pilot Study HRSD Pilot Study Ongoing Research

3 CONVENTIONAL BNR TO MAINSTREAM DEAMMONIFICATION

4 Nitrification/Denitrification (1.0) Autotrophic Aerobic Environment 1 mole Nitrate (NO 3- ) Heterotrophic Anoxic Environment 25% O 2 (energy) 75% O 2 (energy) 100% Alkalinity (caustic) 1 mole Ammonia (NH 3 / NH 4 + ) 1 mole Nitrite (NO 2- ) Nitrite Oxidizing Bacteria (NOB) Ammonia Oxidizing Bacteria (AOB) 40% Org C 1 mole Nitrite (NO 2- ) 60% Org C ½ mole Nitrogen Gas (N 2 )

5 Nitrite Shunt/SND (2.0) Autotrophic Aerobic Environment Heterotrophic Anoxic Environment 75% O 2 (energy) 100% Alkalinity (caustic) 1 mole Ammonia (NH 3 / NH 4 + ) 1 mole Nitrite (NO 2- ) Ammonia Oxidizing Bacteria (AOB) 1 mole Nitrite (NO 2- ) 60% Org C ½ mole Nitrogen Gas (N 2 ) Potential Advantages: 25% reduction in oxygen demand (energy) 40% reduction in carbon demand 40% reduction in biomass production

6 Deammonification (3.0) Anaerobic Ammonia Oxidizing Bacteria = Anammox Autotrophic Aerobic Environment 37% O 2 (energy) ~50% Alkalinity 1 mole Ammonia (NH 3 / NH 4 + ) 0.5 mole Nitrite (NO 2- ) AOB Autotrophic Anoxic Environment Anammox Bacteria ½ mole Nitrogen Gas (N 2 ) + a little bit of nitrate (NO 3- ) Potential Advantages: 63% reduction in oxygen demand (energy) Nearly 100% reduction in carbon demand 80% reduction in biomass production

7 Limitation of Mainstream Deammonification 100% NOB out-selection, which convert NO 2 -N to NO 3 - N, may not be possible under mainstream conditions 11% NO 3 -N production by anammox bacteria, therefore, theoretically only 89% N removal is possible Heterotrophs can reduce NO 3 -N but if C/N is too high they will out-compete anammox for NO 2 -N

8 MAINSTREAM DEAMMONIFICATION STRATEGIES

9 Managing Populations Anammox Bacteria Selective retention in mainstream Bioaugmentation from sidestream deammonification Maximize AOB Growth Rates Maximize substrate (ammonia), electron acceptor (DO), and inorganic carbon (alkalinity) availability AOB bioaugmentation from sidestream deammonification Minimize inhibition Minimize OHO competition for DO and space NOB Out-Selection Aggressive aerobic SRT management Intermittent aeration with rapid transitions to anoxia Maximize inhibition Maximize substrate competition from OHO and anammox bacteria

10 C/N Ratio is an Important Factor for N Removal Pathway Conventional Nitrification/Denitrification Nitrite Shunt Deammonification High C/N 6-10/1 range? Heterotrophs Dominate Medium C/N 3-5/1 range? Low C/N 1-3/1 range? Mostly Anammox

11 Carbon Removal Alternatives Primary Sedimentation >10 C/N dependent on influent C/N 20-30% COD removal (no scod removal) A-stage (HRAS) 3-10 C/N (SRT days) 40-70% COD removal Chemically enhanced primary treatment (CEPT) 3-6 C/N with coagulation/flocculant addition 50-80% COD removal (some scod removal) High-rate activated sludge (or chemically enhanced A-stage) 1-2 C/N 70-90% COD removal

12 ANAMMOX RETENTION

13 Full-scale experiments at WWTP Glarnerland

14 Anammox enrichment in the Cyclone-underflow

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16 Anammox enrichment in the Cyclone-underflow

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18 MAXIMIZE AOB GROWTH RATES

