Acidification is one of the most serious environmental problems - especially in Sweden, which suffers most from the consequences of acid rain. Besides international negotiations to reduce sulphur emissions - 85% of the acid load on Sweden can be traced to emissions from outside the country itself - the Swedish Government has employed large-scale, operative liming activities to counteract acidification of surface waters. The scientific results show that - although acidification cannot be solved by liming alone - the measures taken resulted in substantial improvements to around 8,000 Swedish lakes and watercourses. The idea is that other countries affected by acidification may also profit from this experience.

The biennial International Gothenburg Symposia on Chemical Water and Waste water Treatment have proven to be a unique platform for the exchange of ideas and experiences between administrators, engineers and scientists active in the fields of water supply, wastewater disposal and pollution control. The First Symposium (Gothenburg, 1984) provided a long needed survey over theory and application of chemical water and wastewater treatment. The Second Symposium (Berlin, 1986) was devoted to aspects of recycling in chemical water and wastewater technology. The Third Symposium (Gothenburg, 1988) recognised the growing need and the potentials of pretreatment. These proceedings of the 4th Symposium focus on technology transfer from chemical treatment theory to practical treatment of drinking water and industrial or domestic wastewater. The contributions are devoted to questions of floc for mation and floc separation as well as problems and practical solutions associated with chemicals and dosing control. Special attention is given to the combination of chemical and biological processes for nutrient removal from wastewater. It is the editors' privilege to acknowledge the invaluable help from the authors of this book. It is the editors' hope that they might convey the significance and potential of chemical treatment in solving the challenging problems water purification, wastewater disposal and pollution control.

Marine debris is a global pollution problem affecting marine life, maritime commerce and environmental quality. Scientists, policymakers and the public must be knowledgeable about the source, impact and control efforts if effective solutions are to be developed. Marine Debris addresses the origin of persistent solid waste in the ocean, from urban and rural discharges to waste from ships and the recreational use of oceans. The book identifies key issues from biological, technological, economic and legal perspectives, and gives a framework for controlling each of the main sources of marine debris.

The first summer study at IIASA brought together a cross-section of individ uals from different disciplines and nationalities. All the participants have had an interest in the role of risk analysis given the institutional arrangements which guide decision making for new technologies. This book contains edited versions of the papers presented at the meeting as well as a transcript of the discussions which took place. It provides the ingredients for a broader framework fcr studying the problems associated with technology and society where risk is representative of a much wider set of concerns than simply the probability and consequences of a hazardous accident. The Bundesministerium fuer Forschung und Technologie has an interest in promoting risk and safety research because of these new developments in society over the past ten years. In particular, there has been a diminished confidence in experts' statements on risk and a realization that many of the events which are being examined are not subject to detailed scientific analysis. There has also been an increasing recognition that distinctions must be made between analysis of the risk associated with an event and people's values and preferences. Another important development is the concern by the public that they participate more fully in the decision process on these issues. These concerns were articulated in both the papers and the open discussions at the summer study."

The International Gothenburg Symposia on Chemical Treatment have proven to be a unique platform for the exchange of ideas between theory and practice. They bring together administrators, engineers and scientists, who are concerned with water purification and wastewater treatment through precipitation, coagulation and subsequent solid/liquid separation. This volume contains the proceedings of the 3rd Symposium, focussing on Pretreatment. Pretreatment is understood as the scene total of all measures taken at the pollutant source to protect water supply, the sewerage system, the central treatment plant, and the aqueous environment. It is, where applicable, the most efficient measure in ecological and economic respects. The contributions of this third volume address questions of surveillance, automation and remote control of installations as well as the principles of legal, administrative and economic measures for regulations within the context of pretreatment. Special attention is given to the possibilities and limits of pretreatment of industrial discharges. Again it is the editors'privilege to acknowledge the invaluable help from the authors of this book. It is the editors' hope that they might convey the significance and potential of pretreatment in water supply, in industrial waste management and in municipal wastewater treatment and sludge handling.

