Mainstream Deammonification: Current Projects and Status. S. Murthy, B. Wett and M. van Loosdrecht

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1 Mainstream Deammonification: Current Projects and Status S. Murthy, B. Wett and M. van Loosdrecht

2 Incentives for Mainstream Deammonification? Carbon redirection from aerobic treatment to anaerobic digestion for improved energy balance (A/B process e.g. at WWTP Strass and WWTP Rotterdam) Enhanced N-removal efficiency Mitigating alkalinity limitations

digestion for improved energy balance (A/B process e.g. at WWTP

3 C:N ratio will drive combination of nitritation/denitritation and mainstream deammonification High Rate, CEPT or A-Stage: % COD removal Typical C:N Ratios: CEPT 3:1 to 6:1 (add Fe ) A- Stage 3:1 to 10:1 (SRT of 0.25d to 0.5 d) influent A-stage B-stage effluent SBR thickener dewatering digester biosolids 3

Ratios: CEPT 3:1 to 6:1 (add Fe ) A- Stage 3:1 to 10:1 (SRT of 0.25d to 0.

4 Fundamentals of Nitrification - Denitrification Autotrophic Aerobic Environment 1 mol Nitrate (NO 3- ) Heterotrophic Anoxic Environment 40% Carbon 25% O 2 1 mol Nitrite (NO 2- ) 1 mol Nitrite (NO 2- ) 60% Carbon 75% O 2 1 mol Ammonia (NH 3 / NH 4 + ) Oxygen demand 4.57 g / g NH + 4-N oxidized Carbon demand 4.77 g COD / g NO - 3-N reduced ½ mol Nitrogen Gas (N 2 )

1 mol Nitrite (NO 2- ) 60% Carbon 75% O 2 1 mol Ammonia (NH 3 / NH 4 + ) Oxygen demand 4.

5 Fundamentals of Deammonification Autotrophic Aerobic Environment 1 mol Nitrate (NO 3- ) ANAMMOX Heterotrophic Anaerobic Ammonium Anoxic Environment Oxidation Autotrophic Nitrite Reduction (New Planctomycete, 40% Carbon Strous et. al. 1999) NH NO HCO H + 25% O NO N CH 2 O 0.5 N H 2 O 1 mol Nitrite 0.57 mol (NO ) 1 mol Nitrite (NO 2- ) 60% Carbon Partial Nitrification 75% 40% O 2 1 mol Ammonia (NH 3 / NH 4 + ) Oxygen demand 1.9 g / g NH + 4-N oxidized ½ 0.44 mol mol Nitrogen N GasNO - 3 (N 2 )

13 H + 25% O 2 0.26 NO 3- + 1.02N 2 + 0.066 CH 2 O 0.5 N 0.15 + 2.03 H 2 O 1 mol Nitrite 0.

6 Net energy consumption for 3 WWTP variants Case A: Conventional treatment Case B: Conventional treatment with anammox in the side-stream Case C: Optimized treatment with anammox in the main-stream Reference H. Siegrist, D. Salzgeber, J. Eugster, A. Joss, Water Sci. Technol. 57, 383 (2008).

Case C: Optimized treatment with anammox in the main-stream Reference H.

7 Level of innovation How mature is deammonification technology? Main-stream Deammonification Emerging technology Side-stream Deammonification State of the Art Conventional N-removal technologies Established

8 Sidestream Deammonification Configurations Reactor configuration examples: SBR-type Process DEMON Attached growth MBBR process Deammon AnitaMox Upflow granulation process CANON/Anammox DEMON SBR MBBR Upflow Granulation Process

growth MBBR process Deammon AnitaMox Upflow granulation

9 Side-stream applications: DEMON DEMON-features ph-based process control cyclone for anammox enrichment

10 Side-stream applications: Paques Granular Sludge Anammox Features Granular Sludge Based Continuous Aeration Load controlled