19 Specific growth rate (1/d) Maintain Residual TAN > 1.5 mg/l Ammonia levels and temperature are too low for NH 3 (FA) inhibition High ammonia loading rates favor AOB growth rates Residual ammonia ensures AOB grow closer to their maximum growth rate at all times Monod Curves for AOB and NOB 1.0 mu-aob mu-nob mg/l (AOB:NH 4+ -N, NOB:NO 2- -N)

20 Operate at DO > 1.5 mg/l High DO (>1.5 mg/l) allows AOB (r-strategist) to grow close to their maximum rate and out-select NOB (Kstrategist) 400 Monod Curves for AOB and NOB Activity (mgn/l.d) DO (mg/l) AOB rate NOB rate Monod model NOB fit Monod model AOB fit

21 MAINSTREAM NOB OUT-SELECTION 21

22 Intermittent Aeration with Rapid Transitions to Anoxia Competition for NOB substrate by OHO or anammox NOB lag induced by periods of anoxia

23 Aggressive SRT Control Operate the system at an SRT close to AOB washout Maximizes AOB rates Washout NOB if AOB rates > NOB rates Needs to be automated since operating with small SRT safety factor Can be based on aerobic fraction or in situ AOB rates

24 AVN (AMMONIA VS NOX-N)

25 AVN Aeration Control DO = set point DO Controller/ PLC Aerobic Duration Controller/ PLC NOx-N/NH4-N = setpoint NH4-N D.O. D.O. D.O. D.O. NO2-N NO3-N Residual Ammonia High DO Transient Anoxia Aerobic SRT control M S Air Regmi, P., Miller, M. W., Holgate, B., Bunce, R., Park, H., Chandran, K., et al (2014). Control of aeration, aerobic SRT and COD input for mainstream nitritation/denitritation. Water Research, 57, Pérez, J., Lotti, T., Kleerebezem, R., Picioreanu, C., & Loosdrecht, M. C. M (2014). Outcompeting nitrite-oxidizing bacteria in single-stage nitrogen removal in sewage treatment plants: a model-based study, doi: /j.watres

26 AVN Aeration Control in Action Nitrogen (mg/l) Aerobic Fraction NH4-N NO2-N NO3-N NOx-N A Aerobic Fraction Dissolved Oxygen (mg/l) Dissoved Oxygen (mg/l) hour B DO hour

27 AIZ (ACHENTAL-INNTAL-ZILLERTAL) DEMONSTRATION STUDY AT THE STRASS WWTP

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29 Strass WWTP Demonstration Study Carousel type aeration tank at Strass provides a DO range of 0 to 1.7 mg/l along the flow-path Can be operated in parallel or in series Ammonia-based aeration control Future operation will include AVN aeration control DO= mg/l 0.19 mg/l 0.35mg/L 0.6mg/L 0.09mg/L mg/L

30 nitrogen concentration (mg N/L) nitrogen concentration (mg N/L) Comparison Full-scale experiments of Operational WWTP Glarnerland Data Indicating NOB Out-selection Typically experience high nitrate levels during Christmas peak load Similar temperature (~10 C), load, and ammonia effluent concentrations (2-5 mgn/l) for both years /2011 NO3-N effluent 2010/2011 NO2-N effluent 2011/2012 NO3-N effluent 2011/2012 NO2-N effluent Dec 21-Dec 10-Jan 30-Jan 19-Feb 10-Mar 30-Mar 19-Apr 9-May 29-May /2011 NH4-N influent 2010/2011 NH4-N effluent 2011/2012 NH4-N influent 2011/2012 NH4-N effluent Dec 21-Dec 10-Jan 30-Jan 19-Feb 10-Mar 30-Mar 19-Apr 9-May 29-May

31 Volumetric N Loading (kgn/m 3 /day) Effluent TN (mg/l) N-removal Efficiency of the Strass WWTP 0.20 specific N-load [kgn/m3/d] total N_B [mg/l]

