The purpose of this project was to propose and validate a stochastic rainfall time series model for the UK, where the model is to be applied to the design of sewer systems. After reviewing the literature, the Neyman-Scott Rectangular Pulses model was selected as being potentially suitable for the project. Some mathematical properties for the model were derived, and used to fit the model to 10 years of hourly rainfall time series. The model performed well, and so could be used with reasonable confidence for the remaining part of the project. A full investigation was carried out to find an optimum combination of historical rainfall statistics to be used to fit the model to hourly rainfall time series. A method of fitting the model to daily rainfall time series was also required. It was found that the hourly rainfall statistics used to fit the model to the hourly rainfall time series could successfully be predicted from daily rainfall statistics. Regression equations were developed so that the mean and variance of the maximum daily rainfalls could be predicted using the parameters of the model. These regression equations were included in the fitting procedure when the model showed a poor fit to the historical daily maxima, so that the model was then able to closely match the historical maxima. The model was fitted to rainfall data taken from 112 sites scattered throughout the UK. The parameters of the model were regressed on site characteristics (e. g. altitude, distance from coast, etc), so that the model could be used to generate hourly rainfall time series at sites lacking in data. Finally, a method of disaggregating the generated hourly rainfall time series to 5 minutely time series was developed and tested.

The subject of this diploma thesis is a study of two variants of sewer network of Cetechovice. Variant solutions include the use of existing segments supplemented by new gravitational or pressure sections. The proposed variant solutions are then economically assessed.

Abstract The sewage sewerage system is an important public infrastructure actively pushed by the government presently, since it can improve our environmental quality and promote the nation¡¦s competitiveness. To minimize the government's short-term financial burden and attract the private capital, vigor, and efficient management, the Executive Yuan encourages the private sector to participate the sewage sewer construction plans via the BOT (Build-Operate-Transfer) model for those systems above 10,000 tons capability per day. It is estimated there are totally over 36 such systems in the country. This research consists of two parts. The first part deals with the feasibility study of the BOT model for the sewage sewer in Taitung city. Three factors, including the law, the risk, and the financing were assessed. In the aspect of the law, the completeness of related regulations, the timetable of local government¡¦s plan, the sewage sewer¡¦s fee, and others were important items for the success of the task. In the aspect of the risk, the allocation of risks in the various stages is the important item. Finally, the financial feasibility studies were conducted for the Nantz and Danshuei demonstrated cases, in which the government expenditure and the operation net income of the private part are the important items. Presently, the relevant BOT case documents and materials show that the financial structure is one of the key assessment elements provided that the promotion of the trade and investment, and the sign of contract are successful. So the second part of this research involved the questionnaire survey as to analyze the key factors that are beneficial for the success of the promotions of trade and investment, and the sign of contract. Results show that the successful factors include the favorable financial guarantees, the lowest guaranteed operation amount of sludge, and the take-hold of the construction land by the government. All these factors should be carefully assessed and planned in advance, together with the well-designed coordination mechanism for the agreement/contract. Keywords: Sewage sewer system, privatization, BOT model

In this thesis I deal with the drainage of Hněvošice village (the village up to 2000 inhabitants). I made a technical and economic evaluation of three possible drainage systems (gravity sewers, vacuum sewers, pressure sewers). After assessing I have chosen one of them, the gravity sewers. Then I made a complete design of the sewers including design sewerage treatment plant.

The area of study is the Avery Drive drainage area. The objective of these projects is to alleviate frequent flooding at the Avery Drive neighborhoods. RC&A designed two options for improving the Avery Drive drainage area. Option one increases the capacity of the existing sewer system, and option two constructs a new storm drain system along Simon Street while keeping the existing system in place. Although both options offer preliminary solutions for alleviating flooding, the designs are unviable due to the lack of data that was available for the study. The following research will prove that RC&A fulfilled its contractual obligation of practicing due diligence by recommending further investigation to obtain valuable data for a complete and successful final design, rather than providing a solid recommendation based on existing data. / text

The untreated overflow of combined sewer system contains a variety of pollutants that can contaminate the receiving water body. Total suspended solids (TSS) transported in the sewer networks can adsorb these pollutants and become the main contaminant source. Existing models contain a numerous formulas that make the calculation process complex and time consuming. A simplified model was presented in this thesis to simulate the process of TSS transport in combined sewer pipes. The combined sewer system evaluated was a combination of an existing sewer system in Le Marais and an example system provided with the Storm Water Management Model (SWMM). SWMM was used in this research to simulate the rainfall event, pollutant build-up and wash-off process, and to provide hydraulic calculations for the combined sewer system. A spreadsheet model was created to calculate the TSS concentration profile and flow velocity profile. The total TSS transport rate was computed using a numerical estimation of the integral of the concentration in the cross-section area multiplied by the velocity. The flow depth, velocity, and Froude number of each pipe was calculated to show that the combined sewer system was under proper working conditions. The first flush phenomenon was observed by plotting the TSS concentration pollutograph of the combined sewer system. From the TSS transport pollutograph, the maximum transport rate was found (0.2609 kg/s at 6:45). The study of TSS profile showed that the concentration distribution was based on the solid density. The TSS particle also affected the transport rate. A sensitivity analysis of particle size was conducted in this thesis. A second order polynomial was used to describe the relationship between median particle size d50¬ ¬and TSS transport rate.