11 How to implement anammox bacteria in municipal wastewater treatment? Find new ways to outcompete NOB s High effluent quality required compared to side stream Low process temperature, slow growing bacteria Reliable anammox biomass retention required Higher C/N ratio heterotrophs dilute the autotrophic biomass Biomass selection to enhance short-cut metabolism depends on diffusion resistance provided from process environment (apparent half-saturation values for inhibitions and limitations)

growing bacteria Reliable anammox biomass retention required Higher C/N ratio heterotrophs dilute the autotrophic biomass

12 Mechanisms for NOB-repression? Competition (growth or bioaugmentation of competitors; Heterotrophs and anammox for nitrite; Heterotrophs and AOB for oxygen) Outselection by unfavorable process conditions (DO-level,...) Lag-phase in nitrite availability (intermittent aeration) Inhibiting or toxic impacts on NOB (e.g. NH3, NO,...) - Oxygen - Nitrite lag

nitrite; Heterotrophs and AOB for oxygen) Outselection by unfavorable process conditions

13 Anammox- Diffusion Resistance Sidestream Process Niche Environments Integrated Fixed Film AS Moving Bed Biofilm Reactor Substrate/Inhibitor Diffusion Resistance Activated Sludge Lowest Granular Sludge- Moderate Carrier Biofilm- Highest D Activated Sludge with Cyclone Granular Sludge Full-Scale Implementation Examples: Activated Sludge = DEMON (2004) AS w/ Cyclone = DEMON (2007) Granular Sludge= CANON/Anammox IFAS = BDG Configuration MBBR = Anitamox, Deammon Activated Sludge Ammonia Oxidizing Bacteria - Diffusion Resistance

Sludge with Cyclone Granular Sludge Full-Scale Implementation Examples: Activated Sludge = DEMON (2004) AS w/ Cyclone = DEMON

14 Anammox- Diffusion Resistance Mainstream Process Niche Environments Integrated Fixed Film AS Moving Bed Biofilm Reactor Substrate/Inhibitor Diffusion Resistance Activated Sludge Lowest Granular Sludge- Moderate Carrier Biofilm- Highest D Activated Sludge with Cyclone Granular Sludge Activated Sludge Perhaps possible in tropical climates. Anammox retention approaches needed for colder temperatures Ammonia Oxidizing Bacteria - Diffusion Resistance

Biofilm- Highest D Activated Sludge with Cyclone Granular Sludge Activated Sludge Perhaps possible in tropical

15 Anammox enrichment options Anammox enrichment Anammox Bioaugmentation from the sidestream Anammox Retention (long SRT maintained in granules or biofims)

17 Anammox Retention Approaches Granulation: 1) Settlers (internal or external) 2) Cyclones 3) Sieves Biofilm: 4) Plastic Media

18 Anammox- Diffusion Resistance Mainstream Process Niche Environments Integrated Fixed Film AS Activated Sludge with Cyclone Uncouple SRTs for AnAOB and AOB/NOBs Ammonia Oxidizing Bacteria - Diffusion Resistance

Activated Sludge with Cyclone Uncouple SRTs for

19 WERF-Mainstream Deammonification Project 3 different sites and scales DC Water WWTP Strass HRSD

20 Oxygen- and nitrogen affinities SNPR (mgn/gvss.d) Specific growth rate (1/d) Specific growth rate (1/d) From: Current WERF Study Extracted From: Chandran and Smets (2005) Water Research, 39, A - AOB A - NOB AOB Monod NOB Monod AOB Dissolved Oxygen, mg/l AOB NOB DO (mg/l) NOB Ammonia (AOB) or nitrite (NOB), mg-n/l

and Smets (2005) Water Research, 39, 4969 200 180 160 140 120 100 80 60 40 20 0 1 0.8 0.6 0.4 0.

21 MODEL PARAMETER CALIBRATION Simulation Results DO Profiles N Profiles AMX Activity High/Intermittent aeration -21-

22 Demonstration of mainstream deammonification Carousel type aeration tank at Strass WWTP providing a DOrange of 0 to 1.7 mg/l along the flow-path. DO= mg/l 0.19 mg/l 0.35mg/L 0.6mg/L 0.09mg/L mg/L Cyclones installed at the B- stage in Strass, Cyclone A (left), Cyclone B since early September 2011 (right).

