Presentation on theme: "Sewer System in Japan Dr. ICHIKAWA, Arata Professor Graduate School of Recycling and Environmental engineering Fukuoka University."— Presentation transcript:
Sewer System in Japan Dr. ICHIKAWA, Arata Professor Graduate School of Recycling and Environmental engineering Fukuoka University
Self Introduction 1937, burn in Tokyo 1961 Graduate from Civil Eng., The university of Tokyo 1963 Master Degree form The University of Tokyo (Civil Engineering) 1964 Assistant, Dept. of Urban Eng., UT 1965 Lecturer, Dept. of Urban Eng., UT 1968 Associate Professor, Dept. of Urban Eng., UT 1997 Retire from UT, by the time limitation Professor of Environmental Eng., Kyoto University 2000 Retire from KT, by the time limitation 2001 Professor of Fukuoka University
Self Introduction (2: Majoring study field) Integrated Water Resources and Quality Planning Field: The Tama River in Tokyo The Lake Biwa, in Kyoto Methodology: HydroInformatics Gathering information and their integrated analysis Characteristics on watershed: cross sections, slope of a river Water budget: runoff data, water usage, effluent Water quality, mainly organic matters, eutriphication Human activities: population, industrial activities, housing, including historical views Water Technologies: Purification, sewerage treatment, etc Integration Now, this methodology is the most popular, after the progress of computer science.
Seminar for the integrated understandings on recycling and environmental engineering Students of our department come from various fields, not only civil engineer, chemical engineer, mechanical engineer, but another faculties; such as economics, science and agriculture. As the introductory education, we organize the seminar for the integrated understandings for 100 day. To visit about 15 fields. Recycling and water facilities. Preparatory lectures, preparatory survey by students, study tour, completion of a report, presentation, comments from faculty members and final reports after each study tour, every week. This visit is one of these activities
4 years research activities Construction waste management: 2002-04 by 2 master students tackled with this topics 2003-present: Mr.Matsuda, succeeded their research and developed it to the total system. Joukasou, private treatment facility of sanitary sewarage 2003-present: denitrification system Transportation of hazardous wastes of PCB 2003-05: by working student at the transportation company Recycling of shredder dust: 2002-04: awarded a poster prize from Japan Society of wastes
4 years research activities (2) Rainfall-runoff model: 2002-present: Mr.Yamashita’s theme for forest region 2004-present: Mr.Tateishi, for urban area Local currency: 2002-present: by the alumina of Faculty of Economics
Sewer System in Japan The oldest Sewer system is Taikou Sewer, built in 16 th century, in Osaka, a part of which is still active. Modern SS are in Yokohama (residential Area for foreigners) and in Tokyo (the most active area) in the middle of 19 th century. Those are the combined sewer System Treatment facilities: Mikawashima, Tokyo, in 1922 Followed by Osaka, Nagoya. In Local Cities there were no SS, except Gifu and Toyohashi The basic principle: How to enlarge the served population Combined Sewer System has been introduced. At the age of the rapid economic growth, the public water courses were much polluted, then the Government changed his mind to Separate Sewer System.
Sewer System in Japan (2) Pollution Control at the rapid economic growth Effluent standard, to keep the environmental standard The construction of Sewer System, less than 10% of served population to 67% in 2004. But it takes a long time and huge money. After that, the construction of SS is one of the main political issues in Japan 1.5% increment of the population per year Now about \3 bil per year in 2004 Main target is pollution control, it means rain water is out of the target.
Night soil treatment In Japan, night soil is determined as one of the solid wastes, which managed by the Min. of Public welfares, At the first stage, conduits were managed by Min. of Construction, Treatment facilities by Min. of PW. The government decided to unify the management of SS by Min. of Construction. But Joukasou, private night soil treatment facilities are still controlled by MPW. At the beginning of 1990’s about 450 thousand units were sold. Now, the diffusion of in the middle and small cities is the keen issue, by zoning of sewer system.