This book brings together research into the process of stream acidification and its impact on Welsh surface waters, carried out over the past decade or so. It is perhaps surprising that not until the 1980's was clear evidence of stream acidification assembled. In Wales, concerns over pollution had focused water quality sampling principally on the areas of traditional heavy industry and large urban popula tions served by inadequate sewerage systems and sewage disposal arrange ments. Mistakenly, it had been assumed that, with its prevailing westerly winds, Wales would receive precipitation substantially unpolluted by the industrial and urban emissions from Britain and mainland Europe. Assurance of the high quality of Welsh upland streams, the traditional nursery ground of salmonids, was eroded particularly by studies in the vicinity of Llyn Brianne reservoir in the catchment of the River Tywi of Central Wales. These demonstrated a clear correspondence between the biological quality and fisheries of streams in the catchment and aspects of stream chemistry, par ticularly pH, aluminium and calcium on the one hand, and catchment land use on the other. It is salutary to record that the first signals were of an inexplicable failure of the runs of migratory salmonids into the upper catchment, occupied by the Llyn Brianne reservoir and its influent streams, and the failure to restore the fishery by re-stocking with eggs and fry. Only then did the significance of the recent decline in some other upland lake and reservoir fisheries in Wales become apparent.

Global attention in scientific, industrial, and governmental communities to traces of toxic chemicals in foodstuffs and in both abiotic and biotic environ ments has justified the present triumvirate of specialized publications in this field: comprehensive reviews, rapidly published progress reports, and archival documentations. These three publications are integrated and scheduled to pro vide in international communication the coherency essential for nonduplicative and current progress in a field as dynamic and complex as environmental con tamination and toxicology. Until now there has been no journal or other publica tion series reserved exclusively for the diversified literature on "toxic" chemicals in our foods, our feeds, our geographical surroundings, our domestic animals, our wildlife, and ourselves. Around the world immense efforts and many talents have been mobilized to technical and other evaluations of natures, locales, magnitudes, fates, and toxicology of the persisting residues of these chemicals loosed upon the world. Among the sequelae of this broad new emphasis has been an inescapable need for an articulated set of authoritative publications where one could expect to find the latest important world literature produced by this emerging area of science together with documentation of pertinent ancil lary legislation."

In Physical Processes in Estuaries the present day knowledge of the physics of transport phenomena in estuaries and their mathematical treatment is summarized: It is divided into following parts: - Water movements in estuaries - Estuarine fronts and river plumes - Internal waves and interface stability - Fine sediment transport, aggregation of particles, settling velocity of mud flocs - Sedimentation and erosion of fine sediments. For each topic an up-to-date review and recommendations for future research are given, followed by results of original studies. Since estuarine environments are the first to be threatened by urbanization and industrial exploitation this book is an important tool for students and researchers of environmental problems as well as for consultants and water authorities.

The past 30 years have seen the emergence of a growing desire worldwide that positive actions be taken to restore and protect the environment from the degrading effects of all forms of pollution-air, water, soil, and noise. Because pollution is a direct or indirect consequence of waste, the seemingly idealistic demand for "zero discharge" can be construed as an unrealistic demand for zero waste. However, as long as waste continues to exist, we can only attempt to abate the subsequent pollution by converting it to a less noxious form. Three major questions usually arise when a particular type of pollution has been identi?ed: (1) How serious is the pollution? (2) Is the technology to abate it available? and (3) Do the costs of abatement justify the degree of abatement achieved? This book is one of the volumes of the Handbook of Environmental Engineering series. The principal intention of this series is to help readers formulate answers to the last two questions above. The traditional approach of applying tried-and-true solutions to speci?c pollution problems has been a major contributing factor to the success of environmental en- neering, and has accounted in large measure for the establishment of a "methodology of pollution control. " However, the realization of the ever-increasing complexity and interrelated nature of current environmental problems renders it imperative that intelligent planning of pollution abatement systems be undertaken.

