Characterization of aromatic compound sorptive interactions with black carbon (charcoal) assisted by graphite as a model

被引:374
作者
Zhu, DQ [1 ]
Pignatello, JJ [1 ]
机构
[1] Connecticut Agr Expt Stn, Dept Soil & Water, New Haven, CT 06504 USA
关键词
D O I
10.1021/es0491376
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Molecular interactions controlling the sorption of pollutants to environmental black carbons (soot, charcoal) are not well-resolved. Sorption of a series of aromatic compounds was studied to wood charcoal and nonporous graphite powder as a model adsorbent. Issues of concern were the possible involvement of pi-pi electron donor-acceptor (EDA) interactions of electron-poor and electron-rich solutes with the graphene (polycyclic aromatic) surface and size exclusion effects. Sorption of pi-acceptors, benzonitrile (BNTL), 4-nitrotoluene (MNT), 2,4-dinitrotoluene (DNT), and 2,4,6-trinitrotoluene (TNT), and to a lesser extent pi-donor solutes, naphthalene (NAPH) and phenanthrene (PHEN), was greater than predicted by hydrophobic driving forces in accord with their acceptor or donor strength. Hydrophobic effects were estimated using a concentration-dependent free energy relationship between adsorption and partitioning into an inert solvent (n-hexadecane or benzene) for a non-donor/non-acceptor calibration set (benzene and chlorinated and methylated benzenes). Molecular complexation between acceptors and model graphene donors, NAPH, PHEN, and pyrene (PYR), in chloroform and benzene was tracked by ring-current induced upfield shifts in the H-1 NMR spectrum and by charge-transfer bands in the UV/visible spectrum. The EDA component of graphite-water adsorption for the acceptors correlated with the NMR-determined complexation constant with the model donors in chloroform, which, in turn, correlated with pi-acceptor strength (TNT > DNT > MNT > BNTL) and pi-donor strength (PYR > PHEN > NAPH). Charcoal-graphite isotherms calculated from charcoal-water and graphite-water isotherms indicated molecular sieving effects on charcoal for tetra substituted benzenes (tetramethylbenzenes and TNT) and some trisubstituted benzenes (1,3,5-trichlorobenzene, possibly DNT). When steric effects are taken into account, the order in adsorption among acceptors was qualitatively similar for graphite and charcoal. The results suggest pi-pi EDA interactions of the acceptors-and possibly donors, although the calibration set may underestimate the hydrophobic effect for fused ring systems-with both graphite and charcoal surfaces. For graphite, it is postulated that g-acceptors interact with electron-rich regions of the basal plane near edges and defects and that pi-donors interact with electron-depleted regions further away. A similar mechanism may operate on the charcoal but would be modified by the (mostly) electron-withdrawing effects of 0 functionality on the edges of graphene sheets.
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页码:2033 / 2041
页数:9
相关论文
共 41 条
[1]   HYDROGEN-BONDING .32. AN ANALYSIS OF WATER-OCTANOL AND WATER-ALKANE PARTITIONING AND THE DELTA-LOG-P PARAMETER OF SEILER [J].
ABRAHAM, MH ;
CHADHA, HS ;
WHITING, GS ;
MITCHELL, RC .
JOURNAL OF PHARMACEUTICAL SCIENCES, 1994, 83 (08) :1085-1100
[2]   Assessing the combined roles of natural organic matter and black carbon as sorbents in sediments [J].
Accardi-Dey, A ;
Gschwend, PM .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2002, 36 (01) :21-29
[3]   Classifying NOM - Organic sorbate interactions using compound transfer from an inert solvent to the hydrated sorbent [J].
Borisover, M ;
Graber, ER .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2003, 37 (24) :5657-5664
[4]   Adsorption and the energy changes' at crystalline solid surfaces [J].
Boyd, GE ;
Livingston, HK .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1942, 64 :2383-2388
[5]   Sorption hysteresis of benzene in charcoal particles [J].
Braida, WJ ;
Pignatello, JJ ;
Lu, YF ;
Ravikovitch, PI ;
Neimark, AV ;
Xing, BS .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2003, 37 (02) :409-417
[6]   Stationary phases with chemically bonded fluorene ligands: A new approach for environmental analysis of pi-electron containing solutes [J].
Brindle, R ;
Klaus, A .
JOURNAL OF CHROMATOGRAPHY A, 1997, 757 (1-2) :3-20
[7]   Quantification of the soot-water distribution coefficient of PAHs provides mechanistic basis for enhanced sorption observations [J].
Bucheli, TD ;
Gustafsson, Ö .
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 2000, 34 (24) :5144-5151
[8]   TNT TRANSPORT AND FATE IN CONTAMINATED SOIL [J].
COMFORT, SD ;
SHEA, PJ ;
HUNDAL, LS ;
LI, Z ;
WOODBURY, BL ;
MARTIN, JL ;
POWERS, WL .
JOURNAL OF ENVIRONMENTAL QUALITY, 1995, 24 (06) :1174-1182
[9]  
COUGHLIN ROBERT W., 1968, ENVIRON SCI TECHNOL, V2, P291, DOI 10.1021/es60016a002
[10]  
Foster R., 1969, ORGANIC CHARGE TRANS