23 temperature ( C) PE (60gBOD) /2011 loading PE 2011/2012 loading PE Full-scale experiments at WWTP Glarnerland Dec 31-Dec 30-Jan 29-Feb 30-Mar 29-Apr 29-May plant loading profiles (PE) before and after project start 2010/2011 temperature 2011/2012 temperature 1-Dec 31-Dec 30-Jan 29-Feb 30-Mar 29-Apr 29-May comparison of temperature profiles ( C)

24 nitrogen concentration (mg N/L) nitrogen concentration (mg N/L) /2011 NO3-N effluent 2010/2011 NO2-N effluent 2011/2012 NO3-N effluent 2011/2012 NO2-N effluent Full-scale experiments at WWTP Glarnerland Dec 31-Dec 30-Jan 29-Feb 30-Mar 29-Apr 29-May Comparison of this year s and last year s operational data of the full-scale pilot Strass indicating advanced NOB-repression (typically high nitrate level at Christmas peak-load; similar temperature conditions of ca. 10 C, load conditions and ammonia effluent concentrations of ca. 2-5 mgn/l for both years) /2011 NH4-N influent 2010/2011 NH4-N effluent 2011/2012 NH4-N influent 2011/2012 NH4-N effluent Total SRT 1-Dec 31-Dec 30-Jan 29-Feb 30-Mar 29-Apr 29-May

25 The last samples show ammonia removal during anaerobic activity test (anammox activity) Only 25% of NOx produced from ammonia oxidation is converted to nitrate during aerobic activity test of the last sample

26 Nitrite shunt at PUB s Changi WRP in Singapore Step-feed BNR operated at 2.5 d aerobic SRT shows higher nitrite vs nitrate effluent values: NH4-N NO2-N NO3-N Avg Q= m3/d (PUB; Dr. Yeshi Cao)

27 Anammox- Diffusion Resistance Mainstream Process Niche Environments D Granular Sludge Moving Bed Biofilm Reactor Provide conditions for AnAOB inside granule and AOB/NOBs surface of granule Ammonia Oxidizing Bacteria - Diffusion Resistance

28 Biomass Segregation in Granular Sludge NOB seem to be outcompete in larger granules NOB, Anammox, AOB NOB have preference for small granules Selection criterium

29 Test reactor Fed with A-stage effluent Amended with nitrite Pure anoxic 3 gvss/l Conversion capacity at 2.5 kgn/m3.day at 15 C Effective growth of anammox bacteria No negative effect of wastewater COD Growth of anammox bacteria at low T and wastewater conditions is no limitation

30 WWTP Dokhaven Pilot Size 4 m3 A-stage effluent C 75 mgcod/l 30 mg NH4-N/L Granulation O.K.

31 Pilot-scale reactor Process Parameters: Actual A-stage effluent Continuous system TPS COD: 75 mgcod/l NH 4 : mg-n/l COD/N ratio: ~ 2 Volume reactor: 4 m 3 Biomass: ~ 5 gvs/l DO: mg/l Results: Removal Rate: Tot N: 0.03 kgn/m 3 /d Max Tot N: 0.31 kgn/m 3 /d Current B-stage removal rate:: kgn/m 3 /d granules retained in the system No entrapment of influent solids

32 Summary and conclusions: Different technologies providing different diffusion resistance Per se nothing good or bad about diffusion resistance Real half-saturation values are close to zero while apparent half-saturation is mainly affected by diffusion Each technology needs to differentiate niche environments to provide appropriate SRT and diffusion conditions for selected microbial community

33 Summary and conclusions: Potential NOB-outselection strategies Aggressive Aerobic SRT Management Ammonia Residual (online ammonia control) AOB Bioaugmentation Granule size High DO Intermittent Aeration with rapid Transitions to Anoxia

Development and implementation of a robust deammonification process

Development and implementation of a robust deammonification process B. Wett Institute of Infrastructure/Environmental Engineering, University of Innsbruck Technikerstr.13, A-62 Innsbruck, Austria, (e-mail: