1 Supplementary material: Analysing the effects of the aeration pattern and 2 residual ammonium concentration in a partial nitritation-anammox process 3 Luis Corbalá-Roblesa,*, Cristian Picioreanua, Mark C.M. van Loosdrechta, Julio 4 Péreza 5 a 6 The Netherlands 7 * 8 Engineering, Ghent University, Coupure links 653, 9000 Ghent, Belgium. Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628BC, Delft, Corresponding author. E-mail: Luis.CorbalaRobles@UGent.be. 1 Department of Biosystems 9 Temperature and pH effect on ionization constants 10 Eqs. (S1) and (S2), derived from acid-base equilibriums, were used for the calculation of the free 11 ammonia (FA or NH3) and the free nitrous acid (FNA or HNO2). 12 FA 13 FNA 14 The ratio between the ionization constant of the ammonia equilibrium (Kb) and the ionization 15 constant of water (Kw) is related to the temperature as shown in Eq. (S3) and the temperature effect 16 on the ionization constant of the nitrous acid equilibrium (Ka) is shown in Eq. (S4) .[1] 17 Kb 6344 exp Kw 273 T (S3) 18 2300 K a exp 273 T (S4) 19 The kinetics for each of the processes considered i.e. growth and decay of each kind of bacteria 20 are shown in Table S2-Supplementary Material. In addition, the oxygen limitations, substrate and 21 non-competitive inhibitions for AOB and NOB growth processes were also considered. AOB 22 inhibition by FA and NOB inhibition by FNA were described with a Haldane model while AOB 23 inhibition by FNA and NOB inhibition by FA were described with a non-competitive model. S NH 4 10 pH 14 Kb pH 17 10 Kw (S1) S NO 2 47 pH K a 10 1 14 (S2) 2 Table S 1. Stoichiometric matrix .[2] component → SS [gCOD. m-3] process ↓ growth 1. growth of XAOB 2. growth of XNOB 3. growth of anammox 4. aerobic growth of heterotrophs 5. anoxic (on NO2-) growth of heterotrophs 6. anoxic (on NO3-) growth of heterotrophs decay 7. decay of XAOB 8. decay of XNOB 9. decay of XAMX 10. decay of XHET -1/YHET -1/ YHET,NO2 -1/ YHET,NO3 1-fI 1-fI 1-fI 1-fI SNH4 [gN.m-3] SNO2 [gN.m-3] SNO3 [gN.m-3] SN2 [gN.m-3] SO2 [gO2.m-3] SN2AMX [gN. m-3] -1/YAOB iNXB 1/YAOB -iNXB -1/YNOB 1/YNOB -1/YAMXiNXB -iNXB+ 1/YHET. iNSS -iNXB+ 1/YHET. iNSS -iNXB+ 1/YHET. iNSS -(1/YAMX ) (1/1.14) 1/1.14 SN2H [gN m-3] 13.43/YAOB 11.14/YNOB XAOB [gCOD. m-3] XNOB [gCOD. m-3] XAMX [gCOD. m-3] XHET [gCOD.m-3] XO2,HET XNO2,HET [gCOD. [gCOD. m-3] m-3] XNO3,HET [gCOD. m-3] XI [gCOD. m-3] 1 1 2/ YAMX 1 1- 1/YHET 1 (1-YHET,NO2)/ (1.71YHET,NO2) -(1-YHET,NO2)/ (1.71YHET,NO2) 1 1 -(1-YHET,NO3)/ (1-YHET,NO3)/ (1.14YHET,NO3) (1.14YHET,NO3) iNXB - fI iNXI – (1-fI) iNSS iNXB - fI iNXI – (1-fI) iNSS iNXB - fI iNXI – (1-fI) iNSS iNXB - fI iNXI – (1-fI) iNSS -1 fI -1 fI -1 fI -1 3 fI Table S2. Kinetic rate expressions. j 1 2 3 Process rate (d-1) SO2 max, AOB K O2 , AOB SO2 Process Growth of XAOB Reference S NH 4 K S , NH 4, AOB S NH 4 S NH 4 2 K I , NO 2, AOB X AOB K I , NO 2, AOB S NO 2 K I , NH 4, AOB bAOB X AOB Decay of XAOB max, NOB Growth of XNOB [3] [4] SO2 KO2 , NOB SO2 S NO 2 K S , NO 2, NOB S NO 2 S NO 2 2 K I , NH 4, NOB X NOB K I , NH 4, NOB S NH 4 [3] K I , NO 2, NOB 4 Decay of XNOB bNOB X NOB 5 Growth of XAMX max, AMX 6 Decay of XAMX bAMX X AMX 7 Growth of XO2,HET max, HET 8 Growth of XNO2,HET max, HET η NO 2 S NO 2 KO 2,HET SS S NO 2 S NH 4 . X HET KO 2,HET SO 2 K NO 2,HET S NO 2 K S ,HET S S S NO 2 S NO 3 K NH 4,HET S NH 4 [4] 9 Growth XNO3,HET max, HET η NO 3 S NO 3 KO 2,HET SS S NO 3 S NH 4 . X HET KO 2,HET SO 2 K NO 3,HET S NO 3 K S ,HET S S S NO 2 S NO 3 K NH 4,HET S NH 4 [4] 10 Decay of XHET of [4] K I ,O2 , AMX K I ,O2 , AMX SO2 S NH 4 S NO 2 X AMX K NH 4, AMX S NH 4 K NO 2, AMX S NO 2 [4] [4] S O2 SS K O2 , HET S O2 K S , HET S S . S NH 4 X HET K NH 4, HET S NH 4 bHET X HET [4] [4] 4 Table S3. Stoichiometric and kinetics parameters values parameter value Unit Stoichiometric parameters YAOB 0.20 g COD.g-1 N [5] (1) YNOB [5] (1) YAMX YHET