Soil/properties, 4-17 adsorption

Organic phosphorus can affect soil properties. Adsorption of organic phosphates affects the charge and electric potential of colloidal particles and, therefore, their dis-persion/flocculation behaviour (Fig. 6.8). The adsorption of myo-inositol hexakis-... 

The order of the mobilities of alachlor, butylate, and metolachlor in columns of various soils was metolachlor > alachlor > butylate. This correlates directly with the water solubilities and inversely to the adsorption coefficients and octanol/water partition coefficients of these compounds. Diffusion of these compounds in soil thin-layers was as follows butylate > alachlor > metolachlor, which correlates directly with the vapor pressures of these compounds. Significant soil properties affecting diffusion appeared to be bulk density and temperature. Soil moisture is also probably important, but its effect on the diffusion of these compounds was not determined. 

Andon, R.J.E., Counsell, J.F., Tees, E.B., Martin, J.F., and Mash, MJ. Thermodynamic properties of organic oxygen compounds. Part 17. Tow-temperature heat capacity and entropy of the cresols, Trans. Faraday Soc., 63 1115-1121,1967. Andon, R.J.E., Cox, J.D., and Herington, E.F.G. Phase relationships in the pyridine series. Part V. The thermodynamic properties of dilute solutions of pyridine bases in water at 25 °C and 40 °C, J. Chem. Soc. (London), pp. 3188-3196, 1954. Andrades, M.S., Sanchez-Martin, M.J., and Sanchez-Camazano, M. Significance of soil properties in the adsorption and mobility of the fungicide metalaxyl in vineyard soils, J. Agric. Food Chem., 49(5) 2363-2369, 2001. 

Fig. 8.31 Adsorption isotherms of terbuthylazine and atrazine at different depths along the soil profile, as affected by the vertical variability of soil properties. (Dror et al. 1999)...

The conversion of parathion is affected by soil constituents in the order kaolinite > smectite > organic matter and is related inversely to the adsorption affinity of these materials for this contaminant (Mingelgrin and Saltzman 1977). Although the extent of hydrolysis differs among soils, it is apparent that soil-surface degradation of parathion is caused by hydrolysis of the phosphate ester bond. The presence of water in the soil-parathion system led to a decrease in the surface-induced degradation of the organic molecule and diminished the effect of natural soil properties on its persistence. 

Nickel is strongly adsorbed by soil, although to a lesser degree than lead, copper, and zinc (Rai and Zachara 1984). There are many adsorbing species in soil, and many factors affect the extent to which nickel is adsorbed, so the adsorption of nickel by soil is site specific. Soil properties such as texture, bulk density, pH, organic matter, the type and amount of clay minerals, and certain hydroxides influence the retention and release of metals by soil (Richter and Theis 1980). 

Peter, C.J. and J.B. Weber (1985). Adsorption, mobility, and efficacy of metribuzin as influenced by soil properties. Weed Sci., 33 868-873. 

Spencer et al. (14) reported that the degree of reduction in vapor pressure in soil due to adsorption is dependent mainly upon soil water content, the nature of the pesticide, its concentration and soil properties, particularly soil organic matter content. The concentration of the desorbed pesticide in the soil water dictates the vapor density of the pesticide in the soil air in accordance with Henry s law. Hence, soil water adsorption coefficients can be used to calculate relative vapor densities in the soil atmosphere. 

Moreale, A., Van Bladel, R. (1976) Influence of soil properties on adsorption of pesticide-derived aniline and p-chloroaniline. J. Soil Sci. 27, 48-57. 

The method of soil suspensions extracts is based on metal desorption/dissolution processes, which primarily depend on the physico-chemical characteristics of the metals, selected soil properties and environmental conditions. Metal adsorption/ desorption and solubility studies are important in the characterization of metal mobility and availability in soils. Metals are, in fact, present within the soil system in different pools and can follow either adsorption and precipitation reactions or desorption and dissolution reactions (Selim and Sparks, 2001). The main factors affecting the relationship between the soluble/mobile and immobile metal pools are soil pH, redox potential, adsorption and exchange capacity, the ionic strength of soil pore water, competing ions and kinetic effects (e.g. contact time) (Evans, 1989 Impelhtteri et al., 2001 McBride, 1994 Sparks, 1995). 

