Deammonification for Cost-Effective Sidestream Treatment

Transcription

1 Deammonification for Cost-Effective Sidestream Treatment MWEA Process Seminar November 8, 2017 Lucy Pugh, P.E., BCEE Vice President Wastewater Technical Practice Leader

2 Overview 1. What is deammonification? - the fundamentals 2. Why deammonification? 3. Sidestream deammonification DEMON suspended growth AnitaMox attached growth ANAMMOX granular sludge 4. Mainstream deammonification

3 Fundamentals of Deammonification

4 Fundamentals of Nitrification - Denitrification Autotrophic Nitrification Aerobic Environment 1 mol Nitrate (NO 3- ) Heterotrophic Denitrification 40% Carbon Anoxic Environment 25% O 2 1 mol Nitrite (NO 2- ) 1 mol Nitrite (NO 2- ) 60% Carbon 75% O 2 100% Alkalinity 1 mol Ammonia (NH 3 / NH 4 + ) ½ mol Nitrogen Gas (N 2 ) Oxygen demand 4.57 g / g NH + 4-N oxidized Carbon demand 4.77 g COD / g NO - 3-N reduced

5 Fundamentals of Nitritation - Denitritation Autotrophic Nitritation Aerobic Environment 25% O 2 1 mol Nitrate (NO 3- ) 25% reduction in oxygen 40 % reduction in carbon demand 40% reduction in biomass production Heterotrophic Denitrification 40% Carbon Anoxic Environment 1 mol Nitrite (NO 2- ) 1 mol Nitrite (NO 2- ) 60% Carbon 75% O 2 100% Alkalinity 1 mol Ammonia (NH 3 / NH 4 + ) ½ mol Nitrogen Gas (N 2 ) Oxygen demand 3.42 g / g NH + 4-N oxidized Carbon demand 2.86 g COD / g NO - 3-N reduced

6 Fundamentals of Deammonification Partial Nitritation Aerobic Environment 1 mol Nitrate (NO 3- ) ANAMMOX Deammonification Anaerobic Ammonium Oxidation Autotrophic Nitrite Reduction (New Planctomycete, 40% Carbon Strous et. al. 1999) > 60% reduction in oxygen NH NO HCO H Eliminate demand for supplemental + carbon 25% O 2 50% 0.26 of NO the 3- alkalinity N 2 demand CH 2 O 0.5 N H 2 O 0.57 mol NO 2 - Partial Nitritation 40% O 2 50% Alkalinity 1 mol Ammonia (NH 3 / NH 4 + ) 0.44 mol N NO 3 - Oxygen demand 1.9 g / g NH + 4-N oxidized

7 Why Deammonification? - A Strategy for Energy Neutrality

8 kw-hr / kg N removed Overall Benefit of Deammonification Processes Eliminates need for carbon - available for energy recovery Significant reduction in energy demand possible Reduction in alkalinity demand 7 Typical Energy Demand Ranges Nitrification / Denitrification Nitritation / Denitritation Deammonification (a.k.a. ANAMMOX)

9 Distribution of Energy Usage for a Typical BNR WWTP Belt Filter Press 1% Anaerobic Digestion 9% UV Disinfection 4% Chlorination 0% Centrifuge 8% Lighting & Misc. 2% Pumping & Screening 7% Aerated Grit Removal 1% Primary Clarifiers 1% Gravity Belt Thickener 1% Dissolved Air Flotation 7% Gravity Thickening Activated-sludge 0% Aeration 55.6% Filtration 2% Filter Feed Pumping 4% Chemical Addition 2% Secondary Clarifiers 1% RAS Pumping 2% Aeration 48% 400 MLD (105 mgd) Nitrifying Activated Sludge Facility

10 The Road to Sustainable and Efficient Nitrogen Management 1. A-Stage maximize carbon capture 2. Biosolids maximize energy recovery 3. B-Stage minimize carbon and energy demand for nutrient management

11 Sidestream Deammonification Technologies

12 Centrate / Filtrate Characteristics Refuse Screening Primary clarifier Biological treatment Sand, grease Sidestream Treatment Thickener Digester Secondary clarifier Gas holder River CHP Reduce Effluent TN by 20% Sludge disposal / beneficial reuse Dewatering 1% plant influent flow Rich in nitrogen and phosphorus 15 to 25% plant influent TN load Ammonia: 500 to 3,000 mg-n/l Phosphorus: 200 to 800 mg-p/l Temperature: 30 to 38 C Insufficient alkalinity for complete nitrification Insufficient carbon for denitrification 13

13 Challenges of Sidestream Deammonification Low growth rate approximate 10 day doubling time at 30 C <10 day has been reported (Park et. al days) SRT (>30 days) Sensitive to: Nitrite Toxic- irreversible loss of activity based on concentration and exposure time NH 4 + : NO 2- ratio 1 : 1.32 DO - reversible inhibition Free ammonia (<10-15 mg/l) Temperature >30 C preferred ph (neutral range)

