Physical Chemistry of Soil

Soil is a very heterogeneous, more or less humid medium. The humidity level depends on the soil s nature and on the volume of precipitation, and thus on the local climate. Water is retained mainly by capillary action. 

The mineral content of water in soil varies between 0.5 and 1.5 g l .  

On industrial sites, even on former industrial sites, other inorganic elements can be found, the nature of which is related to the industrial activity. 

Soil also contains gases oxygen, nitrogen, and carbon dioxide, originating mainly from the decomposition of organic matter, etc. 

A soil is characterised by a pH value and an electrical resistivity that is closely related to the nature of salts dissolved in the humidity. The pH also depends on the quantity of inorganic and organic acids, and on the carbon dioxide (CO2) level, as well as on possible contamination by industrial or household wastewater. In general, soils have an acidic pH, between 3.5 and 4.5. The pH increases with depth (Figme G.1.1). 

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Sparks DL (ed) (1986) Soil physical chemistry. CRC Press, Boca Raton, Florida Sparks DL (1989) Kinetics of soil processes. Academic Press, San Diego Sparks DL, Huang PM (1985) Physical chemistry of soil potassium. In Munson RE (ed) Potassium in agriculture, ASA, Madison, Wisconsin, pp 201-276 Sparks DL, Jardine PM (1984) Comparison of kinetic equations to describe K-Ca exchange in pure and mixed systems. Soil Sci 138 115-122 Spencer WF, Cliath MM (1969) Vapor densities of dieldrin. Environ Sd Technol 3 670-674 Spencer WF, Chath MM (1973) Pesticide volatilization as related to water loss from soil. J Environ Qual 2 284-289... 

Sparks, D. L. and P. M. Huang. 1985. Physical chemistry of soil potassium. In Potassium in Agriculture. R. D. Munson, Ed. American Society of Agronomy, Madison, WI. 

After this brief survey of the physical chemistry of soils and of the nature of the main textiles, let us come back to the primary and secondary detergent effects. In addition... 

Handbook of Soil Conditioners Substances That Enhance the Physical Properties of Soil, edited by Arthur Wallace and Richard E. Terry Environmental Chemistry of Selenium, edited by William T. Frankenberger, Jr., and Richard A. Engberg... 

Model selection, application and validation are issues of major concern in mathematical soil and groundwater quality modeling. For the model selection, issues of importance are the features (physics, chemistry) of the model its temporal (steady state, dynamic) and spatial (e.g., compartmental approach resolution) the model input data requirements the mathematical techniques employed (finite difference, analytic) monitoring data availability and cost (professional time, computer time). For the model application, issues of importance are the availability of realistic input data (e.g., field hydraulic conductivity, adsorption coefficient) and the existence of monitoring data to verify model predictions. Some of these issues are briefly discussed below. 

Ponnamperuma FN. Some aspects of the physical chemistry of paddy soils. In Institute of Soil Science, Academia Sinica, editor. Proceedings of Symposium on Paddy Soils. Beijing, Science Press 1981. pp. 59-94. 

Dec J, Bollag J-M, Huang PM, Senesi N (2002) Impact of interactions between microorganisms and soil colloids on transformation of organic pollutants. In Huang PM, Bollag J-M, Senesi N (eds) Interactions between soil particles and microorganisms. Impact on Terrestrial Ecosystem, vol 8, IUPAC Series of Analytical and Physical Chemistry of Environmental Systems, Wiley, Chichester, UK, pp 323-378... 

Nannipieri P, Gianfreda L (1999) Kinetics of enzyme reactions in soil environments. In Huang PM, Senesi N, Buffle J (eds) Structure and surface reactions of soil particles, vol 4, IUPAC series on analytical and physical chemistry of environmental systems. Wiley Chichester UK, pp 449-479... 

Senesi N, Loffredo E (1999) The chemistry of soil organic matter. In Sparks DL (ed) Soil physical chemistry. CRC Press, Boca Raton, FL, pp 239-370 Sujatha TV, Hegde MJ (1998) C-mitotic effects of Trichloroethylene (TCE) on bone marrow cells of mice. Mutat Res 413 151-158 Varanini Z, Pinton R (2001) Direct versus indirect effects of soil humic substances on plant growth and nutrition. In Pinton R, Varanini Z, Nannipieri P (eds) The rizosphere. Marcel Dekker, Basel, pp 141-158 Vijayalaxmi KK, Venu R (1999) In vivo anticlastogenic effects of L-ascorbic acid in mice. Mutat Res 438 47-51... 

Both direct and indirect methods are used in studying soil chemistry. While in all cases direct methods are preferable, it is not always possible to make direct observations of all the chemical species, and physical and chemical changes of interest. Thus, it is often necessary to modify the soil before analysis. In many cases, it is essential to extract components before analysis can be carried out. It is also possible to obtain valuable information about the chemistry of soil by carrying out analyses that destroy all or a part of the soil matrix. A summary of analysis types and instruments commonly used in soil analysis is given in Table 8.1. 

Yu T-R. 1985. Physical Chemistry of Paddy Soils. Berlin Springer-Verlag. 

Tadros T (2004) Application of rheology for assessment and prediction of the long-term physical stabdity of emulsions. Adv CoU Interface Sci 108 227-258 Talibuden O (1981) Cation exchange in soils. In Greenland DJ, Hayes MHB (eds) The chemistry of soil processes. WUey, Chichester, pp 115-178 Taylor AW, Spencer WF (1990) Volatilization and vapor transport processes. In Cheng HH (ed) Pesticides in the soil environment. Soil Sci Soc Amer Book Ser 2, Madison, Wisconsin, pp 213-369... 

Guggenberger, G., and Haider, K. M. (2002). Effects of mineral colloids on biogeochemical cycling of C, N, P and S in soil. In Interactions between Soil Particles and Microorganisms. Impact on the Terrestrial Ecosystem, Huang, P. M., Bollag, J.-M., and Senesi, N., eds., IUPAC Series on Analytical and Physical Chemistry of Environmental Systems. Vol. 8, John Wiley Sons, Chichester, UK, pp. 267-322. 

Senesi, N., and Loffredo, E. (1999). The chemistry of soil organic matter. In Soil Physical Chemistry, Sparks, D. L., ed., CRC Press, Boca Raton, FL, pp. 239-370. 

Senesi, N. Loffredo, E. The Chemistry of Soil Organic Matter in Soil Physical Chemistry, 2nd ed., Sparks, D.L. (Ed.) CRC Press Boca Raton, 1999, pp. 239—370. 

However, modern concepts of soil acidity were not developed until the middle of the 20th century. In the U.S.A., Jenny, Stout, Coleman, Harward, and others contributed heavily to a better understanding of the nature of soil acidity and related aspects of soil chemistry and plant nutrition (Coleman and Thomas, 1967). Soil pH has a profound influence on the availability of nutrients to crops, since chemical, microbiological and, to a lesser extent, physical properties of soils are affected by the degree of soil acidity or alkalinity that prevails. 

Besides these important relations between PZC and ion adsorption by soils, the physical properties of soils may also be sensitive to the PZC. It is a general principle of colloid chemistry that colloidal particles dispersed in water tend to maintain their dispersed state if the particles possess relatively high surface charge, either positive or negative. Conversely, aggregation of these individual particles (i.e., flocculation) is most favored when the surface charge is low. This leads to the rule that ... 

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