YHET,NO2 YHET,NO3 iNXB 0.057 g COD.g-1 N 0.17 g COD.g-1 N 0.67 g COD.g-1 COD [7] 0.53 g COD.g-1 COD [8] 0.53 g COD.g-1 COD [8] g N.g-1 COD [2] 0.07 [6] (2) iNXI 0.07 g N.g-1 COD [2] iNSS 0.03 g N.g-1 COD [7] fI 0.08 g COD.g-1 COD [7] Kinetic parameters (at 30°C & pH 7) max, AOB 1.36 d-1 max, NOB 0.79 d-1 max, AMX 0.052 d-1 max, HET 12 d-1 K S , NH 4, AOB 1.1 g N.m-3 S , NO2, NOB 0.51 g N.m-3 K [9] (3) [9] (3) [6] (3) [7] (4) [5] (5) [5] (5) AOB AN Assumed, such that ratio K NH : K NH K NH 4, AMX 0.03 g N.m-3 is about the same as in [10] 5 NOB AN Assumed, such that ratio K NO 2 : K NO 2 K NO2, AMX 0.005 g N.m-3 is about the same as in [10] NO2, HET 0.3 g N.m-3 [11] NO3, HET 0.3 g N.m-3 [11] S , HET 20 g COD.m-3 K O 2, AOB 0.3 g O2.m-3 [5] K O 2, NOB 1.1 g O2.m-3 [5] K 0.05 g O2.m-3 [2] K O 2, HET 0.2 g O2.m-3 K NH 4, HET 0.02 g N.m-3 [2] I , NO2, AOB 828 g N.m-3 [12] I , NH 4, AOB 9563 g N2.m-6 [12] I , NH 4, NOB 154 g N.m-3 [12] I , NO2, NOB 90 g N2.m-6 [13] bAOB 0.068 d-1 AOB = bH: H Assumed, set such that bAOB: max max bNOB 0.04 d-1 NOB H Assumed, set such that bNOB: max = bH: max bAMX 0.0026 d-1 AN H Assumed, set such that bAN: max = bH: max bHET 0.6 d-1 H Assumed max / 20 for this study ηNO2=ηNO3 0.8 - [7] K K K K K K K I , O 2, AMX [7] [7] Mass transfer parameters 6 DNH4 1.5x10-4 m2.d-1 [14] DNO2 1.4x10-4 m2.d-1 [14] DNO3 1.4x10-4 m2.d-1 [14] DO2 2.2x10-4 m2.d-1 [15] DS 1x10-4 m2.d-1 [16] After unit conversion, using a typical biomass composition of CH1.8O0.5N0.2, corresponding with 1.3659 g COD.g-1 (2) After unit conversion, using a anammox biomass composition of CH2O0.5N0.15, corresponding with 36.4 g COD.mole-1 or 1.51 g COD.g-1 (3) Conversion of values given in [9] at 35°C and in [6] at 32.5°C to 30°C using the relationship (written for XAOB, analogous for XNOB and XAMX) (1) AOB1 max (T ) AOB1 max EaAOB T Tref ( Tref ) exp R T T ref with E aAOB =68 kJ.mole-1 ; E aNOB =44 kJ.mole-1; EaAMX = 70 kJ.mole-1 ; R=8.31 J.mole-1.K1 . (4) Conversion of ASM1-values given in [7], at 10°C and 20°C to 30°C using temperature relationship proposed by these authors (ASM3). -3 AOB NOB (5) Calculated value at T=30°C and pH=7 from K NH and from K HNO 3 = 0.028 g NH3-N.m 2= -5 -3 3.2x10 g HNO2-N.m considering the T and pH dependency of the chemical equilibrium NH 4 NH 3 H and HNO2 NO2 H 7 Table S4. References from the oxygen affinity values used in the study of NOB repression.R KO=KO2,AOB/KO2,NOB. KO2,AOB KO2,NOB RKO (gO2/m3) (gO2/m3) (KO2,AOB/KO2,NOB) 0.3 [5] 1.75 [17] 0.17 0.3 [5] 1.1 [5] 0.27 0.16 (This study) 0.16 [18] 1 0.18 [19] 0.13 [19] 1.38 1.16 [18] 0.16 [18] 7.25 8 Figure S1. Comparison of the minimum ammonium concentrations for NOB repression obtained with a CSTR (label: 20°C and 30°C) and a SBR at 30°C (label: SBR 30°C). The values were obtained with an RKO=0.27. It was observed that the values differ in average 13% and no more than 20%. 9 Figure S2. Reduction of anammox growth rate over the granule radius due to inhibition by oxygen in different aeration cases. The oxygen inhibition term I O2 (t , x) K I ,O2 , AMX ( K I ,O2 , AMX SO2 ) averaged in time over the aeration period for each aeration case (A, B and C) was related to the one calculated for continuous aeration. 10 Figure S3. Concentrations in the bulk liquid during two cycles at steady state. The time axis represents the cycle time, not the total time since reactor start up. The dissolved oxygen was 0.25 g/m3 for the six-hour period of simultaneous feeding and continuous aeration, and then no aeration for the last two hours of the cycle. The temperature was 30°C, pH 7 and the granule diameter 1.1 mm. 11 Figure S4. Concentrations during two cycles at steady state regarding bulk concentrations. Same operation parameters as in the multispecies granular sludge case except for the intermittent aeration. 12 Figure S5. 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