Bøger udgivet af IWA Publishing

Coagulation and Flocculation in Water and Wastewater Treatment provides a comprehensive account of coagulation and flocculation techniques and technologies in a single volume covering theoretical principles to practical applications. Thoroughly revised and updated since the 1st Edition it has been progressively modified and increased in scope to cater for the requirements of practitioners involved with water and wastewater treatment. A thorough gamut of treatment scenarios is attempted, including turbidity, color and organics removal, including the technical aspects of enhanced coagulation. The effects of temperature and ionic content are described as well as the removal of specific substances such as arsenic and phosphorus. Chemical phosphorus removal is dealt with in detail, Rapid mixing for efficient coagulant utilization, and flocculation are dealt with in specific chapters. Water treatment plant waste sludge disposal is dealt with in considerable detail, in an Appendix devoted to this subject. Invaluble for water scientists, engineers and students of this field, Coagulation and Flocculation in Water and Wastewater Treatment is a convenient reference handbook in the form of numerous examples and appended information.

In wastewater reclamation systems, microbiological monitoring is conducted to compare the effectiveness of biological treatment, filtration, and disinfection for removal of bacterial and viral indicators, enteric viruses, and protozoan pathogens. This project has six full-scale treatment facilities, sampled a minimum of four times over a year.

There is a pressing need for developing and testing a general set of theories in order to provide a confident basis for prediction of multiple stressor effects. Confident prediction is central to confident decision making in water pollution control. Consequently, WERF commissioned this study, which has as its goal to provide a study design based on good science that helps establish a general, conceptual approach to multiple stressors. The objectives addressed in this report are: (1) review and critique the existing body of knowledge for multiple stressors; (2) develop a searchable, annotated bibliography of multiple stressor research; and, (3) identify gaps in the body of knowledge. A rigorous, theoretical basis for the prediction of multiple stressor effects could not be developed from the literature on experimental studies of multiple stressor effects in aquatic ecosystems. Despite the wealth of observational data, the existence of several useful tools for interpretation of cause/effect relationships (including formal Stressor Identification methods), and the studies reviewed in this report, there are no tools that allow a confident, a priori, prediction of ecosystem response to multiple stressors. The current literature provides, at best, a series of site-specific glimpses of the response of ecological communities and ecosystems to multiple stressors. There is seldom, if ever, any reference to a more generalized model of multiple stressor effects apart from the discussion of the expectations regarding additivity versus synergism. Many articles that purport to be multiple stressor studies do not go beyond an inventory of the various stresses and upsets affecting the ecosystem, without attempting to assess the interactions among them.

Water resource management in the United States is evolving in the face of continuing challenges to protect water quality, provide adequate quantities of water for competing uses, and protect habitat and other natural resources. In many jurisdictions and agencies this evolution is increasingly leading toward adoption of watershed management. This approach is characterized by planning and decision making on a watershed scale, integration of a variety of competing water resource priorities and goals, cooperation of multiple stakeholders and governmental agencies, and increased levels of public participation. This report identifies the most promising watershed planning and management approaches from around the world; evaluates how they operate, their benefits and limitations; and assesses the degree to which these approaches could be successfully adapted to the U.S. context. Drawing on this international experience, the report is intended to inform policy makers and practitioners and to promote the implementation of integrated watershed management approaches that are most likely to succeed. This report: Provides a decision-making framework of watershed management efforts at all scales in the United States. Evaluates past U.S. watershed management experience and identifies key characteristics for success as well as major challenges and opportunities for improving the watershed approach. Summarizes and evaluates international case studies where innovative watershed management techniques have been used. Identifies ten key lessons for sustainable water management, including the role of water/wastewater utilities based on the experience of the international case study watersheds.

This report deals with whether the experience of odors, i.e., odors as sensations, from biosolids at wastewater treatment plants (WWTPs) causes illness. There exists no repository of information on the numbers of complainants with illness, their specific complaints, or the relationship between degree of exposure and complaints. Anecdotal reports nevertheless imply a pattern much like that associated with other industrial malodors. Any connection between odor and illness has received little note among the millions of articles in the medical literature. This state of affairs presumably exists because odors per se generate no objective signs of illness in otherwise healthy persons. However, malodors may exacerbate both symptoms and signs of illness in persons with certain chronic disorders, such as asthma and migraine. Vulnerability to such effects may vary considerably from person to person.

