ANITA Mox MBBR Return on Experience from Start-up of Full Scale Systems and New Developments European Biosolids Conference and Exhibition, 19-20 November 2013 Simon Piveteau, M. Christensson, B. Bigot, R. Lemaire, L. Rohold, B. Nussbaum, J. Ochoa
Context Sidestream impact on WWTP Refuse Screening Primary settler Biological treatment Clarifier River Sand, grease Thickener Digester 1-2% of WWTP inlet flow 15-25% of N-load N-NH 4 : 500-1500 mg/l BOD : < 150mg/L Sidestream Gas holder CHP Impact mainstream design More O 2 required Lower C/N ratio (C addition?) Higher sludge production Sludge disposal Dewatering
Context Dedicated Sidestream process Refuse Screening Primary settler Biological treatment Clarifier River Sand, grease Thickener Digester ANITA Mox Gas holder CHP Cost- & Energy-efficient Sidestream treatment Sludge disposal Dewatering
Principle ANITA Mox 1-stage Deammonification -60% O 2-100% COD NO 3 - NOB O 2 COD Heterotrops AOB NO 2 - NO 2-55% NH 4 + 45% Aerobic O 2 (40%) NH 4 + Anammox COD (0%) N 2 + NO 3-89% 11% Anoxic O 2 COD Anammox Bacteria
ANITA Mox MBBR process MBBR High sludge retention time (SRT) needed Necessity to protect anammox bacteria (O 2 / NO 2 ) Biofilm Necessity to keep bacteria into the system (avoid washout) Maximum robustness and stability desired Liquid NH 4 + N 2 Nitritation O 2 AOB NO 2 - Biofilm Anammox Media Anoxic Aerobic Simultanous in biofilm
ANITA Mox Anammox biomass security + K3 K5 BiofilmChip M 500 m 2 /m 3 800 m 2 /m 3 1200 m 2 /m 3 MBBR = Media + Grid No risk of loosing Anammox biomass No impact of incoming TSS (flow-through) Retention Grid
Anita Mox treating Bio Thelys effluent: bench scale trials
Inhibitions and how to address them Inhibitions from THP effluents Inert soluble COD causing immediate toxicity Biodegradable COD leading to competitive inhibition Strategy applied-bench scale Reference reactor in parallel (conventional reject water) Dilution x4 for THP effluent Low initial N-load, careful increase (>1 HRT) Research questions Stable N-removal? What type of inhibition? 13/11/2013 Veolia Environnement Recherche & Innovation 8
mg/l Influent 1200 1000 800 inert SCOD 600 400 NH4-N NH4-N 200 inert SCOD BSCOD 0 BSCOD Conventional digester effluent Diluted THP post digestion effluent 4 times more soluble COD in diluted THP effluent 3.5 times more biodegradable soluble COD bscod/nh 4 -N = 0,7 in THP against 0,12 in conventional reject water
Results-Bench Scale
gn/m²/day Results- N-load & removal 6 5 Reference reactor R7 surface N load R7 surface N removal R8 Surface N load R8 surface N removal 4 3 2.3 2 1 0 Test reactor 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 days 1,2 30 days of steady increase in N-removal Stable removal at 1.2gN/m2.day (50% of reference reactor) Cause of this lower removal, toxicity and/or competitive inhibition by heterotrophs? 11
gcodrem/gnrem Results- ratio COD removed /N removed 1,80 1,60 1,40 1,20 1,00 0,80 0,60 0,40 R7 R8 0,20 0,00 0 10 20 30 40 50 60 70 80 90 100 110 120 days evolution of the ratio SCOD removed /N removed in R7 (reference reactor) and R8 (THP influent) Increasing heterotrophic activity relatively to autotrophs in test reactor 12
Results-Visual Analysis Dense orange deep layer Loose grey outer layer Thickening of the outer layer in both reactors, more important in R8 Day 49 Day 22 5mm 5mm 5mm Day 66 5mm 5mm 13
Discussion - Bench Scale
Discussion - Identifying Inhibition Negligible physiological/bactericidal toxicity Similar maximum Anammox activity in both reactors for more than 50 days (data not shown) High N-removal efficiency in test reactor (>90%) during 30 days treating THP Bio Thelys effluent, indicating good AOB activity Dilution and slow increase of flow rate were effective Competitive inhibition by heterotrophs SCOD consumption occurred SCOD removed /N removed < 0.2 in reference reactor SCOD removed /N removed > 0.5 in test reactor Denitrification occurred NO3prod/NH4rem < 11% 15
Discussion Consequences of the high heterotrophic activity in test reactor Thick heterotrophic outer layer Lower transport and diffusion of substrates Competition for nitrites and oxygen Higher oxygen flux required Lower Anammox activity 16
Conclusion Operational performances: Anita Mox process applied to Bio Thelys effluent provided a stable Nitrogen removal (1.2gN/m 2.day) Lower rate compared to treatment of conventional reject water mainly due to competitive inhibition by heterotrophs Dilution and careful load increase prevent toxicity effects from Bio Thelys effluent Recommendations BSCOD content should be reduced to a minimum longer residence time in the digester High rate aerobic step prior to Anita Mox process Anita Mox operated in IFAS mode 17
ANITA Mox Sjölunda WWTP, Malmö (Sweden) 4 x 50m 3 MBBR (4 x 13,000 gal) Capacity = 200 kgn/d 440 lbn/d 800-1200 mgn-nh 4 /L 1 st ANITA Mox reference Flexibility for fullscale testing Seeded carriers New carriers during start-up BioFarm concept = Providing seeded carriers for rapid start-up of future full-scale ANITA TM Mox units
NH4 removal (kgn/m3.d) BioFarm Performance last 2 years 1,6 1,4 1,2 y = 0,89x R² = 0,95 1 0,8 0,6 Empty 85% carriers for fullscale start-up 0,4 0,2 0 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 89% NH 4 NH4 removal load (kgn/m3.d) for the last 2 years Average 0.9-1.3 kgn-nh 4 /m 3.d
ANITA Mox Sundets WWTP, Växjö (Sweden) 3.5m depth Fine bubble aeration 350 kgn/d (700lb/d) 430 kgn/d (950 lb/d) reject water Existing 300m 3 SBR MBBR K5 carrier (AnoxKaldnes) Quick seeding (13% from BioFarm) Started in January 2012
NH4 load & NH4 removal rate (kgn/m3.d) Reject water flow (m3/d) Växjö N-load / NH 4 -rem 0,65 0,6 0,55 0,5 0,45 NH4-N load NH4-N rem Reject Water Flow (m3/d) Design Flow = 350 m 3 /d 700 600 500 0,4 0,35 0,3 0,25 400 350 300 0,2 0,15 200 0,1 0,05 0 Real Flow = 100-200 m 3 /d 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 630 Days Treating all reject water after only 30 days (with 13% seeding) 0.4-0.5 kgn/m 3.d ½ design N-load Co-digestion + THP 2014 100 0
NH4 in/out (mgn/l) NO3 out, NO2 out (mgn/l) Växjö Nitrogen species in/out 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 50 0 NH4-N in NH4-N out NO3-N out NO2-N out 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 630 Days 200 180 160 140 120 100 80 60 40 20 0
%NH4rem, %TNrem, ratio NO3/NH4 T C Växjö Performance 100% 90 90% 80% 70% 60% 50% 40 38 36 34 32 30 40% 30% 20% 10% 0% TN removal % NH4-N removal % ratio NO3-prod/NH4-rem T C 0 30 60 90 120 150 180 210 240 270 300 330 360 390 420 450 480 510 540 570 600 630 Days 90% NH 4 removal and 80% TN removal DO control strategy reduce NO 3 production <11% 28 26 24 22 20
ANITA Mox Holbæk (DK) Landfill Leachate storage tank (=600m 3 ) ANITA Mox 120 kgn/d 260 lb-n/d (reject water + leachate) Retrofitting 600m 3 existing tank Quick seeding (BioFarm) Commissioning June 2012
ANITA Mox Grindsted (DK) 110 kgn/d 240 lb-n/d Reject Water from co-digester 140 m 3-37,000 gal (new tank) Quick Seeding (BioFarm) Start-up July 2013 50 000 tons/year to BioPasteur digester: 45% of DS from wastewater sludge 35% of DS from organic household waste 20% of DS from organic industrial waste
ANITA Mox James River WWTP, Newport News, VA US 250 kgn/d 550 lb-n/d (reject water) Retrofit of existing tank Quick seeding (BioFarm) Start-up Oct 2013 Existing Hybas TM system 60,200m 3 /d (16 MGD)
ANITA Mox South Durham, North Carolina US ANITA Mox 890 mg/l 330 ammonia kgn/d 730 reject lb-n/d water combination (reject water) of HRSD sludge 284 m 3 Retrofit /d flow of existing tank Retrofit Quick of existing seeding tank (BioFarm) Seeding Start-up (BioFarm) Q2 2014 Start-up US Q3 based 2013 BioFarm Plant has existing Hybas TM system 60,200m 3 /d
New Development IFAS configuration MBBR IFAS Liquid + NH 4 N 2 Nitritation O AOB - 2 = 0.5-1.5 NO mg/l 2 Flocs (1-3 g/l) Liquid Nitritation AOB + NH 4 - NO 2 N 2 O 2 < 0.5 mg/l Biofilm Anammox Media Aerobic Anoxic Biofilm Anammox Media Anoxic AOB in biofilm = NO 2 - limitation AOB in flocs = less NO 2 - limitation
IFAS ANITA Mox Full-scale
%NH4 and %TN removal NH4 load & removal (kgn/m 3.d) IFAS ANITA Mox Full-scale Results 3,5 3 2,5 2 1,5 1 0,5 0 90 80 70 60 50 40 30 20 10 MBBR Transition IFAS NH4-load NH4-removal %TN-removal %NH4-removal %NO3-prod : NH4-rem 0 930 950 970 990 1010 1030 1050 1070 1090 1110 1130 1150 Higher NH 4 removal after switch to IFAS (x2-3 MBBR) Days
TSSin & MLSS (mg/l) SVI (ml/g) NH4 load & removal (kgn/m 3.d) IFAS ANITA Mox Full-scale Results (2) 3,5 3 2,5 2 1,5 1 0,5 0 10000 9000 8000 7000 6000 5000 4000 3000 2000 1000 NH4-load TSS = 2-7 g/l (depending IFAS incoming NH4-removal TSS) MBBR Transition Good sludge quality (SVI 60-110) MLSS (mg/l) TSSin (mg/l) SVI (ml/g) 0 0 930 950 970 990 1010 1030 1050 1070 1090 1110 1130 1150 Days 200 180 160 140 120 100 80 60 40 20
Bench-scale trial IFAS different C/N ratios A Influent AD Sidestream NH 4 = 900 mgn/l tcod= 400 mg/l BOD = 30 mg/l tcod/n = 0.4 sbcod/n = 0.25 B 4 Pilot/Conditions 30 o C 43 % K5 carrier Volume reactor = 7 L D.O. IFAS =0.1-0.2 mg O 2 /L MLSS = 3g/L Regul out N-NH 4 =50mg/L 1) bcod/n=0,05 (ref) 2) bcod/n = 0,5 3) bcod/n= 1,0 4) bcod/n=1,5 OCDE Settler 4 parallel IFAS reactors Reactor 32
Bench-scale trial IFAS different C/N ratio Maximum anammox activity in batch trials Settler Reactor Similar removal rates (7 g N/m 2.d ) in batch trials after 50 days No heterotrophic growth in biofilm due to higher C/N ratio 33
ANITA Mox Applications (MBBR & IFAS) Municipal : Sidestreams: Anaerobic Digested Sludge centrate Thermal Hydrolysis + AD centrate Different C/N ratio (IFAS) Mainstream: (IFAS = easy retro fit) Post UASB + HRAS (high T o C) Post Primary + HRAS (low T o C) Post CEPT + MBBR-C (low T o C) validated validated validated under evaluation under evaluation under evaluation Industrial : Landfill Leachates (old) validated Post anaerobic from Bio-composting (COD/N=2) validated Micro-electronic / Semi-cond validated Other Post anaerobic effluent (slaughterhouse, F&B) validated
ANITA Mox References Plant Country Capacity Type of effluent Config. Delivery year Sjolunda Sundets Holbaek Grindsted James River South Durham Mars Candy Starch Sweden Sweden Denmark Denmark VA, USA NC, USA Poland 200 kgn/d 440 lb-n/d 430 kgn/d 950 lb-n/d 120 kgn/d 260 lb-n/d 110 kgn/d 240 lb-n/d 250 kgn/d 550 lb-n/d 330 kgn/d 770 lb-n/d 340 kgn/d 750 lb-n/d 300 kgn/d 660 lb-n/d Municipal AD sidestream Municipal AD sidestream (+ Co-dig. + THP in 2014) Municipal AD sidestream (+ leachate) Municipal AD sidestream (+ Co-dig. + THP in 2015) MBBR IFAS 2010 MBBR 2012 MBBR 2012 MBBR ( IFAS) 2013 Municipal AD sidestream MBBR Oct. 2013 Municipal AD sidestream MBBR Mid-2014 F&B Industrial sidestream after AnMBR F&B Industrial sidestream after UASB MBBR 2015 MBBR 2015
ANITA Mox Pilot US Plant Type of effluent Config. Size Denver Metro LA County Cincinnati MSD Municipal AD sidestream Municipal AD sidestream Landfill Leachate MBBR MBBR IFAS MBBR IFAS 3.6m 3 (950 gal) 3.6m 3 (950 gal) 7L Delivery year 2012 (completed) 2013 (on going) 2013 (on going)
ANITA Mox Conclusion Stable and robust Media + Grid No risk to loose Anammox Incoming TSS Limited impact (flow-through syst.) Low OPEX + C-footprint : - 60% O 2 / no COD dosing / 1.2-1.5 kwh/kgn rem N 2 O emission: < 0.5% (MBBR) / < 1-1.5% (IFAS) Efficient aeration control Continuous aeration no mixer / no stop-start blower / low N 2 O Keep NO 3 < 11% no NOB (MBBR & IFAS) N-removal performances : MBBR = 1 kgn rem /m 3.d IFAS = 2-3 kgn rem /m 3.d BioFarm seeding strategy = Quick Start-up (EU/US) 2 configurations: MBBR or IFAS Choice based on project specificity footprint, retrofit