14 Sidestream Nitritation NOB Repression Control Elevated NH 3 -N concentrations Elevated temperature (30-35 deg C) Low SRT (1-2 days) Low DO (~0.5 mg/l) NOB Repression Mechanisms Free NH 3 N inhibition of NOB > AOB Nitrous acid inhibition of NOB > AOB AOB max growth rate > NOB max growth rate at high temperatures AOB DO affinity > NOB DO affinity (perhaps only at high temperatures)

15 Deammonification Technologies DEMON Suspended Growth SBR World Water Works 54 facilities in operation York River, VA; Alexandria, VA; Blue Plains, DC Cleargreen Suspended Growth SBR Infilco Degremont 3 pilots / 3 plants in design TerraMox Hybrid Suspended and Attached Clariant/SÜD Chemie - seepex 4 operational facilities (Germany) ANITA Mox Attached Growth MBBR Veolia Water / Krüger 10 facilities in operation James River, VA; South Durham, NC DEMON, Cleargreen, Terra-N ANITA TM MOx MBBR ANAMMOX Granular Sludge Paques (Ovivo markets technology in NA) 26 facilities in operation; many in design/construction ANAMMOX Granular Process

16 Deammonification Technologies DEMON Suspended Growth SBR World Water Works 54 facilities in operation York River, VA; Alexandria, VA; Blue Plains, DC Cleargreen Suspended Growth SBR Infilco Degremont 3 pilots / 3 plants in design TerraMox Hybrid Suspended and Attached Clariant/SÜD Chemie - seepex 4 operational facilities (Germany) ANITA Mox Attached Growth MBBR Veolia Water / Krüger 10 facilities in operation James River, VA; South Durham, NC DEMON, Cleargreen, Terra-N ANITA TM MOx MBBR ANAMMOX Granular Sludge Paques (Ovivo markets technology in NA) 26 facilities in operation; many in design/construction ANAMMOX Granular Process

17 Demon Operational Philosophy Each DEMON cycle involves 3 time-controlled phases: 1. Fill / React cyclical aeration and mixing 2. Settling phase 3. Decant / Discharge phase

18 Demon Operational Philosophy Reaction Settling Decant Each DEMON process cycle involves 3 time-controlled phases: 1. Reaction cyclical aeration and mixing 2. Settling 3. Decant / Discharge

19 Overview of Several DEMON Plants Typical volumetric design criterion = 0.7 kg N / m 3 / day Typical removal ~90% NH 3 -N and ~85% TN Effluent NO 3 -N ~10% of NH 3 -N removed; less if bcod available Facility Load (kg N / d) Tank Vol. (m 3 ) Design Loading Rate (kg N / m 3 / d) Apeldoorn 1,900 2, Thun Glarnerland Strass

20 SRT Control cyclone retains DEMON granules and wastes NOBs Greatest Anammox activity in the cyclone underflow MLSS Overflow Underflow

21 Robust System reliable operations and faster startup Initially the startup period for DEMON was slow Strass started up over a 2 year period Startup of Glarnerland, Switzerland occurred within 50 days using Strass seed and a cyclone

22 Strass Full Scale DEMON Energy Savings 84% TN Removal at design loading rate of 0.7 kg N / m 3 / day kw-hr / kg N removed

23 Co-Digestion Mainstream Deammonification Net Energy Producer DEMON Sequencing Batch Reactor Energy Demand Strass undertook many energy efficiency activities With the introduction of DEMON it became a net energy producer % Future 81% 84% 95% 108% 105% 109% 124% 175%? Nitritation / Denitritation Deammonification

24 Operational Cost Savings $8.5M / year (methanol, alkalinity, sludge processing) 9 year payback Risk mitigation for effluent TN Sidestream Treatment 20,200 lbs /day NH 3 -N Mainstream Treatment 105,000 lbs/day TKN

25 Deammonification Technologies DEMON Suspended Growth SBR World Water Works 54 facilities in operation York River, VA; Alexandria, VA; Blue Plains, DC Cleargreen Suspended Growth SBR Infilco Degremont 3 pilots / 3 plants in design TerraMox Hybrid Suspended and Attached Clariant/SÜD Chemie - seepex 4 operational facilities (Germany) ANITA Mox Attached Growth MBBR Veolia Water / Krüger 10 facilities in operation James River, VA; South Durham, NC DEMON, Cleargreen, Terra-N ANITA TM MOx MBBR ANAMMOX Granular Sludge Paques (Ovivo markets technology in NA) 26 facilities in operation; many in design/construction ANAMMOX Granular Process

