Böcker i Scientific and Technical Report Series-serien

Scientific and Technical Report No. 24Performance-Based Contracts (PBC) for Improving Utilities Efficiency: Experiences and Perspectives is a compendium of articles written by members of the PBC taskforce. It focuses on new approaches without delegated management to private operator i.e. service contracts, consulting contracts, Alliance approach, public-public partnership. It also mentions new design and generation of more traditional PPPs, (MC, lease, concession), where a larger proportion of performance-based design is being applied. List of Contents:Performance Based Contracts - Setting the scene; PBC and Results Based Financing: the inverse approach; PBC and Energy Efficiency; Internal Performance Contracts: A Case of the National Water and Sewerage Corporation in Uganda; Performance-Based Service Contracts in Navi Mumbai; Financial Comparison of PBCs and Conventional Approach; Tegucigalpa PBC Case Study; Performance Based Contracts - Key Design Issues; NRW Reduction Optimization Framework; How to improve water services performance? Performance Based Contracts (PBC) and Regulatory issues; Peer-to-Peer Partnerships Operational for sustainable water services; Performance Based Contracts in Malawi: Teamwork Works; Performance based affermage contracts; Performance based Contracts, The Aroona Integrated Alliance Experience; Experience from Eastern Europe; NRW Performance Contract - Kingdom of Bahrain; The way forward and perspectives/trends

Guidelines for Using Activated Sludge Models is a Scientific and Technical Report that presents the results of the IWA Task Group on Good Modelling Practice.

Water Reuse: An International Survey of current practice, issues and needs examines water reuse practices around the world from different perspectives. The objective is to show how differently wastewater reuse is conceived and practised around the world as well as to present the varied needs and possibilities for reusing wastewater. In the first section water reuse practices around the world are described for regions having common water availability, reuse needs and social aspects. The second section refers to the "e;stakeholders"e; point of view. Each reuse purpose demands different water quality, not only to protect health and the environment but also to fulfil the requirements of the specific reuse. Reuses considered are agricultural, urban agriculture as a special case of the former, municipal and industrial. Alongside these uses, the indirect reuse for human consumption through aquifer recharge is also discussed. The third section deals with emerging and controversial topics. Ethical and economical dilemmas in the field are presented as a subject not frequently addressed in this field. The role of governments in respect of public policy in reuse is discussed as well as the different international criteria and standards for reusing wastewater. The importance of public acceptance and the way to properly handle it is also considered.The fourth section of the book presents contrasting case studies; typical situations in the developed world (Japan and Germany) are compared to those in developing countries (Pakistan and Brazil) for agricultural and industrial reuse. Indirect planned reuse for human consumption (Germany) is compared with an unplanned one (Mexico). The Windhoek, Namibia case study is presented to emphasize why if the direct reuse of wastewater for human consumption has been performed with success for more than 35 years it is still the only example of this type around the world. To illustrate the difficulties of having a common framework for regulating water reuse in several countries, the Mediterranean situation is described. Other case studies presented refer to the reuse situation in Israel, Spain, Cameroon, Nepal and Vietnam, these latter countries being located in water rich areas.This book will be an invaluable information source for all those concerned with water reuse including water utility managers, wastewater policy makers and water resources planners as well as researchers and students in environmental engineering, water resources planning and sanitary engineering. Scientific and Technical Report No. 20

