Remediation of PAH-Contaminated Soils and Sediments: A ...

More documents

Recommendations

Info

Stiff goldenrod Solidago rigida Olson et al., 2007 Sudangrass Sorghum vulgare L. Schwab and Banks, 1994; Lee, 1996; Reilley et al., 1996 Switchgrass Panicum virgatum Tall fescue Festuca arundinaceae Schreb. Aprill and Sims, 1990; Reilley et al., 1996; Pradhan et al., 1998; Chen et al., 2003; Rugh et al., 2004 Ferro et al., 1994; Schwab and Banks, 1994; Gunther et al., 1996; Reilley et al., 1996; Wrenn and Venosa, 1996; Banks et al., 1998; Banks et al., 1999; Chen et al., 2003; Hutchinson et al., 2003; Robinson et al., 2003; Huang et al., 2004; Olson et al., 2007 Western wheatgrass Agropyron smithii Aprill and Sims, 1990; Olson et al., 2007 Wheat Triticum aestivum Kucerova et al., 2001 Yellow sweetclover Melilotus officinalis Olson et al., 2007 56
Surfactants Mass transfer of PAH compounds to the aqueous phase in the soil solution can be a major limiting factor in the bioremediation of PAHs (Volkering et al., 1992). Compounds like surfactants, cyclodextrins, and vegetable oil may be used to enhance PAH solubility. Properly applied surfactants have been shown to improve desorption, apparent aqueous mobility and bioavailability of hydrophobic organic compounds such as PAHs (Bragg et al., 1994; Mata-Sandoval et al., 2002). Surfactants are amphiphilic (possess both hydrophilic and hydrophobic properties) molecules with a hydrophilic polar head (Gao et al., 2007). They can be classified by the charge on their polar head as anionic, cationic, nonionic or zwitterionic (Mulligan et al., 2001). At or above a certain concentration level called critical micelle concentration, the hydrophobic parts of the surfactants will tend to associate together to form a micelle (an aggregate of surfactant molecules dispersed in a liquid colloid) with a hydrophobic core (Santharam et al., 1997). Surfactants solubilize hydrophobic contaminants by partitioning them into the hydrophobic core of the micelle. If the concentration of surfactant exceeds the critical micelle concentration, solubility of hydrophobic compounds can increase by an order of magnitude over normal aqueous solubility (Edwards et al., 1991; Mulligan et al., 2001; Gao et al., 2007). The critical micelle concentration of a specific surfactant depends on temperature, ionic strength and surfactant chemistry. � In mixed pollutant systems, the extent of solubilization will differ from those in single solutes. For example, Guha et al. (1999) found that naphthalene solubilized by surfactants increased the solubilization of other PAHs such as phenanthrene. � Surfactants are thought to be able to solubilize sorbed organic compounds in a soil-water system only after critical micelle concentration is attained (Laha and Luthy, 1991; Gao et al., 2007). � Several interactions affect the solubilization of hydrophobic compounds by surfactants. These include the micellular phase-organic interactions, surfactants monomer-organic interactions in the aqueous phase, and the interactions of surfactants and organic compounds with the solid phase (Mata-Sandoval et al., 2002). � Soils with predominantly fine particles are generally found to reduce desorption efficiency of surfactants (Mulligan et al., 2001). Organic matter content and clay mineralogy also affect surfactant performance, but the effect differs depending on the type of surfactant used (Rodriquez-Cruz et al., 2005). 57
Page 1 and 2:
Remediation of PAH-Contaminated Soi
Page 3 and 4:
Abstract Polycyclic aromatic hydroc
Page 5 and 6: soil is the primary environmental r
Page 7 and 8: Solubility Solubility of PAH compou
Page 9 and 10: Figure 1. Structures of US EPA’s
Page 11 and 12: � If you were to add 2 benzene ri
Page 13 and 14: and their mutagenic and carcinogeni
Page 15 and 16: PAH in humans The carcinogenicity o
Page 17 and 18: persist in the soil (Alexander, 199
Page 19 and 20: Figure 3. Relative PAH concentratio
Page 21 and 22: the gas phase was attributed to tem
Page 23 and 24: increasing rainfall intensity or wi
Page 25 and 26: in contaminated soils than uncontam
Page 27 and 28: Ideal biodegradation of PAHs, where
Page 29 and 30: Figure 5. Aerobic degradation of PA
Page 31 and 32: Cometabolism is explained by three
Page 33 and 34: donate electrons. The redox potenti
Page 35 and 36: 1. Fenton’s reagent - formation o
Page 37 and 38: Figure 7. Schematic of integrated e
Page 39 and 40: Figure 8. Possible mechanism for di
Page 41 and 42: Freundlich adsorption equation: x/m
Page 43 and 44: Diffusion: Weber et al. (1992), Web
Page 45 and 46: Biological Techniques for Enhancing
Page 47 and 48: oot extract resulted in continuous
Page 49 and 50: Composting Composting is a form of
Page 51 and 52: The addition of inorganic nutrients
Page 53 and 54: � Yu et al. (2006) found no effec
Page 55: Carrot Daucus carota Wild and Jones
Page 59 and 60: � Straube et al. (2003) showed th
Page 61 and 62: encountered with biodegradation, an
Page 63 and 64: volatilization of some compounds, s
Page 65 and 66: Regulatory Framework Dredged materi
Page 67 and 68: transition phase between slurried s
Page 69 and 70: In addition to equation manipulatio
Page 71 and 72: Coastal Zone Management Act (CZMA)
Page 73 and 74: EPA Region V NA http://www.epa.gov/
Page 75 and 76: Indiana Department of Environmental
Page 77 and 78: New York State Department of Enviro
Page 79 and 80: Analytical Methods The following is
Page 81 and 82: Sample Cleanup After extraction, cl
Page 83 and 84: Table 13. Detection limits for cert
Page 85 and 86: Citations Accardi-Dey, A., and P.M.
Page 87 and 88: Cerniglia, C.E., and D.T. Gibson. 1
Page 89 and 90: EPA. 2008. Integrated Risk Informat
Page 91 and 92: Harmsen, J. 2007. Measuring bioavai
Page 93 and 94: Kelsey, J.W., B.D. Kottler, and M.
Page 95 and 96: Mackay, D., and D. Callcott. 1998.
Page 97 and 98: O’Mahony, M., A. Dobson, J. Barne
Page 99 and 100: Saison, C., C. Perrin-Ganier, M. Sc
Page 101 and 102: Vessigaud, S., C Perrin-Ganier, L.
show all

Remediation of PAH-Contaminated Soils and Sediments: A ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?