There is a pressing need for developing and testing a general set of theories in order to provide a confident basis for prediction of multiple stressor effects. Confident prediction is central to confident decision making in water pollution control. Consequently, WERF commissioned this study which has as its goal to provide a study design based on good science that helps establish a general, conceptual approach to multiple stressors. The objectives of the study are to develop a flexible and scientifically defensible conceptual model of the environmental effects of multiple stressors on river and stream ecosystems; develop a study design to test the conceptual model of multiple stressor effects; and, document the process used to arrive at the conceptual model. The multiple stressor conceptual model includes two main components: (1) a diagram that portrays the main features of the study team's understanding of how multiple stressors would interact and the nature of the effects; and (2) a series of three testable risk hypotheses. These two components follow the guidance provided by the U.S. EPA for ecological risk assessment. The proposed conceptual model encompasses the following key assumptions: interactions between the stressor and the ecosystem are dependant upon the existing baseline conditions; for each stressor/baseline combination there will theoretically be a functional and a structural response; effects on habitat are caused by structural or functional responses to stressors; and effects on habitat can cause structural or functional responses.

The presence of cationic pollutant metals in municipal wastewater effluent is a concern because stringent discharge requirements cannot always be met with conventional treatment methods. Attempts to improve metal removal are often unsuccessful because a significant fraction of the cationic metals are complexed by the synthetic chelating agent ethylenediamine tetraacetic acid (EDTA). To identify practical approaches for improving metal removal, an analytical method for measuring metal-EDTA complexes was used to survey metal speciation at a series of wastewater treatment plants. Following these analyses, bench-scale experiments were conducted. The survey data indicated that pollutant metal-EDTA complexes account for a significant fraction of the dissolved metals in wastewater. The bench-scale studies indicated that ferric chloride addition improves the removal of copper and zinc by approximately 20%. To test the results of the bench-scale experiments, a full-scale experiment was conducted by interrupting chemical addition at a municipal wastewater treatment plant that normally adds ferric chloride during primary treatment. Results indicated that ferric chloride addition had a slight impact on metal speciation but no effect on metals removal. The lack of an effect was attributed to changes in metal speciation that occurred during primary treatment irrespective of ferric chloride addition.

Class A biosolids can be produced using low-cost, low-technology biosolids treatment processes including lagoon storage, air drying, and cake storage. This project reviewed the available literature and municipal agency data about these processes. This report presents design and operating guidelines distilled from the review process. It is designed for wastewater treatment plant (WWTP) managers, operators, and engineers who wish to discern whether these processes, used alone or in combination, might be practically applied at specific plants. This report also describes the U.S. regulatory environment in relation to producing Class A Biosolids and defining Class A processes. It also presents a list of recommended research needs. This report: Familiarizes WWTP managers, operators, and engineers with low-cost, low-technology biosolids treatment processes, likely pathogen kill mechanisms, and practices that have reduced pathogen densities to Class A levels at scales ranging from laboratory tests to large municipal biosolids treatment operations. Presents guidelines for producing Class A biosolids under a variety of conditions. Describes low-technology treatment processes within the Class A regulatory framework, identifies satisfactory end conditions for products created from low-tech treatment processes, and provides guidance in developing national or site-specific certification as processes equivalent to a process to further reduce pathogens (PFRP).

