Recommendations and Lessons Learned from the Startup of the First Two Full-Scale Sidestream Deammonification Processes in North America: DEMON and ANITA Mox Andrea Nifong, World Water Works (formerly HRSD) Stephanie Klaus, VT & HRSD
Key Points Training is key but only 2 champions need in depth training Control strategy for long term operation is stable and hands off AOB are the most sensitive bacteria in the process, AOB are limiting not anammox 25 C is a reasonable minimum temperature Long term shutdowns are possible 2
Sidestream Deammonification ~1% of Total Plant Influent Flow ~20-40% of the Total Plant TN load NH 4 Concentration between 900 1,500 mg/l Alkalinity/NH4 ratio 3.5-4.0 Temperature 30-38 C Alkalinity insufficient for complete nitrification Insufficient carbon for denitrification Influent Primary Clarifier Aerobic Secondary Clarifier Tertiary Deammonification Anaerobic Digestor Dewatering Centrate 3
Conventional Nitrification-Denitrification Autotrophic Bacteria Aerobic Environment 25% O 2 (energy) Nitratation 1 mol Nitrate (NO 3- ) 40% Carbon (BOD) Denitratation Heterotrophic Bacteria Anoxic Environment 1 mol Nitrite (NO 2- ) 1 mol Nitrite (NO 2- ) 60% Carbon (BOD) Nitritation Denitritation 75% O 2 (energy) ~100% Alkalinity 1 mol Ammonia (NH 3 / NH 4 + ) NITRIFICATION ½ mol Nitrogen Gas (N 2 ) DENITRIFICATION 4
Partial Nitritation + Anammox = Deammonification NH 4+ + 1.32 NO 2- + 0.066 HCO 3- + 0.13 H + 0.26 NO 3- + 1.02N 2 + 0.066 CH 2 O 0.5 N 0.15 + 2.03 H 2 O Autotrophic Bacteria Aerobic Environment 0.5 mol Nitrite (NO 2- ) Advantages: 63% reduction in oxygen demand (energy) Nearly 100% reduction in carbon demand 80% reduction in biomass production No additional alkalinity required 37% O 2 (energy) ~57% Alkalinity 1 mol Ammonia (NH 3 / NH 4 + ) Autotrophic Anoxic Environment ½ mol Nitrogen Gas (N 2 ) + 0.11 mol Nitrate (NO3 - ) 5
One-Step Sidestream Deammonification (with full-scale applications) Upflow Granular Sludge Paques ANAMMOX SBR DEMON MBBR ANITA Mox Deammon 6
Operation Objectives Target is 90% NH 4 Removal (80% TIN Removal) Target is 10-15% NO 3 Production Typical Guidelines: o Residual alkalinity 150-250 mg/l as CaCO 3 o Residual NH 4 of 50-100 mg/l o Nitrite concentration below 20-40 mg/l 7
ANAEROBIC DEWATERING DIGESTION THICKENING DEMON AERATION BASINS HEADWORKS DENITE FILTERS DEMON at York River
Demon York River WWTP 9
DEMON Process Components Seed Sludge Aeration System Instruments & Controls Tank Blowers Decanter Mixer Cyclone 10
DEMON Control Strategy SBR configuration typically 6 or 8 hour cycle time Last hour of cycle - settle and decant During React Period multiple mini-cycles (10-30 mins): Aerate Mix/fill Mix Aeration: DO ~0.2-0.5 mg/l (PID control or constant airflow) ph based aeration control 11
DEMON Control Strategy - Anammox Enrichment AOB/NOB/OHO/debris Continual enrichment of anammox Large excess of activity Provides stability Ability to Washout NOB if proliferation occurs Anammox returned to Process 12
Confidential; Copyright 2013, World Water Works, Inc. All rights reserved. Seed Sludge 13 13
