Start-Up of a decentralized pilot plant for the anaerobic treatment - - PowerPoint PPT Presentation

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

Laura Fröba, Marisela Vega, Frauke Groß, Antonio Delgado 16.09.16

Objective of the study

industrial scale 200 m³/ d 2000 PE pilot scale 2 m³/ d 20 PE lab scale 0,014 m³/ d

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

• 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%) service water domestic wastewater decentral 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

anaerobic

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

service water R1 R3 Buffer tank anaerobic digestion Anammox post-treatment pre-heating domestic wastewater R2

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

buffer tank reactor 1 reactor 2 reactor 3 sand filter activated carbon

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Pilot plant for treating domestic wastewater

• installation in office container (28 m², H: 2.50 m)

 flexible, modular and space efficient (decentral) caustic reactor 1 reactor 2 reactor 3 post treatment buffer electrical cabinet

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• 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)

Start-Up of the pilot plant

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• start-up procedure

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) adaptation phase 100% SWW (1000 liters of tab water added with ammonia sulfate (40mg/l) and sodium nitrite (50mg/l)) stepwise interconnection of R1 and R2 to 33%, 50%, 75% and 100%  100%: no addition of organic acids to R2 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

(MWW: municipal wastewater, SWW: synthetic wastewater)

• testing of the three-stage pilot plant for

200 days of operation after start-up  feeding of 100% MWW  additive: sodium nitrite (R3)

Start-Up of the two-stage anaerobic digestion (R1 + R2)

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(I) adaptation phase (R2)  COD removal efficiency increased from 31% to 53% 10 20 30 40 50 60 70 80 90 100

75 150 225 300 375 450 525 600 675 750 825 900 975 1050

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 COD removal efficiency [%] chemical oxygen demand (COD) [mg/l] batch-no.

inlet COD [mg/l] COD [mg/l]

• utlet COD [mg/l]

COD removal efficiency [%] (II) (III) (I)

(II) Interconnection of R1 to R2 (33%, 50%, 75%,100%)  COD removal efficiency increased to 71% (III) Testing of the two-stage anaerobic digestion  average COD removal efficiency 62%

 Start-up of two-stage anaerobic digestion was successful  Self-defined service water limit value of 75 mg/ l could almost be reached

Start-Up of the Anammox-stage (R3)

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20 40 60 80 100 120 10 20 30 40 50 60 70 80 90 100 110 120 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

NH4-N removal efficiency [%] nitrogen concentration [mg/L] batch-No.

NH4-N [mg/L] start NO2-N [mg/l] NH4-N Removal efficiency [%]

(I) (II) (III)

(IV) (V)

(VI)

(I): 100% SWW, (II): 20% MWW (III): 50% MWW, (IV): 80% MWW, (Ⅴ): 100% MWW

(I) adaptation phase (R3)  NH4-N removal efficiency inbetween 80% to 90% (I)-(V) interconnection of anaerobic digestion to R3 (20%, 50%, 80%, 100%)  NH4-N removal efficiency decreased from 72% to 48% (VI) adjustment of substrate to feed ratio (NO2-N/ NH4-N)  NH4-N removal efficiency rised to 92%

 start-up of the Anammox-stage was successful self-defined service water limit value of 10 mg/ l could be reached

 Optimum substrate to feed ratio of the Anammox-stage in pilot scale: 1.14 mg/ l

Degradation performance after 200 days of operation

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212 85 39 60% 21% 0% 20% 40% 60% 80% 100% 50 100 150 200 250 300 removal efficiency [%] COD-concentration [mg/ l]

• 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 [%]

46 50 1 96% 0% 20% 40% 60% 80% 100% 10 20 30 40 50 60 70 80 removal efficiency [%] NH4-N concentration [mg/ l]

• 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 [%]

Self-defined service water limit values:

COD: 75 mg/ l NH4-N: 10 mg/ l

further optimization of 2-stage anaerobic digestion needed with Anammox-stage limit value is guaranteed

Conclusion

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• 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
• ptimum 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

• ptimization is needed to increase the plant´s capacity

 

Thank you for your attention!