Our prides on the Technologies in Sewer system The proposal of the equivalent roughness in a small catchment, by Dr. T.Sueishi, the pioneer of the distributed Model, in 1957. Reaeration coefficient, numerically solved by the energy consumption in the flowing water, by Dr.T.Murakami, 1967. De-nitrification Process for the Night soil treatment facility, by Dr. Y.Matuo and Ebara Infilco Group First facility was built in Matsue, front of the lake Nakanoumi, 1968. And now this concept has been applied to many sewerage treatment facilities with high and costless modifications
Our prides on the Technologies in Sewer system (2) Runoff reduction Sewer System, developed by Dr. S.Fujita and Tokyo Met. Gov., at the beginning of 80’s Separation of rain water at the inlet of Sewer System in the combined sewer system. The main concept is the storage and slow discharge, controversy of the old concept of SS. Jacking method: for the construction of conduit system, without excavating the surface, developed by the construction firms from 1960’s. Now, it develops to the less than 500mm pipes and more than 250m length with leading robot. Especially high technology at the high ground water table area. High performance of the effluent from treatment facility. About 5-7 BODmg/l, 1-2 ATU-BODmg/l
Estimation of Runoff from a rain This topic is the main problem for a long times. Lloyd Davis summarized it into the Rational formula. Qmax=c x I x A/360, c: runoff coeff. I: rainfall intensity(mm/hr) A: area(ha) Q: runoff(cubm/s) Easy to handle, less parameters. So it has been used for more than 100 years for all over the world. Especially, in the field of Sewer design (determination of diameter of conduits) Rational formula has been applied. This is one of the lumped Model. In 1962 Road Research lab, UK, developed a new method TRRL method: divided the watershed into the contour line of equal concentration time. This is the beginning of the distributed model with computer technology.
Watershed Lumped Model Down stream Upstream 流下方向 断面 No.1 Only determine the peak flow and/or hydrograph at the end of the watershed
集中型モデル 下流 上流 本流の河川 流 域 Watershed is expressed by the typical parametes and representative rainfall in the whole basin Output is the peak flow and/or the hydrograph. ① convenient with less parameters ② no other model had been developed ③ simple calculation and easily understandable Other lumped models are tank model, reservoir function model Howerer, now-a-day, more detailed information were required by the stakeholders
Distributed Model United States: for the water quality management Europe: for the rehabilitation of Sewer system Where, how and the scale, to be improved. In 1978, volunteers on this problem gathered to exchange information on it, which developed to USD. This month 10 th Conference will be held in Denmark. In 1981, on the 2 nd Conf. new models were introduced: SWWM(USEPA), Wallingford Procedure (now InfoWorks), ILLUDASA (Illinois Univ.) Design concept, mathematic model, idea, computational techniques, scales, targets speed for computation and so on.
My contributions Fortunately, I attended this meeting and got a good relationships between model giants: Prof. Ven Yehn, Dr. R.Price, Prof. W.Huber (Florida Univ.) I had been a vice chairperson on the Joint Committee on Urban Storm Drainage Joint committee: IAHR (quantity), IWPRC (Quality) So I introduced these concepts into Japan. In the field of sewer eng., many cities adapted these models, The biggest applied area is for Tokyo Metro. With more than 105km 2. And more than 300 applications are reported.
Distributed Model Lower stream Up stream 流下方向 Sub Catchment 集水域 断面 No.1 本流の河川 断面 No.2 断面 No.3 断面 No.4 断面 No.5 集水 域 Main river channel and sub catchments, inflowed from tributaries. We could get hydrograph at any points on the main channel.
下流 上流 河道モデ ル 小流域 分布型モデル Main river Dynamic wave model SubcatchmentLumped Model Determined Hydrographs for each sub catchment by a lumped model, and calculates the water movement by a mathematical model. ① hydrological conditions could be changed for each sub catchment. ② hyetograph should be prepared for each sub catchment. ③ High speed calculation on Dynamic Wave model is applied for these models.
Sewer model The complicated structures of sewer system, joints, changes of slope, diameter, were assumed to be impossible to solve mathematically. But recent computer technology could solve these problems. Now 100 thousand nodes (manholes) could be treated. Hydraulic in Sewer Pipes is also complicated: Open channel flow in the usual time and pressured flow in rainy conditions. This phenomena are solved by the introduction of Preissman Slot. Computational technology: differential equation, an itteration methods are introduced. MOUSE (Denmark), XP-SWWM (USA), InfoWorks (UK)
Japanese Improvements on these Model Flood (Inundation) control: Design of networks, enforcement of the sewer system, real time control, risk management by announcement of the occurrence of inundation to habitants. Improvement of Combined sewer system The reduction of CSO (Combined Sewer Outflow): volumes, loadings, the number of times. Improvement of model by Japanese engineers: Practical uses of Sewer Asset inventories Application of GIS to inundation forecasting Surface flow on the roads, double pipe lines Gathering the checking data for the identification of parameters.
Future problems to be solved Integration of analysis on sewer and river system. Sewer system: as a sub catchment, river is main channel. There are many differences between both sites: Design criteria: no flooding for river engineering Design rainfall: 50mm/hr for sewer system, 200years of RP Runoff coefficients for a rational formula Pursuit of surface runoff: after inundation. For a hazard map to the habitants. Real time control: Pumping system, detention tanks, Observation data for the identification of parameters.
Purification works Sewerage treatment facility Closed zone forest Paddy field Urban area Wetland 用水路 Mr. Yamashita is challenging for these problems, Appling this model for the forest zone. Estuary