The purpose of this project was to develop a methodology for deriving site-specific nutrient criteria (SSNC) for surface waters, including streams and rivers, lakes and reservoirs, and coastal estuaries. The methodology was developed to extend the United States Environmental Protection Agency?s regional nutrient criteria for localized conditions characterized by particular desired water quality requirements or designated uses. The proposed SSNC methodology provides local stakeholders with a recipe for estimating nutrient criteria consistent with site-specific water quality management goals and objectives. The SSNC methodology prescribes a three-tiered or sequential approach for defining concentrations of acceptable nutrients in relation to management goals and objectives. Each tier requires successively more site-specific data and information and also develops increasingly quantitative and technologically more detailed relationships between nutrients and stated water quality measurements (chlorophyll a, Secchi depth, dissolved oxygen). The SSNC process can be initiated at any tier, although most applications will likely progress from Tier 1. The derivation of Tier 1 SSNC relies extensively on existing data and regional nutrient criteria. Tier 2 adds additional, more site-specific data and estimates SSNC on the basis of statistical relationships between nutrients and the selected water quality parameters of interest. Tier 3 extends Tier 2 through the development of additional site-specific data and the application of site-specific, process-level water quality models to estimate the SSNC. Follow-up monitoring is a key component of all three tiers for assessing the effectiveness of the SSNC in achieving the desired water quality characteristics and making subsequent decisions about continued implementation or modification of the SSNC. Benefits: SSNC can serve as effective alternatives to regional criteria, which may fail to achieve or sustain locally desired water quality conditions. The proposed methodology prescribes an efficient and economical approach for achieving site-specific water quality objectives. The methodology develops SSNC on the basis of process-level understanding of relationships between nutrients and water quality objectives. The tiered approach permits a sequential, increasingly detailed and sophisticated analysis of relations between nutrients and desired water quality conditions. The results of the tiered SSNC methodology provide direct inputs to localized management and decision-making processes.

The articles compiled in the book describe the current situation in China with respect to surface water quality and wastewater treatment, and provide results of specific research projects, leading the way to a China-specific up-to-date water treatment technology.

Recent technical innovations and significant cost reductions have sharply increased the potential for using Membrane Bioreactor (MBR) technology in municipal wastewater treatment. MBR technology displays several advantages compared to the traditional activated sludge processes, such as high effluent quality, limited space requirement and with the possibility of a flexible and phased extension of existing waste water treatment plants. Membrane Bioreactors for Municipal Wastewater Treatment describes the results of a comparative research programme involving four leading membrane suppliers: Kubota (Japan), Mitsubishi (Japan), X-Flow (Netherlands) and Zenon (Canada). Each supplier provided a pilot to represent a suitable scale - right up to full scale. These pilots were operated and optimised in the course of the research programme to achieve the best operating window under different operating regimes. The research focussed on the functionality of the membrane, the biological treatment, membrane fouling, achieved effluent quality, and system operability as well as other factors. In a number of side studies the required pre-treatment, membrane fouling/cleaning, energy usage, effluent quality and sludge processing were also addressed. The comparative pilot research was carried out by DHV Water on location at the wastewater treatment plant at Beverwijk in the Netherlands.

The objective of this project was to develop and evaluate a practical technique to indicate the probability of the presence of bacterial pathogens in receiving waters. A practical method was defined as one that would limit the use of defined culture-based microbiological methods, and would be based on: (1) validating indicator organisms that predicted the presence of pathogens, or (2) detection of pathogens by polymerase chain reaction (PCR)-based assays. The study also assessed the utility of PCR-based technology for bacterial pathogen detection with respect to technology transfer to a wider range of water and wastewater facilities.

Plant-availability of metals in biosolids-treated soils may be mathematically described by Mt = C x [1 - e- (k x t)] where Mt (mg kg-1) is the cumulative metal removal from the biosolids-treated soils by growing and harvesting plants for t years, C is the total phytoavailable metal pool of the soil (mg kg-1) at t = 0, and k is the metal absorption rate coefficient (yr-1). The total available metal pool, C, is defined as metals extractable by organic acids in the rhizosphere of growing plants and k is related to the kinetics of metal release by organic acids. Half-life of the available metals in biosolids-amended soils may be derived from k.Experiments were conducted to characterize the concentration and composition of the organic acids. A successive extraction method was used to extract metals from biosolids-treated soils for determinging C and k. In this manner, the plant available metals of the biosolids-treated soils are defined by the total available metals, half-life, and duration of plant growing.

