1 Hiroki ITOKAWA (Japan Sewage Works Agency) Japanese situation on practical application of activated sludge models to municipal WWTPs Presentation for BIOMATH, Gent University (12/12/2005)

2 ● Contents  Present status of Japanese municipal WWTPs  Present status of practical application of simulation in Japan  Japanese guideline for practical application of activated sludge model

3 Asteroid ITOKAWA 540m×270m×210m 540m×270m×210m 2 billion km from the earth 2 billion km from the earth Photo from 8km distance by "Hayabusa" Photo from 8km distance by "Hayabusa" ( ( Image of space-probe "Hayabusa" approaching ITOKAWA ( Asteroid ITOKAWA 540m×270m×210m 540m×270m×210m 2 billion km from the earth 2 billion km from the earth Photo from 8km distance by "Hayabusa" Photo from 8km distance by "Hayabusa" ( ( Image of space-probe "Hayabusa" approaching ITOKAWA ( ● About the speaker... Name: Hiroki Itokawa ( 糸川 浩紀 )  Name: Hiroki Itokawa ( 糸川 浩紀 ) Affiliation:  Affiliation: (Original) Research & Technology Development Division, Japan Sewage Works Agency (JS), Japan (Temporal) ISA (Institute of Environmental Engineering), RWTH Aachen University, Germany * As a guest researcher with "Engineer Exchange Program" between RWTH and JS.

4 ● About the speaker... Background:  Background: 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. Projects in JS:  Projects in JS: - COD removal by ozonation and BAC - Cascade denitrification-nitrification process - Hybrid N removal processes by attached growth media - Sludge disintegration processes by ozonation or thermophilic bacteria - Membrane bioreactor - New control technologies for BNR - ACTICATED SLUDGE MODELLING

5 ● About Japan 9,500 km Tokyo 1,300 km 1,900 km N Land area: 378,000 km 2 (80% is mountainous)  Land area: 378,000 km 2 (80% is mountainous) Population: million people (07/2005)  Population: million people (07/2005) Population density: 338 people/km 2 (average)  Population density: 338 people/km 2 (average) * For "inhabitable" land, it's more than 1,600 ! (Tokyo: 5,700) * For "inhabitable" land, it's more than 1,600 ! (Tokyo: 5,700) Temperature: 5 ～ 27 ℃ (monthly average in Tokyo)  Temperature: 5 ～ 27 ℃ (monthly average in Tokyo) Precipitation: 1,700 mm/yr (average)  Precipitation: 1,700 mm/yr (average)

6 ● Fate of domestic wastewater in Japan 76% 24%SeweredNotsewered Johkaso (on-site household wastewater treatment tank) treatment tank) 65% 8% 3% Sewage system (under the Ministry of Land, Infrastructure and Transport) Rural Sewerage Project (under the Ministry of Agriculture, Forestry and Fisheries) 15% 9% Nightsoil treatment Others Totalpopulation (127 million) (2002)

7 ● WWT processes used in Japan (2003) RBC High-Rate Trickling Filter Contact Aeration Biological Aerated Filter Biological Anaerobic-Aerobic Filters Biofilm Other C removal Processes AS for C Removal O 2 Aeration Extended Aeration Oxidation Ditch SBR High-Rate Aeration Step Aeration Conventional AS Process < Total Plant Capacity [thousand m 3 /d] > 500 Total ,845 Conventional AS Oxidation Ditch Pre-Denitrification (MLE) Anaerobic-Anoxic-Oxic (A2O) Nutrient Removal Anaerobic-Oxic C removal + Precipitation

8 ● Outline of Japanese municipal WWT Full-coverage of sewer system in big cities. (CSO and up-grade to BNR is principal concern.)  Full-coverage of sewer system in big cities. (CSO and up-grade to BNR is principal concern.) New plants are exclusively for small municipalities, although sewer system is not always the best choice.  New plants are exclusively for small municipalities, although sewer system is not always the best choice. Task of municipalities, but central government (MLIT) has still power (approval, subsidy, etc.)  Task of municipalities, but central government (MLIT) has still power (approval, subsidy, etc.)

9 ● Outline of Japanese municipal WWT CAS and OD are predominant for C-removal, due to strong design guideline and "standardization".  CAS and OD are predominant for C-removal, due to strong design guideline and "standardization". The number of BNR plants is still small, but increasing.  The number of BNR plants is still small, but increasing. - A/O - MLE + precipitation - Cascade D-N + precipitation - A2O - MBR (+ precipitation) Energy recovery from influent/sludge (e.g. digestion) is not popular (only in 40 plants).  Energy recovery from influent/sludge (e.g. digestion) is not popular (only in 40 plants). Virtually, "DO control" is the only measure used for on-line control of aeration tank.  Virtually, "DO control" is the only measure used for on-line control of aeration tank.

10 ● Effluent regulation for WWTPs Regulation criteria were changed drastically in 2004 (from "universal" to "site-specific" regulation).  Regulation criteria were changed drastically in 2004 (from "universal" to "site-specific" regulation). T-BOD 5 Category * Applied to daily maximum effluent concentration. < 15 < 10 < 20 < 10 < 3 < 1 < 0.5 T-N T-P [mg/L] Treatment process to be used Any processes + sand filtration MLE or A2O * Only BOD 5 is essential. T-N and T-P are optional. + C-addition AO, A2O MLE + precipitation + sand filtration A2O + precipitation + sand filtration

11 ● Effluent regulation for WWTPs New administrative "emission trade"-like frame will be implemented soon for N & P removal.  New administrative "emission trade"-like frame will be implemented soon for N & P removal. Every WWTP discharging to specified closed water body is assigned the amount of N &P reduction. Plant A: Oh, we can't reduce such amount with these old facilities! Plant B: OK! We can reduce extra amount! Instead, give me money! Plant A:...OK. It's cheaper than up-grading...

12 ● What's JS ? A governmental agency under the Ministry of Land, Infrastructure and Transport (MLIT).  A governmental agency under the Ministry of Land, Infrastructure and Transport (MLIT). Established in 1972, according to specific law.  Established in 1972, according to specific law. Principal task is design, construction, and operational assist of municipal WWTPs at the request of municipalities.  Principal task is design, construction, and operational assist of municipal WWTPs at the request of municipalities. 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. It is not a guideline-making organization, but our reports have been principal data source for Japanese guidelines.  It is not a guideline-making organization, but our reports have been principal data source for Japanese guidelines. About 800 staffs, including 350 engineers.  About 800 staffs, including 350 engineers.

13 ● 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 ???

14 ● Trends on ASM in Japan Only a very small community. 'ASM? What is it ?' Consultants started to try to use. 'ASM... Oh, I've heard about that !' Municipalities are getting involved. 'ASM ! I 'm interested in it ! But how can I use it ?' Year No. presentations The number of ASM-related presentations in the Annual JSWA Conference Start of JS Project

15 ● 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."

16 ● Present status of ASM in Japan At the moment, only "trial use". (As far as I know,) there are no project 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 no project 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.

17 ● 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.

18 ● 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 softwares.  Development of simulation softwares. Development of a guideline for practical use of models.  Development of a guideline for practical use of models. Since  Since 2000.

19 ● 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.

20 ● 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.

21 ● 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

22 ● 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

23 ● 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

24 ● 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

25 ● 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

26 ● 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

27 ● 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.

28 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

29 ● 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 ?

30 ● 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.).

31 Thank you for your kind attention !

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