Environmental Colloids and Particles

The IUPAC Series on Analytical and Physical Chemistry of Environmental Systems provides the scientific community with a critical evaluation of important physicochemical structures and reactions in environmental systems, as well as on the analytical techniques required to study them. The series is aimed at promoting rigorous analysis and understanding of the physicochemical functioning of environmental systems. In spite of decades of research, the precise role of colloids and nanoparticles in environmental systems is still poorly understood. For example, in surface waters, trace elements are usually bound to colloids, although values of 0-100% binding have been observed based upon the element that is measured, the analytical technique that is employed, the type of water and other factors. In soils and sediments, colloid-facilitated transport is a well known, though rarely quantified, process. Bioavailability and biological effects are likely to be strongly modified by interactions with colloids, but few studies are able to distinguish between complexation effects and direct effects on the organism. While the lack of consensus can often be attributed to the trace element that has been examined, or the nature of the medium in which it occurred, a large variability is often introduced by the analytical technique used to make the determination and by the fact that environmental colloids are always chemically heterogeneous and polydisperse. Given the complexity of the environmental colloids, this book was written in order to: (i) identify some of the common problems still needing study in colloid research; (ii) summarise our current understanding of environmental colloids and their reactions and (iii) carefully and critically describe a number of important techniques to characterise physical and chemical colloidal properties. Each chapter is designed to be an independent, critical review of the available literature. An emphasis has been placed on modern and novel applications of techniques that have not been previously examined in detail and on techniques that have seen vast methodological improvements over the past ten years. Both characterisation techniques that look at whole samples and those examining properties of sample fractions have been described. Several chapters review our most recent understanding of the environmental colloids and identify colloidal properties that will need further study in the future. This book is relevant for academic and industrial researchers in the field of colloid science. For chapters describing the state-of-the-art research in the field, the literature has been reviewed to bring together the large quantity of independent (and often contradictory) data that are available. In the chapters that describe the analytical techniques that are used to characterise (environmental) colloids, a necessary theoretical explanation of the technique is provided in addition to a critical discussion of the advantages and disadvantages of the application. The book is thus accessible to graduate students who are entering the field yet also useful to more experienced researchers who are interested in deepening their understanding about these difficult to characterise, but critically important phases.