Over 90% of bacterial biomass exists in the form of biofilms. The ability of bacteria to attach to surfaces and to form biofilms often is an important competitive advantage for them over bacteria growing in suspension. Some biofilms are "e;good"e; in natural and engineered systems; they are responsible for nutrient cycling in nature and are used to purify waters in engineering processes. Other biofilms are "e;bad"e; when they cause fouling and infections of humans and plants. Whether we want to promote good biofilms or eliminate bad biofilms, we need to understand how they work and what works to control them. Mathematical Modeling of Biofilms provides guidelines for the selection and use of mathematical models of biofilms. The whole range of existing models - from simple analytical expressions to complex numerical models - is covered. The application of the models for the solution of typical problems is demonstrated, and the performance of the models is tested in comparative studies. With the dramatic evolution of the computational capacity still going on, modeling tools for research and practice will become more and more significant in the next few years. This report provides the foundation to understand the models and to select the most appropriate one for a given use. Mathematical Modeling of Biofilms gives a state-of-the-art overview that is especially valuable for educating students, new biofilm researchers, and design engineers. Through a series of three benchmark problems, the report demonstrates how to use the different models and indicates when simple or highly complex models are most appropriate. This is the first report to give a quantitative comparison of existing biofilm models. The report supports model-based design of biofilm reactors. The report can be used as basis for teaching biofilm-system modeling. The report provides the foundation for researchers seeking to use biofilm modeling or to develop new biofilm models. Scientific and Technical Report No.18

The sequencing batch reactor (SBR) is perhaps the most promising and viable of the proposed activated sludge modifications today for the removal of organic carbon and nutrients. In a relatively short period, it has become increasingly popular for the treatment of domestic and industrial wastewaters, as an effective biological treatment system due to its simplicity and flexibility of operation. Mechanism and Design of Sequencing Batch Reactors for Nutrient Removal has been prepared with the main objective to provide a unified design approach for SBR systems, primarily based on relevant process stoichiometry. Specific emphasis has been placed upon the fact that such a unified design approach is also by nature the determining factor for the selection of the most appropriate cyclic operation scheme, the sequence of necessary phases and filling patterns for the particular application. The proposed basis for design is developed and presented in a stepwise approach to cover both organic carbon and nutrient removal, domestic and industrial wastewaters, strong and specific wastes. The merits of model simulation as an integral complement of process design, along with performance evaluation of SBR models are also emphasized. Scientific and Technical Report No. 19

Instrumentation, control and automation (ICA) in wastewater treatment systems is now an established and recognised area of technology in the profession. There are obvious incentives for ICA, not the least from an economic point of view. Plants are also becoming increasingly complex which necessitates automation and control. Instrumentation, Control and Automation in Wastewater Systems summarizes the state-of-the-art of ICA and its application in wastewater treatment systems and focuses on how leading-edge technology is used for better operation. The book is written for: The practising process engineer and the operator, who wishes to get an updated picture of what is possible to implement in terms of ICA; The process designer, who needs to consider the couplings between design and operation; The researcher or the student, who wishes to get the latest technological overview of an increasingly complex field. There is a clear aim to present a practical ICA approach, based on a technical and economic platform. The economic benefit of different control and operation possibilities is quantified. The more qualitative benefits, such as better process understanding and more challenging work for the operator are also described. Several full-scale experiences of how ICA has improved economy, ease of operation and robustness of plant operation are presented. The book emphasizes both unit process control and plant wide operation. Scientific & Technical Report No. 15

Research into the sampling and measurement of odours has developed in a number of sectors, especially the agriculture, food and process industries, with knowledge from each sector being transferred to the wastewater and solid waste management sectors. Progressive developments in odour research have resulted in researchers re-tracing original research studies to understand the contribution and variability of differing sampling and measurement techniques. There are, however, very few reviews that compile earlier studies across each sector. This study looks at the information used to support current practices in odour sampling and measurement for impact reduction. Sampling for Measurement of Odours reviews European and other internationally available research studies to understand odour sampling and measurement practice in waste applications. The emphasis is placed on appropriate odour sampling and its relationship to differing measurement techniques. As recent developments in standardisation of odour measurement have reduced much of the variation and identified best practice in this area there is, at present, a far greater variation in sampling techniques with serious implications for the quality of samples obtained and their usefulness for assessing odour impact. The review considers the available information on uncontrolled area sources, identifies factors influencing sample losses or transformations and looks at information on the sources of variability identified through standardisation programmes. This need for this report was identified by the Odour Network, an EPSRC-sponsored discussion platform intended to promote multidisciplinary research in the areas of odour measurement, modelling and treatment. Scientific and Technical Report No.17