This is a best practice manual for addressing water losses in water distribution networks worldwide. Systems and methodologies are presented for improving water loss and leakage management in a range of networks, from systems with a well-developed infrastructure to those in developing countries where the network may need to be upgraded. The key feature of the manual is a diagnostic approach to develop a water loss strategy - using the appropriate tools to find the right solutions - which can be applied to any network. The methods of assessing the scale and volume of water loss are outlined, together with the procedures for setting up leakage monitoring and detection systems. As well as real losses (leakage) procedures for addressing apparent losses, by introducing regulatory and customer metering policies are explained. Suggestions are made for demand management and water conservation programmes, to complement the water loss strategy. Recommendations are made for training workshops and operation and maintenance programmes to ensure skills transfer and sustainability. The manual is illustrated throughout with case studies. Losses in Water Distribution Networks will appeal to a wide range of practitioners responsible for designing and managing a water loss strategy. These include consultants, operations managers, engineers, technicians and operational staff. It will also be a valuable reference for senior managers and decision makers, who may require an overview of the principles and procedures for controlling losses. The book will also be suitable as a source document for courses in Water Engineering, Resource Management and Environmental Management.

Water services include water supply, sewerage and stormwater drainage. The facilities needed for these services are pipelines, reservoirs and treatment works; but the service goes beyond the infrastructure. It includes economics, billing, and business management. Although these services exist in every city, being advanced by the growing use of automation and information technology, costs are also increasing without many consumers seeing increased benefits. Customer service is therefore becoming important to the industry. Water Services Management is intended to educate engineers to manage and improve water services, rather than simply designing and constructing treatment works and distribution systems. The text covers water supply and drainage from the hydraulic and economic points of view, and while design and construction practices are reviewed, the focus of the book is on improving existing systems to turn the emerging industry into an attractive business. Topics covered include: Potable water supply, sewerage and stormwater drainage. Hydraulic management: storage, peak flow attenuation and pumping. Water quality: standards, pollution control and treatment. Infrastructure management: rehabilitation, reconstruction, upgrading and maintenance. Economic efficiency: asset management, privatization, and risk analysis. Improving economic viability via efficient use of energy and construction project management. Characteristics encountered in developing countries are also considered, including: Low cost sanitation, water supply standards and off-grid energy sources. Capacity building and appropriate technologies. Financing, operation and benchmarking.

A new development for the treatment of domestic wastewater is a technology based on aerobic granular sludge. This report describes the results of research carried out at the Technical University of Delft.

Sustainable Water Services: A Procedural Guide is the result of the Sustainable Water industry Asset Resource Decisions (SWARD) project, undertaken by a consortium of UK academics in collaboration with water service providers in Scotland, England and Romania. It has been developed to act as a practical tool to assist with the explicit inclusion of ?sustainability? in the decision-making processes of those responsible for providing water services. The book contains a framework that comprises a set of decision support processes that can be used by water service providers to explicitly incorporate sustainability considerations into their decision-making procedures, through the use of sustainability principles, criteria, indicators and processes. These principles and criteria can be applied at an overall corporate strategic level, for example in the service provider?s mission statement, or at an application level, where these strategic principles are being applied to a particular decision. Sustainable Water Services is designed to inform and to provide support for strategic activity, both as a resource containing information about sustainability, and by employing feedback from application to inform the strategic processes of the water service provider. Presents an inclusive and generic set of sustainability criteria for use in water industry decision making processes; Discusses the legislative drivers for sustainable decision making for the UK water industry; Presents clear case study examples of the sustainability framework in action; Discusses the use and applicability of a wide range of tools and techniques for undertaking environmental, economic and social analyses, e.g. life cycle assessment, multi-criteria analysis.

One approach to the introduction of computational material to the classroom is to supplement a textbook with modern computer codes. Unfortunately most codes are expensive, designed for commercial use, without source code and may require special software. Visual Hydrology provides a cheaper and simpler alternative, supplying computational exercises that can be fully assimilated by students, and allowing them to activate, understand and reproduce modern computer code. Visual Hydrology aims to: explain the structure of modern object-oriented computer code provide the source code for worked examples numerically check the worked examples used in text show how worked examples can be used with alternative data describe and reference the underlying theory provide additional exercises with each worked example use Microsoft Excel software alone Requiring only a basic knowledge of Microsoft Excel, this Primer teaches the use of modern and readily-available computer code for engineering computation. Visual Hydrology demonstrates codes for common and practical examples used in hydrological engineering, and will be a valuable resource to students, research workers and consulting engineers in the water-related sector. Examples of source code to accompany this publication can be downloaded by clicking here.