Bibler and Marson 1992). Retention of uranium by the soil may be due to adsorption, chemisorption, ion exchange, or a combination of mechanisms (Allard et al. 1982). Any soil property that alters the sorption mechanism will also alter the mobility of uranium in the soil. The sorption of uranium in most soils is such that it may not leach readily from soil surface to groundwater, particularly in soils containing clay and iron oxide (Sheppard et al. 1987), although other geological materials such as silica, shale, and granite have poor sorption characteristics (Bibler and Marson 1992 Erdal et al. 1979 Silva et al. 1979 Tichnor 1994). 

Soil samples were taken from the experimental field in which spinach is cultivated at the National Institute for Agro-environmental Sciences, Tsukuba, Japan. The top 10 cm of soil was collected from 15 points and then mixed, air-dried, and passed through a 2-mm sieve. For comparison, surface soil was also taken from the adjacent non-cultivated land. The soil classification based on the world reference base for soil resources is Andosols. Relevant soil properties are shown in Table 1. A distinctive feature of this soil is a high amount of organic matter and a higher capacity for phosphate adsorption due to the presence of non-crystalline minerals. 

Sakata, M., 1987, Relationship between adsorption of arsenic(III) and boron by soil and soil properties Environmental Science Technology, v. 21, p. 1126-1130. 

Organic Matter, Clay, and Other Soil Properties Correlated with Adsorption Parameters of Herbicides"... 

Greenland, D. J. (1965). Interaction between clays and organic compounds in soils, II Adsorption of soil organic compounds and its effect on soil properties. Soil Pert. 28, 521-532. 

The original second-order approach (SOTS) was first proposed to describe Cr retention and transport in several soils by Selim and Amacher (1988). Here two types of sites were considered, the first was of the equilibrium type and the second was kinetically controlled type sites. Moreover, Smax (pg g-1 of soil) was considered to represent the total retention capacity or total amount of sites on matrix surfaces. It is also assumed that Smax is an intrinsic soil property that is time invariant. Therefore based on the two-site approach, the total adsorption sites,... 

Adsorption is very important for the biological properties of the chemicals. Many soil pesticides may be applied in higher quantities when the soil has strong adsorption properties. Adsorption inactivates and makes toxicants less harmful and reduces leakage, but on the other hand, it can make the pesticides more recalcitrant to microbial degradation. The adsorption process is quite fast, and often less than an hour is needed to produce equilibrium. The opposite process, desorption, takes longer and sometimes a low residue is bound irreversibly. 

In recent years the octanol/water partition coefficient has become a key parameter in studies of the environmental fate of organic chemicals. It has been found to be related to water solubility, soil/sediment adsorption coefficients, and bioconcentration factors for aquatic life. (Estimation of these three parameters solely on the basis of Kuw is described in Chapters 2, 4, and 5 respectively.) Because of its increasing use in the estimation of these other properties, Kow is considered a required property in studies of new or problematic chemicals. 

The effect of soil properties on the adsorption of substances. Physical and chemical characteristics of adsorbing components in the soil also affect the binding capacity and stability of chemical substances in the soil. The particle size is a further important factor. Colloidal particles exhibit the largest sorption capacity, with a diameter of 10 to 10 mm. The sorption capacity decreases with increasing size, and particles larger than 2 mm in diameter essentially do not affect the soil sorption capacity. From the chemical standpoint the soil sorbents may be divided into two groups ... 

BIOLOGICAL PROPERTIES COD 1.025, ThOD 0.97 Koc for silt loam 33 rapidly percolates through sandy soil little adsorption to soil is expected can be detected in water... 

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