1. 1 Hiroki ITOKAWA (Japan Sewage Works Agency) Japanese guideline for activated sludge models for municipal WWTPs Presentation for IWA Task Group on Guidelines for Use of Activated Sludge Models (12/9/2006)

2. 2 ● Contents  Outline of JS  Present status of practical application of simulation in Japan  Japanese guideline for practical application of activated sludge model

3. 3 ● About the speaker... Name: Hiroki Itokawa ( 糸川 浩紀 )  Name: Hiroki Itokawa ( 糸川 浩紀 ) Affiliation:  Affiliation: Research & Technology Development Division, Japan Sewage Works Agency (JS), Japan Research & Technology Development Division, Japan Sewage Works Agency (JS), Japan Career:  Career: 1998Ph.D. degree at Dept. Sanitary and Environmental Eng., Univ. Tokyo 1998 ~Lecturer at the same department, Univ. Tokyo 2000 ~Engineer at R&D Division, JS 2005 ~Guest researcher at ISA, RWTH Aachen Univ. 2006 2006

4. 4 What is JS ?

5. 5 ● Japan Sewage Works Agency (JS) Head office R&D Div. Local offices Covering all over Japan.  Covering all over Japan. A self-organizing governmental agency under the Ministry of Land, Infrastructure and Transport (MLIT).  A self-organizing governmental agency under the Ministry of Land, Infrastructure and Transport (MLIT). Funded in 1972, according to specific law.  Funded in 1972, according to specific law. Principal task is planning, design, construction, and operational assist of municipal WWTPs requested by municipalities.  Principal task is planning, design, construction, and operational assist of municipal WWTPs requested by municipalities. Engaged also in R&D and training of municipal engineers.  Engaged also in R&D and training of municipal engineers.

6. 6 ● R&D Division, JS R&D Division deals with development and evaluation of new technologies concerning WWT and sludge management, as well as survey of existing WWTPs.  R&D Division deals with development and evaluation of new technologies concerning WWT and sludge management, as well as survey of existing WWTPs. 20 engineers, whose average retention time is only 3 years.  20 engineers, whose average retention time is only 3 years. Conducting 37 projects with annual budget of 3.63 million Euro (FY2004), of which 83% is commissioned by central or municipal governments.  Conducting 37 projects with annual budget of 3.63 million Euro (FY2004), of which 83% is commissioned by central or municipal governments. In addition, 30 joint research projects with private companies are carried out (FY2004).  In addition, 30 joint research projects with private companies are carried out (FY2004).

7. 7 Present status on ASM in Japan

8. 8 ● Existing design criteria in Japan Aerobic tank - Aerobic SRT as a function of temperature (empirical relationship). Anoxic tank - Denitrification rate as a function of BOD-SS loading (empirical relationship). Anaerobic tank - Just HRT ! Secondary clarifier - Surface loading. Difficult to consider dynamic condition (e.g. influent fluctuation, storm event, etc.)  Difficult to consider dynamic condition (e.g. influent fluctuation, storm event, etc.) No kinetics, poor mass-balance.  No kinetics, poor mass-balance. No prediction of EBPR, poor prediction of denitrification.  No prediction of EBPR, poor prediction of denitrification. Dynamic simulation with activated sludge model ???

9. 9 ● Present status of ASM in Japan At least the name is known to most of engineers in the field.  At least the name is known to most of engineers in the field. The number of users is still small (less than 50 persons?).  The number of users is still small (less than 50 persons?). Municipalities (or JS) - Play a key role because they make an order. - Large cities began to use, but most of the engineers are still skeptical about "predicting power" of model. Consultants - Also important, since they could be the main user. - Large companies have a few model users, and they are just waiting for the publication of guideline. Electric manufacturers - There are some "heavy" model uses, traditionally, but experience on biological issues is often lacking. - Concern is mainly towards process control. Machinerysuppliers - Most of large companies have a few model users. - Evaluation of their own product/system is the major application. Universities - Few researchers deal with ASM at the moment. - "Our role has been finished."

