Role of anaerobic digestion in next generation wastewater treatment and biosolids management

Transcription

1 Engineering Conferences International ECI Digital Archives Wastewater and Biosolids Treatment and Reuse: Bridging Modeling and Experimental Studies Proceedings Spring Role of anaerobic digestion in next generation wastewater treatment and biosolids management Damien Batstone Advanced Water Management Centre Follow this and additional works at: Part of the Environmental Engineering Commons Recommended Citation Damien Batstone, "Role of anaerobic digestion in next generation wastewater treatment and biosolids management" in "Wastewater and Biosolids Treatment and Reuse: Bridging Modeling and Experimental Studies", Dr. Domenico Santoro, Trojan Technologies and Western University Eds, ECI Symposium Series, (2014). This Conference Proceeding is brought to you for free and open access by the Proceedings at ECI Digital Archives. It has been accepted for inclusion in Wastewater and Biosolids Treatment and Reuse: Bridging Modeling and Experimental Studies by an authorized administrator of ECI Digital Archives. For more information, please contact

2 ROLE OF ANAEROBIC DIGESTION IN NEXT GENERATION WASTEWATER TREATMENT AND BIOSOLIDS MANAGEMENT Damien Batstone Advanced Water Management Centre

3 From This N 2, CO 2 per person 200 L 1.3 MJ 10 gn 2 gp 200 L 500 g Sludge 0.15 kwh 2 gchemicals

4 To This 200 L per person 200 L 1.3 MJ 10 gn 2 gp kwh 50 g Fertilizer

5 Why? Peak P Rise in P prices due to fertilizer demand Recovered P can fully address fertilizer market N price fluctuations are related to the LPG price 2% of world energy dedicated to N production N cycle management major challenge to long-term sustainability N and P are major challenges for waste and wastewater management

6 Options Sewer mining (Front-end MF-RO) Verstraete Mainline low energy - McCarty Partition-release-recover - UQ Verstraete W, Van de Caveye P, Diamantis V: Maximum use of resources present in domestic used water. Bioresource Technology 2009, 100: McCarty PL, Bae J, Kim J: Domestic Wastewater Treatment as a Net Energy Producer Can This be Achieved? Environmental Science & Technology 2011, 45: Batstone DJ, Hülsen T, Mehta C, Keller J: Platforms for energy and nutrient recovery from domestic wastewater: a review. Chemosphere

7 Mainline Low Energy Treatment Biogas energy N 2 PO 4 2- McCarty PL, Bae J, Kim J: Domestic Wastewater Treatment as a Net Energy Producer Can This be Achieved? Environmental Science & Technology 2011, 45: Batstone DJ, Virdis B: The role of anaerobic digestion in the emerging energy economy. Current Opinion in Biotechnology :

8 Energy dominated by Anaerobic Step

9 Modelling applied to AnMBR Boyle-Gotla A, Jensen PD, Yap SD, Pidou M, Wang Y, Batstone DJ: Dynamic multidimensional modelling of submerged membrane bioreactor fouling. Journal of Membrane Science.

10 Partition-Release-Recover Batstone DJ, Hülsen T, Mehta C, Keller J: Platforms for energy and nutrient recovery from domestic wastewater: a review. Chemosphere

11 Partition Activated sludge (2 d SRT) Algae Natural light Purple phototrophic bacteria IR Yes these are anaerobes

12 The key is in partitioning How to partition CPNK fully? Activated sludge C,P only Algae need light & CO 2 PPB need IR light&cod Hülsen T, Batstone DJ, Keller J: Phototrophic bacteria for nutrient recovery from domestic wastewater. Water Research 2014, 50:18-26.

13 Where to get Carbon from? Biogas High-VFA supernatant to partition via P recovery Supernatant to recovery From partition Solids to stabilisation Solids to reuse First stage thermophilic hydrolysis Rotary drum / gravity thickening Second stage stabilisation Centrifuge How to preferentially extract/release VFAs? How to predict VFA distribution? Batstone DJ, Hülsen T, Mehta C, Keller J: Platforms for energy and nutrient recovery from domestic wastewater: a review. Chemosphere

14 Modelling Challenges Unlike any other process (ASM, ADM, etc) COD from light changes carbon redox Virtually no separate catabolism (under most conditions) Light adds a degree of freedom some key conditions Heterotrophic growth (light, COD, N) Autotrophic growth (light, No COD, N) Accumulation (light, COD, no N or P) Photo-assimilative redn (light, No COD, no N or P) All non-light process All aerobic processes (with/without light)

