Soil surface chemistry effects

Most of the pollutants listed in this chapter find their way into water directly by human or natural discharges (from diffuse or point sources) or indirectly through discharges into soil. It is therefore important to realize that in order to manage or control such direct or indirect pollution, the chemistry of such chemicals must be understood and their physicochemical behavior in soil-water systems predicted. To accomplish these tasks, and to minimize adverse effects on the environment, one needs to have a background in water chemistry, soil mineralogy, soil surface chemistry, and the... 

Jurinak, J.J. (1966) Surface chemistry of hematite Anion penetration effect on water adsorption. Soil Sci. Soc. Am. Proc. 30 559-562... 

Indeed the overall effect of such chemicals on the surface chemistry of soils and sediments remains poorly understood. Despite the difficulties this type of technique is still widely used. As with many operationally defined methods, it is difficult to make direct comparisons between independent studies however, for individual studies sequential extraction can play a useful role in an overall programme of study regarding the chemical forms of radionuclides bound to the solid phase under different environmental conditions so long as it is realised that in this type of study the species are themselves really defined by the nature of the extraction system employed (see Chapter 10). 

Acidic environments have always been characterised by restricted biological populations, but only relatively recently was it realised that the main cause of this is aluminium toxicity. The extensive literature that has developed on the biological effects of A1 has been reviewed by Foy (1984) for crop plants and by Howells et al (1990) for fisheries. It is surprising that the most abundant metal in the earth s crust is highly toxic to organisms, but fortunately in most environments it is completely insoluble and is therefore innocuous. Only in acidic environments is Al sufficiently soluble to be harmful, and increased mobilization of Al in soils, surface waters and groundwaters is therefore an important consequence of acid deposition. A useful detailed review on Al in the environment is given by Driscoll and Schecher (1988), and on the chemistry involved in its mobilization by Bache (1986). 

Both direct and indirect methods were tested in the Lisbon area. Direct methods include the assessment of hydrocarbon compositional signatures in surface soils, outcrop fracture-fill soils and mosses, and 6-ft (2 m) deep free-gas samples. Indirect methods pertain to the major and trace element chemistry of soils to look for alteration effects resulting from hydrocarbon microseepage. 

Previous books in this area typically focus on selected aspects of the subject, such as the properties of the solid phase, or the interactions of selected substances with soil/rock. This book comprehensively treats the soil-liquid-interface system. Drawn chiefly from the authors years of research at the Isotope Laboratory in the Department of Colloid and Environmental Chemistry at the University of Debrecen in Hungary, this book discusses chemical reactions on the surfaces/interfaces of soils and rocks examines the role of these processes in environmental, colloid and geochemistry and explores the effects on agricultural, environmental and industrial applications. 

The steady interest in the effects of the chemistry and physics of the carbon surface on pollutant removal from waters has been ignited by the U.S. Clean Water Act (enacted in 1972, amended as the Water Quality Act in 1987). The most recent interest stems from the Safe Drinking Water Act Amendment of 1996. Activated carbon adsorption has been cited by the U.S. Environmental Protection Agency (www.epa.gov) as one of the best available control technologies. Furthermore, the most recent efforts to understand the adsorption of the same pollutants by soils [7,8] can benefit from comparisons of similarities and differences with respect to the behavior of activated carbons. 

---