Aliphatic hydrocarbons sorption

Grant, B.F. Endrin toxicity and distribution in freshwater a review. Bull Environ. Contam. Toxicol, 15 (3) 283-290, 1976. Grathwohl, P. Influence of organic matter from soils and sediments from various origins on the sorption of some chlorinated aliphatic hydrocarbons implications on Koc correlations. Environ. Sci. Technol, 24(11) 1687-1693, 1990. 

Pignatello, J. J. (1990) Slow reversible sorption of aliphatic hydrocarbons in soils I. Formation of residual fractions. Environ. Toxicol. Chem. 9, 1107-1115. 

The sorption capacity of diatomite (the ratio of lbs of sorbent required to clean up lbs of spilled liquid) ranges from 1.1 for aliphatic hydrocarbons such as isoprene to 2.5 for aliphatic halogenated hydrocarbons such as trichloroethylene. The sorption capacity of diatomite is rather poor. However, this material is relatively inexpensive and can be purchased for approximately 1.50/lb, depending upon quantity ordered. 

The polymer materials mainly used for the membranes are glassy polymers, the first and foremost polyimides. The use of glassy polymers having a rigid ensemble of macromolecules results in high separation effectiveness. Separation effectiveness in pervaporation processes is characterized by the separation factor, /3p, which is determined by the diffusion component, /3d, and the sorption component, /3s [8,55]. Let us consider the effect of chemical composition of polymer membranes on their transport properties with respect to aromatic, alicyclic, aliphatic hydrocarbons and analyze ways to improve these properties. 

G. Unnikrishnan and S. Thomas, Sorption and Diffusion of Aliphatic Hydrocarbons into Crosslinked Natural Rubber, J. Polymer Sci. B Polym Phys, 1997, 35, 725. 

Journal of Polymer Science Polymer Physics Edition 35, No.5, 15th April 1997, p.725-34 SORPTION AND DIFFUSION OF ALIPHATIC HYDROCARBONS INTO CROSSLBVKED NATURAL RUBBER Unnikrishnan G Thomas S Mahatma Gandhi,University... 

The sorption and transport of four aliphatic hydrocarbons (n-hexane, n-heptane, n-octane and n-nonane) into NR crosslinked using conventional, efficient, dicumyl peroxide(DCP) and mixed sulphur/peroxide vulcanisation systems were investigated at temp, of 28 to 60C. The NR vulcanised by DCP exhibited the lowest penetrant uptake of the systems studied. It was observed that the kinetics of liquid sorption in every case deviated from the regular Fickian trend, characteristic of sorption of liquids by rubbers. The diffusion coefficient, activation energy of sorption, enthalpy, entropy and rubber-solvent interaction parameter were evaluated for the four systems from the swelling data. 30 refs. 

Recently, Bonin and Simpson (2007) showed in their study that polycyclic aromatic hydrocarbons sorptive behavior could not be solely attributed to a specific SOM chemical characteristic (i.e., aliphaticity or aromaticity) and concluded that both structure and OM physical conformation are important in sorption processes. Martin-Neto et al. (1994b) used analysis of microwave power saturation curves (Weil et al., 1994) to obtain information about HA conformation. They observed that at pH > 3.5 a typical curve of homogeneous saturation was obtained for the oxisol HA, whereas at pH 2.3 inhomogeneous saturation occurred. The peat HA showed only homogeneous saturation. However, a similar inhomogeneous trend ... 

The sorption capacity of clay ranges from 1.0 for alcohols and basic compo unds such as allyl alcohol and ammonium hydroxide respectively, to 1.6 for aliphatic halogenated hydrocarbons such as trichloroethylene. Therefore, the sorption capacity of clay is very low when compared to the other materials available. However, this material is one of the most inexpensive materials and can be purchased for approximately 0.04/lb to 0.12/lb depending upon supplier and quantity ordered. 

Very recently , we have carried out an intercomperison study of hquid-hquid extraction (LLE) and sorption on polyurethane foam (PUF) and Amberlite XAD-2 for the analysis of aliphatic, aromatic and chlorinated hydrocarbons dissolved in seawater. The application of these methods, sampling in parallel the same body of water, has shown significant differences in the recovery of higher molecular weight components in the complex mixtures of both aliphatic and aromatic hydrocarbons. These are attributed to selective associations of these hydrophobic species with macromolecular organic matter such as fulvic and humic acids and to the effects of the dissolved organic molecules on adsorbent properties. 

Figure 10.19. Adsorption of chlorinated hydrocarbons on a muck soil. Relative molecular sizes are indicated by the molecular diagrams. (Data from R. G. LaPoe. 1985. Sorption and desorption of volatile chlorinated aliphatic compounds by soil and soil components. Ph.D. Thesis, Cornell University, Ithaca, New York.)...

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