15 PRR Energy Flows Batstone DJ, Hülsen T, Mehta C, Keller J: Platforms for energy and nutrient recovery from domestic wastewater: a review. Chemosphere

16 Digester is also important 50%+ of Capex mixing 10 kwh/kl/d Energy recovery Transport & disposal costs Foaming etc

17 Enhancement Technologies 60% THP 165C Methane Yield (gcod gcod fed) 50% 40% 30% 20% 10% Increase degradability Increase rate Enhanced Biogas Heat & Electrical Out 0% Time (d) Influent Heat or electrical energy in Treated sludge Thermophilic Pretreatment Main digester

18 TPAD 2-4 days 55C-65C 12 days 35C 2 MJ/kg DS (~4-5%) Generally sufficient heat from cogen

19 Biogas Production Rate (L/day) Does it Work? 20%-30% additional gas Thermophilic Mesophilic Ge H, Jensen PD, Batstone DJ. (2010) Pre-treatment mechanisms during thermophilicmesophilic temperature phased anaerobic digestion of primary sludge. Water Research 44(1):

20 Lots of Testing ph 5 ph 5 % VS destruction in TP system % VS destruction in MP system Waste activated sludge HRT 12 days 50 VS destruction (%) Period 1 Period 2 Period 3 Period Time in operation (days) Ge H, Jensen PD, Batstone DJ. (2011) Temperature phased anaerobic digestion increases apparent hydrolysis rate for waste activated sludge. Water Research 45(4):

21 Lots more Testing Pre-treatment stage Methanogenic stage CH 4 production (g COD d -1 ) ph 4, 65 C ph 7, 65 C Uncontrolled, 65 C Days Ge H, Jensen PD, Batstone DJ. (2011) Increased temperature in the thermophilic stage in temperature phased anaerobic digestion (TPAD) improves degradability of waste activated sludge. Journal of Hazardous Materials 187(1-3):

22 Summary Outcome (WAS) 1.2 Continuous TPAD 65 C 1.0 Continuous TPAD 70 C 0.8 Continuous TPAD 60 C k hyd (d -1 ) Batch TPAD 60 C Continuous TPAD 50 C Batch TPAD 65 C Batch TPAD 70 C Batch TPAD 50 C f d

23 PC2 (10.9%) Why? TP 65ºC TP 60ºC 208 days 489 bp 187 bp 450 bp days 256 bp 412 bp 255 days 271 bp TP 50ºC MP 35ºC Feed Circle size = days since start of experiment 451 bp bp 449 bp 55 bp 158 bp 419 bp 253 bp 236 bp PC1 (34.7%) Pervin, Dennis, Tyson, Batstone, Bond, Wat. Res.

24 3 d High-Rate Anaerobic Digestion Ho D, Jensen P, Batstone D: Effects of Temperature and Hydraulic Retention Time on Acetotrophic Pathways and Performance in High-Rate Sludge Digestion. Environmental Science & Technology 2014, 48:

25 Why 1?

26 Why 2? ADM1 generally OK for modelling, but need acetate oxidation Ho D, Jensen P, Batstone D: Effects of Temperature and Hydraulic Retention Time on Acetotrophic Pathways and Performance in High-Rate Sludge Digestion. Environmental Science & Technology 2014, 48:

27 Plant Wide Analysis

28 Needs Towards Generalized PCM Emerging processes highly dependent on PC processes:- Gas stripping and absorption Adsorption Precipitation Electroseparation Generally have wider swings in Ionic Strength, Controlling Mechanisms Conventional modelling also needs better PCM Batstone DJ, Amerlinck Y, Ekama G, Goel R, Grau P, Johnson B, Kaya I, Steyer JP, Tait S, Takaćs I and others. (2012) Towards a generalized physicochemical framework. Water Science and Technology 66(6):

29 Generalized Precipitation Model One contestable parameter

30 Conclusions Key processes are mostly anaerobic or physicochemical (Anammox is partly aerobic) No nutrient recovery processes based on activated sludge New challenges range from:- Applying existing models & tools to new processes Better integration of fields of modelling Totally new fundamental models incorporating light Batstone DJ, Amerlinck Y, Ekama G, Goel R, Grau P, Johnson B, Kaya I, Steyer JP, Tait S, Takaćs I and others. (2012) Towards a generalized physicochemical framework. Water Science and Technology 66(6):

31 Further Information AWMC Position Paper (Chemosphere)