The aim of this diploma thesis is to research the possibilities of an odor regulation in a sewerage system. The first part of the thesis is devoted to legislation in sewege odor problematics. The second part includes description of the cause of the odor and methodology related to a hydrogen sulfide elimination either from sewerage atmosphere or straight from waste water. The next part examines the results of a survey, which was given to operators of the sewerage system. The survey examined the cause of an odor, its control and possible solutions of an odor in a sewerage system. Practical part is devoted to a given geographical area, where these problems have occurred the past. In this area the measuring of hydrogen sulfide presence took place by adding chemicals into waste water. From the collected data an evaluation was made. This can serve as a possible recommendation to sewege operators.

La presente investigación tiene por objetivo realizar un diseño del sistema de alcantarillado para la zona de Rinconada Pamplona Alta, que se encuentra ubicada en el distrito San Juan de Miraflores, el cual no cuenta con cobertura de un sistema de desagüe en la zona que les permita tener una adecuada calidad de vida a los pobladores y disminuir la contaminación. Debido a esto se propone realizar un diseño del sistema de alcantarillado usando el programa SewerCAD, con el fin de realizar diferentes proyectos y obtener los parámetros hidráulico de las distintas redes de distribución. Se presentan propuestas con tres tipos de materiales PVC, HDPE y Concreto que cumplan con la normativa OS.070. Finalmente, se realizó la evaluación económica costo efectividad y se concluyó que la Propuesta 1 PVC es la mejor opción, ya que presenta el menor índice de efectividad , lo cual asegurar la viabilidad de la propuesta. / The objective of this research is to design the sewer system for the Rinconada Pamplona Alta area, which is located in the San Juan de Miraflores district, which does not have a drainage system in the area that allows them have an adequate quality of life for residents and reduce pollution. Due to this, it is proposed to make a design with the purpose of carrying out of the sewerage system using the SewerCAD program, carry out different projects and obtain the hydraulic parameters of the different distribution networks. The proposals are presented with three types of PVC, HDPE, and concrete materials that comply with OS.070 rule. Finally, the economic evaluation of cost – effectiveness was carried out. It was concluded that first type of proposel, PVC, is the best option , since it presents the lowest effectiveness rate, which guarantees the viability of the proposal. / Tesis

The study aims to investigate an appropriate wastewater treatment process to treat domestic wastewater in Hanoi City which contain low-strength for COD (120-200 mg/L) but high in nitrogen content (10-40 mg/L). A lab scale anoxic-oxic system with a hollow fiber-Membrane Separation Bioreactor was operated at a flow rate of 5-10 L/h over a period of 150 days. The reactor was operated at different sludge recirculation rates. The MBR maintained relatively constant transmembrane pressure. During 150 days of reactor operation, treated water quality have COD of around 20 mg/L, NH4-N of less than 1 mg/L, NO3-N of less than 5 mg/L. The system shows good and stable efficiency for organic matter and nitrogen removal without adding an external carbon source and coagulants. The results based on the study indicated that the proposed process configuration has potential to treat the low-strength wastewater in Hanoi. / Mục tiêu của nghiên cứu là đề xuất được một công nghệ hiệu quả và phù hợp để xử lý nước thải sinh họat ở các đô thị của Việt nam, là loại nước thải được thu gom từ hệ thống thoát nước chung có nồng độ chất hữu cơ thấp (COD 120-200 mg/l) nhưng hàm lượng chất dinh dưỡng như Nitơ, Phốt pho khá cao (T-N: 10-40 mg/L). Chúng tôi đã nghiên cứu và vận hành chạy thử mô hình xử lý sinh học yếm khí - kỵ khí (AO) kết hợp với màng vi lọc ở quy mô mô hình phòng thí nghiệm (công suất 5-10 L/h) ở các chế độ công suất bùn tuần hoàn khác nhau. Kết quả xử lý trong thời gian 5 tháng vận hành mô hình cho thấy chất lượng nước thải sau xử lý có hàm lượng COD nhỏ hơn 20 mg/L, NH4-N nhỏ hơn 1 mg/L, NO3-N nhỏ hơn 5 mg/L. Hiệu suất xử lý chất hữu cơ và chất dinh dưỡng rất ổn định và hệ thống không phải sử dụng các nguồn bổ sung chất hữu cơ hay các hóa chất trợ lắng như các công nghệ đang áp dụng. Kết quả cho thấy công nghệ AO kết hợp màng vi lọc có khả năng áp dụng thực tế, phù hợp với những nơi có quỹ đất nhỏ, chất lượng nước sau xử lý rất cao có thể phục vụ cho mục đích tái sử dụng.

Most of wastewater treatment plants (WWTP) are operated under low loading both in water quality and water capacity (flow rate) in Taiwan. Because various treatment methods used in WWTP would cause different power consumptions. In general, the flow rate of wastewater treated is proportional to the power consumption. The purpose of this study is simulating water quality and water capacity with a case of municipal wastewater treatment plant, using standard activated sludge method. In this work we will investigate the feasibility of save power using operation and parameters adjustment in wastewater system. A further step is to conduct the save energy in current WWTP under normal wastewater treatment capacity and national effluent standard. Results showed the major save energy was at inflow pump and aeration system of biological treatment stage. Both power consumptions of two were about 60 ~70 % of total power consumption in the plant. Thus we should focus the operating conditions to plan the save energy project, and calculate the total power system and energy consumption of all unit facilities before we are going to improve the energy save in WWTP. Important note is firstly to select units and facilities having high energy consumption for evaluating the possibility of energy save. Secondly is develop and using a good management system to attain the goal of save energy.