Water is the most effective agent in the climate system to modulate energy transfer by radiative processes, through its exchanges of latent heat and within cascades of chemical processes. It is the source of all life on earth, and once convective clouds are formed, it enables large vertical transports of momentum, heat and various atmospheric constituents up to levels above the tropical tropopause. Water triggers very complex processes at the earth's continental surfaces and within the oceans. At last, water in its gaseous phase is the most important greenhouse-gas! Numerical modelling and measurements of the state of the present climate system needs a very thorough understanding of all these processes and their various interactions and forcings. This is a prerequisite for more substantial forecasts of future states in all scales of time, from days to centuries. Therefore, the management of the World Climate Research Programme established in 1988 the new programme GEWEX (Global Energy and Water Cycle Experiment). GEWEX is specifically defined to determine the energy and water transports in the fast components of the climate system with the presently available modelling and measurement means and to provide new capabilities for the future. Research in GEWEX must further develop methods to determine the influence of climatic anomalies on available water resources.

Soil and water pollution have a serious impact on the environment, and soil scientists and hydrologists need fundamental help for the estimation of the consequences. The experiments described in this volume deal with the quantification of the morphology of interaggregate voids and of the flow through such voids as well as around impermeable inclusions. The diagrams given in the appendix can be used as references for such measurements. This work is put into the context of the international literature on the subject. An index and a glossary complete the volume. The subject of this work is of great interest to hydrologists and soil scientists working on the estimation of the consequences of soil and water pollution.

This book presents in an integrated approach results from five years of interdisciplinary research in the project Zirkulation und SchadstojJumsatz in der Nordsee (ZlSCH) (Circulation and Contaminant Fluxes in the North Sea). From 1984 to 1989 over 30 scientists and technicians worked in the project, which was supported by the Bundesminister fUr Forschung und Technologie (German Minister for Research and Technology). Together with the UniversiHit Hamburg, which initiated ZISCH, the following institutions participated: Technische Universitat Hamburg-Harburg, Rheinisch-Westfalische Technische Hochschule Aachen, Deutsches Hydrographisches Institut (now Bundesamt fUr Seeschiffahrt und Hydrographie), GKSS Forschungszentrum Geesthacht, Alfred-Wegener Institut Bremerhaven, Biologische Anstalt Helgoland, Universitat Paderborn. More than other national and international projects, the ZISCH project aimed at a holistic view of the marine ecosystem. For this reason, the different disciplines working together were not limited to purely marine sciences (oceanography, marine biology and chemistry), but atmospheric sciences (meteorology, atmospheric chemistry) and food chemistry also participated. Previous to ZISCH, no North Sea wide investigation of comparable complexity had ever been carried out. The area under investigation is shown in Fig. 1. 1. The ZISCH research project was established in view of the obvious threat to the North Sea environment generated by human activities. The primary causes are considered to be industrial, agricultural and municipal discharges which reach the sea over different pathways. Table 1. 1 summarizes the sources and amounts of various contaminants entering the North Sea."

Organic chemicals constitute minor gaseous components of the earth's atmosphere. Despite low concentrations they play an important role in the global processes influencing the composition of our atmosphere. The author summarizes the multidisciplinary data on sources and thermo- and photochemical transformations of organic components in the atmosphere. Modern methods of atmospheric microimpurity analysis are explained. Models for their time-dimensional distribution both in the urban atmosphere and in unpolluted air are developed. The book provides a unique source of contemporary information for scientists involved in atmospheric chemistry, meteorology, ecology and geophysics.

"Dredged Material and Mine Tailings" are two of the same thing once they are deposited on land: they must be safe-guarded, wash-out must be prevented, and they must be protected by a plantcover. This comprehensive treatise covers both important aspects of their management: "In Chemistry and " "Biology of Solid Waste" the principles and assessment are scientifically studied and discussed, while "Environmental " "Management of Solid Waste" turns to the practical applications, such as prediction, restoration and management. Previously, dredged material was a commodity, it could be sold as soil, e.g. to gardeners. In the meantime, dredged material from the North Sea (e.g. the Rotterdam or Amsterdam harbor) must be treated as toxic waste. Many environmentalists, managers and companies do not know how to solve the inherent problems. This new work deals with the chemical, physical and biological principles; the biological and geochemical assessment; the prediction of effects and treatment; and finally, with the restoration and revegetation. It is written by many leading scientists in the various fields, and will prove invaluable for scientists, managers and politicians who are concerned with the present environmental situation.

