Start-Up of a decentralized pilot plant for the anaerobic treatment of domestic wastewater

Transcription

1 Start-Up of a decentralized pilot plant for the anaerobic treatment of domestic wastewater Laura Fröba, Marisela Vega, Frauke Groß, Antonio Delgado

2 Objective of the study - autarc wastewater treatment of small settlements and megacities - industrial scale (capacity: 200 m³/ d; PE 2000) - saving drinking quality water by using service water (saving potential about 60%) domestic wastewater COD: 200 mg/l NH4-N: 40 mg/l TN: 50 mg/l TP: 5 mg/l E.coli: 10^6 cfu/100ml domestic wastewater decentral anaerobic service water easy to use self-defined limit values (AbwV 2016, BayBadeGewV 2008) COD: 75 mg/l NH4-N: 10 mg/l TN: 13 mg/l TP: 1 mg/l E.coli 900 cfu/ 100 ml lab scale 0,014 m³/ d pilot scale 2 m³/ d 20 PE industrial scale 200 m³/ d 2000 PE 2

3 Pilot plant for treating domestic wastewater three stage biological process C-reduction: anaerobic digestion reactor 1 (R1) and 2 (R2) N-reduction: anaerobic Ammonium Oxidation (Anammox) reactor 3 (R3) pre-heating step due to mesophilic conditions (30 C-40 C) reactors: R1 + R3: anaerobic sequencing batch reactor (1300 liters each) R2: fixed bed reactor domestic wastewater R2 Buffer tank R1 R3 buffer tank reactor 1 reactor 2 reactor 3 sand filter activated carbon pre-heating anaerobic digestion Anammox post-treatment service water 5

4 Pilot plant for treating domestic wastewater installation in office container (28 m², H: 2.50 m) flexible, modular and space efficient (decentral) reactor 3 reactor 1 caustic reactor 2 post treatment electrical cabinet buffer reactors were innoculated each with 60 liters of seeding sludge R1+R2: sludge coming from a two-stage anaerobic digestion plant (Obermichelsbach, GE) R3: sludge coming from a Deammonification (DEMON)-System (Fulda, Gläserzell, GE) 5

5 Start-Up of the pilot plant start-up procedure (MWW: municipal wastewater, SWW: synthetic wastewater) reactor 1 reactor 2 reactor 3 adaptation phase 100% MWW adaptation phase 100% MWW + organic acids (acetic acid: propionic acid: butyric acid in 2:1:1) stepwise interconnection of R1 and R2 to 33%, 50%, 75% and 100% 100%: no addition of organic acids to R2 adaptation phase 100% SWW (1000 liters of tab water added with ammonia sulfate (40mg/l) and sodium nitrite (50mg/l)) stepwise interconnection of anaerobic digestion (outlet of R2) and R3 to 20%, 50%, 80% and 100% 100%: - no addition of ammonia sulfate to R3 - adjsutment of nitrite-nitrogen (NO2-N) to ammonia-nitrogen (NH4-N) ratio testing of the three-stage pilot plant for 200 days of operation after start-up feeding of 100% MWW additive: sodium nitrite (R3) 5

6 chemical oxygen demand (COD) [mg/l] COD removal efficiency [%] Start-Up of the two-stage anaerobic digestion (R1 + R2) (I) (II) (III) inlet COD [mg/l] COD [mg/l] outlet COD [mg/l] COD removal efficiency [%] batch-no. (I) adaptation phase (R2) COD removal efficiency increased from 31% to 53% Start-up of two-stage anaerobic digestion was (II) Interconnection successful of R1 to R2 (33%, 50%, 75%,100%) COD removal efficiency increased to 71% (III) Testing of the two-stage anaerobic digestion average could almost COD removal be reached efficiency 62% Self-defined service water limit value of 75 mg/ l

