The object of sludge characterization must be to get quantitative mea- sures for sludge behaviour in treatment processes and when disposed of. Thus the incentive for characterization could be one of the following: 1. Because sludges exist in large quantities we want to know the amounts and the expenees involved in their treatment and disposal. 2. Because sludges are environmental nuicances/hazards, energy sourc:-es, fertilizers or even food sources; we want to know their potential. 3. Because the processes change the sludge propert~es, we w~nt to know their "treatability". 4. 5ecause sludges have a history, we want to know how the generation process affects the quantities and the properties of raw sludge. Parallel to the characterization of the sludges runs characterization of the sludge treatment-processes and the environment in which we dispose of the sludge. In the following discussion we will group parameters related to sludges into three cathegories: 1. Sludge Quantity. Both total ~nd per capita sludge production data from all connnon sewage and sludge treatment methods are of "interest. 2. Treatability parameters. These are characteristics of how a sludge behaves in a specific process. Typically; dewaterability and digesta- bility. 3. Sludge quality parameters. These are indicators of how the sludge could influence the environment when disposed of. Sludge quality changes through most sludge treatment processes (stabilization, ther- mal etc.) and include concentrations of chemical compounds, pathogenes etc.

Proceedings of a Workshop held at Stevenage, May 25-26, 1982

Proceedings of a Workshop held in Dublin, July 6, 1983

Proceedings of a Round Table Seminar organized by the Commission of the European Communities, Directorate-General for Science, Research and Development Environment Research Programme, held in Metz, France, 21-23 May 1985.

Includes proceedings of a seminar held in Silsoe, UK, 26-28 March 1990.

This book demonstrates the prospects for enhancing thickening or dewatering of sewage sludges and outlines some of the methods which might come into consideration. It is based on the proceedings of a 'round-table' meeting held at Bilthoven, The Netherlands, in April 1985.

Anaerobic digestion has no effect on the quantity of the waste treated, but it affects its quality and its usefulness as fertilizer. This conference proceedings collection of twenty papers delves into the issue.

Proceedings of the Third International Symposium held at Brighton, September 27-30, 1983

An examination of the growth and different varieties of anchoritism throughout medieval Europe. The practice of anchoritism - religious enclosure which was frequently solitary and voluntarily embraced, very often in a permanent capacity - was widespread in many areas of Europe throughout the middle ages. Originating in the desert withdrawal of the earliest Christians and prefiguring even the monastic life, anchoritism developed into an elite vocation which was popular amongst both men and women. Within this reclusive vocation, the anchorite would withdraw, either alone or with others like her or him, to a small cell or building, very frequently attached to a church or other religious institution, where she or he would - theoretically at least - remain locked up until death. In the later period it was a vocation which was particularly associated with pious laywomen who appear to have opted for this extreme way of life in their thousands throughout western Europe, often as an alternative to marriage orremarriage, allowing them, instead, to undertake the role of "living saint" within the community. This volume brings together for the first time in English much of the most important European scholarship on the subject to date. Tracing the vocation's origins from the Egyptian deserts of early Christian activity through to its multiple expressions in western Europe, it also identifies some of those regions - Wales and Scotland, for example - where thephenomenon does not appear to have been as widespread. As such, the volume provides an invaluable resource for those interested in the theories and practices of medieval anchoritism in particular, and the development of medieval religiosity more widely. Dr LIZ HERBERT MCAVOY is Professor of Medieval Literature at Swansea University. CONTRIBUTORS: Anneke B. Mulder-Bakker, Gabriela Signori, M. Sensi, G. Cavero Dominguez, P. L'Hermite-Leclercq, Mari Hughes-Edwards, Colman O Clabaigh, Anna McHugh, Liz Herbert McAvoy.

Proceedings of a Workshop, held in Zurich, May 11-13, 1982

Proceedings of a Seminar held at Uppsala, Sweden, June 7-9, 1983

Proceedings of a seminar held in Silsoe, UK, 26-28 March 1990.

This publication constitutes the Proceedings of a Workshop held in Bordeaux (France) on 8th - 10th October, 1980, under the auspices of the Commissior: of the European Communities, as part of the CEC research programme on 'Effluents from Livestock' and the Concerted Action COST 68 bis 'Treatment and Use of Sewage Sludge'. Major changes have taken place in livestock production techniques in recent years. One of the most important developments has been in the field of animal nutrition. Animals are fed to gain maximum liveweight in close relationship with market requirements for carcass and meat quality. With regard to pig production, dietary formulation is based on scientific principles and feed includes a large variety of ingredients to supply optimum feed rations for 'standardised' animals. In order to increase growth rate and to improve feed conversion, copper is added to the ratio s of fattening pigs in a number of countries, in accordance with the provisions of Council Directives concerning additives in feedingstuffs, as last amended by the 23rd Commission Directive of 4th July 1980.