% NH4-N Removal ; % NO3-N Production NO2-N Concentration (mg/l); Temperature ( C) NH 4 and TIN Removal Percentages 100% NH4-N Removal NO3-N Production 100 90% NO2-N Cencentration Temperature 90 80% 80 70% 60% removal efficiency loss due to low temperatures 70 60 50% 50 40% 40 30% 30 20% 20 10% 10 0% 8-Oct-12 28-Oct-12 17-Nov-12 7-Dec-12 27-Dec-12 16-Jan-13 5-Feb-13 25-Feb-13 0 14
NH4-N kgn/m3/day) NH4 Loading and Removal Rates 0.50 0.45 0.40 NH4-N Influent Load (kgn/m3/day) NH4-N Load Removed (kgn/m3/day) 0.35 0.30 0.25 0.20 0.15 0.10 0.05 System Shut- down 0.00 15
HRSD James River Treatment Plant 16
ANITA Mox Process Components Aeration System Instrumentation Centrate Feed Mixers and Heaters K5 Media Media Retention 17
Supplemental Heating DEMON Temp maintained above 25 C after supplemental heating was supplied Lesson Learned: Insulate or provide heating during startup ANITA Mox Temp maintained above 30 C during startup and 25 C long term 18
Anitamox Process Control Centrate Feed Control Aeration Control Continuous and Intermittent Three Different Modes 1. Airflow setpoint (scfm) 2. Fixed DO setpoint 3. ph-based DO or airflow Mixer Control 19
Seeding and Startup 20
Biofilm Growth New media 12/12/13 New media 2/26/14 New media 4/10/14 New media 7/15/14 Seed media 12/12/13 Seed media 2/26/14 Seed media 4/10/14 Seed media 7/15/14 21
%, mg/l, C 100.0 NH 4 and TIN Removal Percentages 90.0 80.0 70.0 60.0 50.0 40.0 Startup Complete TIN Removal % NH4 Removal % NO2 out (mg/l) Temperature NO3 Production Ratio 30.0 20.0 10.0 0.0 12/3/13 1/2/14 2/1/14 3/3/14 4/2/14 5/2/14 6/1/14 7/1/14 22
kg/m3/day 1.0 0.9 NH4 Loading and Removal Rates Intermittent Aeration Continuous Aeration 0.8 0.7 0.6 NH4 Load (kg/m3/day) NH4 Removed (kg/m3/day) 0.5 0.4 0.3 0.2 Startup Complete 0.1 0.0 12/3/13 1/2/14 2/1/14 3/3/14 4/2/14 5/2/14 6/1/14 7/1/14 23
ph-based Aeration Control 24
DEMON ph-based Aeration Control Aeration time is based on a low ph setpoint Anoxic/Feed time based on a timer or high ph setpoint 25
Option 1: ANITA Mox Fixed DO or Airflow Setpoint DO (mg/l), Centrate Flow (m 3 /hr) 14 12 10 8 6 4 2 0 0 200 400 600 800 1000 1200 1400 7.0 6.9 6.8 6.7 6.6 6.5 6.4 ph ph DO Centrate Flow DO setpoint Time (min) 26
Option 2: ANITA Mox ph-based Aeration Control DO (mg/l), Centrate Flow (m 3 /hr), ph 20 15 10 5 0 0 420 430 440 450 460 470 480 Day 100 80 60 40 20 NO3 Production %, NH4 Removal % ph Feedback Centrate Flow ph Setpoint DO Setpoint NO3 Production % NH4 Removal % 27
DEMON and ANITA Mox Both use a form ph-based Aeration Control Control modes: DEMON ph affects aeration time at controlled DO ANITA Mox ph affects DO concentration ph Probe minimal maintenance/calibration Use handheld/lab probe to verify Consistent ammonia load & removal = constant OUR 1 or 2 Lead Operators trained on ph Based aeration control 28
Alarms and Fail Safes Low ph = air shut off High DO = air and centrate feed shut off Low Level = air and centrate feed shut off Centrate Feed Pump Low Flow/Fail = air shut off High Level = centrate feed shutoff High/Low Temperature = alarm Cyclone Pump Low Pressure= shut off Manual Mode Alarm = alarm 29