26 ANITA Mox MBBR process Simultaneous aerobic and anaerobic conditions in biofilm layers NH 3 -N, alkalinity and DO in the bulk liquid AOBs in the outer aerobic layer ANAMMOX in the inner anaerobic layer MBBR Liquid NH 4 + N 2 O 2 Nitritation AOB NO 2 - Biofilm Anammox Media Anoxic Aerobic Simultanous aerobic and anoxic layers in biofilm

27 ANITA Mox MBBR process ANAMMOX organisms in biofilm are protected from high concentrations in the bulk liquid Less vulnerable to inhibitory compounds DO: 2 mg/l vs. 0.2 mg/l suspended NO 2 -N: 50 mg/l vs. 5 mg/l suspended Liquid NH 4 + N 2 O 2 Nitritation AOB NO 2 - Biofilm Anammox Media Anoxic Aerobic Simultanous aerobic and anoxic layers in biofilm

28 ANITA Mox Different Media K5 BiofilmChip M 800 m 2 /m m 2 /m 3 MBBR = Media + Screen +Aeration Mitigate risk of losing Anammox biomass

29 ANITA TM Mox MBBR Deammonification Soljunda WWTP, Malmo, Sweden Pilot BioFarm Tested carrier media, mixing, aeration Patented aeration control to prevent NO 3 - N production <10% without supplemental mixing Continuous aeration mg/l DO Demonstrated energy demand of kwh / kg NH 3 -N removed (Christesson et al., 2011)

30 ANITA TM Mox Performance Soljunda BioFarm ~90% NH 3 -N removal; ~85% TN removal Patented DO control strategy reduces NO 3 production <11% kwh/kgn-nh 4 removed Removal rates of up to 1.2 kg TN / m 3 / day Loading rates up to 1.4 kg N / m 3 / day BiofilmChip Best Performer (Christesson et al., 2011)

31 James River TP Newport News, VA Centrate characteristics Flow = MGD NH 3 -N = 890 mg/l Temperature = 30 C Retrofit of existing tank Seeded from Malmö BioFarm James River also has 16 MGD Hybas (IFAS) treatment Serves as BioFarm

32 James River TP Newport News, VA 33

33 James River TP Newport News, VA Process startup period 4 months to reach full NH 4 -N load 4 Month Start-up Phase

34 James River TP Newport News, VA 30-day performance test 90% NH 3 -N and 83% TN removal 90% 83%

35 ANITA Mox Ease of Operation Simple, robust, reliable Preferred for conditions with high inert TSS Process Attribute Continuous flow Promotes Ease of Operation 304 SS air grids (reduced maintenance) No decanting No sludge wasting (MBBR) No SRT control No pre-settling No equipment to recycle Anammox (MBBR) Resistant to nitrite in influent U.S.-based process support and MBBR expertise

36 LA County Sanitation District, CA Pilot Stress Testing Summary of robustness and perturbation testing Test No. Scenario Perturbation Period Recovery Time 1 Process power outage 24 hr < 8 hr 2 System underfeed 24 hr < 8 hr 3 System overfeed (2X) 24 hr 16 hr 4 Under aeration (No Air) 24 hr 32 hr 5 Over aeration (+23%) 24 hr < 8 hr

37 Updates on Ongoing Technology Development MBBR IFAS 3X the loading rate of MBBR but requires a clarifier Liquid + NH 4 N 2 Nitritation O AOB - 2 NO 2 = mg/l Liquid Nitritation AOB + NH 4 - NO 2 N 2 O 2 Flocs (1-3 g/l) < 0.5 mg/l Biofilm Anammox Media Aerobic Anoxic Biofilm Anammox Media Anoxic x AOB in biofilm = NO 2- limitation AOB in flocs = less NO 2- limitation

38 N-removal (gn/m 2.d) N-removal (gn/m2.d) IFAS ANITA Mox Bench-scale MBBR IFAS N-NO 2 (mg/l) N-NO 2 (mg/l) Higher N-removal rates with higher NO 2 level Higher NO 2 level in IFAS

39 Deammonification Technologies DEMON Suspended Growth SBR World Water Works 54 facilities in operation York River, VA; Alexandria, VA; Blue Plains, DC Cleargreen Suspended Growth SBR Infilco Degremont 3 pilots / 3 plants in design TerraMox Hybrid Suspended and Attached Clariant/SÜD Chemie - seepex 4 operational facilities (Germany) ANITA Mox Attached Growth MBBR Veolia Water / Krüger 10 facilities in operation James River, VA; South Durham, NC DEMON, Cleargreen, Terra-N ANITA TM MOx MBBR ANAMMOX Granular Sludge Paques (Ovivo markets technology in NA) 26 facilities in operation; many in design/construction ANAMMOX Granular Process