This book encourages and demonstrates an innovative approach to the design and operation of urban wastewater systems: integrated modelling and control. Consideration of sewer system, wastewater treatment plant and receiving water body as a single system (rather than as three moderately independent units as before) opens up new types of analyses and new control algorithms for urban wastewater systems. After a comprehensive review of the literature of various fields including processes affecting water flow and quality in urban wastewater systems and their description by different types of models, this book also introduces some of the fundamental concepts of the operation of such systems. It discusses conventional as well as innovative control approaches - ranging from control by simple set-points to elaborate hierarchical control concepts taking into account the water flow and the quality of sewer systems, treatment plants and receiving water body. Thus it will enable the researcher as well as the practising engineer to analyse and to implement various types of control for a particular case study site.In order to illustrate the concepts developed, a detailed simulation study, covering the complete urban wastewater system, is presented. The conclusions drawn demonstrate that the application of innovative control concepts can lead to improved performance of wastewater systems. In addition, a comprehensive survey of mathematical optimisation methods is presented. This book can assist the practising engineer and the student to gain knowledge of all aspects of wastewater systems. To the researcher, this book provides a thorough survey of existing simulation and control concepts and inspiration for further work.

Nowadays, major environmental issues are the object of large public debates de- spite the fact that scientific knowledge is often insufficient to draw unequivocal conclusions. Such is the case in the ongoing debate regarding the specific contri- butions of anthropogenic greenhouse gas emissions and of natural climate changes to global warming. At least 10 to 20 years of additional observations will be re- quired, before we will be able to conclude, with certainty, on this subject. In the mean time, and as directed by their immediate interests, people will continue to promote contradictory opinions. The media are, in part, responsible for perpetuat- ing such debates in that they convey indiscriminately the opinion of highly credi- ble scientists as that of dogmatic researchers, the latter, unfortunately too often expressing working hypotheses as established facts. Naturally, in a similarly mis- informed manner, pressure groups tend to support the researcher whose opinions most closely represent either their particular ideological battles or their economic interests and, hence, in their own way, add further to the confusion and obscurity of the debate. Only a few years ago, mercury (Hg)contamination in hydroelectric reservoirs was the object of such media and social biases. At the time, analytical data used to support the discourse were themselves uncertain and numerous hypotheses, often times fanciful, were proposed and hastily "delivered" to the public.

This book analyses the treatment of uncertainties within risk management and regulation for hazardous wastes, in five national case-studies. It is shown that, although institutional uncertainties vary between national political cultures, regulatory bureaucracies everywhere understate these more fundamental uncertainties (which are often structural conflicts, of different rationalities) and define them instead as marginal technical uncertainties or imprecision in risk-definitions. Close comparative analysis shows that technical regulatory standards depend upon their local institutional setting in systematic ways, so that conventional regulatory emphasis on technical precision or standardisation should be replaced by greater social negotiation, and educated public involvement and control. Readers will find the book valuable for its novel analytical approach especially in relation to public acceptance issues, and the argument for fresh practical approaches derived from this; in addition there is new information and analysis from the descriptive materials in case studies. Its main aim is to stimulate fresh thinking and approaches to an urgent problem.

Polychlorinated Dibenzodioxins and -furans (PCDDs and PCDFs) are potent environmental toxins. Environmental exposures to these compounds in part-per-billion (ppb) and part-per-trillion (ppt) concentrations are of particular interest. These exposures may arise from bleached paper products, paper production process sludge, effluent waste water from paper plants, consumption of food and water from contaminated sources and contact to paper products.

