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Natural organic matter
Environment Intemational, Vol. 25, No. 2/3, pp. 143-144,1999 Copyright 01999 Ehvier Science ud printed in the USA. All rights msewed 01604120/99/S+front-
PII s0160-4120(98)00120-2
EDITORIAL
NATURAL
ORGANIC
MATTER the known toxicity of a number of these chlorinated organic compounds. For obvious reasons, the potential toxicity of compounds resulting from the chlorination of NOM varies widely. However, the complexity and the number of uncertainties related to this hygienic problem have led to attempts to reduce the concentration of or eliminate NOM from raw waters prior to disinfection. There is another hereto unrecognized area of NOM research addressing the contribution of fossil-fuelgenerated CO, to the biosphere. One of the most uncertain parameters in the current global temperature modeling is the net increase in the CO, uptake by the biosphere resulting from the increasing COZ in the atmosphere. The study of 14C in NOM is likely to decrease uncertainties associated with this important parameter. One of the reasons for the lack of recognition of the importance of these studies is the extremely high accuracy required from them-far beyond that achieved with the current techniques. The fluctuation of atmospheric 14C is well known and must be taken into account. In addition, the decomposition time of NOM is short as compared to the half-life of 14Cof 5700 years. Undoubtedly, major efforts-both in modeling and measurementsare required to establish the small differences in the 14Cmeasurements. Overcoming these difficulties will require major economic and scientific commitments on an international level. However, the enormous economic and social costs associated with the mitigation of the projected global temperature change justifies the initiation of an international cooperative effort to study the feasibility of application of NOM to the understanding of global climate. The idea behind the “typing of NOM’ has been twofold. First, the need for more economical and more
Natural organic matter (NOM) consists of complex organic matter, which is synthesized or produced in the lithosphere. Until recently, humic substances were considered to include NOM. However, the evolution of research on humic substances has led to several confusing definitions used by various investigators and must be considered to be outdated. During the last decade, the environmental scientific community including ecologists, chemists, and biologists has gradually realized that the dissolved organic matter is involved in essentially all reactions in aquatic systems. Clearly, the term Humic Substances does not “cover the whole thing”. Meanwhile, a consensus has been reached within the scientific community on the following facts: 1. NOM is present in all fresh waters. 2. NOM takes part in essentially all chemical and biological processes in the aquatic environment. 3. NOM is an extremely complicated mixture of degradation products from plants and micro-organisms. 4. The concentration of organic humic matter is often comparable to that of inorganic salts, and its mean concentration is as high as 5 mg C/L. Accordingly, there is a clear need for an international and coordinated research effort to ensure the availability of fundamental knowledge in this important segment of environmental science. However, in spite of the obvious ecological importance of NOM, until recently, resources allocated for NOM research have been limited. Both in Europe and in North America, there is concern over numerous chlorinated by-products of chlorination of the drinking water. The concern is based on
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efficient methods for the removal from drinking water necessitates more knowledge about the matter. Besides, because of its ecological importance and its very complex nature, we are urged to improve the international communication, As there are 5.5 billion different human blood samples in the world, there are also differences between the world-wide NOMS. Therefore, is a NOM-typing possible? The purpose of the present pilot project was to test a hypothesis that the international exchange of NOM samples among ecologists, chemists, and biologists, for multi-method characterization, is not only possible but also practical. Further, to demonstrate that the available chemometric tools are suitable for an evaluation of the resulting data load, in the attempts to group or type the NOMS, according to typical characteristics. These activities have been sponsored by the Norwegian Research Council and
Editorial
by 13 different laboratories and institutions in Europe and North America. The purpose of the present publication is to demonstrate that international research cooperation on NOM is necessary and possible. In addition, the organizers of the meeting upon which this volume is based desired to hear the views of the impressive participating group of international NOM researchers on the NOM-typing approach. The published papers in this volume speak for the outcome of this effort.
