Sorption index

To test this hypothesis further, a partition or distribution coefficient was calculated from the sorption at pH 2 by a number of soils. The same experimental technique was used as previously described. A sorption index is calculated by the following expression ... 

Since at pH 2 virtually all the 4-amino-3,5,6-trichloropicolinic acid will be in the free acid form, this partition coefficient—and therefore the sorption index—would be constant if extraction is the mechanism by which the free acid is absorbed. Table IV shows reasonable constancy for the sorption index over a wide range of organic contents except for the first three soils—i.e., soils 3, 4, and 7. There are at least two possible causes for failure of this relationship in these cases other components contributing significantly to sorption, and analytical uncertainty in or-... 

Soil % Organic Matter % in Solution % Sorbed Ratio h Sorption Index 0... 

Single-point isotherms were initially used by Bache and Williams (1971) to determine phosphorus sorption capacity of a wide range of soils. The approach involves measuring phosphorus sorption at one fixed concentration after hxed equilibration period (18 h). The phosphorus sorption index (PSI) (Bache-Williams index) is calculated as follows ... 

Soil—water nutrient exchange rates Substrate-induced respiration Arginine mineralization Microbial diversity Cellular fatty adds rRNA sequence analysis Organic matter accretion rates Cs-137 and Pb-210 profiles Phosphate sorption index Equilibrium phosphorous concentration (EPCo)... 

Scenario II assumes that indicator variables are collocated, meaning they are sampled at the same sites X , that is, sample sites are shared (isotopic data) (Wackernagel, 2003). A special case arises if an indicator variable of interest (e.g., level III indicator that is difficult to measure, labor-intensive or costly to measure—phosphate sorption index) is known at a few sites and an auxiliary variable known at many sites (e.g., level I indicator that is easy and cheap to measure—total phosphorus). 

The sorption index uses time and contact angles to measure how quickly a water droplet (ie, sweat) is absorbed by the textile. As the skin becomes more moist, it becomes more sensitive to mechanical irritation. That is why it is important for a textile material to transport sweat away from the skin as quickly as possible. The sorption index indicates... 

Grathwohl (1990) found a relationship between sorption capacity and the the atomic H/O ratio of NOM. Similarly, there is a good relationship between log Koc and the polarity index (PI) of SOM, defined as the (0+N)/C ratio (DePaolis and Kukkonen 1997 Rutherford et al. 1992 Xing 1997 Xing et al. 1994a). The effect of SOM polarity on sorption of organic compounds is consistent with the well-known theory of solvent polarity on solute solubility. In studying the influence of SOM composition... 

Fig. 6. Relationship between the log Koc for phenanthrene sorption and the polarity index of humic acids and humin, sequentially extracted from a soil. F-l, F-4, F-7, and F-9 are the first, fourth, seventh, and nineth extracted humic acids, respectively. 0.005, 0.05, and 0.5 ig mL 1 are selected liquid-phase equilbrium concentration of phenathrene (Kang and Xing 2005).

Fig. 7. Relationship between polarity index, (N+0)/C, and the Koc of a-Naphthol sorption to peat, black shale, and humic acids (HA) from different horizons of a soil. Modified from Chen et al. (1996).

Fig. 10. Relationship between polarity index ((O + N)/C) and sorption capacity of HOCs from the literature.

Lambert M (1968) Omega (Q) a useful index of soil sorption equilibria. J Agric Food Chem 15 340-343... 

Laird DA, Barriuso E, Dowdy RH, Koskinen WC (1992) Adsorption of atrazine on smectites. Soil Sci Soc Am J 56 62-67 Laird DA, Fleming PD (1999) Mechanisms for adsorption of organic bases on hydrated smectite surfaces. Environ Toxicol Chem 18 1668-1672 Lambert SM (1967) Functional relationship between sorption in soil and chemical structure. J Agric Food Chem 15 572-576 Lambert SM (1968) Omega, a useful index of soil sorption equilibria. J Agric Food Chem 16 340-343... 

The sPS has been exploited as sensitive material for fiber optic chemical sensors based on reflectance measurements and aimed to detection of chloroform and toluene in water and air environments48 50. The refractive index of sPS thin films is estimated to be about 1.578. The effect of the analyte sorption in the crystalline domain was modeled as an increase in the material density, which in turn leads to an increase in the refractive index according to the Lorentz-Lorenz law ... 

Sacan MT, Balcioglu IA. 1996. Prediction of the soil sorption coefficient of organic pollutants by the characteristic root index model. Chemosphere 32 1993-2001. 

Fig. 8.47 Phenanthrene adsorption-desorption hysteresis observed for Lachine and Chelsa humic acid aggregate the hysteresis index is given by n. Reprinted from Huang W, Peng, P. Yu, Z. and Fu J (2003) Effects of organic matter heterogeneity on sorption and desorption of organic contaminants by soils and sediments. Appl Geochem 18 955-972. Copyright 2003 with permission of Elsevier...

Okouchi, S., and H. Saegusa, Prediction of Soil Sorption Coefficients of Hydrophobic Organic Pollutants by Adsorbability Index. Bull. Chem. Soc. Jpn., 1989 62, 922-924. 

The index m, representing the maximum sorption in the cavity, may he derived from considerations of the zeolitic cavity volume and molar volume of the sorhate, as m <. v/0. However Schirmer et al. (7 ) state that a maximum of 6 terms has been used in their work. 

---