10. 10 ● Present status of ASM in Japan At the moment, only "trial use". (As far as I know,) there are very few projects in which model was used really for practical purpose in the field of municipal WWTPs.  At the moment, only "trial use". (As far as I know,) there are very few projects in which model was used really for practical purpose in the field of municipal WWTPs. Simulation software used in Japan:  Simulation software used in Japan: Japanese translation - BioWin (OEC) - GPS-X (KURITA) - WEST (EMORI) English - AQUASIM - SIMBA * Most of electric companies dealing with ASM have their own software, although principally for internal use. No integrated modelling approach.  No integrated modelling approach.

11. 11 ● What is the obstacle ? Too strong existing design guideline, in terms not only of design freedom, but also of evidence for audit inspection.  Too strong existing design guideline, in terms not only of design freedom, but also of evidence for audit inspection. Use of COD Mn, not COD Cr.  Use of COD Mn, not COD Cr. English environment (e.g. IWA technical report, literatures, software, etc.).  English environment (e.g. IWA technical report, literatures, software, etc.). Poor motivation for optimizing design/operation of WWTPs.  Poor motivation for optimizing design/operation of WWTPs. Lack of engineers who have BOTH "motivation to use models" and "experience of process engineering".  Lack of engineers who have BOTH "motivation to use models" and "experience of process engineering". Absence of guideline for modelling study.  Absence of guideline for modelling study. Lack of "good example" of practical application in Japan.  Lack of "good example" of practical application in Japan.

12. 12 ● Activity of R&D Division, JS on ASM Survey of influent characteristics in terms of ASM (correlation between COD Cr and COD Mn /BOD 5, COD components).  Survey of influent characteristics in terms of ASM (correlation between COD Cr and COD Mn /BOD 5, COD components). Sampling campaigns for model calibration.  Sampling campaigns for model calibration. Calibration and simulation case studies to develop a model application procedure.  Calibration and simulation case studies to develop a model application procedure. Development of simulation software.  Development of simulation software. Development of a guideline for practical use of models.  Development of a guideline for practical use of models. Since 2000.  Since 2000.

13. 13 JS Guideline for Practical Use of ASM

14. 14 ● JS Guideline of modelling "Evaluation of the Method of Practical Application of Activated Sludge Model".  "Evaluation of the Method of Practical Application of Activated Sludge Model". Supervised by a committee, headed by Prof. Mino, Univ. Tokyo.  Supervised by a committee, headed by Prof. Mino, Univ. Tokyo. Aims:  Aims: - To be "a trigger" of model application in Japan. - To ensure a certain level of simulation studies. - To be implemented in general design guideline. - To let the modelling study authorized.

15. 15 ● JS Guideline of modelling Basic ideas:  Basic ideas: - To be not only a guideline, but also a handbook. - Calibration is essential for individual plant (no standard influent/parameter values) in most cases. - Make it as simple as possible. - Not put too much stress on "predictability" of effluent qualities. - Additional data collection is necessary in most cases, but no lab-experiments for parameter estimation.

16. 16 ● Contents of the report 1.Introduction 2.Detailed description of ASM 3.Application of ASM 4.Procedure of modelling study 5.Case studies 6.Future perspectives Appendixes Appendixes 1.Introduction 2.Detailed description of ASM 3.Application of ASM 4.Procedure of modelling study 5.Case studies 6.Future perspectives Appendixes Appendixes

17. 17 ● Procedure of modelling study - Biological model: ASM2d - Secondary clarifier model: not specified - Calibration: fitting to plant data (no lab-experiments) - Software: not specified 1. Problem/target definition 2. Existing data collection 3. Additional survey 4. Process analysis 5. Process modelling 6. Calibration/verification 7. Simulation 8. Evaluation/implementation

18. 18 ● Procedure of ASM application 1. Problem/target definition - Overall and simulation objectives - Index for results evaluation/comparison - Required predicting accuracy - Range of investigation - Possible scenarios 2. Existing data collection - Design documents - Historical operating data - Plant inspection and interview - Evaluation of data

19. 19 ● Procedure of ASM application - Definition of target lane - Daily average influent/effluent qualities - Diurnal fluctuation of influent/effluent - "Profile" of water quality of bioreactor - Water quality of return sludge - DO in aerobic reactor - Influent characterization (COD) - Sludge characterization (COD, N and P) - Reactor/clarifier hydraulics - Oxygen supply by aeration devices - Clarifier sludge blanket 3. Additional survey