32 DC WATER PILOT STUDY AT THE BLUE PLAINS ADVANCED WATER TREATMENT FACILITY

33 Blue Plains AWTP 370 mgd (AA) to 518 mgd (Max Day) TN ~3-4 mg/l & TP < 0.18 mg/l 12 C winter monthly average Potomac River Final Dualmedia Filters Nitrification Denitrification Clarifiers Nitrification Denitrification AS reactors Highrate AS reactors Secondary Clarifiers Bar Screens and Grit Chambers Primary Clarifiers

34 Relevant CIP Projects at Blue Plains New Biosolids Management Program Enhanced Nutrient Removal Facilities Upgrade & expansion of the Nit/ Denit system High Rate Process Rehabilitation New Filtrate Treatment Process

35 The Road to Sustainable and Efficient Nitrogen Management 1. A-Stage Maximize carbon capture 2. Biosolids Maximize energy recovery 3. B-Stage Minimize carbon & energy demand for N & P removal

36 Sequential Oxic/Anoxic Mainstream Pilot Study

37 Volumetric removal rates (mg N/L/d) Nitrogen concentration (mgn/l) DO (mg/l) Nitrogen Concentrations in Space Cell number in Pilot 400 Nitrogen Volumetric Removal Rates NH4 NO2 NO cell 1 cell 2 cell 3 cell 4 cell 5 cell 6 cell 7 cell 8 cell 9 cell 10 NH3 NO2 NO3 Ntot

38 HRSD PILOT STUDY AT THE CHESAPEAKE- ELIZABETH TREATMENT PLANT

39 Chesapeake-Elizabeth Treatment Plant Screening FeCl 3 FeCl 3 Chlorine Contact Raw Wastewater Grit Removal High Rate Aeration Tanks (SRT=1.5 to 2 days) WAS RAS Gravity Thickener Discharge to Chesapeake Bay Multiple Hearth Incinerators Centrifuge CH 4 ASH Parameter Value Design Flow (MGD) 24 Operating Flow (MGD) Annual TP Limit (mg P/L) 2 TN Limit (mg N/L) N/A

40 Adsorption/Bio-oxidation Process AER A-stage RAS PCL WAS PSL B-stage MLE ANX AER AER SCL Shortcut N Removal Nitrite Shunt SND Deammonification MLR RAS WAS TN TN < 5 mg/l TN mg/l Advantages Increased sludge production Redirect carbon for energy recovery Low aeration energy requirement Lower overall volume (or increased removal capacity) Disadvantages Chemical addition for P removal B-stage is C limited A-stage lacks process control 40

41 HRSD CE BNR Pilot Study A-stage HRAS B-stage AVN Anammox MBBR WAS Inf Air IMLR RWI Influent Air RAS RAS WAS

42 NITRATE POLISHING

43 Anoxic Organisms - NO 3 NO 2 - N 2 NH 4 + NO 2 - N 2 OHO Anammox NO 3 - scod CO 2 New Biomass COD (VFA) CO 2 NO 3 - Novel Anammox No biomass from COD NO 2 - Kartal, B., Kuypers, M.M.M., Lavik, G., Schalk, J., Op den Camp, H.J.M., Jetten, M.S.M., Strous, M Anammox bacteria disguised as denitrifiers: nitrate reduction to dinitrogen gas via nitrite and ammonium. Environmental Microbiology 9,

44 Nitrate Removal with Limited COD Addition Acetate (COD) AVN effluent COD added/inf Nitrate NO 2 -N removed/nh 4 -N removed = 1.32 (Anammox Stoichiometry)

45 Ongoing Research Continued work on COD removal mechanisms and control strategies for CEPT, HRAS, A-stage, and high-rate CSAS Implementation of AVN controller at the Strass WWTP NO and N 2 O inhibition and NOB lag Impact of mainstream deammonification on GHG emissions

46 Collaborators