Hazard assessment of a compound (xenobiotic) discharged to the aquatic environment requires data on both exposure and effects to various components of the ecosystem. The multitude of ecological gradients in the Baltic Sea is used as a background example for discussing the complexity of the issue and the need for new approaches. Therefore, this book attempts to go beyond the simplistic, standardized short-term laboratory tests traditionally used as a basis for hazard assessment of chemicals, and gives strong emphasis to the interpretation of ecotoxicological data in their real, ecological context, pointing out the need to consider the natural mortality distribution of the population under study, the role of keystone species and of species with broad ecological niches versus those with narrow, specialized niches.

Aquatic hyphomycetes were discovered 50 years ago by C.T. Ingold. They remained a relatively obscure group until their role as intermediaries between deciduous leaves and stream invertebrates was established some 20 years ago. This book, for the first time, provides a comprehensive summary and critical evaluation of the biology and ecology of these organisms. Aspecial effort was made to evaluate the potential and actual insight that have been or will be derived from work in related disciplines such as the ecology of other fungal groups, stream ecology, or population ecology. The topics treated include the basic life history of the fungi and the potential role of wood, a discussion of how the fungi have adjusted to life in running water, their interactions with invertebrates, the attachment and germination of their spores, what is known about sexual reproduction, how water chemistry may influence their distribution and activity, how they react to human degradation of their environment, and a summary of the research done on the Indian subcontinent. The volume is of special interest to mycologists and stream ecologists and should facilitate the entry of new workers into this exciting area.

Worldwide concern in scientific, industrial, and governmental com munities over traces of toxic chemicals in foodstuffs and in both abiotic and biotic environments has justified the present triumvirate of specialized publications in this field: comprehensive reviews, rapidly published progress reports, and archival documentations. These three publications are integrated and scheduled to provide in international communication the coherency essential for nonduplicative and current progress in a field as dynamic and complex as environmental contamination and toxicology. Until now there has been no journal or other publication series reserved exclusively for the diversified literature on toxic" chemicals in our foods, our feeds, our geographical surroundings, our domestic animals, our wild life, and ourselves. Around the world immense efforts and many talents have been mobilized to technical and other evaluations of natures, locales, magnitudes, . fates, and toxicology of the persisting residues of these chemicals loosed upon the world. Among the sequelae of this broad new emphasis has been an inescapable need for an articulated set of authorita tive publications where one could expect to find the latest important world literature produced by this emerging area of science together with documentation of pertinent ancillary legislation."

Worldwide concern in scientific, industrial, and governmental com munities over traces of toxic chemicals in foodstuffs and in both abiotic and biotic environments has justified the present triumvirate of specialized publications in this field: comprehensive reviews, rapidly published progress reports, and archival documentations. These three publications are integrated and scheduled to provide in international communication the coherency essential for nonduplicative and current progress in a field as dynamic and complex as environmental contamination and toxicology. Until now there has been no journal or other publication series reserved exclusively for the diversified literature on "toxic" chemicals in our foods, our feeds, our geographical surroundings, our domestic animals, our wild life, and ourselves. Around the world immense efforts and many talents have been mobilized to technical and other evaluations of natures, locales, magnitudes, fates, and toxicology of the persisting residues of these chemicals loosed upon the world. Among the sequelae of this broad new emphasis has been an inescapable need for an articulated set of authorita tive publications where one could expect to find the latest important world literature produced by this emerging area of science together with documentation of pertinent ancillary legislation."

In this book major construction projects are reviewed. The aim is to present case studies or topics which would stimulate discussion within the areas of environmental policy, economy, ethics or science. By carefully balancing the needs and interests of all involved stakeholders and by observing basic ethical principles, it is possible to resolve the conflicts and to proceed towards constructive cooperation with commonly accepted environmental objectives. The book further contains the key conclusions and recommendations resulting from the "First International Symposium on Large-Scale Constructions in Coastal Environments" held on the island of Norderney from 21-25 April 1997.

This book focuses on innovative treatment technologies for the elimination of emerging contaminants in wastewater and drinking water treatment processes. The book also discusses sources and occurrence of emerging contaminants in municipal and industrial waste, giving an overview of state-of-the-art analytical methods for their identification. Further important aspects covered include the acute and chronic effects and overall impact of emerging contaminants on the environment.