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buffer tank reactor 1 reactor 2 reactor 3 sand filter activated carbon

anaerobic digestion Anammox post-treatment pre-heating

Acknowledgements:

• Hans Sauer Stiftung
• Klärwerk Erlangen
• Siemens AG
• ZWT Wasser- und Abwassertechnik GmbH
• Maschienenbau Biermann GmbH
• Webfactory GmbH

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Challenges of the project guarantee Process stability Challenges of decentral installation easy to use energy- and cost efficency domestic purpose different wastewater composition (place of installation) Varying concetrations (seasonal)

• perating parameters

(pH, T)

• dourless

noise emission < 35 dB space saving low investment costs low operation costs automated low maintenace robust

Concept of the pilot plant

R3 R2

LSH

312

LSL

311

LSH

212

LSL

211

LSH

112

LSL

111

QIRC

230

QIRC

340

QIRC

130

QIRC

140

TRC

120

TR

220

QIRC

330

TRC

320

influent

Organikabbau (2. Stufe)

base R1

LSH

001

LSL

002

Effluent

Biogas

Puffer- tank

M 10 M 4 M 1 M 5 M 7 M 2 M 6

buffer- tank

Organic digestion (1. step) Organic digestion (2. step) Nitrogen removal (3. step)

Sandfilte r 3 Sandfilte r 2 Sandfilte r 1 buffer- tank Activated carbon

Conecpt of process control Basic automation and process monitoring State detection Fuzzy-Neuro experts ystem Ablaufplan basic automation (PCS7) 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 I/O-cuppler

[ET 200 M] [IM 153 -2]

analytic sensors (Hach-Lange) FU

Profibus DP DC-USV DP/ PA - Link Profibus PA R 1 R 2 R 3 plant bus ES/OS-Single Station (Web-Anbindung) PG-Gerät

temperature sensors

CPU 417-4H

[SIMATIC PCS7]

FU

Methods for guaranteeing process stability Fuzzy Logic (FL) (expert knowledge) Proportional Integral Differential (PID) controller Mathematic models (differential equations) Artificial Neuronal Nets (ANN)  For pH-control

• Temp. (F°)

 for state detection  Protection against overload in anaerobic digestion (Anaerobic Digestion Model

• No. 1)

Process stability

 Estimation of NH4 degradation

based on ΔpH/ Δt

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 (𝑇𝑗|𝑗=1 −12) 12 particulate components (𝑌𝑗|𝑗=13 −24) (7 groups of microorganisms)  19 biochemical processes  5 physico-chemical processes  4 inhibition functions

Modeling Two-stage Anaerobic Digestion

Plant specific Modifications:

• Two-stage system

(hydrolysis + acidogenesis → R1

acetogenesis + methanogenesis → R2)

• Batch operation with different reactors (mass balance + initial condition equations)

R 2

Hydrolysis Acidogenesis Acetogenesis Methanogenesis

Xsu, Xaa, Xfa

⃰ 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.

Xc4, Xpro Xac, Xh2 Sch4, Sco2 Sbu, Sva, Spro Sac Sh2,Sco2 Xch, Xpr, Xli Ssu, Saa, Sfa

R 1

Total inorganic carbon Total ammonia-nitrogen

† ‡

COD → *0.5𝑌𝑑ℎ + 0.4𝑌𝑞𝑠 + 0.1𝑌𝑚𝑗 TIC → 𝑇𝐼𝐷𝑃3 TAN → 𝑇𝑂𝐼4 1) 2) 3)

* Schlegel, H.G. and Fuchs, G. (2007). General Microbiology (Allgemeine Mikrobiologie), Eigth Edition. Georg Thieme Verlag, Stuttgart. P. 625.

Transformation method for domestic wastewater

Chemical measurements:

Model input

Modeling Two-stage Anaerobic Digestion

† ‡

Model calibration/validation: Total COD

Model R2 Model R1

Easy to use

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Economic feasability study

Wastewater costs of central wastewater treatment in Germany Middle Franconia: 2,25 €/ m³ Brandenburg: 3,35 € /m³ 20 PE plant 200 PE plant capacity 730 m³/ a 7.300 m³/ a useful life 30 Jahre 30 Jahre required rate of return 7 % 7 % fixed costs 7.251 €/ a 8.967 €/ a investment costs 103.185 € 128.300 € amortisation costs 3.439 €/ a 4.277 €/ a

• perating costs

200 €/ a 200 €/ a average interest 3.611 €/ a 4.491 €/ a variable costs 6.733 €/ a 24.511 €/ a total average costs 13.983 €/ a 33.478 €/ a wastewater costs 19,16 €/ m³ 4,59 €/ m³

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