20. 20 ● Procedure of ASM application 4. Process analysis - Estimating the amount of COD, N and P conversions - Estimating "phenomena" in each compartment of reactor and clarifier - "Representativity" check for calibration data - "Stability" check for calibration data - Mass balance check for calibration data

21. 21 ● Procedure of ASM application 5. Process modelling Definition of the modelling range Return sludge Excesssludge EffluentRawWW PS SC Bioreactor - Tank-in-series model Aeration - K L a model - DO control - Fixed DO Secondary clarifier - " Ideal clarifier" with/without reactions - Fixed return sludge concentrations

22. 22 ● Procedure of ASM application 6. Calibration - Getting general idea of fitting from simulation result with "default" values. - Fitting to observed data by all the "unreliable" input data including parameters. - Verifying parameters with other data set(s), and evaluate simulation "reliability". - Determining simulation method (e.g. static or dynamic?, initial condition?), considering "representability" and "stability" of data. - Defining data sets to be used. - Setting all the information on simulator. - Sensitivity analysis, if possible.

23. 23 Fitting to observed data ● Procedure of ASM application Solids production Influent COD (X I /X S )  Influent COD (X I /X S ) Influent/solids N&P Conversion factors (f N and f P )  Conversion factors (f N and f P ) Nitrification Nitrifiers kinetics (μ AUT K O2, K NH4 )  Nitrifiers kinetics (μ AUT, K O2, K NH4 ) Aeration, if DO data is not reliable  Aeration, if DO data is not reliable Denitrification X H anoxic kinetics (η NO3 K O2 )  X H anoxic kinetics (η NO3, K O2 ) Hydrolysis anoxic kinetics (η NO3 K O2 )  Hydrolysis anoxic kinetics (η NO3, K O2 ) EBPR X PAO kinetics (b PAO, q pp, q PHA, Y PAO )  X PAO kinetics (b PAO, q pp, q PHA, Y PAO ) Hydrolysis anaerobic kinetics (η fe )  Hydrolysis anaerobic kinetics (η fe ) Influent COD, RS NO x -N, if unreliable  Influent COD, RS NO x -N, if unreliable

24. 24 ● Additional information Influent characterization data (variation, fluctuation, influence on simulation results, etc.).  Influent characterization data (variation, fluctuation, influence on simulation results, etc.). Examples of sensitivity analysis.  Examples of sensitivity analysis. Case studies (OD and A2O).  Case studies (OD and A2O). “What-To-Do” sheets for cases of calibration failure  “What-To-Do” sheets for cases of calibration failure

25. 25 ● FAQ on modelling in Japan By non model user:  By non model user: - How precise the model can predict effluent qualities ? - Do I have to understand all these (terrible) equations ? - How much cost is required as a whole ? - Can you predict specific phenomena (e.g. effluent solids conc., sludge bulking, storm event, etc.) ? By model user:  By model user: - How much data should I take for calibration ? - Which parameter should be changed in calibration and how much extent ? - How much extent should I "fit" to the observed data ? - How can I have confidence on my calibration result ?

26. 26 ● Future perspective Limitation of existing design guideline is getting realized more and more.  Limitation of existing design guideline is getting realized more and more. A case where simulation study can make a contribution will increase significantly.  A case where simulation study can make a contribution will increase significantly. Use of simulation study will increase anyway, but actual "launch" will be after implemented in general guideline.  Use of simulation study will increase anyway, but actual "launch" will be after implemented in general guideline. Present method of calibration could be more "systematic" and "automatic", reducing efforts and deviation of results from person to person, where importance of verifying and evaluating the result has to be emphasized more and more.  Present method of calibration could be more "systematic" and "automatic", reducing efforts and deviation of results from person to person, where importance of verifying and evaluating the result has to be emphasized more and more. Predictions of specific cases are also matters of concern (e.g. storm event, nightsoil addition, MBR, hybrid process, etc.).  Predictions of specific cases are also matters of concern (e.g. storm event, nightsoil addition, MBR, hybrid process, etc.).