Per Kristian Egeberg Egil T. Gjessing Harsha Ratnaweera A. Alan Moghissi
PII s0160-4120(98)00120-2
EDITORIAL
NATURAL
ORGANIC
MATTER the known toxicity of a number of these chlorinated organic compounds. For obvious reasons, the potential toxicity of compounds resulting from the chlorination of NOM varies widely. However, the complexity and the number of uncertainties related to this hygienic problem have led to attempts to reduce the concentration of or eliminate NOM from raw waters prior to disinfection. There is another hereto unrecognized area of NOM research addressing the contribution of fossil-fuelgenerated CO, to the biosphere. One of the most uncertain parameters in the current global temperature modeling is the net increase in the CO, uptake by the biosphere resulting from the increasing COZ in the atmosphere. The study of 14C in NOM is likely to decrease uncertainties associated with this important parameter. One of the reasons for the lack of recognition of the importance of these studies is the extremely high accuracy required from them-far beyond that achieved with the current techniques. The fluctuation of atmospheric 14C is well known and must be taken into account. In addition, the decomposition time of NOM is short as compared to the half-life of 14Cof 5700 years. Undoubtedly, major efforts-both in modeling and measurementsare required to establish the small differences in the 14Cmeasurements. Overcoming these difficulties will require major economic and scientific commitments on an international level. However, the enormous economic and social costs associated with the mitigation of the projected global temperature change justifies the initiation of an international cooperative effort to study the feasibility of application of NOM to the understanding of global climate. The idea behind the “typing of NOM’ has been twofold. First, the need for more economical and more
Natural organic matter (NOM) consists of complex organic matter, which is synthesized or produced in the lithosphere. Until recently, humic substances were considered to include NOM. However, the evolution of research on humic substances has led to several confusing definitions used by various investigators and must be considered to be outdated. During the last decade, the environmental scientific community including ecologists, chemists, and biologists has gradually realized that the dissolved organic matter is involved in essentially all reactions in aquatic systems. Clearly, the term Humic Substances does not “cover the whole thing”. Meanwhile, a consensus has been reached within the scientific community on the following facts: 1. NOM is present in all fresh waters. 2. NOM takes part in essentially all chemical and biological processes in the aquatic environment. 3. NOM is an extremely complicated mixture of degradation products from plants and micro-organisms. 4. The concentration of organic humic matter is often comparable to that of inorganic salts, and its mean concentration is as high as 5 mg C/L. Accordingly, there is a clear need for an international and coordinated research effort to ensure the availability of fundamental knowledge in this important segment of environmental science. However, in spite of the obvious ecological importance of NOM, until recently, resources allocated for NOM research have been limited. Both in Europe and in North America, there is concern over numerous chlorinated by-products of chlorination of the drinking water. The concern is based on
143
144
efficient methods for the removal from drinking water necessitates more knowledge about the matter. Besides, because of its ecological importance and its very complex nature, we are urged to improve the international communication, As there are 5.5 billion different human blood samples in the world, there are also differences between the world-wide NOMS. Therefore, is a NOM-typing possible? The purpose of the present pilot project was to test a hypothesis that the international exchange of NOM samples among ecologists, chemists, and biologists, for multi-method characterization, is not only possible but also practical. Further, to demonstrate that the available chemometric tools are suitable for an evaluation of the resulting data load, in the attempts to group or type the NOMS, according to typical characteristics. These activities have been sponsored by the Norwegian Research Council and
Editorial
by 13 different laboratories and institutions in Europe and North America. The purpose of the present publication is to demonstrate that international research cooperation on NOM is necessary and possible. In addition, the organizers of the meeting upon which this volume is based desired to hear the views of the impressive participating group of international NOM researchers on the NOM-typing approach. The published papers in this volume speak for the outcome of this effort.
Per Kristian Egeberg Egil T. Gjessing Harsha Ratnaweera A. Alan Moghissi