Sorption hydrophobic organic solutes

Two conclusions might be derived from this observation First, that sorption of hydrophobic organic solutes by soil organic matter is not strictly a surface phenomenon and second, that surfaces associated with soil organic matter are much more reactive for such organic solutes than are mineral... 

Figure 11.7 Apolar and slightly monopolar organic compound sorption coefficients, K,min (L nr2), observed for exchange between aluminum oxides and aqueous solutions plotted as a function of sor-bate hydrophobicity (as measured by yw) apolar series of chlorobenzenes (squares, Schwarzenbach and Westall, 1981) and aromatic and chloroaromatic compounds (diamonds, Maderet al., 1997).

Wu and Gschwend (1986) reviewed and evaluated several kinetic models to investigate sorption kinetics of hydrophobic organic substances on sediments and soils. They evaluated a first-order model (one-box) where the reaction is evaluated with one rate coefficient (k) as well as a two-site model (two-box) whereby there are two classes of sorbing sites, two chemical reactions in series, or a sorbent with easily accessible sites and difficultly accessible sites. Unfortunately, the latter model has three independent fitting parameters kx, the exchange rate from the solution to the first (accessible sites) box k2, the exchange rate from the first box to the... 

In some sorption cases 1/n equals 1. When this condition is met, a plot of -SC versus C will produce a straight line with KD as slope (C-type isotherm Fig. 4.16). This type of isotherm best describes soil sorption of hydrophobic organics (e.g., chlorinated hydrocarbons) (Fig. 4.17). The linearity of such data can be explained by the schematic model in Figure 4.18. In this model, (linear partition model), the hydrophobic organic contaminant distributes itself linearly between hydrophobic organic matter adsorbed on an inorganic mineral particle and solution. Linearity... 

The most promising is the application of the Taylor-vortex column with Taylor-Couette flow. Sorption of hydrophobic organic compounds can lead to under estimation of actual removal efficiency of wastewater treatment, as weU as cross-contamination of the batches of the effluent due to release ofthe sorbed solute molecules. This is supported by the results ofthe laboratory studies, along with the ease ofthe potential scale-up. The critical part in the context ofthe removal of organic compounds from wastewater(s) is the material of the inner cylinder. The surface of the inner cylinder provides a potential sorption surface for hydrophobic organic molecules. Since the PTFE price could be prohibitive for the scale-up, stainless steel, or other materials should be explored as replacements for potential industrial applications. 

The sorption and desorption of chlorinated pesticides limits the potential success of electro-osmotic transport. The sorption of hydrophobic organic compounds (HOCs) is a partitioning type of process and can be represented by linear isotherms until aqueous phase solubility is approached (Chiou, Peters, and Freed, 1979). Karickhoff (1981) reported that the sorption isotherm was linear for HOCs up to half of the aqueous phase solubility level of the solute. Although HOCs adsorb to mineral surfaces mainly due to van der Waals forces (Schwarzenbach, Gschwend,... 

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