7 nitrogen concentration [mg/l] NH4-N removal efficiency [%] Start-Up of the Anammox-stage (R3) (I) NH4-N [mg/l] start NO2-N [mg/l] NH4-N Removal efficiency [%] (II) (III) (IV) batch-no. (I): 100% SWW, (II): 20% MWW (III): 50% MWW, (IV): 80% MWW, (Ⅴ): 100% MWW start-up of the Anammox-stage was successful (I) adaptation phase (R3) NH4-N removal efficiency inbetween 80% to 90% self-defined service water limit value of 10 mg/ l could be (I)-(V) interconnection of anaerobic digestion to R3 (20%, 50%, 80%, 100%) reached NH4-N removal efficiency decreased from 72% to 48% (VI) adjustment Optimum substrate of to feed to feed ratio ratio of the (NO2-N/ Anammox-stage NH4-N) in pilot scale: NH4-N 1.14 mg/ removal l efficiency rised to 92% (V) (VI)

8 COD-concentration [mg/ l] removal efficiency [%] NH4-N concentration [mg/ l] removal efficiency [%] Degradation performance after 200 days of operation Self-defined service water limit values: COD: mg/ l NH4-N: 10 mg/ l % 60% 100% 80% 60% 40% 20% 0% av. inlet COD of MWW [mg/l] av. outlet COD after reactor 2 {mg/ l] av. outlet COD after reactor 3 [mg/ l] av. COD removal efficiency after reactor 2 [%] av. COD removal efficiency in reactor 3 [%] % 100% 80% 60% 40% 20% 0% av. inlet NH4-N of MWW [mg/l] av. outlet NH4-N after reactor 2 {mg/ l] av. outlet NH4-N after reactor 3 [mg/ l] av. NH4-N removal efficiency in reactor 3 [%] further optimization of 2-stage anaerobic digestion needed with Anammox-stage limit value is guaranteed 8

9 Conclusion start-up of the two-stage anaerobic digestion (R1 + R2) for a temperature range of 34 C to 38 C without automated ph-control final average COD removal efficiency: 62% start-up of the Anammox-stage (R3) for a temperature range of 28 C to 35 C optimum NO2-N to NH4-N ratio: 1.14 final average NH4-N removal efficiency: 92% after testing the pilot plant for 200 days of operation total COD removal efficiency is 81% self-defined service water limit value of 75 mg/l could always be reached with R3 connected in downstream total NH4-N removal efficiency is 96% self-defined service water limit value of 10 mg/l could always reached only by R3 two-stage anaerobic digestion is limiting process-step, thus further optimization is needed to increase the plant s capacity 9

10 Acknowledgements: Hans Sauer Stiftung Klärwerk Erlangen Siemens AG ZWT Wasser- und Abwassertechnik GmbH Maschienenbau Biermann GmbH Webfactory GmbH Thank you for your attention! buffer tank reactor 1 reactor 2 reactor 3 sand filter activated carbon pre-heating anaerobic digestion Anammox post-treatment 10

11 11

12 Challenges of the project Varying concetrations (seasonal) operating parameters (ph, T) different wastewater composition (place of installation) odourless guarantee Process stability automated space saving domestic purpose Challenges of decentral installation easy to use robust noise emission < 35 db energy- and cost efficency low maintenace low investment costs low operation costs

13 Φ 1 PVC Φ 1 PVC Φ 1 PVC BV_R3 VB_1 VB_2 Concept of the pilot plant base influent V_P_ 1 M 10 V_R1_ 2 LSH 112 R1 V_R3_1 TRC TRC ph QIRC V_R2_1 V_R2_ V_R3_2 M M 6 LSH 212 Biogas R2 3 V_R3_4 V_R3_3 LSH 312 R3 QIRC 330 ph conductivity QIRC 340 NH4 QIRC 140 LSH 001 LSL 002 Puffer- buffertank V_R1_1 1 PVC LSL 111 M 1 M 5 Organic digestion (1. step) M 4 V_R1_5 Organikabbau Organic digestion (2. Stufe) (2. step) TR 220 LSL 211 ph QIRC 230 V_R2_2 LSL 311 Nitrogen removal (3. step) V_R3_5 M 7 Sandfilte r 3 V_N_5 Sandfilte r 2 V_N_6 Sandfilte r 1 V_N_7 Activated carbon V_A_1 buffertank V_N_2 Φ 1 PVC Effluent