The agricultural value of sewage sludges is well known and a lot of published data has demonstrated the positive effects of sludge appli cations on plant growth and yield. These effects are probably due mainly to the nitrogen and phosphorus content of sewage sludges. But, as sludges are more organic than mineral, we can expect an effect of the organic matter added to the soil on soil fertility. Certainly, in the future, landspreading of sludges will be regulated, taking into account pollution hazards for waters (excess of nitrogen and phosphorus supply compared to plant needs and soil storage capacities) and for soils (excess of heavy metals supply and build up in soils). There will be regulations fixing what low level of sludges may be spread each year, decreasing their comparative value with respect to mineral fertilizers. In this eventuality, the organic value of sludges will take on a greater importance and several questions arise: - what is the lowest amount of sludge to be spread to have an immediate effect on soil physical properties? - are sludges effective on soil physical properties when spreading repeated low amounts? On the other hand, organic matter and soil biology are closely linked and there are few data on the possible effects - beneficial or detrimenta- on soil organisms."

Disposal of organic sludge and liquid agricultural wastes is a universal problem. Their production cannot be halted and as steps are taken to maintain or improve the quality of rivers and lakes it grows in quanti ty. The Commission's early awareness of the need for action to prepare for substantial growth in the Community's' sludge disposal problem led to the setting up of the COST 68 project to coordinate and guide European research and development work with particular emphasis on recycling sludge to agricultural land. Two years ago the field of research activi ties was extended to liquid agricultural wastes. This Symposium is the latest opportunity to provide a comprehensive review of the results of the project, to define current trends in practice and to establish by discussion the priorities for research over the next few years. The development of instrumentation and of analytical techniques during the period has extended our knowledge of the organic and inorganic constituents of sewage sludge and agricultural wastes and enabled us more readily to identify and measure the risks to which our general environment may be exposed when disposing of it. This evolution of understanding is a continuing process and an essential guide to the modification of disposal practices to achieve safer and more efficient operations. However, it is important to take a broad view of the application of research findings in the light of the considerable contrast in conditions in different parts of the world.

PH. BOURDEAU Directorate-General Science. Research and Development. Commission of the European Communities. Brussels. Belgium We are living on a unique planet, the only one in the solar system where life exists. The very existence of life has modified the physical and chemical environment of the earth, its atmosphere and oceans, in a way that makes life sustainable. This system with its complex cybernetic mechanisms has been named GAIA by Lovelock. Man has always interfered with it on a more or less limited scale. This interference is now reaching global proportions such as climate modifications resulting from CO and trace gas 2 accumulation in the atmosphere or the destruction of stratospheric ozone, not to speak of global radioactive contamination. GAIA will probably prevail as a living system but it probably does not give much importance to man's survival as such, and it is man that has to take care of his own survival. In the ecosystem of Planet Earth, soils are the thin interface between lithosphere and atmosphere which constitutes the essential substrate for the terrestrial biosphere, the productivity of which far exceeds that of the oceans, even though the latter cover a much larger area than the continents. Soils themselves are complex systems. They develop through weathering of minerals, are colonised by living organisms which in turn modify their substrate making it suitable for other organisms. This induces a primary ecological succession which eventually reaches a climax, in equilibrium between climate, soil and the biological communities.

The object of sludge characterization must be to get quantitative mea- sures for sludge behaviour in treatment processes and when disposed of. Thus the incentive for characterization could be one of the following: 1. Because sludges exist in large quantities we want to know the amounts and the expenees involved in their treatment and disposal. 2. Because sludges are environmental nuicances/hazards, energy sourc:-es, fertilizers or even food sources; we want to know their potential. 3. Because the processes change the sludge propert~es, we w~nt to know their "treatability". 4. 5ecause sludges have a history, we want to know how the generation process affects the quantities and the properties of raw sludge. Parallel to the characterization of the sludges runs characterization of the sludge treatment-processes and the environment in which we dispose of the sludge. In the following discussion we will group parameters related to sludges into three cathegories: 1. Sludge Quantity. Both total ~nd per capita sludge production data from all connnon sewage and sludge treatment methods are of "interest. 2. Treatability parameters. These are characteristics of how a sludge behaves in a specific process. Typically; dewaterability and digesta- bility. 3. Sludge quality parameters. These are indicators of how the sludge could influence the environment when disposed of. Sludge quality changes through most sludge treatment processes (stabilization, ther- mal etc.) and include concentrations of chemical compounds, pathogenes etc.