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

Drinking water provides an efficient source for the spread of gastrointestinal microbial pathogens capable of causing serious human disease. The massive death toll and burden of disease worldwide caused by unsafe drinking water is a compelling reason to value the privilege of having safe drinking water delivered to individual homes. On rare occasions, that privilege has been undermined in affluent nations by waterborne disease outbreaks traced to the water supply. Using the rich and detailed perspectives offered by the evidence and reports from the Canadian public inquiries into the Walkerton (2000) and North Battleford (2001) outbreaks to develop templates for understanding their key dimensions, over 60 waterborne outbreaks from 15 affluent countries over the past 30 years are explored as individual case studies. Recurring themes and patterns are revealed and the critical human dimensions are highlighted suggesting insights for more effective and more individualized preventive strategies, personnel training, management, and regulatory control. Safe Drinking Water aims to raise understanding and awareness of those factors that have most commonly contributed to or caused drinking-water-transmitted disease outbreaks - essentially a case-history analysis within the multi-barrier framework. It contains detailed analysis of the failures underlying drinking-water-transmitted disease epidemics that have been documented in the open literature, by public inquiry, in investigation reports, in surveillance databases and other reliable information sources. The book adopts a theme of 'converting hindsight into foresight', to inform drinking-water and health professionals including operators, managers, engineers, chemists and microbiologists, regulators, as well as undergraduates and graduates at specialty level. Key Features: Contains details and perspectives of major outbreaks not widely known or understood beyond those directly involved in the investigations. Technical and scientific background associated with case studies is offered in an accessible summary form. Does not require specialist training or experience to comprehend the details of the numerous outbreaks reviewed. By providing a broad-spectrum review using a consistent approach, several key recurring themes are revealed that offer insights for developing localized, tailor-made prevention strategies.

What are the rules of international water law that govern the use of the transboundary aquifers shared by Palestine and Israel? This book addresses this issue through an interdisciplinary approach, identifying first the special problems tied to the management of shared groundwater, and next critically analysing the applicable rules of international law. The innovative contribution of this work is its attempt to devise and suggest the means to implement a "e;progressive framework"e; for cooperation in the development and management of these shared waters. A solid review of hydro-politics, supported by current up to date information and rigorous examination of the evolution of the relevant rules of international law makes this book an important contribution to this very problematic area. Dr Fadia Diabes-Murad was awarded the Edberg Award 2005, presented at a special awards ceremony in Stockholm. The award recognised her contribution to peace in the Middle East through her work on water law, including using water as a catalyst for peace in the Middle East.

Implementing the goal of sustainable development has long been heralded as the means by which the needs of both present and future generations can be met. However, finding a long-term balance between economic, social and environmental interests, the basic tenet of sustainable development, has proved largely illusive in practice. This book shows that while a number of legal frameworks to help promote the goal of sustainable development have been proposed at the international level they fail to fully capture the essence of sustainable development and international law's capacity to support its implementation. The book offers a critical analysis of past attempts to develop legal frameworks for promoting sustainable development at the international level, and advocates for a fresh approach based on lessons learnt from the law of international watercourses. The book is divided into four sections. The first section includes an overview of the topic area and an understanding of international law. In section two the book explores the meaning of sustainable development and considers the term's relationship with international law. A detailed analysis of how the law of international watercourses seeks to reconcile competing economic, social and environmental interests is carried out in section three. The book concludes with a section advocating the need for a fresh approach to international law and sustainable development and offering the foundations for this approach based on lessons learnt from the law of international watercourses.

Competition and Economic Regulation in Water: The Future of the European Water Industry reviews the main developments in economic regulation and competition in the European water industry and considers ways in which economic regulation and competition should be further developed. The book focusses on the best means of regulating or introducing competition into the industry in light of its present structure. Competition and Regulation in Water: The Future of the European Water Industry concentrates on the water industry, however, many of the conclusions are equally applicable also to the wastewater industry. Contents Introduction Water industry fundamentals: the rationale for regulation and the scope for competition A framework for evaluating different models of water industry regulation England & Wales: private ownership and independent regulation France: competition for the market and contract-based regulation Germany: public-private partnerships and multi-sector utilities Developing water sector regulatory frameworks in less developed countries Appendix: The legislative framework for the water industry in England & Wales