40 Principle One Step ANAMMOX

41 Principle One Step ANAMMOX O 2 NH 4 + NO 2 - N 2 NH 4 + NH 4 + NO 3-2 NH O NO NH N NO 3 -

42 Benefits of AOB-ANAMMOX granules? Robust - less sensitive to NO 2 -N inhibition and scaling Compact reactors Responds well to peak flows and loads Better separation from influent TSS Rapid settling velocities 5 10 m/h

43 Single-Stage ANAMMOX Process Second generation design: Single Stage Both nitritation and Anammox reactions Air lift design initially used for aeration Gas/liquid/solids separation modules Controlled by: Continuous aeration DO adjusted to control NOB growth NO 2 -N Hydrodynamic conditions select for granulated sludge; lighter flocculated solids not retained Granular biomass beneficial Operate solids at 10 to 15 g/l Diffusion resistance reduces sensitivity to inhibition e.g. NO 2 > 30 mg/l ~1mm Dia. Granules ~1mm Dia. Granules

44 Upflow Granulation Process: ANAMMOX Rendac Performance Biofuels Plant (The Netherlands) Design load: 5,700 kg-n/d Startup 1 month with seeding Removal rates kg N/m 3 /d 85% TN removal ANAMMOX systems in China successfully treating loads up to 11,000 kg-n/d at design loading of 2 kg-n/m 3 /d Energy consumption reported to be 1.0 to 1.5 kw-hr/kg-nremoved ammonia load (kg/m³.d) ammonia removed (kg/m³.d) 27-Mar 16-Apr 6-May 26-May 15-Jun

45 Comparative Summary of Deammonification Processes Pros: energy efficient; widely used; very small footprint Cons: operator attention, NO 2 -N tolerance Suspended SBR (DEMON ) Volumetric Loading Rates Performance TN Removal Energy Demand Startup Sensitivity / Flexibility kg N /m 3 /day % kw hrs/ kg N removed ~90% NH 3 -N ~85% TN Attached MBBR (ANITA TM Mox) IFAS > 3.2? ~90% NH 3 -N ~85% TN Granular Single-Stage (ANAMMOX ) ~90% NH 3 -N ~85% TN months with cyclone & 30% seeding ph & DO control NO 2 < 5 mg/l Pre-settling ~4 mo w/ 10% seeding DO control Tolerates elevated DO & NO 2 well 1 mo w/ seeding DO control Tolerates elevated NO 2

46 Sidestream Deammonification - Proven Technology ANAMMOX DEMON Final Generation Mature Technology MBBR AnitaMox First Demonstration Second Generation (building on lessons learned from first applications) IFAS AnitaMox Pilot Clear Green Terra-N First Applications

47 Sidestream Treatment 70 operational facilities Proven process, sustainable, small footprint, cost-effective 60% less oxygen 90% less carbon 50% less alkalinity 40% less biomass

48 Future Ready for New Frontiers - Mainstream Deammonification

49 Strass WWTP, Austria- Cold Climate Full Scale Mainstream Deammonification Demonstration First cold climate demonstration A-B type plant Temperature C range A-Stage - ½ day SRT high rate activated sludge with 65% carbon capture for energy recovery B-Stage - carousel type aeration tank providing high DO transient anoxia (DO mg/l). Sidestream DEMON for AOB & Anammox bio-augmentation Cyclones for mainstream Anammox retention

50 nitrogen concentration (mg N/L) Full Scale Cold Climate Success - Strass WWTP, Austria Deammonification performance was better and more reliable than the conventional BNR process resulting in less nitrogen to the river /2011 NO3-N effluent 2010/2011 NO2-N effluent 2011/2012 NO3-N effluent 2011/2012 NO2-N effluent Conventional BNR Effluent Nitrogen 2010 Mainstream Deammonification Effluent Nitrogen Dec 11-Dec 31-Dec 21-Dec 30-Jan 31-Dec 29-Feb 10-Jan 30-Mar 20-Jan 29-Apr 30-Jan 29-May

51 Mainstream Granular Deammonification Performance at Dokhaven WWTP, Rotterdam at Cold Temperatures At temperatures down to 12 C, removal rates sustained at 80% to 100% of that expected at 20C Need good DO control and control of BOD and TSS from the A-Stage High BOD and TSS loading will encourage growth of NOB and other microorganisms that hamper selection of AOB on the granule surface

52 Key Findings of Mainstream Granular ANAMMOX 3-year Demonstration NOB activity was successfully suppressed and controlled. High removal rates were achieved with a low NOB activity. Long term process stability remains a challenge; fluctuations in influent BOD are an important factor. Fluctuating BOD loads can be better handled in a plug flow reactor, instead of the mixed tank reactor as used in the demonstration project. New full scale demonstration planned for China

53 Conclusions Sidestream deammonification is a proven, mature technology. Mainstream deammonification strategy is promising. When upgrading your plant, consider incorporating sidestream deammonification along with flexibility for mainstream in the future.

54 Thank you! (616) November 8, 2017