14 Conecpt of process control State detection Fuzzy-Neuro experts ystem basic automation (PCS7) CPU 417-4H [SIMATIC PCS7] ES/OS-Single Station (Web-Anbindung) Ablaufplan Basic automation and process monitoring analytics R 1 R 2 R 3 Online: Temperature X X X ph X X X conductivity X Offline: COD X X X NH4-N X X TN X DC-USV plant bus R 1 R 2 R 3 temperature sensors FU FU Profibus DP I/O-cuppler [ET 200 M] [IM 153-2] DP/ PA - Link Profibus PA analytic sensors (Hach-Lange) PG-Gerät

15 Methods for guaranteeing process stability Proportional Integral Differential (PID) controller For ph-control Process stability Fuzzy Logic (FL) (expert knowledge) for state detection 1 Freezing Cool Warm Hot Temp. (F ) Mathematic models (differential equations) Protection against overload in anaerobic digestion (Anaerobic Digestion Model No. 1) Artificial Neuronal Nets (ANN) Estimation of NH4 degradation based on ΔpH/ Δt Input Net: ph, HRT / Otuput Net: Acetic, Butyric & Propionic Acid 4000 ph = ph = Concentration [mg/l] Acetic Net Butyric Net Propionic Net Acetic Exp Butyric Exp Propionic Exp Time [h]

16 Modeling Two-stage Anaerobic Digestion Ordinary differential equations (ODE) model: Anaerobic Digestion Model No. 1 (ADM1)* - Continuous stirred tank reactor configuration - COD base unit (mg COD/L) - 24 components: 12 soluble components (S i i=1 12 ) 12 particulate components (X i i=13 24 ) (7 groups of microorganisms) 19 biochemical processes 5 physico-chemical processes 4 inhibition functions Plant specific Modifications: - Two-stage system (hydrolysis + acidogenesis R1 acetogenesis + methanogenesis R2) - Batch operation with different reactors (mass balance + initial condition equations) R 1 Hydrolysis Acidogenesis Acetogenesis Methanogenesis R 2 Sac Xch, Xpr, Xli Ssu, Saa, Sfa Xsu, Xaa, Xfa Sbu, Sva, Spro Xc4, Xpro Xac, Xh2 Sch4, Sco2 Sh2,Sco2 Batstone, D.J., Keller, J., Angelidaki, I., Kalyuzhnyi, S.V., Pavlostathis, S.G., Rozzi, A., Sanders, W.T.M., Siegrist, H. and Vavilin, V.A. (2002). Anaerobic digestion model no. 1. Scientific and Technical Report No. 13, IWA Publishing, London.

17 Modeling Two-stage Anaerobic Digestion Transformation method for domestic wastewater Chemical measurements: 1) COD *0.5X ch + 0.4X pr + 0.1X li 2) TIC S HCO3 3) TAN S NH4 Total inorganic carbon Total ammonia-nitrogen Model input Model calibration/validation: Total COD Model R2 Model R1 * Schlegel, H.G. and Fuchs, G. (2007). General Microbiology (Allgemeine Mikrobiologie), Eigth Edition. Georg Thieme Verlag, Stuttgart. P. 625.

18 Easy to use 18

19 Economic feasability study 20 PE plant 200 PE plant capacity 730 m³/ a m³/ a useful life 30 Jahre 30 Jahre required rate of return 7 % 7 % fixed costs / a / a investment costs amortisation costs / a / a operating costs 200 / a 200 / a average interest / a / a variable costs / a / a total average costs / a / a wastewater costs 19,16 / m³ 4,59 / m³ Wastewater costs of central wastewater treatment in Germany Middle Franconia: 2,25 / m³ Brandenburg: 3,35 /m³ 19