Training Entire plant staff trained on basic understanding of process theory, process components, analysis requirements and controls Daily meetings during startup, tapering to weekly meeting. Participants included: Plant staff, R&D team, and vendor. 1-2 of the plant staff understand in depth theory, troubleshooting, and process control 30
Sampling/Analysis Sampling Frequency: Daily during startup tapering down to weekly Parameters: -On site: HACH test kit NH 3, NO 2, NO 3 -Lab data: Alk, scod, TSS, OP Training: 2 Lab Technicians Convenient Sample Ports 31
Sensor Management Instrument Calibration Frequency Maintenance ph Quarterly Max Weekly Cleaning DO Annual Weekly Cleaning/Air Blast Function Control Control Conductivity Annual No issue Monitoring Ammonia/Nitrate As needed compared to lab values Air Blast Monitoring 32
Specific Conductivity Specific conductivity represents the measure of all relevant ions For deammonification the most important are NH 4+, NO 2-, NO 3-, HCO 3 - Great monitoring tool 33
Specific Conductivity- ANITA Mox 7.2 240 ph 7.0 6.8 6.6 6.4 6.2 6.0 5.8 5.6 5.4 420 430 440 450 460 470 220 200 180 160 140 120 100 80 60 Specific Conductivity, NH4 ph NH4 Specific Conductivity Day 34
Centrate Quality Automate centrate diversion valves Eliminate sources of dilution water Sufficient EQ size and settling Temperature control if necessary 35
Micronutrient Addition Source: Grady, C., Daigger, G., Love, N., Filipe, C. (2011). Biological Wastewater Treatment, IWA Publishing. 36
% NH4-N Removal ; % NO3-N Production NO2-N Concentration (mg/l); Temperature ( C) Micronutrient Deficiency - DEMON 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% Micronutrient Addition 45 40 35 30 25 20 15 10 5 0% 26-Jan-13 15-Feb-13 7-Mar-13 27-Mar-13 16-Apr-13 6-May-13 26-May-13 15-Jun-13 5-Jul-13 NH4-N Removal NO3-N Production NO2-N Cencentration Temperature 0 37
Percent % ph ANITA Mox Micronutrient Deficiency 100 NH4 Removal % 90 NO3 Production Ratio ph 80 70 60 50 40 14 12 10 8 6 30 20 10 12% NO3 Production Resume Micronutrient Addition 4 2 0 9/26/2014 10/26/2014 11/25/2014 12/25/2014 1/24/2015 0 38
Shutdowns Shutdown for a week at a time with no significant change in operation strategy > 1 week requires a reduced load during startup AOB are the limiting factor Anammox are very robust (very slow decay rate) DEMON and ANITA Mox appear similar One month shutdown for DEMON = one month restart 39
ANITA Mox Shutdown Test James River Main Plant Performance with and without ANITA Mox FIN EFF FIN EFF FIN EFF TKN NOx T-N 4/5/2015 2.42 2.33 4.75 4/6/2015 3.72 2.8 6.52 4/7/2015 3.63 3.28 6.91 4/8/2015 2.87 3.3 6.17 4/9/2015 4/10/2015 4/11/2015 4/12/2015 4.36 3.13 7.49 4/13/2015 5.95 3.07 9.02 4/14/2015 5.82 3.5 9.32 4/15/2015 5.99 3.92 9.91 With sidestream treatment Without sidestream treatment 40
Conclusions Complete ownership of the system starts with daily, then weekly performance discussions with two champions of the system Anammox are robust, all limiting issues have been caused by AOB ph control is simple and effective Sidestream deammonification is a proven technology Process is not plug & play, careful attention required during startup Thoughtful attention during normal operation; set point changes ~1-2X/week (assuming good EQ) Lessons learned from DEMON applied to ANITA Mox 41