Autor: Chuen Huey Chiu, Tsair Fuh Lin, Chiu-Chung Young
Rok vydání: 2003
Předmět:
Zdroj: Water, Air, and Soil Pollution. 144:223-241
ISSN: 0049-6979
Popis: The effects of surface area, micro-porosity, and surfacechemical structure on the sorption of toluene vapor ontothree model natural organic materials (NOMs), including two peats(CH and HS) and one tree bark compost (TB) were examined. The BETsurface area, pore size distribution, element composition,sorption kinetics and isotherms, and carbon functionality (CP/MAS13C-NMR spectra) were measured for the model organic matters.All the three NOMs have small BET-surface areas (below 5 m2g-1), and small porosity (ranging from 0.6 to 3.4 cm3g-1). Sorption of toluene vapor on NOMs was found to reachequilibrium in about one hour. A weak interaction (van der Waals'forces) was found between toluene and the three NOMs, withsorption uptake in the order of peat CH > compost TB > peat HS.This toluene uptake order is similar to that for pore volume.Compared to the pore size distribution data measured by liquidnitrogen, sorption of toluene vapor onto the model NOMs may beattributed to the mechanisms similar to that for nitrogenadsorption, suggesting that nitrogen may be used as a probe fordetermining the sorption of toluene on the three NOMs. For peat HSand compost TB, the sorption processes may be regarded as `pore-filling' in a glassy phase SOM. In addition, based on thefunctional group composition analysis with CP/MAS-13C-NMR, it was not aromatic carbon group but the alkyl carbon group thatprobably supplied a more flexible space (rubbery phase SOM) fortoluene to penetrate. This flexible space may contribute somewhatto the sorption capacity so that the uptake of toluene by peat CHis higher than that of nitrogen.
Databáze: OpenAIRE
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